From 556826b5d52152450259311c613695ee5adcac04 Mon Sep 17 00:00:00 2001
From: Oleg Moiseenko <olegmsn@gmail.com>
Date: Tue, 18 Sep 2018 08:15:34 +0300
Subject: [PATCH] Added loading EMV transaction parameters from json file
 (#659)

* added default params file
* added jansson
* added test function.
* added tlv tree to function
* add params from json works
* added to `hf emv exec`: load params from json and some refactoring
* added `scan` command
---
 client/Makefile                    |   13 +-
 client/emv/cmdemv.c                |  212 ++++-
 client/emv/defparams.json          |   58 ++
 client/emv/tlv.c                   |   64 ++
 client/emv/tlv.h                   |    2 +
 client/jansson/Makefile            |   63 ++
 client/jansson/dump.c              |  504 ++++++++++++
 client/jansson/error.c             |   66 ++
 client/jansson/hashtable.c         |  356 +++++++++
 client/jansson/hashtable.h         |  176 +++++
 client/jansson/hashtable_seed.c    |  277 +++++++
 client/jansson/jansson.def         |   75 ++
 client/jansson/jansson.h           |  362 +++++++++
 client/jansson/jansson_config.h    |   51 ++
 client/jansson/jansson_config.h.in |   51 ++
 client/jansson/jansson_private.h   |  112 +++
 client/jansson/load.c              | 1155 ++++++++++++++++++++++++++++
 client/jansson/lookup3.h           |  381 +++++++++
 client/jansson/memory.c            |   69 ++
 client/jansson/pack_unpack.c       |  909 ++++++++++++++++++++++
 client/jansson/strbuffer.c         |  111 +++
 client/jansson/strbuffer.h         |   34 +
 client/jansson/strconv.c           |  145 ++++
 client/jansson/utf.c               |  187 +++++
 client/jansson/utf.h               |   27 +
 client/jansson/value.c             | 1078 ++++++++++++++++++++++++++
 26 files changed, 6515 insertions(+), 23 deletions(-)
 create mode 100644 client/emv/defparams.json
 create mode 100644 client/jansson/Makefile
 create mode 100644 client/jansson/dump.c
 create mode 100644 client/jansson/error.c
 create mode 100644 client/jansson/hashtable.c
 create mode 100644 client/jansson/hashtable.h
 create mode 100644 client/jansson/hashtable_seed.c
 create mode 100644 client/jansson/jansson.def
 create mode 100644 client/jansson/jansson.h
 create mode 100644 client/jansson/jansson_config.h
 create mode 100644 client/jansson/jansson_config.h.in
 create mode 100644 client/jansson/jansson_private.h
 create mode 100644 client/jansson/load.c
 create mode 100644 client/jansson/lookup3.h
 create mode 100644 client/jansson/memory.c
 create mode 100644 client/jansson/pack_unpack.c
 create mode 100644 client/jansson/strbuffer.c
 create mode 100644 client/jansson/strbuffer.h
 create mode 100644 client/jansson/strconv.c
 create mode 100644 client/jansson/utf.c
 create mode 100644 client/jansson/utf.h
 create mode 100644 client/jansson/value.c

diff --git a/client/Makefile b/client/Makefile
index 54a77a84..d223a921 100644
--- a/client/Makefile
+++ b/client/Makefile
@@ -19,8 +19,10 @@ OBJDIR = obj
 
 LDLIBS = -L/opt/local/lib -L/usr/local/lib -lreadline -lpthread -lm
 LUALIB = ../liblua/liblua.a
+JANSSONLIBPATH = ./jansson
+JANSSONLIB = $(JANSSONLIBPATH)/libjansson.a
 LDFLAGS = $(ENV_LDFLAGS)
-CFLAGS = $(ENV_CFLAGS) -std=c99 -D_ISOC99_SOURCE -I. -I../include -I../common -I../common/polarssl -I../zlib -I../uart -I/opt/local/include -I../liblua -Wall -g -O3
+CFLAGS = $(ENV_CFLAGS) -std=c99 -D_ISOC99_SOURCE -I. -I../include -I../common -I../common/polarssl -I../zlib -I../uart -I/opt/local/include -I../liblua -I$(JANSSONLIBPATH) -Wall -g -O3
 CXXFLAGS = -I../include -Wall -O3
 
 APP_CFLAGS =
@@ -234,12 +236,12 @@ WINBINS = $(patsubst %, %.exe, $(BINS))
 CLEAN = $(BINS) $(WINBINS) $(COREOBJS) $(CMDOBJS) $(ZLIBOBJS) $(QTGUIOBJS) $(MULTIARCHOBJS) $(OBJDIR)/*.o *.moc.cpp ui/ui_overlays.h
 
 # need to assign dependancies to build these first...
-all: lua_build $(BINS)
+all: lua_build jansson_build $(BINS)
 
 all-static: LDLIBS:=-static $(LDLIBS)
 all-static: proxmark3 flasher fpga_compress
 
-proxmark3: LDLIBS+=$(LUALIB) $(QTLDLIBS)
+proxmark3: LDLIBS+=$(LUALIB) $(JANSSONLIB) $(QTLDLIBS)
 proxmark3: $(OBJDIR)/proxmark3.o $(COREOBJS) $(CMDOBJS) $(QTGUIOBJS) $(MULTIARCHOBJS) $(ZLIBOBJS) lualibs/usb_cmd.lua
 	$(LD) $(LDFLAGS) $(OBJDIR)/proxmark3.o $(COREOBJS) $(CMDOBJS) $(QTGUIOBJS) $(MULTIARCHOBJS) $(ZLIBOBJS) $(LDLIBS) -o $@
 
@@ -263,6 +265,7 @@ lualibs/usb_cmd.lua: ../include/usb_cmd.h
 clean:
 	$(RM) $(CLEAN)
 	cd ../liblua && make clean
+	cd ./jansson && make clean
 
 tarbin: $(BINS)
 	$(TAR) $(TARFLAGS) ../proxmark3-$(platform)-bin.tar $(BINS:%=client/%) $(WINBINS:%=client/%)
@@ -270,6 +273,10 @@ tarbin: $(BINS)
 lua_build:
 	@echo Compiling liblua, using platform $(LUAPLATFORM)
 	cd ../liblua && make $(LUAPLATFORM)
+	
+jansson_build:
+	@echo Compiling jansson
+	cd ./jansson && make all
 
 .PHONY: all clean
 
diff --git a/client/emv/cmdemv.c b/client/emv/cmdemv.c
index c53b02af..541f505a 100644
--- a/client/emv/cmdemv.c
+++ b/client/emv/cmdemv.c
@@ -11,6 +11,7 @@
 #include <ctype.h>
 #include "cmdemv.h"
 #include "test/cryptotest.h"
+#include <jansson.h>
 
 int UsageCmdHFEMVSelect(void) {
 	PrintAndLog("HELP :  Executes select applet command:\n");
@@ -279,11 +280,12 @@ int CmdHFEMVPPSE(const char *cmd) {
 
 int UsageCmdHFEMVExec(void) {
 	PrintAndLog("HELP :  Executes EMV contactless transaction:\n");
-	PrintAndLog("Usage:  hf emv exec [-s][-a][-t][-f][-v][-c][-x][-g]\n");
+	PrintAndLog("Usage:  hf emv exec [-s][-a][-t][-j][-f][-v][-c][-x][-g]\n");
 	PrintAndLog("  Options:");
 	PrintAndLog("  -s       : select card");
 	PrintAndLog("  -a       : show APDU reqests and responses\n");
 	PrintAndLog("  -t       : TLV decode results\n");
+	PrintAndLog("  -j       : load transaction parameters from `emv/defparams.json` file\n");
 	PrintAndLog("  -f       : force search AID. Search AID instead of execute PPSE.\n");
 	PrintAndLog("  -v       : transaction type - qVSDC or M/Chip.\n");
 	PrintAndLog("  -c       : transaction type - qVSDC or M/Chip plus CDA (SDAD generation).\n");
@@ -296,9 +298,159 @@ int UsageCmdHFEMVExec(void) {
 	return 0;
 }
 
-#define TLV_ADD(tag, value)( tlvdb_add(tlvRoot, tlvdb_fixed(tag, sizeof(value) - 1, (const unsigned char *)value)) )
+#define TLV_ADD(tag, value)( tlvdb_change_or_add_node(tlvRoot, tag, sizeof(value) - 1, (const unsigned char *)value) )
 #define dreturn(n) {free(pdol_data_tlv);tlvdb_free(tlvSelect);tlvdb_free(tlvRoot);DropField();return n;}
 
+bool HexToBuffer(const char *errormsg, const char *hexvalue, uint8_t * buffer, size_t maxbufferlen, size_t *bufferlen) {
+	int buflen = 0;	
+	
+	switch(param_gethex_to_eol(hexvalue, 0, buffer, maxbufferlen, &buflen)) {
+	case 1:
+		PrintAndLog("%s Invalid HEX value.", errormsg);
+		return false;
+	case 2:
+		PrintAndLog("%s Hex value too large.", errormsg);
+		return false;
+	case 3:
+		PrintAndLog("%s Hex value must have even number of digits.", errormsg);
+		return false;
+	}
+	
+	if (buflen > maxbufferlen) {
+		PrintAndLog("%s HEX length (%d) more than %d", errormsg, *bufferlen, maxbufferlen);
+		return false;
+	}
+	
+	*bufferlen = buflen;
+	
+	return true;
+}
+
+bool ParamLoadFromJson(struct tlvdb *tlv) {
+	json_t *root;
+	json_error_t error;
+
+	if (!tlv) {
+		PrintAndLog("ERROR load params: tlv tree is NULL.");
+		return false; 
+	}
+
+	// current path + file name
+	const char *relfname = "emv/defparams.json"; 
+	char fname[strlen(get_my_executable_directory()) + strlen(relfname) + 1];
+	strcpy(fname, get_my_executable_directory());
+	strcat(fname, relfname);
+
+	root = json_load_file(fname, 0, &error);
+	if (!root) {
+		PrintAndLog("Load params: json error on line %d: %s", error.line, error.text);
+		return false; 
+	}
+	
+	if (!json_is_array(root)) {
+		PrintAndLog("Load params: Invalid json format. root must be array.");
+		return false; 
+	}
+	
+	PrintAndLog("Load params: json OK");
+	
+	for(int i = 0; i < json_array_size(root); i++) {
+		json_t *data, *jtype, *jlength, *jvalue;
+
+		data = json_array_get(root, i);
+		if(!json_is_object(data))
+		{
+			PrintAndLog("Load params: data [%d] is not an object", i + 1);
+			json_decref(root);
+			return false;
+		}
+		
+		jtype = json_object_get(data, "type");
+		if(!json_is_string(jtype))
+		{
+			PrintAndLog("Load params: data [%d] type is not a string", i + 1);
+			json_decref(root);
+			return false;
+		}
+		const char *tlvType = json_string_value(jtype);
+
+		jvalue = json_object_get(data, "value");
+		if(!json_is_string(jvalue))
+		{
+			PrintAndLog("Load params: data [%d] value is not a string", i + 1);
+			json_decref(root);
+			return false;
+		}
+		const char *tlvValue = json_string_value(jvalue);
+
+		jlength = json_object_get(data, "length");
+		if(!json_is_number(jlength))
+		{
+			PrintAndLog("Load params: data [%d] length is not a number", i + 1);
+			json_decref(root);
+			return false;
+		}
+		
+		int tlvLength = json_integer_value(jlength);
+		if (tlvLength > 250) {
+			PrintAndLog("Load params: data [%d] length more than 250", i + 1);
+			json_decref(root);
+			return false;
+		}
+		
+		PrintAndLog("TLV param: %s[%d]=%s", tlvType, tlvLength, tlvValue);
+		uint8_t buf[251] = {0};
+		size_t buflen = 0;
+		
+		// here max length must be 4, but now tlv_tag_t is 2-byte var. so let it be 2 by now...  TODO: needs refactoring tlv_tag_t...
+		if (!HexToBuffer("TLV Error type:", tlvType, buf, 2, &buflen)) { 
+			json_decref(root);
+			return false;
+		}
+		tlv_tag_t tag = 0;
+		for (int i = 0; i < buflen; i++) {
+			tag = (tag << 8) + buf[i];
+		}	
+		
+		if (!HexToBuffer("TLV Error value:", tlvValue, buf, sizeof(buf) - 1, &buflen)) {
+			json_decref(root);
+			return false;
+		}
+		
+		if (buflen != tlvLength) {
+			PrintAndLog("Load params: data [%d] length of HEX must(%d) be identical to length in TLV param(%d)", i + 1, buflen, tlvLength);
+			json_decref(root);
+			return false;
+		}
+		
+		tlvdb_change_or_add_node(tlv, tag, tlvLength, (const unsigned char *)buf);		
+	}
+
+	json_decref(root);
+
+	return true;
+}
+
+void ParamLoadDefaults(struct tlvdb *tlvRoot) {
+	//9F02:(Amount, authorized (Numeric)) len:6
+	TLV_ADD(0x9F02, "\x00\x00\x00\x00\x01\x00");
+	//9F1A:(Terminal Country Code) len:2
+	TLV_ADD(0x9F1A, "ru");
+	//5F2A:(Transaction Currency Code) len:2
+	// USD 840, EUR 978, RUR 810, RUB 643, RUR 810(old), UAH 980, AZN 031, n/a 999
+	TLV_ADD(0x5F2A, "\x09\x80");
+	//9A:(Transaction Date) len:3
+	TLV_ADD(0x9A,   "\x00\x00\x00");
+	//9C:(Transaction Type) len:1   |  00 => Goods and service #01 => Cash
+	TLV_ADD(0x9C,   "\x00");
+	// 9F37 Unpredictable Number len:4
+	TLV_ADD(0x9F37, "\x01\x02\x03\x04");
+	// 9F6A Unpredictable Number (MSD for UDOL) len:4
+	TLV_ADD(0x9F6A, "\x01\x02\x03\x04");
+	//9F66:(Terminal Transaction Qualifiers (TTQ)) len:4
+	TLV_ADD(0x9F66, "\x26\x00\x00\x00"); // qVSDC
+}
+
 int CmdHFEMVExec(const char *cmd) {
 	bool activateField = false;
 	bool showAPDU = false;
@@ -306,6 +458,7 @@ int CmdHFEMVExec(const char *cmd) {
 	bool forceSearch = false;
 	enum TransactionType TrType = TT_MSD;
 	bool GenACGPO = false;
+	bool paramLoadJSON = false;
 
 	uint8_t buf[APDU_RES_LEN] = {0};
 	size_t len = 0;
@@ -367,6 +520,10 @@ int CmdHFEMVExec(const char *cmd) {
 				case 'G':
 					GenACGPO = true;
 					break;
+				case 'j':
+				case 'J':
+					paramLoadJSON = true;
+					break;
 				default:
 					PrintAndLog("Unknown parameter '%c'", param_getchar_indx(cmd, 1, cmdp));
 					return 1;
@@ -433,7 +590,14 @@ int CmdHFEMVExec(const char *cmd) {
 	
 	PrintAndLog("\n* Init transaction parameters.");
 
-    //9F66:(Terminal Transaction Qualifiers (TTQ)) len:4
+	ParamLoadDefaults(tlvRoot);
+
+	if (paramLoadJSON) {
+		PrintAndLog("* * Transaction parameters loading from JSON...");
+		ParamLoadFromJson(tlvRoot);
+	}
+	
+	//9F66:(Terminal Transaction Qualifiers (TTQ)) len:4
 	char *qVSDC = "\x26\x00\x00\x00";
 	if (GenACGPO) {
 		qVSDC = "\x26\x80\x00\x00";
@@ -453,26 +617,9 @@ int CmdHFEMVExec(const char *cmd) {
 			TLV_ADD(0x9F66, qVSDC); // qVSDC (VISA CDA not enabled)
 			break;
 		default:
-			TLV_ADD(0x9F66, "\x26\x00\x00\x00"); // qVSDC
 			break;
 	}
 	
-    //9F02:(Amount, authorized (Numeric)) len:6
-	TLV_ADD(0x9F02, "\x00\x00\x00\x00\x01\x00");
-    //9F1A:(Terminal Country Code) len:2
-	TLV_ADD(0x9F1A, "ru");
-    //5F2A:(Transaction Currency Code) len:2
-    // USD 840, EUR 978, RUR 810, RUB 643, RUR 810(old), UAH 980, AZN 031, n/a 999
-	TLV_ADD(0x5F2A, "\x09\x80");
-    //9A:(Transaction Date) len:3
-	TLV_ADD(0x9A,   "\x00\x00\x00");
-    //9C:(Transaction Type) len:1   |  00 => Goods and service #01 => Cash
-	TLV_ADD(0x9C,   "\x00");
-	// 9F37 Unpredictable Number len:4
-	TLV_ADD(0x9F37, "\x01\x02\x03\x04");
-	// 9F6A Unpredictable Number (MSD for UDOL) len:4
-	TLV_ADD(0x9F6A, "\x01\x02\x03\x04");
-
 	TLVPrintFromTLV(tlvRoot); // TODO delete!!!
 	
 	PrintAndLog("\n* Calc PDOL.");
@@ -828,6 +975,30 @@ int CmdHFEMVExec(const char *cmd) {
 	return 0;
 }
 
+int UsageCmdHFEMVScan(void) {
+	PrintAndLog("HELP :  Scan EMV card and save it contents to a file. \n");
+	PrintAndLog("        It executes EMV contactless transaction and saves result to a file which can be used for emulation.\n");
+	PrintAndLog("Usage:  hf emv scan [-a][-t][-v][-c][-x][-g] <file_name>\n");
+	PrintAndLog("  Options:");
+	PrintAndLog("  -a       : show APDU reqests and responses\n");
+	PrintAndLog("  -t       : TLV decode results\n");
+	PrintAndLog("  -v       : transaction type - qVSDC or M/Chip.\n");
+	PrintAndLog("  -c       : transaction type - qVSDC or M/Chip plus CDA (SDAD generation).\n");
+	PrintAndLog("  -x       : transaction type - VSDC. For test only. Not a standart behavior.\n");
+	PrintAndLog("  -g       : VISA. generate AC from GPO\n");
+	PrintAndLog("By default : transaction type - MSD.\n");
+	PrintAndLog("Samples:");
+	PrintAndLog(" hf emv scan -a -t -> scan MSD transaction mode");
+	PrintAndLog(" hf emv scan -a -t -c -> scan CDA transaction mode");
+	return 0;
+}
+
+int CmdHFEMVScan(const char *cmd) {
+	UsageCmdHFEMVScan();
+	
+	return 0;
+}
+
 int CmdHFEMVTest(const char *cmd) {
 	return ExecuteCryptoTests(true);
 }
@@ -839,6 +1010,7 @@ static command_t CommandTable[] =  {
 	{"pse",		CmdHFEMVPPSE,	0,	"Execute PPSE. It selects 2PAY.SYS.DDF01 or 1PAY.SYS.DDF01 directory."},
 	{"search",	CmdHFEMVSearch,	0,	"Try to select all applets from applets list and print installed applets."},
 	{"select",	CmdHFEMVSelect,	0,	"Select applet."},
+//	{"scan",	CmdHFEMVScan,	0,	"Scan EMV card and save it contents to json file for emulator."},
 	{"test",	CmdHFEMVTest,	0,	"Crypto logic test."},
 	{NULL, NULL, 0, NULL}
 };
diff --git a/client/emv/defparams.json b/client/emv/defparams.json
new file mode 100644
index 00000000..47f1c8a1
--- /dev/null
+++ b/client/emv/defparams.json
@@ -0,0 +1,58 @@
+[
+  {
+    "name": "Transaction Date",
+    "type": "9A",
+    "value": "00 00 00",
+    "length": 3,
+    "hint": "format: YYMMDD"
+  },
+  {
+    "name": "Transaction Type",
+    "type": "9C",
+    "value": "00",
+    "length": 1,
+    "hint": "00: Goods and service, 01: Cash"
+  },
+  {
+    "name": "Amount, authorized",
+    "type": "9F 02",
+    "value": "00 00 00 00 01 00",
+    "length": 6,
+    "hint": "amount (numberic) in cents"
+  },
+  {
+    "name": "Transaction Currency Code",
+    "type": "5F 2A",
+    "value": "09 80",
+    "length": 2,
+    "hint": "USD 840, EUR 978, RUB 643, RUR 810(old), UAH 980, AZN 031, n/a 999"
+  },
+  {
+    "name": "Terminal Country Code",
+    "type": "9F 1A",
+    "value": "72 75",
+    "length": 2,
+    "hint": "ISO3166: de, en (65 6e), uk(75 6b), ru (72 75), us, ua"
+  },
+  {
+    "name": "Terminal Transaction Qualifiers (TTQ)",
+    "type": "9F 66",
+    "value": "26 00 00 00",
+    "length": 4,
+    "hint": "qVSDC 26 00 00 00, gen AC from GPO 26 80 00 00, MSD 86 00 00 00, VSDC 46 00 00 00"
+  },
+  {
+    "name": "Unpredictable Number",
+    "type": "9F 37",
+    "value": "01 02 03 04",
+    "length": 4,
+    "hint": "4 byte random number"
+  },
+  {
+    "name": "Unpredictable Number (MSD for UDOL)",
+    "type": "9F 6A",
+    "value": "01 02 03 05",
+    "length": 4,
+    "hint": "4 byte random number"
+  }
+]
diff --git a/client/emv/tlv.c b/client/emv/tlv.c
index 1be91777..776fdeed 100644
--- a/client/emv/tlv.c
+++ b/client/emv/tlv.c
@@ -318,6 +318,24 @@ struct tlvdb *tlvdb_find(struct tlvdb *tlvdb, tlv_tag_t tag) {
 	return NULL;
 }
 
+struct tlvdb *tlvdb_find_full(struct tlvdb *tlvdb, tlv_tag_t tag) {
+	if (!tlvdb)
+		return NULL;
+	
+	for (; tlvdb; tlvdb = tlvdb->next) {
+		if (tlvdb->tag.tag == tag)
+			return tlvdb;
+		
+		if (tlvdb->children) {
+			struct tlvdb * ch = tlvdb_find_full(tlvdb->children, tag);
+			if (ch)
+				return ch;
+		}			
+	}
+
+	return NULL;
+}
+
 struct tlvdb *tlvdb_find_path(struct tlvdb *tlvdb, tlv_tag_t tag[]) {
 	int i = 0;
 	struct tlvdb *tnext = tlvdb;
@@ -342,6 +360,52 @@ void tlvdb_add(struct tlvdb *tlvdb, struct tlvdb *other)
 	tlvdb->next = other;
 }
 
+void tlvdb_change_or_add_node(struct tlvdb *tlvdb, tlv_tag_t tag, size_t len, const unsigned char *value)
+{
+	struct tlvdb *telm = tlvdb_find_full(tlvdb, tag);
+	if (telm == NULL) {
+		// new tlv element
+		tlvdb_add(tlvdb, tlvdb_fixed(tag, len, value));
+	} else {
+		// the same tlv structure
+		if (telm->tag.tag == tag && telm->tag.len == len && !memcmp(telm->tag.value, value, len))
+			return;
+
+		// replace tlv element
+		struct tlvdb *tnewelm = tlvdb_fixed(tag, len, value);
+		tnewelm->next = telm->next;
+		tnewelm->parent = telm->parent;
+		
+		// if telm stayed first in children chain
+		if (telm->parent && telm->parent->children == telm) {
+			telm->parent->children = tnewelm;
+		}
+		
+		// if telm have previous element
+		if (telm != tlvdb) {
+			// elm in root
+			struct tlvdb *celm = tlvdb;
+			// elm in child list of node
+			if (telm->parent && telm->parent->children)
+				celm = telm->parent->children;		
+			
+			// find previous element
+			for (; celm; celm = celm->next) {
+				if (celm->next == telm) {
+					celm->next = tnewelm;
+					break;
+				}
+			}
+		}
+		
+		// free old element with childrens
+		telm->next = NULL;
+		tlvdb_free(telm);
+	}
+	
+	return;
+}
+
 void tlvdb_visit(const struct tlvdb *tlvdb, tlv_cb cb, void *data, int level)
 {
 	struct tlvdb *next = NULL;
diff --git a/client/emv/tlv.h b/client/emv/tlv.h
index 5b8b6825..963abb2a 100644
--- a/client/emv/tlv.h
+++ b/client/emv/tlv.h
@@ -39,11 +39,13 @@ struct tlvdb *tlvdb_parse(const unsigned char *buf, size_t len);
 struct tlvdb *tlvdb_parse_multi(const unsigned char *buf, size_t len);
 void tlvdb_free(struct tlvdb *tlvdb);
 
+struct tlvdb *tlvdb_find_full(struct tlvdb *tlvdb, tlv_tag_t tag); // search also in childrens
 struct tlvdb *tlvdb_find(struct tlvdb *tlvdb, tlv_tag_t tag);
 struct tlvdb *tlvdb_find_next(struct tlvdb *tlvdb, tlv_tag_t tag);
 struct tlvdb *tlvdb_find_path(struct tlvdb *tlvdb, tlv_tag_t tag[]);
 
 void tlvdb_add(struct tlvdb *tlvdb, struct tlvdb *other);
+void tlvdb_change_or_add_node(struct tlvdb *tlvdb, tlv_tag_t tag, size_t len, const unsigned char *value);
 
 void tlvdb_visit(const struct tlvdb *tlvdb, tlv_cb cb, void *data, int level);
 const struct tlv *tlvdb_get(const struct tlvdb *tlvdb, tlv_tag_t tag, const struct tlv *prev);
diff --git a/client/jansson/Makefile b/client/jansson/Makefile
new file mode 100644
index 00000000..7a262f8b
--- /dev/null
+++ b/client/jansson/Makefile
@@ -0,0 +1,63 @@
+
+include_HEADERS = jansson.h
+nodist_include_HEADERS = jansson_config.h
+
+LIB_A = libjansson.a
+libjansson_la_SOURCES = \
+	dump.c \
+	error.c \
+	hashtable.c \
+	hashtable.h \
+	hashtable_seed.c \
+	jansson_private.h \
+	load.c \
+	lookup3.h \
+	memory.c \
+	pack_unpack.c \
+	strbuffer.c \
+	strbuffer.h \
+	strconv.c \
+	utf.c \
+	utf.h \
+	value.c
+libjansson_la_LDFLAGS = \
+	-no-undefined \
+	-export-symbols-regex '^json_' \
+	-version-info 15:0:11
+
+	
+CFILES = $(filter %.c, $(libjansson_la_SOURCES))
+CMDOBJS = $(CFILES:%.c=%.o)
+CLEAN = $(CMDOBJS)
+	
+CC= gcc
+CFLAGS= -O2 -Wall -Wno-unused-variable -Wno-unused-function
+LDFLAGS= $(SYSLDFLAGS) $(libjansson_la_LDFLAGS)
+LIBS= -lm $(SYSLIBS) $(MYLIBS)
+DEFAULT_INCLUDES = -I.
+DEFS = -DHAVE_STDINT_H
+
+AR= ar rcs
+RANLIB= ranlib
+RM= rm -f
+TST= echo
+
+SYSLDFLAGS=
+SYSLIBS=
+
+MYLIBS=
+MYOBJS=
+
+all: $(CMDOBJS)
+	$(AR) $(LIB_A) $(CMDOBJS)
+	$(RANLIB) $(LIB_A)
+	
+clean:
+	$(RM) $(CLEAN)
+	$(RM) $(LIB_A)
+	
+%.o: %.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(CFLAGS) -c -o $@ $< $(LIBS)
+	
+.PHONY: all clean
+
diff --git a/client/jansson/dump.c b/client/jansson/dump.c
new file mode 100644
index 00000000..8e725c93
--- /dev/null
+++ b/client/jansson/dump.c
@@ -0,0 +1,504 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include "jansson_private.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include "jansson.h"
+#include "strbuffer.h"
+#include "utf.h"
+
+#define MAX_INTEGER_STR_LENGTH  100
+#define MAX_REAL_STR_LENGTH     100
+
+#define FLAGS_TO_INDENT(f)      ((f) & 0x1F)
+#define FLAGS_TO_PRECISION(f)   (((f) >> 11) & 0x1F)
+
+struct buffer {
+    const size_t size;
+    size_t used;
+    char *data;
+};
+
+static int dump_to_strbuffer(const char *buffer, size_t size, void *data)
+{
+    return strbuffer_append_bytes((strbuffer_t *)data, buffer, size);
+}
+
+static int dump_to_buffer(const char *buffer, size_t size, void *data)
+{
+    struct buffer *buf = (struct buffer *)data;
+
+    if(buf->used + size <= buf->size)
+        memcpy(&buf->data[buf->used], buffer, size);
+
+    buf->used += size;
+    return 0;
+}
+
+static int dump_to_file(const char *buffer, size_t size, void *data)
+{
+    FILE *dest = (FILE *)data;
+    if(fwrite(buffer, size, 1, dest) != 1)
+        return -1;
+    return 0;
+}
+
+static int dump_to_fd(const char *buffer, size_t size, void *data)
+{
+    int *dest = (int *)data;
+#ifdef HAVE_UNISTD_H
+    if(write(*dest, buffer, size) == (ssize_t)size)
+        return 0;
+#endif
+    return -1;
+}
+
+/* 32 spaces (the maximum indentation size) */
+static const char whitespace[] = "                                ";
+
+static int dump_indent(size_t flags, int depth, int space, json_dump_callback_t dump, void *data)
+{
+    if(FLAGS_TO_INDENT(flags) > 0)
+    {
+        unsigned int ws_count = FLAGS_TO_INDENT(flags), n_spaces = depth * ws_count;
+
+        if(dump("\n", 1, data))
+            return -1;
+
+        while(n_spaces > 0)
+        {
+            int cur_n = n_spaces < sizeof whitespace - 1 ? n_spaces : sizeof whitespace - 1;
+
+            if(dump(whitespace, cur_n, data))
+                return -1;
+
+            n_spaces -= cur_n;
+        }
+    }
+    else if(space && !(flags & JSON_COMPACT))
+    {
+        return dump(" ", 1, data);
+    }
+    return 0;
+}
+
+static int dump_string(const char *str, size_t len, json_dump_callback_t dump, void *data, size_t flags)
+{
+    const char *pos, *end, *lim;
+    int32_t codepoint;
+
+    if(dump("\"", 1, data))
+        return -1;
+
+    end = pos = str;
+    lim = str + len;
+    while(1)
+    {
+        const char *text;
+        char seq[13];
+        int length;
+
+        while(end < lim)
+        {
+            end = utf8_iterate(pos, lim - pos, &codepoint);
+            if(!end)
+                return -1;
+
+            /* mandatory escape or control char */
+            if(codepoint == '\\' || codepoint == '"' || codepoint < 0x20)
+                break;
+
+            /* slash */
+            if((flags & JSON_ESCAPE_SLASH) && codepoint == '/')
+                break;
+
+            /* non-ASCII */
+            if((flags & JSON_ENSURE_ASCII) && codepoint > 0x7F)
+                break;
+
+            pos = end;
+        }
+
+        if(pos != str) {
+            if(dump(str, pos - str, data))
+                return -1;
+        }
+
+        if(end == pos)
+            break;
+
+        /* handle \, /, ", and control codes */
+        length = 2;
+        switch(codepoint)
+        {
+            case '\\': text = "\\\\"; break;
+            case '\"': text = "\\\""; break;
+            case '\b': text = "\\b"; break;
+            case '\f': text = "\\f"; break;
+            case '\n': text = "\\n"; break;
+            case '\r': text = "\\r"; break;
+            case '\t': text = "\\t"; break;
+            case '/':  text = "\\/"; break;
+            default:
+            {
+                /* codepoint is in BMP */
+                if(codepoint < 0x10000)
+                {
+                    snprintf(seq, sizeof(seq), "\\u%04X", (unsigned int)codepoint);
+                    length = 6;
+                }
+
+                /* not in BMP -> construct a UTF-16 surrogate pair */
+                else
+                {
+                    int32_t first, last;
+
+                    codepoint -= 0x10000;
+                    first = 0xD800 | ((codepoint & 0xffc00) >> 10);
+                    last = 0xDC00 | (codepoint & 0x003ff);
+
+                    snprintf(seq, sizeof(seq), "\\u%04X\\u%04X", (unsigned int)first, (unsigned int)last);
+                    length = 12;
+                }
+
+                text = seq;
+                break;
+            }
+        }
+
+        if(dump(text, length, data))
+            return -1;
+
+        str = pos = end;
+    }
+
+    return dump("\"", 1, data);
+}
+
+static int compare_keys(const void *key1, const void *key2)
+{
+    return strcmp(*(const char **)key1, *(const char **)key2);
+}
+
+static int loop_check(hashtable_t *parents, const json_t *json, char *key, size_t key_size)
+{
+    snprintf(key, key_size, "%p", json);
+    if (hashtable_get(parents, key))
+        return -1;
+
+    return hashtable_set(parents, key, json_null());
+}
+
+static int do_dump(const json_t *json, size_t flags, int depth,
+                   hashtable_t *parents, json_dump_callback_t dump, void *data)
+{
+    int embed = flags & JSON_EMBED;
+
+    flags &= ~JSON_EMBED;
+
+    if(!json)
+        return -1;
+
+    switch(json_typeof(json)) {
+        case JSON_NULL:
+            return dump("null", 4, data);
+
+        case JSON_TRUE:
+            return dump("true", 4, data);
+
+        case JSON_FALSE:
+            return dump("false", 5, data);
+
+        case JSON_INTEGER:
+        {
+            char buffer[MAX_INTEGER_STR_LENGTH];
+            int size;
+
+            size = snprintf(buffer, MAX_INTEGER_STR_LENGTH,
+                            "%" JSON_INTEGER_FORMAT,
+                            json_integer_value(json));
+            if(size < 0 || size >= MAX_INTEGER_STR_LENGTH)
+                return -1;
+
+            return dump(buffer, size, data);
+        }
+
+        case JSON_REAL:
+        {
+            char buffer[MAX_REAL_STR_LENGTH];
+            int size;
+            double value = json_real_value(json);
+
+            size = jsonp_dtostr(buffer, MAX_REAL_STR_LENGTH, value,
+                                FLAGS_TO_PRECISION(flags));
+            if(size < 0)
+                return -1;
+
+            return dump(buffer, size, data);
+        }
+
+        case JSON_STRING:
+            return dump_string(json_string_value(json), json_string_length(json), dump, data, flags);
+
+        case JSON_ARRAY:
+        {
+            size_t n;
+            size_t i;
+            /* Space for "0x", double the sizeof a pointer for the hex and a terminator. */
+            char key[2 + (sizeof(json) * 2) + 1];
+
+            /* detect circular references */
+            if (loop_check(parents, json, key, sizeof(key)))
+                return -1;
+
+            n = json_array_size(json);
+
+            if(!embed && dump("[", 1, data))
+                return -1;
+            if(n == 0) {
+                hashtable_del(parents, key);
+                return embed ? 0 : dump("]", 1, data);
+            }
+            if(dump_indent(flags, depth + 1, 0, dump, data))
+                return -1;
+
+            for(i = 0; i < n; ++i) {
+                if(do_dump(json_array_get(json, i), flags, depth + 1,
+                           parents, dump, data))
+                    return -1;
+
+                if(i < n - 1)
+                {
+                    if(dump(",", 1, data) ||
+                       dump_indent(flags, depth + 1, 1, dump, data))
+                        return -1;
+                }
+                else
+                {
+                    if(dump_indent(flags, depth, 0, dump, data))
+                        return -1;
+                }
+            }
+
+            hashtable_del(parents, key);
+            return embed ? 0 : dump("]", 1, data);
+        }
+
+        case JSON_OBJECT:
+        {
+            void *iter;
+            const char *separator;
+            int separator_length;
+            /* Space for "0x", double the sizeof a pointer for the hex and a terminator. */
+            char key[2 + (sizeof(json) * 2) + 1];
+
+            if(flags & JSON_COMPACT) {
+                separator = ":";
+                separator_length = 1;
+            }
+            else {
+                separator = ": ";
+                separator_length = 2;
+            }
+
+            /* detect circular references */
+            if (loop_check(parents, json, key, sizeof(key)))
+                return -1;
+
+            iter = json_object_iter((json_t *)json);
+
+            if(!embed && dump("{", 1, data))
+                return -1;
+            if(!iter) {
+                hashtable_del(parents, key);
+                return embed ? 0 : dump("}", 1, data);
+            }
+            if(dump_indent(flags, depth + 1, 0, dump, data))
+                return -1;
+
+            if(flags & JSON_SORT_KEYS)
+            {
+                const char **keys;
+                size_t size, i;
+
+                size = json_object_size(json);
+                keys = jsonp_malloc(size * sizeof(const char *));
+                if(!keys)
+                    return -1;
+
+                i = 0;
+                while(iter)
+                {
+                    keys[i] = json_object_iter_key(iter);
+                    iter = json_object_iter_next((json_t *)json, iter);
+                    i++;
+                }
+                assert(i == size);
+
+                qsort(keys, size, sizeof(const char *), compare_keys);
+
+                for(i = 0; i < size; i++)
+                {
+                    const char *key;
+                    json_t *value;
+
+                    key = keys[i];
+                    value = json_object_get(json, key);
+                    assert(value);
+
+                    dump_string(key, strlen(key), dump, data, flags);
+                    if(dump(separator, separator_length, data) ||
+                       do_dump(value, flags, depth + 1, parents, dump, data))
+                    {
+                        jsonp_free(keys);
+                        return -1;
+                    }
+
+                    if(i < size - 1)
+                    {
+                        if(dump(",", 1, data) ||
+                           dump_indent(flags, depth + 1, 1, dump, data))
+                        {
+                            jsonp_free(keys);
+                            return -1;
+                        }
+                    }
+                    else
+                    {
+                        if(dump_indent(flags, depth, 0, dump, data))
+                        {
+                            jsonp_free(keys);
+                            return -1;
+                        }
+                    }
+                }
+
+                jsonp_free(keys);
+            }
+            else
+            {
+                /* Don't sort keys */
+
+                while(iter)
+                {
+                    void *next = json_object_iter_next((json_t *)json, iter);
+                    const char *key = json_object_iter_key(iter);
+
+                    dump_string(key, strlen(key), dump, data, flags);
+                    if(dump(separator, separator_length, data) ||
+                       do_dump(json_object_iter_value(iter), flags, depth + 1,
+                               parents, dump, data))
+                        return -1;
+
+                    if(next)
+                    {
+                        if(dump(",", 1, data) ||
+                           dump_indent(flags, depth + 1, 1, dump, data))
+                            return -1;
+                    }
+                    else
+                    {
+                        if(dump_indent(flags, depth, 0, dump, data))
+                            return -1;
+                    }
+
+                    iter = next;
+                }
+            }
+
+            hashtable_del(parents, key);
+            return embed ? 0 : dump("}", 1, data);
+        }
+
+        default:
+            /* not reached */
+            return -1;
+    }
+}
+
+char *json_dumps(const json_t *json, size_t flags)
+{
+    strbuffer_t strbuff;
+    char *result;
+
+    if(strbuffer_init(&strbuff))
+        return NULL;
+
+    if(json_dump_callback(json, dump_to_strbuffer, (void *)&strbuff, flags))
+        result = NULL;
+    else
+        result = jsonp_strdup(strbuffer_value(&strbuff));
+
+    strbuffer_close(&strbuff);
+    return result;
+}
+
+size_t json_dumpb(const json_t *json, char *buffer, size_t size, size_t flags)
+{
+    struct buffer buf = { size, 0, buffer };
+
+    if(json_dump_callback(json, dump_to_buffer, (void *)&buf, flags))
+        return 0;
+
+    return buf.used;
+}
+
+int json_dumpf(const json_t *json, FILE *output, size_t flags)
+{
+    return json_dump_callback(json, dump_to_file, (void *)output, flags);
+}
+
+int json_dumpfd(const json_t *json, int output, size_t flags)
+{
+    return json_dump_callback(json, dump_to_fd, (void *)&output, flags);
+}
+
+int json_dump_file(const json_t *json, const char *path, size_t flags)
+{
+    int result;
+
+    FILE *output = fopen(path, "w");
+    if(!output)
+        return -1;
+
+    result = json_dumpf(json, output, flags);
+
+    if(fclose(output) != 0)
+        return -1;
+
+    return result;
+}
+
+int json_dump_callback(const json_t *json, json_dump_callback_t callback, void *data, size_t flags)
+{
+    int res;
+    hashtable_t parents_set;
+
+    if(!(flags & JSON_ENCODE_ANY)) {
+        if(!json_is_array(json) && !json_is_object(json))
+           return -1;
+    }
+
+    if (hashtable_init(&parents_set))
+        return -1;
+    res = do_dump(json, flags, 0, &parents_set, callback, data);
+    hashtable_close(&parents_set);
+
+    return res;
+}
diff --git a/client/jansson/error.c b/client/jansson/error.c
new file mode 100644
index 00000000..cbd50d7e
--- /dev/null
+++ b/client/jansson/error.c
@@ -0,0 +1,66 @@
+#include <string.h>
+#include "jansson_private.h"
+
+void jsonp_error_init(json_error_t *error, const char *source)
+{
+    if(error)
+    {
+        error->text[0] = '\0';
+        error->line = -1;
+        error->column = -1;
+        error->position = 0;
+        if(source)
+            jsonp_error_set_source(error, source);
+        else
+            error->source[0] = '\0';
+    }
+}
+
+void jsonp_error_set_source(json_error_t *error, const char *source)
+{
+    size_t length;
+
+    if(!error || !source)
+        return;
+
+    length = strlen(source);
+    if(length < JSON_ERROR_SOURCE_LENGTH)
+        strncpy(error->source, source, length + 1);
+    else {
+        size_t extra = length - JSON_ERROR_SOURCE_LENGTH + 4;
+        strncpy(error->source, "...", 3);
+        strncpy(error->source + 3, source + extra, length - extra + 1);
+    }
+}
+
+void jsonp_error_set(json_error_t *error, int line, int column,
+                     size_t position, enum json_error_code code,
+                     const char *msg, ...)
+{
+    va_list ap;
+
+    va_start(ap, msg);
+    jsonp_error_vset(error, line, column, position, code, msg, ap);
+    va_end(ap);
+}
+
+void jsonp_error_vset(json_error_t *error, int line, int column,
+                      size_t position, enum json_error_code code,
+                      const char *msg, va_list ap)
+{
+    if(!error)
+        return;
+
+    if(error->text[0] != '\0') {
+        /* error already set */
+        return;
+    }
+
+    error->line = line;
+    error->column = column;
+    error->position = (int)position;
+
+    vsnprintf(error->text, JSON_ERROR_TEXT_LENGTH - 1, msg, ap);
+    error->text[JSON_ERROR_TEXT_LENGTH - 2] = '\0';
+    error->text[JSON_ERROR_TEXT_LENGTH - 1] = code;
+}
diff --git a/client/jansson/hashtable.c b/client/jansson/hashtable.c
new file mode 100644
index 00000000..c819319a
--- /dev/null
+++ b/client/jansson/hashtable.c
@@ -0,0 +1,356 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#if HAVE_CONFIG_H
+#include <jansson_private_config.h>
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+
+#if HAVE_STDINT_H
+#include <stdint.h>
+#endif
+
+#include <jansson_config.h>   /* for JSON_INLINE */
+#include "jansson_private.h"  /* for container_of() */
+#include "hashtable.h"
+
+#ifndef INITIAL_HASHTABLE_ORDER
+#define INITIAL_HASHTABLE_ORDER 3
+#endif
+
+typedef struct hashtable_list list_t;
+typedef struct hashtable_pair pair_t;
+typedef struct hashtable_bucket bucket_t;
+
+extern volatile uint32_t hashtable_seed;
+
+/* Implementation of the hash function */
+#include "lookup3.h"
+
+#define list_to_pair(list_)  container_of(list_, pair_t, list)
+#define ordered_list_to_pair(list_)  container_of(list_, pair_t, ordered_list)
+#define hash_str(key)        ((size_t)hashlittle((key), strlen(key), hashtable_seed))
+
+static JSON_INLINE void list_init(list_t *list)
+{
+    list->next = list;
+    list->prev = list;
+}
+
+static JSON_INLINE void list_insert(list_t *list, list_t *node)
+{
+    node->next = list;
+    node->prev = list->prev;
+    list->prev->next = node;
+    list->prev = node;
+}
+
+static JSON_INLINE void list_remove(list_t *list)
+{
+    list->prev->next = list->next;
+    list->next->prev = list->prev;
+}
+
+static JSON_INLINE int bucket_is_empty(hashtable_t *hashtable, bucket_t *bucket)
+{
+    return bucket->first == &hashtable->list && bucket->first == bucket->last;
+}
+
+static void insert_to_bucket(hashtable_t *hashtable, bucket_t *bucket,
+                             list_t *list)
+{
+    if(bucket_is_empty(hashtable, bucket))
+    {
+        list_insert(&hashtable->list, list);
+        bucket->first = bucket->last = list;
+    }
+    else
+    {
+        list_insert(bucket->first, list);
+        bucket->first = list;
+    }
+}
+
+static pair_t *hashtable_find_pair(hashtable_t *hashtable, bucket_t *bucket,
+                                   const char *key, size_t hash)
+{
+    list_t *list;
+    pair_t *pair;
+
+    if(bucket_is_empty(hashtable, bucket))
+        return NULL;
+
+    list = bucket->first;
+    while(1)
+    {
+        pair = list_to_pair(list);
+        if(pair->hash == hash && strcmp(pair->key, key) == 0)
+            return pair;
+
+        if(list == bucket->last)
+            break;
+
+        list = list->next;
+    }
+
+    return NULL;
+}
+
+/* returns 0 on success, -1 if key was not found */
+static int hashtable_do_del(hashtable_t *hashtable,
+                            const char *key, size_t hash)
+{
+    pair_t *pair;
+    bucket_t *bucket;
+    size_t index;
+
+    index = hash & hashmask(hashtable->order);
+    bucket = &hashtable->buckets[index];
+
+    pair = hashtable_find_pair(hashtable, bucket, key, hash);
+    if(!pair)
+        return -1;
+
+    if(&pair->list == bucket->first && &pair->list == bucket->last)
+        bucket->first = bucket->last = &hashtable->list;
+
+    else if(&pair->list == bucket->first)
+        bucket->first = pair->list.next;
+
+    else if(&pair->list == bucket->last)
+        bucket->last = pair->list.prev;
+
+    list_remove(&pair->list);
+    list_remove(&pair->ordered_list);
+    json_decref(pair->value);
+
+    jsonp_free(pair);
+    hashtable->size--;
+
+    return 0;
+}
+
+static void hashtable_do_clear(hashtable_t *hashtable)
+{
+    list_t *list, *next;
+    pair_t *pair;
+
+    for(list = hashtable->list.next; list != &hashtable->list; list = next)
+    {
+        next = list->next;
+        pair = list_to_pair(list);
+        json_decref(pair->value);
+        jsonp_free(pair);
+    }
+}
+
+static int hashtable_do_rehash(hashtable_t *hashtable)
+{
+    list_t *list, *next;
+    pair_t *pair;
+    size_t i, index, new_size, new_order;
+    struct hashtable_bucket *new_buckets;
+
+    new_order = hashtable->order + 1;
+    new_size = hashsize(new_order);
+
+    new_buckets = jsonp_malloc(new_size * sizeof(bucket_t));
+    if(!new_buckets)
+        return -1;
+
+    jsonp_free(hashtable->buckets);
+    hashtable->buckets = new_buckets;
+    hashtable->order = new_order;
+
+    for(i = 0; i < hashsize(hashtable->order); i++)
+    {
+        hashtable->buckets[i].first = hashtable->buckets[i].last =
+            &hashtable->list;
+    }
+
+    list = hashtable->list.next;
+    list_init(&hashtable->list);
+
+    for(; list != &hashtable->list; list = next) {
+        next = list->next;
+        pair = list_to_pair(list);
+        index = pair->hash % new_size;
+        insert_to_bucket(hashtable, &hashtable->buckets[index], &pair->list);
+    }
+
+    return 0;
+}
+
+
+int hashtable_init(hashtable_t *hashtable)
+{
+    size_t i;
+
+    hashtable->size = 0;
+    hashtable->order = INITIAL_HASHTABLE_ORDER;
+    hashtable->buckets = jsonp_malloc(hashsize(hashtable->order) * sizeof(bucket_t));
+    if(!hashtable->buckets)
+        return -1;
+
+    list_init(&hashtable->list);
+    list_init(&hashtable->ordered_list);
+
+    for(i = 0; i < hashsize(hashtable->order); i++)
+    {
+        hashtable->buckets[i].first = hashtable->buckets[i].last =
+            &hashtable->list;
+    }
+
+    return 0;
+}
+
+void hashtable_close(hashtable_t *hashtable)
+{
+    hashtable_do_clear(hashtable);
+    jsonp_free(hashtable->buckets);
+}
+
+int hashtable_set(hashtable_t *hashtable, const char *key, json_t *value)
+{
+    pair_t *pair;
+    bucket_t *bucket;
+    size_t hash, index;
+
+    /* rehash if the load ratio exceeds 1 */
+    if(hashtable->size >= hashsize(hashtable->order))
+        if(hashtable_do_rehash(hashtable))
+            return -1;
+
+    hash = hash_str(key);
+    index = hash & hashmask(hashtable->order);
+    bucket = &hashtable->buckets[index];
+    pair = hashtable_find_pair(hashtable, bucket, key, hash);
+
+    if(pair)
+    {
+        json_decref(pair->value);
+        pair->value = value;
+    }
+    else
+    {
+        /* offsetof(...) returns the size of pair_t without the last,
+           flexible member. This way, the correct amount is
+           allocated. */
+
+        size_t len = strlen(key);
+        if(len >= (size_t)-1 - offsetof(pair_t, key)) {
+            /* Avoid an overflow if the key is very long */
+            return -1;
+        }
+
+        pair = jsonp_malloc(offsetof(pair_t, key) + len + 1);
+        if(!pair)
+            return -1;
+
+        pair->hash = hash;
+        strncpy(pair->key, key, len + 1);
+        pair->value = value;
+        list_init(&pair->list);
+        list_init(&pair->ordered_list);
+
+        insert_to_bucket(hashtable, bucket, &pair->list);
+        list_insert(&hashtable->ordered_list, &pair->ordered_list);
+
+        hashtable->size++;
+    }
+    return 0;
+}
+
+void *hashtable_get(hashtable_t *hashtable, const char *key)
+{
+    pair_t *pair;
+    size_t hash;
+    bucket_t *bucket;
+
+    hash = hash_str(key);
+    bucket = &hashtable->buckets[hash & hashmask(hashtable->order)];
+
+    pair = hashtable_find_pair(hashtable, bucket, key, hash);
+    if(!pair)
+        return NULL;
+
+    return pair->value;
+}
+
+int hashtable_del(hashtable_t *hashtable, const char *key)
+{
+    size_t hash = hash_str(key);
+    return hashtable_do_del(hashtable, key, hash);
+}
+
+void hashtable_clear(hashtable_t *hashtable)
+{
+    size_t i;
+
+    hashtable_do_clear(hashtable);
+
+    for(i = 0; i < hashsize(hashtable->order); i++)
+    {
+        hashtable->buckets[i].first = hashtable->buckets[i].last =
+            &hashtable->list;
+    }
+
+    list_init(&hashtable->list);
+    list_init(&hashtable->ordered_list);
+    hashtable->size = 0;
+}
+
+void *hashtable_iter(hashtable_t *hashtable)
+{
+    return hashtable_iter_next(hashtable, &hashtable->ordered_list);
+}
+
+void *hashtable_iter_at(hashtable_t *hashtable, const char *key)
+{
+    pair_t *pair;
+    size_t hash;
+    bucket_t *bucket;
+
+    hash = hash_str(key);
+    bucket = &hashtable->buckets[hash & hashmask(hashtable->order)];
+
+    pair = hashtable_find_pair(hashtable, bucket, key, hash);
+    if(!pair)
+        return NULL;
+
+    return &pair->ordered_list;
+}
+
+void *hashtable_iter_next(hashtable_t *hashtable, void *iter)
+{
+    list_t *list = (list_t *)iter;
+    if(list->next == &hashtable->ordered_list)
+        return NULL;
+    return list->next;
+}
+
+void *hashtable_iter_key(void *iter)
+{
+    pair_t *pair = ordered_list_to_pair((list_t *)iter);
+    return pair->key;
+}
+
+void *hashtable_iter_value(void *iter)
+{
+    pair_t *pair = ordered_list_to_pair((list_t *)iter);
+    return pair->value;
+}
+
+void hashtable_iter_set(void *iter, json_t *value)
+{
+    pair_t *pair = ordered_list_to_pair((list_t *)iter);
+
+    json_decref(pair->value);
+    pair->value = value;
+}
diff --git a/client/jansson/hashtable.h b/client/jansson/hashtable.h
new file mode 100644
index 00000000..d4c32ae0
--- /dev/null
+++ b/client/jansson/hashtable.h
@@ -0,0 +1,176 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef HASHTABLE_H
+#define HASHTABLE_H
+
+#include <stdlib.h>
+#include "jansson.h"
+
+struct hashtable_list {
+    struct hashtable_list *prev;
+    struct hashtable_list *next;
+};
+
+/* "pair" may be a bit confusing a name, but think of it as a
+   key-value pair. In this case, it just encodes some extra data,
+   too */
+struct hashtable_pair {
+    struct hashtable_list list;
+    struct hashtable_list ordered_list;
+    size_t hash;
+    json_t *value;
+    char key[1];
+};
+
+struct hashtable_bucket {
+    struct hashtable_list *first;
+    struct hashtable_list *last;
+};
+
+typedef struct hashtable {
+    size_t size;
+    struct hashtable_bucket *buckets;
+    size_t order;  /* hashtable has pow(2, order) buckets */
+    struct hashtable_list list;
+    struct hashtable_list ordered_list;
+} hashtable_t;
+
+
+#define hashtable_key_to_iter(key_) \
+    (&(container_of(key_, struct hashtable_pair, key)->ordered_list))
+
+
+/**
+ * hashtable_init - Initialize a hashtable object
+ *
+ * @hashtable: The (statically allocated) hashtable object
+ *
+ * Initializes a statically allocated hashtable object. The object
+ * should be cleared with hashtable_close when it's no longer used.
+ *
+ * Returns 0 on success, -1 on error (out of memory).
+ */
+int hashtable_init(hashtable_t *hashtable);
+
+/**
+ * hashtable_close - Release all resources used by a hashtable object
+ *
+ * @hashtable: The hashtable
+ *
+ * Destroys a statically allocated hashtable object.
+ */
+void hashtable_close(hashtable_t *hashtable);
+
+/**
+ * hashtable_set - Add/modify value in hashtable
+ *
+ * @hashtable: The hashtable object
+ * @key: The key
+ * @serial: For addition order of keys
+ * @value: The value
+ *
+ * If a value with the given key already exists, its value is replaced
+ * with the new value. Value is "stealed" in the sense that hashtable
+ * doesn't increment its refcount but decreases the refcount when the
+ * value is no longer needed.
+ *
+ * Returns 0 on success, -1 on failure (out of memory).
+ */
+int hashtable_set(hashtable_t *hashtable, const char *key, json_t *value);
+
+/**
+ * hashtable_get - Get a value associated with a key
+ *
+ * @hashtable: The hashtable object
+ * @key: The key
+ *
+ * Returns value if it is found, or NULL otherwise.
+ */
+void *hashtable_get(hashtable_t *hashtable, const char *key);
+
+/**
+ * hashtable_del - Remove a value from the hashtable
+ *
+ * @hashtable: The hashtable object
+ * @key: The key
+ *
+ * Returns 0 on success, or -1 if the key was not found.
+ */
+int hashtable_del(hashtable_t *hashtable, const char *key);
+
+/**
+ * hashtable_clear - Clear hashtable
+ *
+ * @hashtable: The hashtable object
+ *
+ * Removes all items from the hashtable.
+ */
+void hashtable_clear(hashtable_t *hashtable);
+
+/**
+ * hashtable_iter - Iterate over hashtable
+ *
+ * @hashtable: The hashtable object
+ *
+ * Returns an opaque iterator to the first element in the hashtable.
+ * The iterator should be passed to hashtable_iter_* functions.
+ * The hashtable items are not iterated over in any particular order.
+ *
+ * There's no need to free the iterator in any way. The iterator is
+ * valid as long as the item that is referenced by the iterator is not
+ * deleted. Other values may be added or deleted. In particular,
+ * hashtable_iter_next() may be called on an iterator, and after that
+ * the key/value pair pointed by the old iterator may be deleted.
+ */
+void *hashtable_iter(hashtable_t *hashtable);
+
+/**
+ * hashtable_iter_at - Return an iterator at a specific key
+ *
+ * @hashtable: The hashtable object
+ * @key: The key that the iterator should point to
+ *
+ * Like hashtable_iter() but returns an iterator pointing to a
+ * specific key.
+ */
+void *hashtable_iter_at(hashtable_t *hashtable, const char *key);
+
+/**
+ * hashtable_iter_next - Advance an iterator
+ *
+ * @hashtable: The hashtable object
+ * @iter: The iterator
+ *
+ * Returns a new iterator pointing to the next element in the
+ * hashtable or NULL if the whole hastable has been iterated over.
+ */
+void *hashtable_iter_next(hashtable_t *hashtable, void *iter);
+
+/**
+ * hashtable_iter_key - Retrieve the key pointed by an iterator
+ *
+ * @iter: The iterator
+ */
+void *hashtable_iter_key(void *iter);
+
+/**
+ * hashtable_iter_value - Retrieve the value pointed by an iterator
+ *
+ * @iter: The iterator
+ */
+void *hashtable_iter_value(void *iter);
+
+/**
+ * hashtable_iter_set - Set the value pointed by an iterator
+ *
+ * @iter: The iterator
+ * @value: The value to set
+ */
+void hashtable_iter_set(void *iter, json_t *value);
+
+#endif
diff --git a/client/jansson/hashtable_seed.c b/client/jansson/hashtable_seed.c
new file mode 100644
index 00000000..8aed5406
--- /dev/null
+++ b/client/jansson/hashtable_seed.c
@@ -0,0 +1,277 @@
+/* Generate sizeof(uint32_t) bytes of as random data as possible to seed
+   the hash function.
+*/
+
+#ifdef HAVE_CONFIG_H
+#include <jansson_private_config.h>
+#endif
+
+#include <stdio.h>
+#include <time.h>
+
+#ifdef HAVE_STDINT_H
+#include <stdint.h>
+#endif
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#ifdef HAVE_SCHED_H
+#include <sched.h>
+#endif
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#if defined(_WIN32)
+/* For GetModuleHandle(), GetProcAddress() and GetCurrentProcessId() */
+#include <windows.h>
+#endif
+
+#include "jansson.h"
+
+
+static uint32_t buf_to_uint32(char *data) {
+    size_t i;
+    uint32_t result = 0;
+
+    for (i = 0; i < sizeof(uint32_t); i++)
+        result = (result << 8) | (unsigned char)data[i];
+
+    return result;
+}
+
+
+
+/* /dev/urandom */
+#if !defined(_WIN32) && defined(USE_URANDOM)
+static int seed_from_urandom(uint32_t *seed) {
+    /* Use unbuffered I/O if we have open(), close() and read(). Otherwise
+       fall back to fopen() */
+
+    char data[sizeof(uint32_t)];
+    int ok;
+
+#if defined(HAVE_OPEN) && defined(HAVE_CLOSE) && defined(HAVE_READ)
+    int urandom;
+    urandom = open("/dev/urandom", O_RDONLY);
+    if (urandom == -1)
+        return 1;
+
+    ok = read(urandom, data, sizeof(uint32_t)) == sizeof(uint32_t);
+    close(urandom);
+#else
+    FILE *urandom;
+
+    urandom = fopen("/dev/urandom", "rb");
+    if (!urandom)
+        return 1;
+
+    ok = fread(data, 1, sizeof(uint32_t), urandom) == sizeof(uint32_t);
+    fclose(urandom);
+#endif
+
+    if (!ok)
+        return 1;
+
+    *seed = buf_to_uint32(data);
+    return 0;
+}
+#endif
+
+/* Windows Crypto API */
+#if defined(_WIN32) && defined(USE_WINDOWS_CRYPTOAPI)
+#include <wincrypt.h>
+
+typedef BOOL (WINAPI *CRYPTACQUIRECONTEXTA)(HCRYPTPROV *phProv, LPCSTR pszContainer, LPCSTR pszProvider, DWORD dwProvType, DWORD dwFlags);
+typedef BOOL (WINAPI *CRYPTGENRANDOM)(HCRYPTPROV hProv, DWORD dwLen, BYTE *pbBuffer);
+typedef BOOL (WINAPI *CRYPTRELEASECONTEXT)(HCRYPTPROV hProv, DWORD dwFlags);
+
+static int seed_from_windows_cryptoapi(uint32_t *seed)
+{
+    HINSTANCE hAdvAPI32 = NULL;
+    CRYPTACQUIRECONTEXTA pCryptAcquireContext = NULL;
+    CRYPTGENRANDOM pCryptGenRandom = NULL;
+    CRYPTRELEASECONTEXT pCryptReleaseContext = NULL;
+    HCRYPTPROV hCryptProv = 0;
+    BYTE data[sizeof(uint32_t)];
+    int ok;
+
+    hAdvAPI32 = GetModuleHandle(TEXT("advapi32.dll"));
+    if(hAdvAPI32 == NULL)
+        return 1;
+
+    pCryptAcquireContext = (CRYPTACQUIRECONTEXTA)GetProcAddress(hAdvAPI32, "CryptAcquireContextA");
+    if (!pCryptAcquireContext)
+        return 1;
+
+    pCryptGenRandom = (CRYPTGENRANDOM)GetProcAddress(hAdvAPI32, "CryptGenRandom");
+    if (!pCryptGenRandom)
+        return 1;
+
+    pCryptReleaseContext = (CRYPTRELEASECONTEXT)GetProcAddress(hAdvAPI32, "CryptReleaseContext");
+    if (!pCryptReleaseContext)
+        return 1;
+
+    if (!pCryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
+        return 1;
+
+    ok = pCryptGenRandom(hCryptProv, sizeof(uint32_t), data);
+    pCryptReleaseContext(hCryptProv, 0);
+
+    if (!ok)
+        return 1;
+
+    *seed = buf_to_uint32((char *)data);
+    return 0;
+}
+#endif
+
+/* gettimeofday() and getpid() */
+static int seed_from_timestamp_and_pid(uint32_t *seed) {
+#ifdef HAVE_GETTIMEOFDAY
+    /* XOR of seconds and microseconds */
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    *seed = (uint32_t)tv.tv_sec ^ (uint32_t)tv.tv_usec;
+#else
+    /* Seconds only */
+    *seed = (uint32_t)time(NULL);
+#endif
+
+    /* XOR with PID for more randomness */
+#if defined(_WIN32)
+    *seed ^= (uint32_t)GetCurrentProcessId();
+#elif defined(HAVE_GETPID)
+    *seed ^= (uint32_t)getpid();
+#endif
+
+    return 0;
+}
+
+static uint32_t generate_seed() {
+    uint32_t seed;
+    int done = 0;
+
+#if !defined(_WIN32) && defined(USE_URANDOM)
+    if (seed_from_urandom(&seed) == 0)
+        done = 1;
+#endif
+
+#if defined(_WIN32) && defined(USE_WINDOWS_CRYPTOAPI)
+    if (seed_from_windows_cryptoapi(&seed) == 0)
+        done = 1;
+#endif
+
+    if (!done) {
+        /* Fall back to timestamp and PID if no better randomness is
+           available */
+        seed_from_timestamp_and_pid(&seed);
+    }
+
+    /* Make sure the seed is never zero */
+    if (seed == 0)
+        seed = 1;
+
+    return seed;
+}
+
+
+volatile uint32_t hashtable_seed = 0;
+
+#if defined(HAVE_ATOMIC_BUILTINS) && (defined(HAVE_SCHED_YIELD) || !defined(_WIN32))
+static volatile char seed_initialized = 0;
+
+void json_object_seed(size_t seed) {
+    uint32_t new_seed = (uint32_t)seed;
+
+    if (hashtable_seed == 0) {
+        if (__atomic_test_and_set(&seed_initialized, __ATOMIC_RELAXED) == 0) {
+            /* Do the seeding ourselves */
+            if (new_seed == 0)
+                new_seed = generate_seed();
+
+            __atomic_store_n(&hashtable_seed, new_seed, __ATOMIC_RELEASE);
+        } else {
+            /* Wait for another thread to do the seeding */
+            do {
+#ifdef HAVE_SCHED_YIELD
+                sched_yield();
+#endif
+            } while(__atomic_load_n(&hashtable_seed, __ATOMIC_ACQUIRE) == 0);
+        }
+    }
+}
+#elif defined(HAVE_SYNC_BUILTINS) && (defined(HAVE_SCHED_YIELD) || !defined(_WIN32))
+void json_object_seed(size_t seed) {
+    uint32_t new_seed = (uint32_t)seed;
+
+    if (hashtable_seed == 0) {
+        if (new_seed == 0) {
+            /* Explicit synchronization fences are not supported by the
+               __sync builtins, so every thread getting here has to
+               generate the seed value.
+            */
+            new_seed = generate_seed();
+        }
+
+        do {
+            if (__sync_bool_compare_and_swap(&hashtable_seed, 0, new_seed)) {
+                /* We were the first to seed */
+                break;
+            } else {
+                /* Wait for another thread to do the seeding */
+#ifdef HAVE_SCHED_YIELD
+                sched_yield();
+#endif
+            }
+        } while(hashtable_seed == 0);
+    }
+}
+#elif defined(_WIN32)
+static long seed_initialized = 0;
+void json_object_seed(size_t seed) {
+    uint32_t new_seed = (uint32_t)seed;
+
+    if (hashtable_seed == 0) {
+        if (InterlockedIncrement(&seed_initialized) == 1) {
+            /* Do the seeding ourselves */
+            if (new_seed == 0)
+                new_seed = generate_seed();
+
+            hashtable_seed = new_seed;
+        } else {
+            /* Wait for another thread to do the seeding */
+            do {
+                SwitchToThread();
+            } while (hashtable_seed == 0);
+        }
+    }
+}
+#else
+/* Fall back to a thread-unsafe version */
+void json_object_seed(size_t seed) {
+    uint32_t new_seed = (uint32_t)seed;
+
+    if (hashtable_seed == 0) {
+        if (new_seed == 0)
+            new_seed = generate_seed();
+
+        hashtable_seed = new_seed;
+    }
+}
+#endif
diff --git a/client/jansson/jansson.def b/client/jansson/jansson.def
new file mode 100644
index 00000000..15f35c95
--- /dev/null
+++ b/client/jansson/jansson.def
@@ -0,0 +1,75 @@
+EXPORTS
+    json_delete
+    json_true
+    json_false
+    json_null
+    json_sprintf
+    json_vsprintf
+    json_string
+    json_stringn
+    json_string_nocheck
+    json_stringn_nocheck
+    json_string_value
+    json_string_length
+    json_string_set
+    json_string_setn
+    json_string_set_nocheck
+    json_string_setn_nocheck
+    json_integer
+    json_integer_value
+    json_integer_set
+    json_real
+    json_real_value
+    json_real_set
+    json_number_value
+    json_array
+    json_array_size
+    json_array_get
+    json_array_set_new
+    json_array_append_new
+    json_array_insert_new
+    json_array_remove
+    json_array_clear
+    json_array_extend
+    json_object
+    json_object_size
+    json_object_get
+    json_object_set_new
+    json_object_set_new_nocheck
+    json_object_del
+    json_object_clear
+    json_object_update
+    json_object_update_existing
+    json_object_update_missing
+    json_object_iter
+    json_object_iter_at
+    json_object_iter_next
+    json_object_iter_key
+    json_object_iter_value
+    json_object_iter_set_new
+    json_object_key_to_iter
+    json_object_seed
+    json_dumps
+    json_dumpb
+    json_dumpf
+    json_dumpfd
+    json_dump_file
+    json_dump_callback
+    json_loads
+    json_loadb
+    json_loadf
+    json_loadfd
+    json_load_file
+    json_load_callback
+    json_equal
+    json_copy
+    json_deep_copy
+    json_pack
+    json_pack_ex
+    json_vpack_ex
+    json_unpack
+    json_unpack_ex
+    json_vunpack_ex
+    json_set_alloc_funcs
+    json_get_alloc_funcs
+
diff --git a/client/jansson/jansson.h b/client/jansson/jansson.h
new file mode 100644
index 00000000..43332895
--- /dev/null
+++ b/client/jansson/jansson.h
@@ -0,0 +1,362 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef JANSSON_H
+#define JANSSON_H
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>  /* for size_t */
+#include <stdarg.h>
+
+#include "jansson_config.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* version */
+
+#define JANSSON_MAJOR_VERSION  2
+#define JANSSON_MINOR_VERSION  11
+#define JANSSON_MICRO_VERSION  0
+
+/* Micro version is omitted if it's 0 */
+#define JANSSON_VERSION  "2.11"
+
+/* Version as a 3-byte hex number, e.g. 0x010201 == 1.2.1. Use this
+   for numeric comparisons, e.g. #if JANSSON_VERSION_HEX >= ... */
+#define JANSSON_VERSION_HEX  ((JANSSON_MAJOR_VERSION << 16) |   \
+                              (JANSSON_MINOR_VERSION << 8)  |   \
+                              (JANSSON_MICRO_VERSION << 0))
+
+/* If __atomic or __sync builtins are available the library is thread
+ * safe for all read-only functions plus reference counting. */
+#if JSON_HAVE_ATOMIC_BUILTINS || JSON_HAVE_SYNC_BUILTINS
+#define JANSSON_THREAD_SAFE_REFCOUNT 1
+#endif
+
+/* types */
+
+typedef enum {
+    JSON_OBJECT,
+    JSON_ARRAY,
+    JSON_STRING,
+    JSON_INTEGER,
+    JSON_REAL,
+    JSON_TRUE,
+    JSON_FALSE,
+    JSON_NULL
+} json_type;
+
+typedef struct json_t {
+    json_type type;
+    volatile size_t refcount;
+} json_t;
+
+#ifndef JANSSON_USING_CMAKE /* disabled if using cmake */
+#if JSON_INTEGER_IS_LONG_LONG
+#ifdef _WIN32
+#define JSON_INTEGER_FORMAT "I64d"
+#else
+#define JSON_INTEGER_FORMAT "lld"
+#endif
+typedef long long json_int_t;
+#else
+#define JSON_INTEGER_FORMAT "ld"
+typedef long json_int_t;
+#endif /* JSON_INTEGER_IS_LONG_LONG */
+#endif
+
+#define json_typeof(json)      ((json)->type)
+#define json_is_object(json)   ((json) && json_typeof(json) == JSON_OBJECT)
+#define json_is_array(json)    ((json) && json_typeof(json) == JSON_ARRAY)
+#define json_is_string(json)   ((json) && json_typeof(json) == JSON_STRING)
+#define json_is_integer(json)  ((json) && json_typeof(json) == JSON_INTEGER)
+#define json_is_real(json)     ((json) && json_typeof(json) == JSON_REAL)
+#define json_is_number(json)   (json_is_integer(json) || json_is_real(json))
+#define json_is_true(json)     ((json) && json_typeof(json) == JSON_TRUE)
+#define json_is_false(json)    ((json) && json_typeof(json) == JSON_FALSE)
+#define json_boolean_value     json_is_true
+#define json_is_boolean(json)  (json_is_true(json) || json_is_false(json))
+#define json_is_null(json)     ((json) && json_typeof(json) == JSON_NULL)
+
+/* construction, destruction, reference counting */
+
+json_t *json_object(void);
+json_t *json_array(void);
+json_t *json_string(const char *value);
+json_t *json_stringn(const char *value, size_t len);
+json_t *json_string_nocheck(const char *value);
+json_t *json_stringn_nocheck(const char *value, size_t len);
+json_t *json_integer(json_int_t value);
+json_t *json_real(double value);
+json_t *json_true(void);
+json_t *json_false(void);
+#define json_boolean(val)      ((val) ? json_true() : json_false())
+json_t *json_null(void);
+
+/* do not call JSON_INTERNAL_INCREF or JSON_INTERNAL_DECREF directly */
+#if JSON_HAVE_ATOMIC_BUILTINS
+#define JSON_INTERNAL_INCREF(json) __atomic_add_fetch(&json->refcount, 1, __ATOMIC_ACQUIRE)
+#define JSON_INTERNAL_DECREF(json) __atomic_sub_fetch(&json->refcount, 1, __ATOMIC_RELEASE)
+#elif JSON_HAVE_SYNC_BUILTINS
+#define JSON_INTERNAL_INCREF(json) __sync_add_and_fetch(&json->refcount, 1)
+#define JSON_INTERNAL_DECREF(json) __sync_sub_and_fetch(&json->refcount, 1)
+#else
+#define JSON_INTERNAL_INCREF(json) (++json->refcount)
+#define JSON_INTERNAL_DECREF(json) (--json->refcount)
+#endif
+
+static JSON_INLINE
+json_t *json_incref(json_t *json)
+{
+    if(json && json->refcount != (size_t)-1)
+        JSON_INTERNAL_INCREF(json);
+    return json;
+}
+
+/* do not call json_delete directly */
+void json_delete(json_t *json);
+
+static JSON_INLINE
+void json_decref(json_t *json)
+{
+    if(json && json->refcount != (size_t)-1 && JSON_INTERNAL_DECREF(json) == 0)
+        json_delete(json);
+}
+
+#if defined(__GNUC__) || defined(__clang__)
+static JSON_INLINE
+void json_decrefp(json_t **json)
+{
+    if(json) {
+        json_decref(*json);
+	*json = NULL;
+    }
+}
+
+#define json_auto_t json_t __attribute__((cleanup(json_decrefp)))
+#endif
+
+
+/* error reporting */
+
+#define JSON_ERROR_TEXT_LENGTH    160
+#define JSON_ERROR_SOURCE_LENGTH   80
+
+typedef struct json_error_t {
+    int line;
+    int column;
+    int position;
+    char source[JSON_ERROR_SOURCE_LENGTH];
+    char text[JSON_ERROR_TEXT_LENGTH];
+} json_error_t;
+
+enum json_error_code {
+    json_error_unknown,
+    json_error_out_of_memory,
+    json_error_stack_overflow,
+    json_error_cannot_open_file,
+    json_error_invalid_argument,
+    json_error_invalid_utf8,
+    json_error_premature_end_of_input,
+    json_error_end_of_input_expected,
+    json_error_invalid_syntax,
+    json_error_invalid_format,
+    json_error_wrong_type,
+    json_error_null_character,
+    json_error_null_value,
+    json_error_null_byte_in_key,
+    json_error_duplicate_key,
+    json_error_numeric_overflow,
+    json_error_item_not_found,
+    json_error_index_out_of_range
+};
+
+static JSON_INLINE enum json_error_code json_error_code(const json_error_t *e) {
+    return (enum json_error_code)e->text[JSON_ERROR_TEXT_LENGTH - 1];
+}
+
+/* getters, setters, manipulation */
+
+void json_object_seed(size_t seed);
+size_t json_object_size(const json_t *object);
+json_t *json_object_get(const json_t *object, const char *key);
+int json_object_set_new(json_t *object, const char *key, json_t *value);
+int json_object_set_new_nocheck(json_t *object, const char *key, json_t *value);
+int json_object_del(json_t *object, const char *key);
+int json_object_clear(json_t *object);
+int json_object_update(json_t *object, json_t *other);
+int json_object_update_existing(json_t *object, json_t *other);
+int json_object_update_missing(json_t *object, json_t *other);
+void *json_object_iter(json_t *object);
+void *json_object_iter_at(json_t *object, const char *key);
+void *json_object_key_to_iter(const char *key);
+void *json_object_iter_next(json_t *object, void *iter);
+const char *json_object_iter_key(void *iter);
+json_t *json_object_iter_value(void *iter);
+int json_object_iter_set_new(json_t *object, void *iter, json_t *value);
+
+#define json_object_foreach(object, key, value) \
+    for(key = json_object_iter_key(json_object_iter(object)); \
+        key && (value = json_object_iter_value(json_object_key_to_iter(key))); \
+        key = json_object_iter_key(json_object_iter_next(object, json_object_key_to_iter(key))))
+
+#define json_object_foreach_safe(object, n, key, value)     \
+    for(key = json_object_iter_key(json_object_iter(object)), \
+            n = json_object_iter_next(object, json_object_key_to_iter(key)); \
+        key && (value = json_object_iter_value(json_object_key_to_iter(key))); \
+        key = json_object_iter_key(n), \
+            n = json_object_iter_next(object, json_object_key_to_iter(key)))
+
+#define json_array_foreach(array, index, value) \
+	for(index = 0; \
+		index < json_array_size(array) && (value = json_array_get(array, index)); \
+		index++)
+
+static JSON_INLINE
+int json_object_set(json_t *object, const char *key, json_t *value)
+{
+    return json_object_set_new(object, key, json_incref(value));
+}
+
+static JSON_INLINE
+int json_object_set_nocheck(json_t *object, const char *key, json_t *value)
+{
+    return json_object_set_new_nocheck(object, key, json_incref(value));
+}
+
+static JSON_INLINE
+int json_object_iter_set(json_t *object, void *iter, json_t *value)
+{
+    return json_object_iter_set_new(object, iter, json_incref(value));
+}
+
+size_t json_array_size(const json_t *array);
+json_t *json_array_get(const json_t *array, size_t index);
+int json_array_set_new(json_t *array, size_t index, json_t *value);
+int json_array_append_new(json_t *array, json_t *value);
+int json_array_insert_new(json_t *array, size_t index, json_t *value);
+int json_array_remove(json_t *array, size_t index);
+int json_array_clear(json_t *array);
+int json_array_extend(json_t *array, json_t *other);
+
+static JSON_INLINE
+int json_array_set(json_t *array, size_t ind, json_t *value)
+{
+    return json_array_set_new(array, ind, json_incref(value));
+}
+
+static JSON_INLINE
+int json_array_append(json_t *array, json_t *value)
+{
+    return json_array_append_new(array, json_incref(value));
+}
+
+static JSON_INLINE
+int json_array_insert(json_t *array, size_t ind, json_t *value)
+{
+    return json_array_insert_new(array, ind, json_incref(value));
+}
+
+const char *json_string_value(const json_t *string);
+size_t json_string_length(const json_t *string);
+json_int_t json_integer_value(const json_t *integer);
+double json_real_value(const json_t *real);
+double json_number_value(const json_t *json);
+
+int json_string_set(json_t *string, const char *value);
+int json_string_setn(json_t *string, const char *value, size_t len);
+int json_string_set_nocheck(json_t *string, const char *value);
+int json_string_setn_nocheck(json_t *string, const char *value, size_t len);
+int json_integer_set(json_t *integer, json_int_t value);
+int json_real_set(json_t *real, double value);
+
+/* pack, unpack */
+
+json_t *json_pack(const char *fmt, ...);
+json_t *json_pack_ex(json_error_t *error, size_t flags, const char *fmt, ...);
+json_t *json_vpack_ex(json_error_t *error, size_t flags, const char *fmt, va_list ap);
+
+#define JSON_VALIDATE_ONLY  0x1
+#define JSON_STRICT         0x2
+
+int json_unpack(json_t *root, const char *fmt, ...);
+int json_unpack_ex(json_t *root, json_error_t *error, size_t flags, const char *fmt, ...);
+int json_vunpack_ex(json_t *root, json_error_t *error, size_t flags, const char *fmt, va_list ap);
+
+/* sprintf */
+
+json_t *json_sprintf(const char *fmt, ...);
+json_t *json_vsprintf(const char *fmt, va_list ap);
+
+
+/* equality */
+
+int json_equal(const json_t *value1, const json_t *value2);
+
+
+/* copying */
+
+json_t *json_copy(json_t *value);
+json_t *json_deep_copy(const json_t *value);
+
+
+/* decoding */
+
+#define JSON_REJECT_DUPLICATES  0x1
+#define JSON_DISABLE_EOF_CHECK  0x2
+#define JSON_DECODE_ANY         0x4
+#define JSON_DECODE_INT_AS_REAL 0x8
+#define JSON_ALLOW_NUL          0x10
+
+typedef size_t (*json_load_callback_t)(void *buffer, size_t buflen, void *data);
+
+json_t *json_loads(const char *input, size_t flags, json_error_t *error);
+json_t *json_loadb(const char *buffer, size_t buflen, size_t flags, json_error_t *error);
+json_t *json_loadf(FILE *input, size_t flags, json_error_t *error);
+json_t *json_loadfd(int input, size_t flags, json_error_t *error);
+json_t *json_load_file(const char *path, size_t flags, json_error_t *error);
+json_t *json_load_callback(json_load_callback_t callback, void *data, size_t flags, json_error_t *error);
+
+
+/* encoding */
+
+#define JSON_MAX_INDENT         0x1F
+#define JSON_INDENT(n)          ((n) & JSON_MAX_INDENT)
+#define JSON_COMPACT            0x20
+#define JSON_ENSURE_ASCII       0x40
+#define JSON_SORT_KEYS          0x80
+#define JSON_PRESERVE_ORDER     0x100
+#define JSON_ENCODE_ANY         0x200
+#define JSON_ESCAPE_SLASH       0x400
+#define JSON_REAL_PRECISION(n)  (((n) & 0x1F) << 11)
+#define JSON_EMBED              0x10000
+
+typedef int (*json_dump_callback_t)(const char *buffer, size_t size, void *data);
+
+char *json_dumps(const json_t *json, size_t flags);
+size_t json_dumpb(const json_t *json, char *buffer, size_t size, size_t flags);
+int json_dumpf(const json_t *json, FILE *output, size_t flags);
+int json_dumpfd(const json_t *json, int output, size_t flags);
+int json_dump_file(const json_t *json, const char *path, size_t flags);
+int json_dump_callback(const json_t *json, json_dump_callback_t callback, void *data, size_t flags);
+
+/* custom memory allocation */
+
+typedef void *(*json_malloc_t)(size_t);
+typedef void (*json_free_t)(void *);
+
+void json_set_alloc_funcs(json_malloc_t malloc_fn, json_free_t free_fn);
+void json_get_alloc_funcs(json_malloc_t *malloc_fn, json_free_t *free_fn);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/client/jansson/jansson_config.h b/client/jansson/jansson_config.h
new file mode 100644
index 00000000..b34baa55
--- /dev/null
+++ b/client/jansson/jansson_config.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2010-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ *
+ *
+ * This file specifies a part of the site-specific configuration for
+ * Jansson, namely those things that affect the public API in
+ * jansson.h.
+ *
+ * The configure script copies this file to jansson_config.h and
+ * replaces @var@ substitutions by values that fit your system. If you
+ * cannot run the configure script, you can do the value substitution
+ * by hand.
+ */
+
+#ifndef JANSSON_CONFIG_H
+#define JANSSON_CONFIG_H
+
+/* If your compiler supports the inline keyword in C, JSON_INLINE is
+   defined to `inline', otherwise empty. In C++, the inline is always
+   supported. */
+#ifdef __cplusplus
+#define JSON_INLINE inline
+#else
+#define JSON_INLINE inline
+#endif
+
+/* If your compiler supports the `long long` type and the strtoll()
+   library function, JSON_INTEGER_IS_LONG_LONG is defined to 1,
+   otherwise to 0. */
+#define JSON_INTEGER_IS_LONG_LONG 1
+
+/* If locale.h and localeconv() are available, define to 1,
+   otherwise to 0. */
+#define JSON_HAVE_LOCALECONV 1
+
+/* If __atomic builtins are available they will be used to manage
+   reference counts of json_t. */
+#define JSON_HAVE_ATOMIC_BUILTINS 1
+
+/* If __atomic builtins are not available we try using __sync builtins
+   to manage reference counts of json_t. */
+#define JSON_HAVE_SYNC_BUILTINS 1
+
+/* Maximum recursion depth for parsing JSON input.
+   This limits the depth of e.g. array-within-array constructions. */
+#define JSON_PARSER_MAX_DEPTH 2048
+
+#endif
diff --git a/client/jansson/jansson_config.h.in b/client/jansson/jansson_config.h.in
new file mode 100644
index 00000000..fe692ab4
--- /dev/null
+++ b/client/jansson/jansson_config.h.in
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2010-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ *
+ *
+ * This file specifies a part of the site-specific configuration for
+ * Jansson, namely those things that affect the public API in
+ * jansson.h.
+ *
+ * The configure script copies this file to jansson_config.h and
+ * replaces @var@ substitutions by values that fit your system. If you
+ * cannot run the configure script, you can do the value substitution
+ * by hand.
+ */
+
+#ifndef JANSSON_CONFIG_H
+#define JANSSON_CONFIG_H
+
+/* If your compiler supports the inline keyword in C, JSON_INLINE is
+   defined to `inline', otherwise empty. In C++, the inline is always
+   supported. */
+#ifdef __cplusplus
+#define JSON_INLINE inline
+#else
+#define JSON_INLINE @json_inline@
+#endif
+
+/* If your compiler supports the `long long` type and the strtoll()
+   library function, JSON_INTEGER_IS_LONG_LONG is defined to 1,
+   otherwise to 0. */
+#define JSON_INTEGER_IS_LONG_LONG @json_have_long_long@
+
+/* If locale.h and localeconv() are available, define to 1,
+   otherwise to 0. */
+#define JSON_HAVE_LOCALECONV @json_have_localeconv@
+
+/* If __atomic builtins are available they will be used to manage
+   reference counts of json_t. */
+#define JSON_HAVE_ATOMIC_BUILTINS @json_have_atomic_builtins@
+
+/* If __atomic builtins are not available we try using __sync builtins
+   to manage reference counts of json_t. */
+#define JSON_HAVE_SYNC_BUILTINS @json_have_sync_builtins@
+
+/* Maximum recursion depth for parsing JSON input.
+   This limits the depth of e.g. array-within-array constructions. */
+#define JSON_PARSER_MAX_DEPTH 2048
+
+#endif
diff --git a/client/jansson/jansson_private.h b/client/jansson/jansson_private.h
new file mode 100644
index 00000000..7b0985aa
--- /dev/null
+++ b/client/jansson/jansson_private.h
@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef JANSSON_PRIVATE_H
+#define JANSSON_PRIVATE_H
+
+#ifdef HAVE_CONFIG_H
+#include <jansson_private_config.h>
+#endif
+
+#include <stddef.h>
+#include "jansson.h"
+#include "hashtable.h"
+#include "strbuffer.h"
+
+#define container_of(ptr_, type_, member_)  \
+    ((type_ *)((char *)ptr_ - offsetof(type_, member_)))
+
+/* On some platforms, max() may already be defined */
+#ifndef max
+#define max(a, b)  ((a) > (b) ? (a) : (b))
+#endif
+
+/* va_copy is a C99 feature. In C89 implementations, it's sometimes
+   available as __va_copy. If not, memcpy() should do the trick. */
+#ifndef va_copy
+#ifdef __va_copy
+#define va_copy __va_copy
+#else
+#define va_copy(a, b)  memcpy(&(a), &(b), sizeof(va_list))
+#endif
+#endif
+
+typedef struct {
+    json_t json;
+    hashtable_t hashtable;
+} json_object_t;
+
+typedef struct {
+    json_t json;
+    size_t size;
+    size_t entries;
+    json_t **table;
+} json_array_t;
+
+typedef struct {
+    json_t json;
+    char *value;
+    size_t length;
+} json_string_t;
+
+typedef struct {
+    json_t json;
+    double value;
+} json_real_t;
+
+typedef struct {
+    json_t json;
+    json_int_t value;
+} json_integer_t;
+
+#define json_to_object(json_)  container_of(json_, json_object_t, json)
+#define json_to_array(json_)   container_of(json_, json_array_t, json)
+#define json_to_string(json_)  container_of(json_, json_string_t, json)
+#define json_to_real(json_)    container_of(json_, json_real_t, json)
+#define json_to_integer(json_) container_of(json_, json_integer_t, json)
+
+/* Create a string by taking ownership of an existing buffer */
+json_t *jsonp_stringn_nocheck_own(const char *value, size_t len);
+
+/* Error message formatting */
+void jsonp_error_init(json_error_t *error, const char *source);
+void jsonp_error_set_source(json_error_t *error, const char *source);
+void jsonp_error_set(json_error_t *error, int line, int column,
+                     size_t position, enum json_error_code code,
+                     const char *msg, ...);
+void jsonp_error_vset(json_error_t *error, int line, int column,
+                      size_t position, enum json_error_code code,
+                      const char *msg, va_list ap);
+
+/* Locale independent string<->double conversions */
+int jsonp_strtod(strbuffer_t *strbuffer, double *out);
+int jsonp_dtostr(char *buffer, size_t size, double value, int prec);
+
+/* Wrappers for custom memory functions */
+void* jsonp_malloc(size_t size);
+void jsonp_free(void *ptr);
+char *jsonp_strndup(const char *str, size_t length);
+char *jsonp_strdup(const char *str);
+char *jsonp_strndup(const char *str, size_t len);
+
+
+/* Windows compatibility */
+#if defined(_WIN32) || defined(WIN32)
+#  if defined(_MSC_VER)  /* MS compiller */
+#    if (_MSC_VER < 1900) && !defined(snprintf)  /* snprintf not defined yet & not introduced */
+#      define snprintf _snprintf
+#    endif
+#    if (_MSC_VER < 1500) && !defined(vsnprintf)  /* vsnprintf not defined yet & not introduced */
+#      define vsnprintf(b,c,f,a) _vsnprintf(b,c,f,a)
+#    endif
+#  else  /* Other Windows compiller, old definition */
+#    define snprintf _snprintf
+#    define vsnprintf _vsnprintf
+#  endif
+#endif
+
+#endif
diff --git a/client/jansson/load.c b/client/jansson/load.c
new file mode 100644
index 00000000..deb36f32
--- /dev/null
+++ b/client/jansson/load.c
@@ -0,0 +1,1155 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include "jansson_private.h"
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include "jansson.h"
+#include "strbuffer.h"
+#include "utf.h"
+
+#define STREAM_STATE_OK        0
+#define STREAM_STATE_EOF      -1
+#define STREAM_STATE_ERROR    -2
+
+#define TOKEN_INVALID         -1
+#define TOKEN_EOF              0
+#define TOKEN_STRING         256
+#define TOKEN_INTEGER        257
+#define TOKEN_REAL           258
+#define TOKEN_TRUE           259
+#define TOKEN_FALSE          260
+#define TOKEN_NULL           261
+
+/* Locale independent versions of isxxx() functions */
+#define l_isupper(c)  ('A' <= (c) && (c) <= 'Z')
+#define l_islower(c)  ('a' <= (c) && (c) <= 'z')
+#define l_isalpha(c)  (l_isupper(c) || l_islower(c))
+#define l_isdigit(c)  ('0' <= (c) && (c) <= '9')
+#define l_isxdigit(c) \
+    (l_isdigit(c) || ('A' <= (c) && (c) <= 'F') || ('a' <= (c) && (c) <= 'f'))
+
+/* Read one byte from stream, convert to unsigned char, then int, and
+   return. return EOF on end of file. This corresponds to the
+   behaviour of fgetc(). */
+typedef int (*get_func)(void *data);
+
+typedef struct {
+    get_func get;
+    void *data;
+    char buffer[5];
+    size_t buffer_pos;
+    int state;
+    int line;
+    int column, last_column;
+    size_t position;
+} stream_t;
+
+typedef struct {
+    stream_t stream;
+    strbuffer_t saved_text;
+    size_t flags;
+    size_t depth;
+    int token;
+    union {
+        struct {
+            char *val;
+            size_t len;
+        } string;
+        json_int_t integer;
+        double real;
+    } value;
+} lex_t;
+
+#define stream_to_lex(stream) container_of(stream, lex_t, stream)
+
+
+/*** error reporting ***/
+
+static void error_set(json_error_t *error, const lex_t *lex,
+                      enum json_error_code code,
+                      const char *msg, ...)
+{
+    va_list ap;
+    char msg_text[JSON_ERROR_TEXT_LENGTH];
+    char msg_with_context[JSON_ERROR_TEXT_LENGTH];
+
+    int line = -1, col = -1;
+    size_t pos = 0;
+    const char *result = msg_text;
+
+    if(!error)
+        return;
+
+    va_start(ap, msg);
+    vsnprintf(msg_text, JSON_ERROR_TEXT_LENGTH, msg, ap);
+    msg_text[JSON_ERROR_TEXT_LENGTH - 1] = '\0';
+    va_end(ap);
+
+    if(lex)
+    {
+        const char *saved_text = strbuffer_value(&lex->saved_text);
+
+        line = lex->stream.line;
+        col = lex->stream.column;
+        pos = lex->stream.position;
+
+        if(saved_text && saved_text[0])
+        {
+            if(lex->saved_text.length <= 20) {
+                snprintf(msg_with_context, JSON_ERROR_TEXT_LENGTH,
+                         "%s near '%s'", msg_text, saved_text);
+                msg_with_context[JSON_ERROR_TEXT_LENGTH - 1] = '\0';
+                result = msg_with_context;
+            }
+        }
+        else
+        {
+            if(code == json_error_invalid_syntax) {
+                /* More specific error code for premature end of file. */
+                code = json_error_premature_end_of_input;
+            }
+            if(lex->stream.state == STREAM_STATE_ERROR) {
+                /* No context for UTF-8 decoding errors */
+                result = msg_text;
+            }
+            else {
+                snprintf(msg_with_context, JSON_ERROR_TEXT_LENGTH,
+                         "%s near end of file", msg_text);
+                msg_with_context[JSON_ERROR_TEXT_LENGTH - 1] = '\0';
+                result = msg_with_context;
+            }
+        }
+    }
+
+    jsonp_error_set(error, line, col, pos, code, "%s", result);
+}
+
+
+/*** lexical analyzer ***/
+
+static void
+stream_init(stream_t *stream, get_func get, void *data)
+{
+    stream->get = get;
+    stream->data = data;
+    stream->buffer[0] = '\0';
+    stream->buffer_pos = 0;
+
+    stream->state = STREAM_STATE_OK;
+    stream->line = 1;
+    stream->column = 0;
+    stream->position = 0;
+}
+
+static int stream_get(stream_t *stream, json_error_t *error)
+{
+    int c;
+
+    if(stream->state != STREAM_STATE_OK)
+        return stream->state;
+
+    if(!stream->buffer[stream->buffer_pos])
+    {
+        c = stream->get(stream->data);
+        if(c == EOF) {
+            stream->state = STREAM_STATE_EOF;
+            return STREAM_STATE_EOF;
+        }
+
+        stream->buffer[0] = c;
+        stream->buffer_pos = 0;
+
+        if(0x80 <= c && c <= 0xFF)
+        {
+            /* multi-byte UTF-8 sequence */
+            size_t i, count;
+
+            count = utf8_check_first(c);
+            if(!count)
+                goto out;
+
+            assert(count >= 2);
+
+            for(i = 1; i < count; i++)
+                stream->buffer[i] = stream->get(stream->data);
+
+            if(!utf8_check_full(stream->buffer, count, NULL))
+                goto out;
+
+            stream->buffer[count] = '\0';
+        }
+        else
+            stream->buffer[1] = '\0';
+    }
+
+    c = stream->buffer[stream->buffer_pos++];
+
+    stream->position++;
+    if(c == '\n') {
+        stream->line++;
+        stream->last_column = stream->column;
+        stream->column = 0;
+    }
+    else if(utf8_check_first(c)) {
+        /* track the Unicode character column, so increment only if
+           this is the first character of a UTF-8 sequence */
+        stream->column++;
+    }
+
+    return c;
+
+out:
+    stream->state = STREAM_STATE_ERROR;
+    error_set(error, stream_to_lex(stream), json_error_invalid_utf8, "unable to decode byte 0x%x", c);
+    return STREAM_STATE_ERROR;
+}
+
+static void stream_unget(stream_t *stream, int c)
+{
+    if(c == STREAM_STATE_EOF || c == STREAM_STATE_ERROR)
+        return;
+
+    stream->position--;
+    if(c == '\n') {
+        stream->line--;
+        stream->column = stream->last_column;
+    }
+    else if(utf8_check_first(c))
+        stream->column--;
+
+    assert(stream->buffer_pos > 0);
+    stream->buffer_pos--;
+    assert(stream->buffer[stream->buffer_pos] == c);
+}
+
+
+static int lex_get(lex_t *lex, json_error_t *error)
+{
+    return stream_get(&lex->stream, error);
+}
+
+static void lex_save(lex_t *lex, int c)
+{
+    strbuffer_append_byte(&lex->saved_text, c);
+}
+
+static int lex_get_save(lex_t *lex, json_error_t *error)
+{
+    int c = stream_get(&lex->stream, error);
+    if(c != STREAM_STATE_EOF && c != STREAM_STATE_ERROR)
+        lex_save(lex, c);
+    return c;
+}
+
+static void lex_unget(lex_t *lex, int c)
+{
+    stream_unget(&lex->stream, c);
+}
+
+static void lex_unget_unsave(lex_t *lex, int c)
+{
+    if(c != STREAM_STATE_EOF && c != STREAM_STATE_ERROR) {
+        /* Since we treat warnings as errors, when assertions are turned
+         * off the "d" variable would be set but never used. Which is
+         * treated as an error by GCC.
+         */
+        #ifndef NDEBUG
+        char d;
+        #endif
+        stream_unget(&lex->stream, c);
+        #ifndef NDEBUG
+        d =
+        #endif
+            strbuffer_pop(&lex->saved_text);
+        assert(c == d);
+    }
+}
+
+static void lex_save_cached(lex_t *lex)
+{
+    while(lex->stream.buffer[lex->stream.buffer_pos] != '\0')
+    {
+        lex_save(lex, lex->stream.buffer[lex->stream.buffer_pos]);
+        lex->stream.buffer_pos++;
+        lex->stream.position++;
+    }
+}
+
+static void lex_free_string(lex_t *lex)
+{
+    jsonp_free(lex->value.string.val);
+    lex->value.string.val = NULL;
+    lex->value.string.len = 0;
+}
+
+/* assumes that str points to 'u' plus at least 4 valid hex digits */
+static int32_t decode_unicode_escape(const char *str)
+{
+    int i;
+    int32_t value = 0;
+
+    assert(str[0] == 'u');
+
+    for(i = 1; i <= 4; i++) {
+        char c = str[i];
+        value <<= 4;
+        if(l_isdigit(c))
+            value += c - '0';
+        else if(l_islower(c))
+            value += c - 'a' + 10;
+        else if(l_isupper(c))
+            value += c - 'A' + 10;
+        else
+            return -1;
+    }
+
+    return value;
+}
+
+static void lex_scan_string(lex_t *lex, json_error_t *error)
+{
+    int c;
+    const char *p;
+    char *t;
+    int i;
+
+    lex->value.string.val = NULL;
+    lex->token = TOKEN_INVALID;
+
+    c = lex_get_save(lex, error);
+
+    while(c != '"') {
+        if(c == STREAM_STATE_ERROR)
+            goto out;
+
+        else if(c == STREAM_STATE_EOF) {
+            error_set(error, lex, json_error_premature_end_of_input, "premature end of input");
+            goto out;
+        }
+
+        else if(0 <= c && c <= 0x1F) {
+            /* control character */
+            lex_unget_unsave(lex, c);
+            if(c == '\n')
+                error_set(error, lex, json_error_invalid_syntax, "unexpected newline");
+            else
+                error_set(error, lex, json_error_invalid_syntax, "control character 0x%x", c);
+            goto out;
+        }
+
+        else if(c == '\\') {
+            c = lex_get_save(lex, error);
+            if(c == 'u') {
+                c = lex_get_save(lex, error);
+                for(i = 0; i < 4; i++) {
+                    if(!l_isxdigit(c)) {
+                        error_set(error, lex, json_error_invalid_syntax, "invalid escape");
+                        goto out;
+                    }
+                    c = lex_get_save(lex, error);
+                }
+            }
+            else if(c == '"' || c == '\\' || c == '/' || c == 'b' ||
+                    c == 'f' || c == 'n' || c == 'r' || c == 't')
+                c = lex_get_save(lex, error);
+            else {
+                error_set(error, lex, json_error_invalid_syntax, "invalid escape");
+                goto out;
+            }
+        }
+        else
+            c = lex_get_save(lex, error);
+    }
+
+    /* the actual value is at most of the same length as the source
+       string, because:
+         - shortcut escapes (e.g. "\t") (length 2) are converted to 1 byte
+         - a single \uXXXX escape (length 6) is converted to at most 3 bytes
+         - two \uXXXX escapes (length 12) forming an UTF-16 surrogate pair
+           are converted to 4 bytes
+    */
+    t = jsonp_malloc(lex->saved_text.length + 1);
+    if(!t) {
+        /* this is not very nice, since TOKEN_INVALID is returned */
+        goto out;
+    }
+    lex->value.string.val = t;
+
+    /* + 1 to skip the " */
+    p = strbuffer_value(&lex->saved_text) + 1;
+
+    while(*p != '"') {
+        if(*p == '\\') {
+            p++;
+            if(*p == 'u') {
+                size_t length;
+                int32_t value;
+
+                value = decode_unicode_escape(p);
+                if(value < 0) {
+                    error_set(error, lex, json_error_invalid_syntax, "invalid Unicode escape '%.6s'", p - 1);
+                    goto out;
+                }
+                p += 5;
+
+                if(0xD800 <= value && value <= 0xDBFF) {
+                    /* surrogate pair */
+                    if(*p == '\\' && *(p + 1) == 'u') {
+                        int32_t value2 = decode_unicode_escape(++p);
+                        if(value2 < 0) {
+                            error_set(error, lex, json_error_invalid_syntax, "invalid Unicode escape '%.6s'", p - 1);
+                            goto out;
+                        }
+                        p += 5;
+
+                        if(0xDC00 <= value2 && value2 <= 0xDFFF) {
+                            /* valid second surrogate */
+                            value =
+                                ((value - 0xD800) << 10) +
+                                (value2 - 0xDC00) +
+                                0x10000;
+                        }
+                        else {
+                            /* invalid second surrogate */
+                            error_set(error, lex,
+                                      json_error_invalid_syntax,
+                                      "invalid Unicode '\\u%04X\\u%04X'",
+                                      value, value2);
+                            goto out;
+                        }
+                    }
+                    else {
+                        /* no second surrogate */
+                        error_set(error, lex, json_error_invalid_syntax, "invalid Unicode '\\u%04X'",
+                                  value);
+                        goto out;
+                    }
+                }
+                else if(0xDC00 <= value && value <= 0xDFFF) {
+                    error_set(error, lex, json_error_invalid_syntax, "invalid Unicode '\\u%04X'", value);
+                    goto out;
+                }
+
+                if(utf8_encode(value, t, &length))
+                    assert(0);
+                t += length;
+            }
+            else {
+                switch(*p) {
+                    case '"': case '\\': case '/':
+                        *t = *p; break;
+                    case 'b': *t = '\b'; break;
+                    case 'f': *t = '\f'; break;
+                    case 'n': *t = '\n'; break;
+                    case 'r': *t = '\r'; break;
+                    case 't': *t = '\t'; break;
+                    default: assert(0);
+                }
+                t++;
+                p++;
+            }
+        }
+        else
+            *(t++) = *(p++);
+    }
+    *t = '\0';
+    lex->value.string.len = t - lex->value.string.val;
+    lex->token = TOKEN_STRING;
+    return;
+
+out:
+    lex_free_string(lex);
+}
+
+#ifndef JANSSON_USING_CMAKE /* disabled if using cmake */
+#if JSON_INTEGER_IS_LONG_LONG
+#ifdef _MSC_VER  /* Microsoft Visual Studio */
+#define json_strtoint     _strtoi64
+#else
+#define json_strtoint     strtoll
+#endif
+#else
+#define json_strtoint     strtol
+#endif
+#endif
+
+static int lex_scan_number(lex_t *lex, int c, json_error_t *error)
+{
+    const char *saved_text;
+    char *end;
+    double doubleval;
+
+    lex->token = TOKEN_INVALID;
+
+    if(c == '-')
+        c = lex_get_save(lex, error);
+
+    if(c == '0') {
+        c = lex_get_save(lex, error);
+        if(l_isdigit(c)) {
+            lex_unget_unsave(lex, c);
+            goto out;
+        }
+    }
+    else if(l_isdigit(c)) {
+        do
+            c = lex_get_save(lex, error);
+        while(l_isdigit(c));
+    }
+    else {
+        lex_unget_unsave(lex, c);
+        goto out;
+    }
+
+    if(!(lex->flags & JSON_DECODE_INT_AS_REAL) &&
+       c != '.' && c != 'E' && c != 'e')
+    {
+        json_int_t intval;
+
+        lex_unget_unsave(lex, c);
+
+        saved_text = strbuffer_value(&lex->saved_text);
+
+        errno = 0;
+        intval = json_strtoint(saved_text, &end, 10);
+        if(errno == ERANGE) {
+            if(intval < 0)
+                error_set(error, lex, json_error_numeric_overflow, "too big negative integer");
+            else
+                error_set(error, lex, json_error_numeric_overflow, "too big integer");
+            goto out;
+        }
+
+        assert(end == saved_text + lex->saved_text.length);
+
+        lex->token = TOKEN_INTEGER;
+        lex->value.integer = intval;
+        return 0;
+    }
+
+    if(c == '.') {
+        c = lex_get(lex, error);
+        if(!l_isdigit(c)) {
+            lex_unget(lex, c);
+            goto out;
+        }
+        lex_save(lex, c);
+
+        do
+            c = lex_get_save(lex, error);
+        while(l_isdigit(c));
+    }
+
+    if(c == 'E' || c == 'e') {
+        c = lex_get_save(lex, error);
+        if(c == '+' || c == '-')
+            c = lex_get_save(lex, error);
+
+        if(!l_isdigit(c)) {
+            lex_unget_unsave(lex, c);
+            goto out;
+        }
+
+        do
+            c = lex_get_save(lex, error);
+        while(l_isdigit(c));
+    }
+
+    lex_unget_unsave(lex, c);
+
+    if(jsonp_strtod(&lex->saved_text, &doubleval)) {
+        error_set(error, lex, json_error_numeric_overflow, "real number overflow");
+        goto out;
+    }
+
+    lex->token = TOKEN_REAL;
+    lex->value.real = doubleval;
+    return 0;
+
+out:
+    return -1;
+}
+
+static int lex_scan(lex_t *lex, json_error_t *error)
+{
+    int c;
+
+    strbuffer_clear(&lex->saved_text);
+
+    if(lex->token == TOKEN_STRING)
+        lex_free_string(lex);
+
+    do
+        c = lex_get(lex, error);
+    while(c == ' ' || c == '\t' || c == '\n' || c == '\r');
+
+    if(c == STREAM_STATE_EOF) {
+        lex->token = TOKEN_EOF;
+        goto out;
+    }
+
+    if(c == STREAM_STATE_ERROR) {
+        lex->token = TOKEN_INVALID;
+        goto out;
+    }
+
+    lex_save(lex, c);
+
+    if(c == '{' || c == '}' || c == '[' || c == ']' || c == ':' || c == ',')
+        lex->token = c;
+
+    else if(c == '"')
+        lex_scan_string(lex, error);
+
+    else if(l_isdigit(c) || c == '-') {
+        if(lex_scan_number(lex, c, error))
+            goto out;
+    }
+
+    else if(l_isalpha(c)) {
+        /* eat up the whole identifier for clearer error messages */
+        const char *saved_text;
+
+        do
+            c = lex_get_save(lex, error);
+        while(l_isalpha(c));
+        lex_unget_unsave(lex, c);
+
+        saved_text = strbuffer_value(&lex->saved_text);
+
+        if(strcmp(saved_text, "true") == 0)
+            lex->token = TOKEN_TRUE;
+        else if(strcmp(saved_text, "false") == 0)
+            lex->token = TOKEN_FALSE;
+        else if(strcmp(saved_text, "null") == 0)
+            lex->token = TOKEN_NULL;
+        else
+            lex->token = TOKEN_INVALID;
+    }
+
+    else {
+        /* save the rest of the input UTF-8 sequence to get an error
+           message of valid UTF-8 */
+        lex_save_cached(lex);
+        lex->token = TOKEN_INVALID;
+    }
+
+out:
+    return lex->token;
+}
+
+static char *lex_steal_string(lex_t *lex, size_t *out_len)
+{
+    char *result = NULL;
+    if(lex->token == TOKEN_STRING) {
+        result = lex->value.string.val;
+        *out_len = lex->value.string.len;
+        lex->value.string.val = NULL;
+        lex->value.string.len = 0;
+    }
+    return result;
+}
+
+static int lex_init(lex_t *lex, get_func get, size_t flags, void *data)
+{
+    stream_init(&lex->stream, get, data);
+    if(strbuffer_init(&lex->saved_text))
+        return -1;
+
+    lex->flags = flags;
+    lex->token = TOKEN_INVALID;
+    return 0;
+}
+
+static void lex_close(lex_t *lex)
+{
+    if(lex->token == TOKEN_STRING)
+        lex_free_string(lex);
+    strbuffer_close(&lex->saved_text);
+}
+
+
+/*** parser ***/
+
+static json_t *parse_value(lex_t *lex, size_t flags, json_error_t *error);
+
+static json_t *parse_object(lex_t *lex, size_t flags, json_error_t *error)
+{
+    json_t *object = json_object();
+    if(!object)
+        return NULL;
+
+    lex_scan(lex, error);
+    if(lex->token == '}')
+        return object;
+
+    while(1) {
+        char *key;
+        size_t len;
+        json_t *value;
+
+        if(lex->token != TOKEN_STRING) {
+            error_set(error, lex, json_error_invalid_syntax, "string or '}' expected");
+            goto error;
+        }
+
+        key = lex_steal_string(lex, &len);
+        if(!key)
+            return NULL;
+        if (memchr(key, '\0', len)) {
+            jsonp_free(key);
+            error_set(error, lex, json_error_null_byte_in_key, "NUL byte in object key not supported");
+            goto error;
+        }
+
+        if(flags & JSON_REJECT_DUPLICATES) {
+            if(json_object_get(object, key)) {
+                jsonp_free(key);
+                error_set(error, lex, json_error_duplicate_key, "duplicate object key");
+                goto error;
+            }
+        }
+
+        lex_scan(lex, error);
+        if(lex->token != ':') {
+            jsonp_free(key);
+            error_set(error, lex, json_error_invalid_syntax, "':' expected");
+            goto error;
+        }
+
+        lex_scan(lex, error);
+        value = parse_value(lex, flags, error);
+        if(!value) {
+            jsonp_free(key);
+            goto error;
+        }
+
+        if(json_object_set_new_nocheck(object, key, value)) {
+            jsonp_free(key);
+            goto error;
+        }
+
+        jsonp_free(key);
+
+        lex_scan(lex, error);
+        if(lex->token != ',')
+            break;
+
+        lex_scan(lex, error);
+    }
+
+    if(lex->token != '}') {
+        error_set(error, lex, json_error_invalid_syntax, "'}' expected");
+        goto error;
+    }
+
+    return object;
+
+error:
+    json_decref(object);
+    return NULL;
+}
+
+static json_t *parse_array(lex_t *lex, size_t flags, json_error_t *error)
+{
+    json_t *array = json_array();
+    if(!array)
+        return NULL;
+
+    lex_scan(lex, error);
+    if(lex->token == ']')
+        return array;
+
+    while(lex->token) {
+        json_t *elem = parse_value(lex, flags, error);
+        if(!elem)
+            goto error;
+
+        if(json_array_append_new(array, elem)) {
+            goto error;
+        }
+
+        lex_scan(lex, error);
+        if(lex->token != ',')
+            break;
+
+        lex_scan(lex, error);
+    }
+
+    if(lex->token != ']') {
+        error_set(error, lex, json_error_invalid_syntax, "']' expected");
+        goto error;
+    }
+
+    return array;
+
+error:
+    json_decref(array);
+    return NULL;
+}
+
+static json_t *parse_value(lex_t *lex, size_t flags, json_error_t *error)
+{
+    json_t *json;
+
+    lex->depth++;
+    if(lex->depth > JSON_PARSER_MAX_DEPTH) {
+        error_set(error, lex, json_error_stack_overflow, "maximum parsing depth reached");
+        return NULL;
+    }
+
+    switch(lex->token) {
+        case TOKEN_STRING: {
+            const char *value = lex->value.string.val;
+            size_t len = lex->value.string.len;
+
+            if(!(flags & JSON_ALLOW_NUL)) {
+                if(memchr(value, '\0', len)) {
+                    error_set(error, lex, json_error_null_character, "\\u0000 is not allowed without JSON_ALLOW_NUL");
+                    return NULL;
+                }
+            }
+
+            json = jsonp_stringn_nocheck_own(value, len);
+            if(json) {
+                lex->value.string.val = NULL;
+                lex->value.string.len = 0;
+            }
+            break;
+        }
+
+        case TOKEN_INTEGER: {
+            json = json_integer(lex->value.integer);
+            break;
+        }
+
+        case TOKEN_REAL: {
+            json = json_real(lex->value.real);
+            break;
+        }
+
+        case TOKEN_TRUE:
+            json = json_true();
+            break;
+
+        case TOKEN_FALSE:
+            json = json_false();
+            break;
+
+        case TOKEN_NULL:
+            json = json_null();
+            break;
+
+        case '{':
+            json = parse_object(lex, flags, error);
+            break;
+
+        case '[':
+            json = parse_array(lex, flags, error);
+            break;
+
+        case TOKEN_INVALID:
+            error_set(error, lex, json_error_invalid_syntax, "invalid token");
+            return NULL;
+
+        default:
+            error_set(error, lex, json_error_invalid_syntax, "unexpected token");
+            return NULL;
+    }
+
+    if(!json)
+        return NULL;
+
+    lex->depth--;
+    return json;
+}
+
+static json_t *parse_json(lex_t *lex, size_t flags, json_error_t *error)
+{
+    json_t *result;
+
+    lex->depth = 0;
+
+    lex_scan(lex, error);
+    if(!(flags & JSON_DECODE_ANY)) {
+        if(lex->token != '[' && lex->token != '{') {
+            error_set(error, lex, json_error_invalid_syntax, "'[' or '{' expected");
+            return NULL;
+        }
+    }
+
+    result = parse_value(lex, flags, error);
+    if(!result)
+        return NULL;
+
+    if(!(flags & JSON_DISABLE_EOF_CHECK)) {
+        lex_scan(lex, error);
+        if(lex->token != TOKEN_EOF) {
+            error_set(error, lex, json_error_end_of_input_expected, "end of file expected");
+            json_decref(result);
+            return NULL;
+        }
+    }
+
+    if(error) {
+        /* Save the position even though there was no error */
+        error->position = (int)lex->stream.position;
+    }
+
+    return result;
+}
+
+typedef struct
+{
+    const char *data;
+    size_t pos;
+} string_data_t;
+
+static int string_get(void *data)
+{
+    char c;
+    string_data_t *stream = (string_data_t *)data;
+    c = stream->data[stream->pos];
+    if(c == '\0')
+        return EOF;
+    else
+    {
+        stream->pos++;
+        return (unsigned char)c;
+    }
+}
+
+json_t *json_loads(const char *string, size_t flags, json_error_t *error)
+{
+    lex_t lex;
+    json_t *result;
+    string_data_t stream_data;
+
+    jsonp_error_init(error, "<string>");
+
+    if (string == NULL) {
+        error_set(error, NULL, json_error_invalid_argument, "wrong arguments");
+        return NULL;
+    }
+
+    stream_data.data = string;
+    stream_data.pos = 0;
+
+    if(lex_init(&lex, string_get, flags, (void *)&stream_data))
+        return NULL;
+
+    result = parse_json(&lex, flags, error);
+
+    lex_close(&lex);
+    return result;
+}
+
+typedef struct
+{
+    const char *data;
+    size_t len;
+    size_t pos;
+} buffer_data_t;
+
+static int buffer_get(void *data)
+{
+    char c;
+    buffer_data_t *stream = data;
+    if(stream->pos >= stream->len)
+      return EOF;
+
+    c = stream->data[stream->pos];
+    stream->pos++;
+    return (unsigned char)c;
+}
+
+json_t *json_loadb(const char *buffer, size_t buflen, size_t flags, json_error_t *error)
+{
+    lex_t lex;
+    json_t *result;
+    buffer_data_t stream_data;
+
+    jsonp_error_init(error, "<buffer>");
+
+    if (buffer == NULL) {
+        error_set(error, NULL, json_error_invalid_argument, "wrong arguments");
+        return NULL;
+    }
+
+    stream_data.data = buffer;
+    stream_data.pos = 0;
+    stream_data.len = buflen;
+
+    if(lex_init(&lex, buffer_get, flags, (void *)&stream_data))
+        return NULL;
+
+    result = parse_json(&lex, flags, error);
+
+    lex_close(&lex);
+    return result;
+}
+
+json_t *json_loadf(FILE *input, size_t flags, json_error_t *error)
+{
+    lex_t lex;
+    const char *source;
+    json_t *result;
+
+    if(input == stdin)
+        source = "<stdin>";
+    else
+        source = "<stream>";
+
+    jsonp_error_init(error, source);
+
+    if (input == NULL) {
+        error_set(error, NULL, json_error_invalid_argument, "wrong arguments");
+        return NULL;
+    }
+
+    if(lex_init(&lex, (get_func)fgetc, flags, input))
+        return NULL;
+
+    result = parse_json(&lex, flags, error);
+
+    lex_close(&lex);
+    return result;
+}
+
+static int fd_get_func(int *fd)
+{
+    uint8_t c;
+#ifdef HAVE_UNISTD_H
+    if (read(*fd, &c, 1) == 1)
+        return c;
+#endif
+    return EOF;
+}
+
+json_t *json_loadfd(int input, size_t flags, json_error_t *error)
+{
+    lex_t lex;
+    const char *source;
+    json_t *result;
+
+#ifdef HAVE_UNISTD_H
+    if(input == STDIN_FILENO)
+        source = "<stdin>";
+    else
+#endif
+        source = "<stream>";
+
+    jsonp_error_init(error, source);
+
+    if (input < 0) {
+        error_set(error, NULL, json_error_invalid_argument, "wrong arguments");
+        return NULL;
+    }
+
+    if(lex_init(&lex, (get_func)fd_get_func, flags, &input))
+        return NULL;
+
+    result = parse_json(&lex, flags, error);
+
+    lex_close(&lex);
+    return result;
+}
+
+json_t *json_load_file(const char *path, size_t flags, json_error_t *error)
+{
+    json_t *result;
+    FILE *fp;
+
+    jsonp_error_init(error, path);
+
+    if (path == NULL) {
+        error_set(error, NULL, json_error_invalid_argument, "wrong arguments");
+        return NULL;
+    }
+
+    fp = fopen(path, "rb");
+    if(!fp)
+    {
+        error_set(error, NULL, json_error_cannot_open_file, "unable to open %s: %s",
+                  path, strerror(errno));
+        return NULL;
+    }
+
+    result = json_loadf(fp, flags, error);
+
+    fclose(fp);
+    return result;
+}
+
+#define MAX_BUF_LEN 1024
+
+typedef struct
+{
+    char data[MAX_BUF_LEN];
+    size_t len;
+    size_t pos;
+    json_load_callback_t callback;
+    void *arg;
+} callback_data_t;
+
+static int callback_get(void *data)
+{
+    char c;
+    callback_data_t *stream = data;
+
+    if(stream->pos >= stream->len) {
+        stream->pos = 0;
+        stream->len = stream->callback(stream->data, MAX_BUF_LEN, stream->arg);
+        if(stream->len == 0 || stream->len == (size_t)-1)
+            return EOF;
+    }
+
+    c = stream->data[stream->pos];
+    stream->pos++;
+    return (unsigned char)c;
+}
+
+json_t *json_load_callback(json_load_callback_t callback, void *arg, size_t flags, json_error_t *error)
+{
+    lex_t lex;
+    json_t *result;
+
+    callback_data_t stream_data;
+
+    memset(&stream_data, 0, sizeof(stream_data));
+    stream_data.callback = callback;
+    stream_data.arg = arg;
+
+    jsonp_error_init(error, "<callback>");
+
+    if (callback == NULL) {
+        error_set(error, NULL, json_error_invalid_argument, "wrong arguments");
+        return NULL;
+    }
+
+    if(lex_init(&lex, (get_func)callback_get, flags, &stream_data))
+        return NULL;
+
+    result = parse_json(&lex, flags, error);
+
+    lex_close(&lex);
+    return result;
+}
diff --git a/client/jansson/lookup3.h b/client/jansson/lookup3.h
new file mode 100644
index 00000000..2fe4c258
--- /dev/null
+++ b/client/jansson/lookup3.h
@@ -0,0 +1,381 @@
+/*
+-------------------------------------------------------------------------------
+lookup3.c, by Bob Jenkins, May 2006, Public Domain.
+
+These are functions for producing 32-bit hashes for hash table lookup.
+hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final() 
+are externally useful functions.  Routines to test the hash are included 
+if SELF_TEST is defined.  You can use this free for any purpose.  It's in
+the public domain.  It has no warranty.
+
+You probably want to use hashlittle().  hashlittle() and hashbig()
+hash byte arrays.  hashlittle() is is faster than hashbig() on
+little-endian machines.  Intel and AMD are little-endian machines.
+On second thought, you probably want hashlittle2(), which is identical to
+hashlittle() except it returns two 32-bit hashes for the price of one.  
+You could implement hashbig2() if you wanted but I haven't bothered here.
+
+If you want to find a hash of, say, exactly 7 integers, do
+  a = i1;  b = i2;  c = i3;
+  mix(a,b,c);
+  a += i4; b += i5; c += i6;
+  mix(a,b,c);
+  a += i7;
+  final(a,b,c);
+then use c as the hash value.  If you have a variable length array of
+4-byte integers to hash, use hashword().  If you have a byte array (like
+a character string), use hashlittle().  If you have several byte arrays, or
+a mix of things, see the comments above hashlittle().  
+
+Why is this so big?  I read 12 bytes at a time into 3 4-byte integers, 
+then mix those integers.  This is fast (you can do a lot more thorough
+mixing with 12*3 instructions on 3 integers than you can with 3 instructions
+on 1 byte), but shoehorning those bytes into integers efficiently is messy.
+-------------------------------------------------------------------------------
+*/
+
+#include <stdlib.h>
+
+#ifdef HAVE_CONFIG_H
+#include <jansson_private_config.h>
+#endif
+
+#ifdef HAVE_STDINT_H
+#include <stdint.h>     /* defines uint32_t etc */
+#endif
+
+#ifdef HAVE_SYS_PARAM_H
+#include <sys/param.h>  /* attempt to define endianness */
+#endif
+
+#ifdef HAVE_ENDIAN_H
+# include <endian.h>    /* attempt to define endianness */
+#endif
+
+/*
+ * My best guess at if you are big-endian or little-endian.  This may
+ * need adjustment.
+ */
+#if (defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && \
+     __BYTE_ORDER == __LITTLE_ENDIAN) || \
+    (defined(i386) || defined(__i386__) || defined(__i486__) || \
+     defined(__i586__) || defined(__i686__) || defined(vax) || defined(MIPSEL))
+# define HASH_LITTLE_ENDIAN 1
+# define HASH_BIG_ENDIAN 0
+#elif (defined(__BYTE_ORDER) && defined(__BIG_ENDIAN) && \
+       __BYTE_ORDER == __BIG_ENDIAN) || \
+      (defined(sparc) || defined(POWERPC) || defined(mc68000) || defined(sel))
+# define HASH_LITTLE_ENDIAN 0
+# define HASH_BIG_ENDIAN 1
+#else
+# define HASH_LITTLE_ENDIAN 0
+# define HASH_BIG_ENDIAN 0
+#endif
+
+#define hashsize(n) ((uint32_t)1<<(n))
+#define hashmask(n) (hashsize(n)-1)
+#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
+
+/*
+-------------------------------------------------------------------------------
+mix -- mix 3 32-bit values reversibly.
+
+This is reversible, so any information in (a,b,c) before mix() is
+still in (a,b,c) after mix().
+
+If four pairs of (a,b,c) inputs are run through mix(), or through
+mix() in reverse, there are at least 32 bits of the output that
+are sometimes the same for one pair and different for another pair.
+This was tested for:
+* pairs that differed by one bit, by two bits, in any combination
+  of top bits of (a,b,c), or in any combination of bottom bits of
+  (a,b,c).
+* "differ" is defined as +, -, ^, or ~^.  For + and -, I transformed
+  the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
+  is commonly produced by subtraction) look like a single 1-bit
+  difference.
+* the base values were pseudorandom, all zero but one bit set, or 
+  all zero plus a counter that starts at zero.
+
+Some k values for my "a-=c; a^=rot(c,k); c+=b;" arrangement that
+satisfy this are
+    4  6  8 16 19  4
+    9 15  3 18 27 15
+   14  9  3  7 17  3
+Well, "9 15 3 18 27 15" didn't quite get 32 bits diffing
+for "differ" defined as + with a one-bit base and a two-bit delta.  I
+used http://burtleburtle.net/bob/hash/avalanche.html to choose 
+the operations, constants, and arrangements of the variables.
+
+This does not achieve avalanche.  There are input bits of (a,b,c)
+that fail to affect some output bits of (a,b,c), especially of a.  The
+most thoroughly mixed value is c, but it doesn't really even achieve
+avalanche in c.
+
+This allows some parallelism.  Read-after-writes are good at doubling
+the number of bits affected, so the goal of mixing pulls in the opposite
+direction as the goal of parallelism.  I did what I could.  Rotates
+seem to cost as much as shifts on every machine I could lay my hands
+on, and rotates are much kinder to the top and bottom bits, so I used
+rotates.
+-------------------------------------------------------------------------------
+*/
+#define mix(a,b,c) \
+{ \
+  a -= c;  a ^= rot(c, 4);  c += b; \
+  b -= a;  b ^= rot(a, 6);  a += c; \
+  c -= b;  c ^= rot(b, 8);  b += a; \
+  a -= c;  a ^= rot(c,16);  c += b; \
+  b -= a;  b ^= rot(a,19);  a += c; \
+  c -= b;  c ^= rot(b, 4);  b += a; \
+}
+
+/*
+-------------------------------------------------------------------------------
+final -- final mixing of 3 32-bit values (a,b,c) into c
+
+Pairs of (a,b,c) values differing in only a few bits will usually
+produce values of c that look totally different.  This was tested for
+* pairs that differed by one bit, by two bits, in any combination
+  of top bits of (a,b,c), or in any combination of bottom bits of
+  (a,b,c).
+* "differ" is defined as +, -, ^, or ~^.  For + and -, I transformed
+  the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
+  is commonly produced by subtraction) look like a single 1-bit
+  difference.
+* the base values were pseudorandom, all zero but one bit set, or 
+  all zero plus a counter that starts at zero.
+
+These constants passed:
+ 14 11 25 16 4 14 24
+ 12 14 25 16 4 14 24
+and these came close:
+  4  8 15 26 3 22 24
+ 10  8 15 26 3 22 24
+ 11  8 15 26 3 22 24
+-------------------------------------------------------------------------------
+*/
+#define final(a,b,c) \
+{ \
+  c ^= b; c -= rot(b,14); \
+  a ^= c; a -= rot(c,11); \
+  b ^= a; b -= rot(a,25); \
+  c ^= b; c -= rot(b,16); \
+  a ^= c; a -= rot(c,4);  \
+  b ^= a; b -= rot(a,14); \
+  c ^= b; c -= rot(b,24); \
+}
+
+/*
+-------------------------------------------------------------------------------
+hashlittle() -- hash a variable-length key into a 32-bit value
+  k       : the key (the unaligned variable-length array of bytes)
+  length  : the length of the key, counting by bytes
+  initval : can be any 4-byte value
+Returns a 32-bit value.  Every bit of the key affects every bit of
+the return value.  Two keys differing by one or two bits will have
+totally different hash values.
+
+The best hash table sizes are powers of 2.  There is no need to do
+mod a prime (mod is sooo slow!).  If you need less than 32 bits,
+use a bitmask.  For example, if you need only 10 bits, do
+  h = (h & hashmask(10));
+In which case, the hash table should have hashsize(10) elements.
+
+If you are hashing n strings (uint8_t **)k, do it like this:
+  for (i=0, h=0; i<n; ++i) h = hashlittle( k[i], len[i], h);
+
+By Bob Jenkins, 2006.  bob_jenkins@burtleburtle.net.  You may use this
+code any way you wish, private, educational, or commercial.  It's free.
+
+Use for hash table lookup, or anything where one collision in 2^^32 is
+acceptable.  Do NOT use for cryptographic purposes.
+-------------------------------------------------------------------------------
+*/
+
+static uint32_t hashlittle(const void *key, size_t length, uint32_t initval)
+{
+  uint32_t a,b,c;                                          /* internal state */
+  union { const void *ptr; size_t i; } u;     /* needed for Mac Powerbook G4 */
+
+  /* Set up the internal state */
+  a = b = c = 0xdeadbeef + ((uint32_t)length) + initval;
+
+  u.ptr = key;
+  if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) {
+    const uint32_t *k = (const uint32_t *)key;         /* read 32-bit chunks */
+
+/* Detect Valgrind or AddressSanitizer */
+#ifdef VALGRIND
+# define NO_MASKING_TRICK 1
+#else
+# if defined(__has_feature)  /* Clang */
+#  if __has_feature(address_sanitizer)  /* is ASAN enabled? */
+#   define NO_MASKING_TRICK 1
+#  endif
+# else
+#  if defined(__SANITIZE_ADDRESS__)  /* GCC 4.8.x, is ASAN enabled? */
+#   define NO_MASKING_TRICK 1
+#  endif
+# endif
+#endif
+
+#ifdef NO_MASKING_TRICK
+    const uint8_t  *k8;
+#endif
+
+    /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */
+    while (length > 12)
+    {
+      a += k[0];
+      b += k[1];
+      c += k[2];
+      mix(a,b,c);
+      length -= 12;
+      k += 3;
+    }
+
+    /*----------------------------- handle the last (probably partial) block */
+    /* 
+     * "k[2]&0xffffff" actually reads beyond the end of the string, but
+     * then masks off the part it's not allowed to read.  Because the
+     * string is aligned, the masked-off tail is in the same word as the
+     * rest of the string.  Every machine with memory protection I've seen
+     * does it on word boundaries, so is OK with this.  But VALGRIND will
+     * still catch it and complain.  The masking trick does make the hash
+     * noticably faster for short strings (like English words).
+     */
+#ifndef NO_MASKING_TRICK
+
+    switch(length)
+    {
+    case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
+    case 11: c+=k[2]&0xffffff; b+=k[1]; a+=k[0]; break;
+    case 10: c+=k[2]&0xffff; b+=k[1]; a+=k[0]; break;
+    case 9 : c+=k[2]&0xff; b+=k[1]; a+=k[0]; break;
+    case 8 : b+=k[1]; a+=k[0]; break;
+    case 7 : b+=k[1]&0xffffff; a+=k[0]; break;
+    case 6 : b+=k[1]&0xffff; a+=k[0]; break;
+    case 5 : b+=k[1]&0xff; a+=k[0]; break;
+    case 4 : a+=k[0]; break;
+    case 3 : a+=k[0]&0xffffff; break;
+    case 2 : a+=k[0]&0xffff; break;
+    case 1 : a+=k[0]&0xff; break;
+    case 0 : return c;              /* zero length strings require no mixing */
+    }
+
+#else /* make valgrind happy */
+
+    k8 = (const uint8_t *)k;
+    switch(length)
+    {
+    case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
+    case 11: c+=((uint32_t)k8[10])<<16;  /* fall through */
+    case 10: c+=((uint32_t)k8[9])<<8;    /* fall through */
+    case 9 : c+=k8[8];                   /* fall through */
+    case 8 : b+=k[1]; a+=k[0]; break;
+    case 7 : b+=((uint32_t)k8[6])<<16;   /* fall through */
+    case 6 : b+=((uint32_t)k8[5])<<8;    /* fall through */
+    case 5 : b+=k8[4];                   /* fall through */
+    case 4 : a+=k[0]; break;
+    case 3 : a+=((uint32_t)k8[2])<<16;   /* fall through */
+    case 2 : a+=((uint32_t)k8[1])<<8;    /* fall through */
+    case 1 : a+=k8[0]; break;
+    case 0 : return c;
+    }
+
+#endif /* !valgrind */
+
+  } else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) {
+    const uint16_t *k = (const uint16_t *)key;         /* read 16-bit chunks */
+    const uint8_t  *k8;
+
+    /*--------------- all but last block: aligned reads and different mixing */
+    while (length > 12)
+    {
+      a += k[0] + (((uint32_t)k[1])<<16);
+      b += k[2] + (((uint32_t)k[3])<<16);
+      c += k[4] + (((uint32_t)k[5])<<16);
+      mix(a,b,c);
+      length -= 12;
+      k += 6;
+    }
+
+    /*----------------------------- handle the last (probably partial) block */
+    k8 = (const uint8_t *)k;
+    switch(length)
+    {
+    case 12: c+=k[4]+(((uint32_t)k[5])<<16);
+             b+=k[2]+(((uint32_t)k[3])<<16);
+             a+=k[0]+(((uint32_t)k[1])<<16);
+             break;
+    case 11: c+=((uint32_t)k8[10])<<16;     /* fall through */
+    case 10: c+=k[4];
+             b+=k[2]+(((uint32_t)k[3])<<16);
+             a+=k[0]+(((uint32_t)k[1])<<16);
+             break;
+    case 9 : c+=k8[8];                      /* fall through */
+    case 8 : b+=k[2]+(((uint32_t)k[3])<<16);
+             a+=k[0]+(((uint32_t)k[1])<<16);
+             break;
+    case 7 : b+=((uint32_t)k8[6])<<16;      /* fall through */
+    case 6 : b+=k[2];
+             a+=k[0]+(((uint32_t)k[1])<<16);
+             break;
+    case 5 : b+=k8[4];                      /* fall through */
+    case 4 : a+=k[0]+(((uint32_t)k[1])<<16);
+             break;
+    case 3 : a+=((uint32_t)k8[2])<<16;      /* fall through */
+    case 2 : a+=k[0];
+             break;
+    case 1 : a+=k8[0];
+             break;
+    case 0 : return c;                     /* zero length requires no mixing */
+    }
+
+  } else {                        /* need to read the key one byte at a time */
+    const uint8_t *k = (const uint8_t *)key;
+
+    /*--------------- all but the last block: affect some 32 bits of (a,b,c) */
+    while (length > 12)
+    {
+      a += k[0];
+      a += ((uint32_t)k[1])<<8;
+      a += ((uint32_t)k[2])<<16;
+      a += ((uint32_t)k[3])<<24;
+      b += k[4];
+      b += ((uint32_t)k[5])<<8;
+      b += ((uint32_t)k[6])<<16;
+      b += ((uint32_t)k[7])<<24;
+      c += k[8];
+      c += ((uint32_t)k[9])<<8;
+      c += ((uint32_t)k[10])<<16;
+      c += ((uint32_t)k[11])<<24;
+      mix(a,b,c);
+      length -= 12;
+      k += 12;
+    }
+
+    /*-------------------------------- last block: affect all 32 bits of (c) */
+    switch(length)                   /* all the case statements fall through */
+    {
+    case 12: c+=((uint32_t)k[11])<<24; /* fall through */
+    case 11: c+=((uint32_t)k[10])<<16; /* fall through */
+    case 10: c+=((uint32_t)k[9])<<8; /* fall through */
+    case 9 : c+=k[8]; /* fall through */
+    case 8 : b+=((uint32_t)k[7])<<24; /* fall through */
+    case 7 : b+=((uint32_t)k[6])<<16; /* fall through */
+    case 6 : b+=((uint32_t)k[5])<<8; /* fall through */
+    case 5 : b+=k[4]; /* fall through */
+    case 4 : a+=((uint32_t)k[3])<<24; /* fall through */
+    case 3 : a+=((uint32_t)k[2])<<16; /* fall through */
+    case 2 : a+=((uint32_t)k[1])<<8; /* fall through */
+    case 1 : a+=k[0];
+             break;
+    case 0 : return c;
+    }
+  }
+
+  final(a,b,c);
+  return c;
+}
diff --git a/client/jansson/memory.c b/client/jansson/memory.c
new file mode 100644
index 00000000..a2be5d23
--- /dev/null
+++ b/client/jansson/memory.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ * Copyright (c) 2011-2012 Basile Starynkevitch <basile@starynkevitch.net>
+ *
+ * Jansson is free software; you can redistribute it and/or modify it
+ * under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "jansson.h"
+#include "jansson_private.h"
+
+/* C89 allows these to be macros */
+#undef malloc
+#undef free
+
+/* memory function pointers */
+static json_malloc_t do_malloc = malloc;
+static json_free_t do_free = free;
+
+void *jsonp_malloc(size_t size)
+{
+    if(!size)
+        return NULL;
+
+    return (*do_malloc)(size);
+}
+
+void jsonp_free(void *ptr)
+{
+    if(!ptr)
+        return;
+
+    (*do_free)(ptr);
+}
+
+char *jsonp_strdup(const char *str)
+{
+    return jsonp_strndup(str, strlen(str));
+}
+
+char *jsonp_strndup(const char *str, size_t len)
+{
+    char *new_str;
+
+    new_str = jsonp_malloc(len + 1);
+    if(!new_str)
+        return NULL;
+
+    memcpy(new_str, str, len);
+    new_str[len] = '\0';
+    return new_str;
+}
+
+void json_set_alloc_funcs(json_malloc_t malloc_fn, json_free_t free_fn)
+{
+    do_malloc = malloc_fn;
+    do_free = free_fn;
+}
+
+void json_get_alloc_funcs(json_malloc_t *malloc_fn, json_free_t *free_fn)
+{
+    if (malloc_fn)
+        *malloc_fn = do_malloc;
+    if (free_fn)
+        *free_fn = do_free;
+}
diff --git a/client/jansson/pack_unpack.c b/client/jansson/pack_unpack.c
new file mode 100644
index 00000000..153f64d1
--- /dev/null
+++ b/client/jansson/pack_unpack.c
@@ -0,0 +1,909 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ * Copyright (c) 2011-2012 Graeme Smecher <graeme.smecher@mail.mcgill.ca>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <string.h>
+#include "jansson.h"
+#include "jansson_private.h"
+#include "utf.h"
+
+typedef struct {
+    int line;
+    int column;
+    size_t pos;
+    char token;
+} token_t;
+
+typedef struct {
+    const char *start;
+    const char *fmt;
+    token_t prev_token;
+    token_t token;
+    token_t next_token;
+    json_error_t *error;
+    size_t flags;
+    int line;
+    int column;
+    size_t pos;
+    int has_error;
+} scanner_t;
+
+#define token(scanner) ((scanner)->token.token)
+
+static const char * const type_names[] = {
+    "object",
+    "array",
+    "string",
+    "integer",
+    "real",
+    "true",
+    "false",
+    "null"
+};
+
+#define type_name(x) type_names[json_typeof(x)]
+
+static const char unpack_value_starters[] = "{[siIbfFOon";
+
+static void scanner_init(scanner_t *s, json_error_t *error,
+                         size_t flags, const char *fmt)
+{
+    s->error = error;
+    s->flags = flags;
+    s->fmt = s->start = fmt;
+    memset(&s->prev_token, 0, sizeof(token_t));
+    memset(&s->token, 0, sizeof(token_t));
+    memset(&s->next_token, 0, sizeof(token_t));
+    s->line = 1;
+    s->column = 0;
+    s->pos = 0;
+    s->has_error = 0;
+}
+
+static void next_token(scanner_t *s)
+{
+    const char *t;
+    s->prev_token = s->token;
+
+    if(s->next_token.line) {
+        s->token = s->next_token;
+        s->next_token.line = 0;
+        return;
+    }
+
+    t = s->fmt;
+    s->column++;
+    s->pos++;
+
+    /* skip space and ignored chars */
+    while(*t == ' ' || *t == '\t' || *t == '\n' || *t == ',' || *t == ':') {
+        if(*t == '\n') {
+            s->line++;
+            s->column = 1;
+        }
+        else
+            s->column++;
+
+        s->pos++;
+        t++;
+    }
+
+    s->token.token = *t;
+    s->token.line = s->line;
+    s->token.column = s->column;
+    s->token.pos = s->pos;
+
+    t++;
+    s->fmt = t;
+}
+
+static void prev_token(scanner_t *s)
+{
+    s->next_token = s->token;
+    s->token = s->prev_token;
+}
+
+static void set_error(scanner_t *s, const char *source, enum json_error_code code,
+                      const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+
+    jsonp_error_vset(s->error, s->token.line, s->token.column, s->token.pos,
+                     code, fmt, ap);
+
+    jsonp_error_set_source(s->error, source);
+
+    va_end(ap);
+}
+
+static json_t *pack(scanner_t *s, va_list *ap);
+
+
+/* ours will be set to 1 if jsonp_free() must be called for the result
+   afterwards */
+static char *read_string(scanner_t *s, va_list *ap,
+                         const char *purpose, size_t *out_len, int *ours)
+{
+    char t;
+    strbuffer_t strbuff;
+    const char *str;
+    size_t length;
+
+    next_token(s);
+    t = token(s);
+    prev_token(s);
+
+    *ours = 0;
+    if(t != '#' && t != '%' && t != '+') {
+        /* Optimize the simple case */
+        str = va_arg(*ap, const char *);
+
+        if(!str) {
+            set_error(s, "<args>", json_error_null_value, "NULL string argument");
+            return NULL;
+        }
+
+        length = strlen(str);
+
+        if(!utf8_check_string(str, length)) {
+            set_error(s, "<args>", json_error_invalid_utf8, "Invalid UTF-8 %s", purpose);
+            return NULL;
+        }
+
+        *out_len = length;
+        return (char *)str;
+    }
+
+    strbuffer_init(&strbuff);
+
+    while(1) {
+        str = va_arg(*ap, const char *);
+        if(!str) {
+            set_error(s, "<args>", json_error_null_value, "NULL string argument");
+            s->has_error = 1;
+        }
+
+        next_token(s);
+
+        if(token(s) == '#') {
+            length = va_arg(*ap, int);
+        }
+        else if(token(s) == '%') {
+            length = va_arg(*ap, size_t);
+        }
+        else {
+            prev_token(s);
+            length = s->has_error ? 0 : strlen(str);
+        }
+
+        if(!s->has_error && strbuffer_append_bytes(&strbuff, str, length) == -1) {
+            set_error(s, "<internal>", json_error_out_of_memory, "Out of memory");
+            s->has_error = 1;
+        }
+
+        next_token(s);
+        if(token(s) != '+') {
+            prev_token(s);
+            break;
+        }
+    }
+
+    if(s->has_error) {
+        strbuffer_close(&strbuff);
+        return NULL;
+    }
+
+    if(!utf8_check_string(strbuff.value, strbuff.length)) {
+        set_error(s, "<args>", json_error_invalid_utf8, "Invalid UTF-8 %s", purpose);
+        strbuffer_close(&strbuff);
+        s->has_error = 1;
+        return NULL;
+    }
+
+    *out_len = strbuff.length;
+    *ours = 1;
+    return strbuffer_steal_value(&strbuff);
+}
+
+static json_t *pack_object(scanner_t *s, va_list *ap)
+{
+    json_t *object = json_object();
+    next_token(s);
+
+    while(token(s) != '}') {
+        char *key;
+        size_t len;
+        int ours;
+        json_t *value;
+
+        if(!token(s)) {
+            set_error(s, "<format>", json_error_invalid_format, "Unexpected end of format string");
+            goto error;
+        }
+
+        if(token(s) != 's') {
+            set_error(s, "<format>", json_error_invalid_format, "Expected format 's', got '%c'", token(s));
+            goto error;
+        }
+
+        key = read_string(s, ap, "object key", &len, &ours);
+        if (!key)
+            s->has_error = 1;
+
+        next_token(s);
+
+        value = pack(s, ap);
+        if(!value) {
+            if(ours)
+                jsonp_free(key);
+
+            if(strchr("soO", token(s)) && s->next_token.token == '*') {
+                next_token(s);
+            } else {
+                s->has_error = 1;
+            }
+
+            next_token(s);
+            continue;
+        }
+
+        if(s->has_error)
+            json_decref(value);
+
+        if(!s->has_error && json_object_set_new_nocheck(object, key, value)) {
+            set_error(s, "<internal>", json_error_out_of_memory, "Unable to add key \"%s\"", key);
+            s->has_error = 1;
+        }
+
+        if(ours)
+            jsonp_free(key);
+
+        if(strchr("soO", token(s)) && s->next_token.token == '*')
+            next_token(s);
+        next_token(s);
+    }
+
+    if(!s->has_error)
+        return object;
+
+error:
+    json_decref(object);
+    return NULL;
+}
+
+static json_t *pack_array(scanner_t *s, va_list *ap)
+{
+    json_t *array = json_array();
+    next_token(s);
+
+    while(token(s) != ']') {
+        json_t *value;
+
+        if(!token(s)) {
+            set_error(s, "<format>", json_error_invalid_format, "Unexpected end of format string");
+            /* Format string errors are unrecoverable. */
+            goto error;
+        }
+
+        value = pack(s, ap);
+        if(!value) {
+            if(strchr("soO", token(s)) && s->next_token.token == '*') {
+                next_token(s);
+            } else {
+                s->has_error = 1;
+            }
+
+            next_token(s);
+            continue;
+        }
+
+        if(s->has_error)
+            json_decref(value);
+
+        if(!s->has_error && json_array_append_new(array, value)) {
+            set_error(s, "<internal>", json_error_out_of_memory, "Unable to append to array");
+            s->has_error = 1;
+        }
+
+        if(strchr("soO", token(s)) && s->next_token.token == '*')
+            next_token(s);
+        next_token(s);
+    }
+
+    if(!s->has_error)
+        return array;
+
+error:
+    json_decref(array);
+    return NULL;
+}
+
+static json_t *pack_string(scanner_t *s, va_list *ap)
+{
+    char *str;
+    size_t len;
+    int ours;
+    int nullable;
+
+    next_token(s);
+    nullable = token(s) == '?';
+    if (!nullable)
+        prev_token(s);
+
+    str = read_string(s, ap, "string", &len, &ours);
+    if (!str) {
+        return nullable ? json_null() : NULL;
+    } else if (ours) {
+        return jsonp_stringn_nocheck_own(str, len);
+    } else {
+        return json_stringn_nocheck(str, len);
+    }
+}
+
+static json_t *pack(scanner_t *s, va_list *ap)
+{
+    switch(token(s)) {
+        case '{':
+            return pack_object(s, ap);
+
+        case '[':
+            return pack_array(s, ap);
+
+        case 's': /* string */
+            return pack_string(s, ap);
+
+        case 'n': /* null */
+            return json_null();
+
+        case 'b': /* boolean */
+            return va_arg(*ap, int) ? json_true() : json_false();
+
+        case 'i': /* integer from int */
+            return json_integer(va_arg(*ap, int));
+
+        case 'I': /* integer from json_int_t */
+            return json_integer(va_arg(*ap, json_int_t));
+
+        case 'f': /* real */
+            return json_real(va_arg(*ap, double));
+
+        case 'O': /* a json_t object; increments refcount */
+        {
+            int nullable;
+            json_t *json;
+
+            next_token(s);
+            nullable = token(s) == '?';
+            if (!nullable)
+                prev_token(s);
+
+            json = va_arg(*ap, json_t *);
+            if (!json && nullable) {
+                return json_null();
+            } else {
+                return json_incref(json);
+            }
+        }
+
+        case 'o': /* a json_t object; doesn't increment refcount */
+        {
+            int nullable;
+            json_t *json;
+
+            next_token(s);
+            nullable = token(s) == '?';
+            if (!nullable)
+                prev_token(s);
+
+            json = va_arg(*ap, json_t *);
+            if (!json && nullable) {
+                return json_null();
+            } else {
+                return json;
+            }
+        }
+
+        default:
+            set_error(s, "<format>", json_error_invalid_format, "Unexpected format character '%c'",
+                      token(s));
+            s->has_error = 1;
+            return NULL;
+    }
+}
+
+static int unpack(scanner_t *s, json_t *root, va_list *ap);
+
+static int unpack_object(scanner_t *s, json_t *root, va_list *ap)
+{
+    int ret = -1;
+    int strict = 0;
+    int gotopt = 0;
+
+    /* Use a set (emulated by a hashtable) to check that all object
+       keys are accessed. Checking that the correct number of keys
+       were accessed is not enough, as the same key can be unpacked
+       multiple times.
+    */
+    hashtable_t key_set;
+
+    if(hashtable_init(&key_set)) {
+        set_error(s, "<internal>", json_error_out_of_memory, "Out of memory");
+        return -1;
+    }
+
+    if(root && !json_is_object(root)) {
+        set_error(s, "<validation>", json_error_wrong_type, "Expected object, got %s",
+                  type_name(root));
+        goto out;
+    }
+    next_token(s);
+
+    while(token(s) != '}') {
+        const char *key;
+        json_t *value;
+        int opt = 0;
+
+        if(strict != 0) {
+            set_error(s, "<format>", json_error_invalid_format, "Expected '}' after '%c', got '%c'",
+                      (strict == 1 ? '!' : '*'), token(s));
+            goto out;
+        }
+
+        if(!token(s)) {
+            set_error(s, "<format>", json_error_invalid_format, "Unexpected end of format string");
+            goto out;
+        }
+
+        if(token(s) == '!' || token(s) == '*') {
+            strict = (token(s) == '!' ? 1 : -1);
+            next_token(s);
+            continue;
+        }
+
+        if(token(s) != 's') {
+            set_error(s, "<format>", json_error_invalid_format, "Expected format 's', got '%c'", token(s));
+            goto out;
+        }
+
+        key = va_arg(*ap, const char *);
+        if(!key) {
+            set_error(s, "<args>", json_error_null_value, "NULL object key");
+            goto out;
+        }
+
+        next_token(s);
+
+        if(token(s) == '?') {
+            opt = gotopt = 1;
+            next_token(s);
+        }
+
+        if(!root) {
+            /* skipping */
+            value = NULL;
+        }
+        else {
+            value = json_object_get(root, key);
+            if(!value && !opt) {
+                set_error(s, "<validation>", json_error_item_not_found, "Object item not found: %s", key);
+                goto out;
+            }
+        }
+
+        if(unpack(s, value, ap))
+            goto out;
+
+        hashtable_set(&key_set, key, json_null());
+        next_token(s);
+    }
+
+    if(strict == 0 && (s->flags & JSON_STRICT))
+        strict = 1;
+
+    if(root && strict == 1) {
+        /* We need to check that all non optional items have been parsed */
+        const char *key;
+        int have_unrecognized_keys = 0;
+        strbuffer_t unrecognized_keys;
+        json_t *value;
+        long unpacked = 0;
+        if (gotopt) {
+            /* We have optional keys, we need to iter on each key */
+            json_object_foreach(root, key, value) {
+                if(!hashtable_get(&key_set, key)) {
+                    unpacked++;
+
+                    /* Save unrecognized keys for the error message */
+                    if (!have_unrecognized_keys) {
+                        strbuffer_init(&unrecognized_keys);
+                        have_unrecognized_keys = 1;
+                    } else {
+                        strbuffer_append_bytes(&unrecognized_keys, ", ", 2);
+                    }
+                    strbuffer_append_bytes(&unrecognized_keys, key, strlen(key));
+                }
+            }
+        } else {
+            /* No optional keys, we can just compare the number of items */
+            unpacked = (long)json_object_size(root) - (long)key_set.size;
+        }
+        if (unpacked) {
+            if (!gotopt) {
+                /* Save unrecognized keys for the error message */
+                json_object_foreach(root, key, value) {
+                    if(!hashtable_get(&key_set, key)) {
+                        if (!have_unrecognized_keys) {
+                            strbuffer_init(&unrecognized_keys);
+                            have_unrecognized_keys = 1;
+                        } else {
+                            strbuffer_append_bytes(&unrecognized_keys, ", ", 2);
+                        }
+                        strbuffer_append_bytes(&unrecognized_keys, key, strlen(key));
+                    }
+                }
+            }
+            set_error(s, "<validation>", json_error_end_of_input_expected,
+                      "%li object item(s) left unpacked: %s",
+                      unpacked, strbuffer_value(&unrecognized_keys));
+            strbuffer_close(&unrecognized_keys);
+            goto out;
+        }
+    }
+
+    ret = 0;
+
+out:
+    hashtable_close(&key_set);
+    return ret;
+}
+
+static int unpack_array(scanner_t *s, json_t *root, va_list *ap)
+{
+    size_t i = 0;
+    int strict = 0;
+
+    if(root && !json_is_array(root)) {
+        set_error(s, "<validation>", json_error_wrong_type, "Expected array, got %s", type_name(root));
+        return -1;
+    }
+    next_token(s);
+
+    while(token(s) != ']') {
+        json_t *value;
+
+        if(strict != 0) {
+            set_error(s, "<format>", json_error_invalid_format, "Expected ']' after '%c', got '%c'",
+                      (strict == 1 ? '!' : '*'),
+                      token(s));
+            return -1;
+        }
+
+        if(!token(s)) {
+            set_error(s, "<format>", json_error_invalid_format, "Unexpected end of format string");
+            return -1;
+        }
+
+        if(token(s) == '!' || token(s) == '*') {
+            strict = (token(s) == '!' ? 1 : -1);
+            next_token(s);
+            continue;
+        }
+
+        if(!strchr(unpack_value_starters, token(s))) {
+            set_error(s, "<format>", json_error_invalid_format, "Unexpected format character '%c'",
+                      token(s));
+            return -1;
+        }
+
+        if(!root) {
+            /* skipping */
+            value = NULL;
+        }
+        else {
+            value = json_array_get(root, i);
+            if(!value) {
+                set_error(s, "<validation>", json_error_index_out_of_range, "Array index %lu out of range",
+                          (unsigned long)i);
+                return -1;
+            }
+        }
+
+        if(unpack(s, value, ap))
+            return -1;
+
+        next_token(s);
+        i++;
+    }
+
+    if(strict == 0 && (s->flags & JSON_STRICT))
+        strict = 1;
+
+    if(root && strict == 1 && i != json_array_size(root)) {
+        long diff = (long)json_array_size(root) - (long)i;
+        set_error(s, "<validation>", json_error_end_of_input_expected, "%li array item(s) left unpacked", diff);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int unpack(scanner_t *s, json_t *root, va_list *ap)
+{
+    switch(token(s))
+    {
+        case '{':
+            return unpack_object(s, root, ap);
+
+        case '[':
+            return unpack_array(s, root, ap);
+
+        case 's':
+            if(root && !json_is_string(root)) {
+                set_error(s, "<validation>", json_error_wrong_type, "Expected string, got %s",
+                          type_name(root));
+                return -1;
+            }
+
+            if(!(s->flags & JSON_VALIDATE_ONLY)) {
+                const char **str_target;
+                size_t *len_target = NULL;
+
+                str_target = va_arg(*ap, const char **);
+                if(!str_target) {
+                    set_error(s, "<args>", json_error_null_value, "NULL string argument");
+                    return -1;
+                }
+
+                next_token(s);
+
+                if(token(s) == '%') {
+                    len_target = va_arg(*ap, size_t *);
+                    if(!len_target) {
+                        set_error(s, "<args>", json_error_null_value, "NULL string length argument");
+                        return -1;
+                    }
+                }
+                else
+                    prev_token(s);
+
+                if(root) {
+                    *str_target = json_string_value(root);
+                    if(len_target)
+                        *len_target = json_string_length(root);
+                }
+            }
+            return 0;
+
+        case 'i':
+            if(root && !json_is_integer(root)) {
+                set_error(s, "<validation>", json_error_wrong_type, "Expected integer, got %s",
+                          type_name(root));
+                return -1;
+            }
+
+            if(!(s->flags & JSON_VALIDATE_ONLY)) {
+                int *target = va_arg(*ap, int*);
+                if(root)
+                    *target = (int)json_integer_value(root);
+            }
+
+            return 0;
+
+        case 'I':
+            if(root && !json_is_integer(root)) {
+                set_error(s, "<validation>", json_error_wrong_type, "Expected integer, got %s",
+                          type_name(root));
+                return -1;
+            }
+
+            if(!(s->flags & JSON_VALIDATE_ONLY)) {
+                json_int_t *target = va_arg(*ap, json_int_t*);
+                if(root)
+                    *target = json_integer_value(root);
+            }
+
+            return 0;
+
+        case 'b':
+            if(root && !json_is_boolean(root)) {
+                set_error(s, "<validation>", json_error_wrong_type, "Expected true or false, got %s",
+                          type_name(root));
+                return -1;
+            }
+
+            if(!(s->flags & JSON_VALIDATE_ONLY)) {
+                int *target = va_arg(*ap, int*);
+                if(root)
+                    *target = json_is_true(root);
+            }
+
+            return 0;
+
+        case 'f':
+            if(root && !json_is_real(root)) {
+                set_error(s, "<validation>", json_error_wrong_type, "Expected real, got %s",
+                          type_name(root));
+                return -1;
+            }
+
+            if(!(s->flags & JSON_VALIDATE_ONLY)) {
+                double *target = va_arg(*ap, double*);
+                if(root)
+                    *target = json_real_value(root);
+            }
+
+            return 0;
+
+        case 'F':
+            if(root && !json_is_number(root)) {
+                set_error(s, "<validation>", json_error_wrong_type, "Expected real or integer, got %s",
+                          type_name(root));
+                return -1;
+            }
+
+            if(!(s->flags & JSON_VALIDATE_ONLY)) {
+                double *target = va_arg(*ap, double*);
+                if(root)
+                    *target = json_number_value(root);
+            }
+
+            return 0;
+
+        case 'O':
+            if(root && !(s->flags & JSON_VALIDATE_ONLY))
+                json_incref(root);
+            /* Fall through */
+
+        case 'o':
+            if(!(s->flags & JSON_VALIDATE_ONLY)) {
+                json_t **target = va_arg(*ap, json_t**);
+                if(root)
+                    *target = root;
+            }
+
+            return 0;
+
+        case 'n':
+            /* Never assign, just validate */
+            if(root && !json_is_null(root)) {
+                set_error(s, "<validation>", json_error_wrong_type, "Expected null, got %s",
+                          type_name(root));
+                return -1;
+            }
+            return 0;
+
+        default:
+            set_error(s, "<format>", json_error_invalid_format, "Unexpected format character '%c'",
+                      token(s));
+            return -1;
+    }
+}
+
+json_t *json_vpack_ex(json_error_t *error, size_t flags,
+                      const char *fmt, va_list ap)
+{
+    scanner_t s;
+    va_list ap_copy;
+    json_t *value;
+
+    if(!fmt || !*fmt) {
+        jsonp_error_init(error, "<format>");
+        jsonp_error_set(error, -1, -1, 0, json_error_invalid_argument, "NULL or empty format string");
+        return NULL;
+    }
+    jsonp_error_init(error, NULL);
+
+    scanner_init(&s, error, flags, fmt);
+    next_token(&s);
+
+    va_copy(ap_copy, ap);
+    value = pack(&s, &ap_copy);
+    va_end(ap_copy);
+
+    if(!value)
+        return NULL;
+
+    next_token(&s);
+    if(token(&s)) {
+        json_decref(value);
+        set_error(&s, "<format>", json_error_invalid_format, "Garbage after format string");
+        return NULL;
+    }
+    if(s.has_error) {
+        json_decref(value);
+        return NULL;
+    }
+
+    return value;
+}
+
+json_t *json_pack_ex(json_error_t *error, size_t flags, const char *fmt, ...)
+{
+    json_t *value;
+    va_list ap;
+
+    va_start(ap, fmt);
+    value = json_vpack_ex(error, flags, fmt, ap);
+    va_end(ap);
+
+    return value;
+}
+
+json_t *json_pack(const char *fmt, ...)
+{
+    json_t *value;
+    va_list ap;
+
+    va_start(ap, fmt);
+    value = json_vpack_ex(NULL, 0, fmt, ap);
+    va_end(ap);
+
+    return value;
+}
+
+int json_vunpack_ex(json_t *root, json_error_t *error, size_t flags,
+                    const char *fmt, va_list ap)
+{
+    scanner_t s;
+    va_list ap_copy;
+
+    if(!root) {
+        jsonp_error_init(error, "<root>");
+        jsonp_error_set(error, -1, -1, 0, json_error_null_value, "NULL root value");
+        return -1;
+    }
+
+    if(!fmt || !*fmt) {
+        jsonp_error_init(error, "<format>");
+        jsonp_error_set(error, -1, -1, 0, json_error_invalid_argument, "NULL or empty format string");
+        return -1;
+    }
+    jsonp_error_init(error, NULL);
+
+    scanner_init(&s, error, flags, fmt);
+    next_token(&s);
+
+    va_copy(ap_copy, ap);
+    if(unpack(&s, root, &ap_copy)) {
+        va_end(ap_copy);
+        return -1;
+    }
+    va_end(ap_copy);
+
+    next_token(&s);
+    if(token(&s)) {
+        set_error(&s, "<format>", json_error_invalid_format, "Garbage after format string");
+        return -1;
+    }
+
+    return 0;
+}
+
+int json_unpack_ex(json_t *root, json_error_t *error, size_t flags, const char *fmt, ...)
+{
+    int ret;
+    va_list ap;
+
+    va_start(ap, fmt);
+    ret = json_vunpack_ex(root, error, flags, fmt, ap);
+    va_end(ap);
+
+    return ret;
+}
+
+int json_unpack(json_t *root, const char *fmt, ...)
+{
+    int ret;
+    va_list ap;
+
+    va_start(ap, fmt);
+    ret = json_vunpack_ex(root, NULL, 0, fmt, ap);
+    va_end(ap);
+
+    return ret;
+}
diff --git a/client/jansson/strbuffer.c b/client/jansson/strbuffer.c
new file mode 100644
index 00000000..5e8c0039
--- /dev/null
+++ b/client/jansson/strbuffer.c
@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include "jansson_private.h"
+#include "strbuffer.h"
+
+#define STRBUFFER_MIN_SIZE  16
+#define STRBUFFER_FACTOR    2
+#define STRBUFFER_SIZE_MAX  ((size_t)-1)
+
+int strbuffer_init(strbuffer_t *strbuff)
+{
+    strbuff->size = STRBUFFER_MIN_SIZE;
+    strbuff->length = 0;
+
+    strbuff->value = jsonp_malloc(strbuff->size);
+    if(!strbuff->value)
+        return -1;
+
+    /* initialize to empty */
+    strbuff->value[0] = '\0';
+    return 0;
+}
+
+void strbuffer_close(strbuffer_t *strbuff)
+{
+    if(strbuff->value)
+        jsonp_free(strbuff->value);
+
+    strbuff->size = 0;
+    strbuff->length = 0;
+    strbuff->value = NULL;
+}
+
+void strbuffer_clear(strbuffer_t *strbuff)
+{
+    strbuff->length = 0;
+    strbuff->value[0] = '\0';
+}
+
+const char *strbuffer_value(const strbuffer_t *strbuff)
+{
+    return strbuff->value;
+}
+
+char *strbuffer_steal_value(strbuffer_t *strbuff)
+{
+    char *result = strbuff->value;
+    strbuff->value = NULL;
+    return result;
+}
+
+int strbuffer_append_byte(strbuffer_t *strbuff, char byte)
+{
+    return strbuffer_append_bytes(strbuff, &byte, 1);
+}
+
+int strbuffer_append_bytes(strbuffer_t *strbuff, const char *data, size_t size)
+{
+    if(size >= strbuff->size - strbuff->length)
+    {
+        size_t new_size;
+        char *new_value;
+
+        /* avoid integer overflow */
+        if (strbuff->size > STRBUFFER_SIZE_MAX / STRBUFFER_FACTOR
+            || size > STRBUFFER_SIZE_MAX - 1
+            || strbuff->length > STRBUFFER_SIZE_MAX - 1 - size)
+            return -1;
+
+        new_size = max(strbuff->size * STRBUFFER_FACTOR,
+                       strbuff->length + size + 1);
+
+        new_value = jsonp_malloc(new_size);
+        if(!new_value)
+            return -1;
+
+        memcpy(new_value, strbuff->value, strbuff->length);
+
+        jsonp_free(strbuff->value);
+        strbuff->value = new_value;
+        strbuff->size = new_size;
+    }
+
+    memcpy(strbuff->value + strbuff->length, data, size);
+    strbuff->length += size;
+    strbuff->value[strbuff->length] = '\0';
+
+    return 0;
+}
+
+char strbuffer_pop(strbuffer_t *strbuff)
+{
+    if(strbuff->length > 0) {
+        char c = strbuff->value[--strbuff->length];
+        strbuff->value[strbuff->length] = '\0';
+        return c;
+    }
+    else
+        return '\0';
+}
diff --git a/client/jansson/strbuffer.h b/client/jansson/strbuffer.h
new file mode 100644
index 00000000..615b7f5f
--- /dev/null
+++ b/client/jansson/strbuffer.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef STRBUFFER_H
+#define STRBUFFER_H
+
+#include <stdlib.h>
+
+typedef struct {
+    char *value;
+    size_t length;   /* bytes used */
+    size_t size;     /* bytes allocated */
+} strbuffer_t;
+
+int strbuffer_init(strbuffer_t *strbuff);
+void strbuffer_close(strbuffer_t *strbuff);
+
+void strbuffer_clear(strbuffer_t *strbuff);
+
+const char *strbuffer_value(const strbuffer_t *strbuff);
+
+/* Steal the value and close the strbuffer */
+char *strbuffer_steal_value(strbuffer_t *strbuff);
+
+int strbuffer_append_byte(strbuffer_t *strbuff, char byte);
+int strbuffer_append_bytes(strbuffer_t *strbuff, const char *data, size_t size);
+
+char strbuffer_pop(strbuffer_t *strbuff);
+
+#endif
diff --git a/client/jansson/strconv.c b/client/jansson/strconv.c
new file mode 100644
index 00000000..8075481e
--- /dev/null
+++ b/client/jansson/strconv.c
@@ -0,0 +1,145 @@
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+#ifdef __MINGW32__
+#undef __NO_ISOCEXT /* ensure stdlib.h will declare prototypes for mingw own 'strtod' replacement, called '__strtod' */
+#endif
+#include "jansson_private.h"
+#include "strbuffer.h"
+
+/* need jansson_private_config.h to get the correct snprintf */
+#ifdef HAVE_CONFIG_H
+#include <jansson_private_config.h>
+#endif
+
+#ifdef __MINGW32__
+#define strtod __strtod
+#endif
+
+#if JSON_HAVE_LOCALECONV
+#include <locale.h>
+
+/*
+  - This code assumes that the decimal separator is exactly one
+    character.
+
+  - If setlocale() is called by another thread between the call to
+    localeconv() and the call to sprintf() or strtod(), the result may
+    be wrong. setlocale() is not thread-safe and should not be used
+    this way. Multi-threaded programs should use uselocale() instead.
+*/
+
+static void to_locale(strbuffer_t *strbuffer)
+{
+    const char *point;
+    char *pos;
+
+    point = localeconv()->decimal_point;
+    if(*point == '.') {
+        /* No conversion needed */
+        return;
+    }
+
+    pos = strchr(strbuffer->value, '.');
+    if(pos)
+        *pos = *point;
+}
+
+static void from_locale(char *buffer)
+{
+    const char *point;
+    char *pos;
+
+    point = localeconv()->decimal_point;
+    if(*point == '.') {
+        /* No conversion needed */
+        return;
+    }
+
+    pos = strchr(buffer, *point);
+    if(pos)
+        *pos = '.';
+}
+#endif
+
+int jsonp_strtod(strbuffer_t *strbuffer, double *out)
+{
+    double value;
+    char *end;
+
+#if JSON_HAVE_LOCALECONV
+    to_locale(strbuffer);
+#endif
+
+    errno = 0;
+    value = strtod(strbuffer->value, &end);
+    assert(end == strbuffer->value + strbuffer->length);
+
+    if((value == HUGE_VAL || value == -HUGE_VAL) && errno == ERANGE) {
+        /* Overflow */
+        return -1;
+    }
+
+    *out = value;
+    return 0;
+}
+
+int jsonp_dtostr(char *buffer, size_t size, double value, int precision)
+{
+    int ret;
+    char *start, *end;
+    size_t length;
+
+    if (precision == 0)
+        precision = 17;
+
+    ret = snprintf(buffer, size, "%.*g", precision, value);
+    if(ret < 0)
+        return -1;
+
+    length = (size_t)ret;
+    if(length >= size)
+        return -1;
+
+#if JSON_HAVE_LOCALECONV
+    from_locale(buffer);
+#endif
+
+    /* Make sure there's a dot or 'e' in the output. Otherwise
+       a real is converted to an integer when decoding */
+    if(strchr(buffer, '.') == NULL &&
+       strchr(buffer, 'e') == NULL)
+    {
+        if(length + 3 >= size) {
+            /* No space to append ".0" */
+            return -1;
+        }
+        buffer[length] = '.';
+        buffer[length + 1] = '0';
+        buffer[length + 2] = '\0';
+        length += 2;
+    }
+
+    /* Remove leading '+' from positive exponent. Also remove leading
+       zeros from exponents (added by some printf() implementations) */
+    start = strchr(buffer, 'e');
+    if(start) {
+        start++;
+        end = start + 1;
+
+        if(*start == '-')
+            start++;
+
+        while(*end == '0')
+            end++;
+
+        if(end != start) {
+            memmove(start, end, length - (size_t)(end - buffer));
+            length -= (size_t)(end - start);
+        }
+    }
+
+    return (int)length;
+}
diff --git a/client/jansson/utf.c b/client/jansson/utf.c
new file mode 100644
index 00000000..be966cbd
--- /dev/null
+++ b/client/jansson/utf.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <string.h>
+#include "utf.h"
+
+int utf8_encode(int32_t codepoint, char *buffer, size_t *size)
+{
+    if(codepoint < 0)
+        return -1;
+    else if(codepoint < 0x80)
+    {
+        buffer[0] = (char)codepoint;
+        *size = 1;
+    }
+    else if(codepoint < 0x800)
+    {
+        buffer[0] = 0xC0 + ((codepoint & 0x7C0) >> 6);
+        buffer[1] = 0x80 + ((codepoint & 0x03F));
+        *size = 2;
+    }
+    else if(codepoint < 0x10000)
+    {
+        buffer[0] = 0xE0 + ((codepoint & 0xF000) >> 12);
+        buffer[1] = 0x80 + ((codepoint & 0x0FC0) >> 6);
+        buffer[2] = 0x80 + ((codepoint & 0x003F));
+        *size = 3;
+    }
+    else if(codepoint <= 0x10FFFF)
+    {
+        buffer[0] = 0xF0 + ((codepoint & 0x1C0000) >> 18);
+        buffer[1] = 0x80 + ((codepoint & 0x03F000) >> 12);
+        buffer[2] = 0x80 + ((codepoint & 0x000FC0) >> 6);
+        buffer[3] = 0x80 + ((codepoint & 0x00003F));
+        *size = 4;
+    }
+    else
+        return -1;
+
+    return 0;
+}
+
+size_t utf8_check_first(char byte)
+{
+    unsigned char u = (unsigned char)byte;
+
+    if(u < 0x80)
+        return 1;
+
+    if(0x80 <= u && u <= 0xBF) {
+        /* second, third or fourth byte of a multi-byte
+           sequence, i.e. a "continuation byte" */
+        return 0;
+    }
+    else if(u == 0xC0 || u == 0xC1) {
+        /* overlong encoding of an ASCII byte */
+        return 0;
+    }
+    else if(0xC2 <= u && u <= 0xDF) {
+        /* 2-byte sequence */
+        return 2;
+    }
+
+    else if(0xE0 <= u && u <= 0xEF) {
+        /* 3-byte sequence */
+        return 3;
+    }
+    else if(0xF0 <= u && u <= 0xF4) {
+        /* 4-byte sequence */
+        return 4;
+    }
+    else { /* u >= 0xF5 */
+        /* Restricted (start of 4-, 5- or 6-byte sequence) or invalid
+           UTF-8 */
+        return 0;
+    }
+}
+
+size_t utf8_check_full(const char *buffer, size_t size, int32_t *codepoint)
+{
+    size_t i;
+    int32_t value = 0;
+    unsigned char u = (unsigned char)buffer[0];
+
+    if(size == 2)
+    {
+        value = u & 0x1F;
+    }
+    else if(size == 3)
+    {
+        value = u & 0xF;
+    }
+    else if(size == 4)
+    {
+        value = u & 0x7;
+    }
+    else
+        return 0;
+
+    for(i = 1; i < size; i++)
+    {
+        u = (unsigned char)buffer[i];
+
+        if(u < 0x80 || u > 0xBF) {
+            /* not a continuation byte */
+            return 0;
+        }
+
+        value = (value << 6) + (u & 0x3F);
+    }
+
+    if(value > 0x10FFFF) {
+        /* not in Unicode range */
+        return 0;
+    }
+
+    else if(0xD800 <= value && value <= 0xDFFF) {
+        /* invalid code point (UTF-16 surrogate halves) */
+        return 0;
+    }
+
+    else if((size == 2 && value < 0x80) ||
+            (size == 3 && value < 0x800) ||
+            (size == 4 && value < 0x10000)) {
+        /* overlong encoding */
+        return 0;
+    }
+
+    if(codepoint)
+        *codepoint = value;
+
+    return 1;
+}
+
+const char *utf8_iterate(const char *buffer, size_t bufsize, int32_t *codepoint)
+{
+    size_t count;
+    int32_t value;
+
+    if(!bufsize)
+        return buffer;
+
+    count = utf8_check_first(buffer[0]);
+    if(count <= 0)
+        return NULL;
+
+    if(count == 1)
+        value = (unsigned char)buffer[0];
+    else
+    {
+        if(count > bufsize || !utf8_check_full(buffer, count, &value))
+            return NULL;
+    }
+
+    if(codepoint)
+        *codepoint = value;
+
+    return buffer + count;
+}
+
+int utf8_check_string(const char *string, size_t length)
+{
+    size_t i;
+
+    for(i = 0; i < length; i++)
+    {
+        size_t count = utf8_check_first(string[i]);
+        if(count == 0)
+            return 0;
+        else if(count > 1)
+        {
+            if(count > length - i)
+                return 0;
+
+            if(!utf8_check_full(&string[i], count, NULL))
+                return 0;
+
+            i += count - 1;
+        }
+    }
+
+    return 1;
+}
diff --git a/client/jansson/utf.h b/client/jansson/utf.h
new file mode 100644
index 00000000..e182df78
--- /dev/null
+++ b/client/jansson/utf.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef UTF_H
+#define UTF_H
+
+#ifdef HAVE_CONFIG_H
+#include <jansson_private_config.h>
+#endif
+
+#ifdef HAVE_STDINT_H
+#include <stdint.h>
+#endif
+
+int utf8_encode(int32_t codepoint, char *buffer, size_t *size);
+
+size_t utf8_check_first(char byte);
+size_t utf8_check_full(const char *buffer, size_t size, int32_t *codepoint);
+const char *utf8_iterate(const char *buffer, size_t size, int32_t *codepoint);
+
+int utf8_check_string(const char *string, size_t length);
+
+#endif
diff --git a/client/jansson/value.c b/client/jansson/value.c
new file mode 100644
index 00000000..b3b31412
--- /dev/null
+++ b/client/jansson/value.c
@@ -0,0 +1,1078 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#ifdef HAVE_CONFIG_H
+#include <jansson_private_config.h>
+#endif
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+#ifdef HAVE_STDINT_H
+#include <stdint.h>
+#endif
+
+#include "jansson.h"
+#include "hashtable.h"
+#include "jansson_private.h"
+#include "utf.h"
+
+/* Work around nonstandard isnan() and isinf() implementations */
+#ifndef isnan
+#ifndef __sun
+static JSON_INLINE int isnan(double x) { return x != x; }
+#endif
+#endif
+#ifndef isinf
+static JSON_INLINE int isinf(double x) { return !isnan(x) && isnan(x - x); }
+#endif
+
+static JSON_INLINE void json_init(json_t *json, json_type type)
+{
+    json->type = type;
+    json->refcount = 1;
+}
+
+
+/*** object ***/
+
+extern volatile uint32_t hashtable_seed;
+
+json_t *json_object(void)
+{
+    json_object_t *object = jsonp_malloc(sizeof(json_object_t));
+    if(!object)
+        return NULL;
+
+    if (!hashtable_seed) {
+        /* Autoseed */
+        json_object_seed(0);
+    }
+
+    json_init(&object->json, JSON_OBJECT);
+
+    if(hashtable_init(&object->hashtable))
+    {
+        jsonp_free(object);
+        return NULL;
+    }
+
+    return &object->json;
+}
+
+static void json_delete_object(json_object_t *object)
+{
+    hashtable_close(&object->hashtable);
+    jsonp_free(object);
+}
+
+size_t json_object_size(const json_t *json)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json))
+        return 0;
+
+    object = json_to_object(json);
+    return object->hashtable.size;
+}
+
+json_t *json_object_get(const json_t *json, const char *key)
+{
+    json_object_t *object;
+
+    if(!key || !json_is_object(json))
+        return NULL;
+
+    object = json_to_object(json);
+    return hashtable_get(&object->hashtable, key);
+}
+
+int json_object_set_new_nocheck(json_t *json, const char *key, json_t *value)
+{
+    json_object_t *object;
+
+    if(!value)
+        return -1;
+
+    if(!key || !json_is_object(json) || json == value)
+    {
+        json_decref(value);
+        return -1;
+    }
+    object = json_to_object(json);
+
+    if(hashtable_set(&object->hashtable, key, value))
+    {
+        json_decref(value);
+        return -1;
+    }
+
+    return 0;
+}
+
+int json_object_set_new(json_t *json, const char *key, json_t *value)
+{
+    if(!key || !utf8_check_string(key, strlen(key)))
+    {
+        json_decref(value);
+        return -1;
+    }
+
+    return json_object_set_new_nocheck(json, key, value);
+}
+
+int json_object_del(json_t *json, const char *key)
+{
+    json_object_t *object;
+
+    if(!key || !json_is_object(json))
+        return -1;
+
+    object = json_to_object(json);
+    return hashtable_del(&object->hashtable, key);
+}
+
+int json_object_clear(json_t *json)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json))
+        return -1;
+
+    object = json_to_object(json);
+    hashtable_clear(&object->hashtable);
+
+    return 0;
+}
+
+int json_object_update(json_t *object, json_t *other)
+{
+    const char *key;
+    json_t *value;
+
+    if(!json_is_object(object) || !json_is_object(other))
+        return -1;
+
+    json_object_foreach(other, key, value) {
+        if(json_object_set_nocheck(object, key, value))
+            return -1;
+    }
+
+    return 0;
+}
+
+int json_object_update_existing(json_t *object, json_t *other)
+{
+    const char *key;
+    json_t *value;
+
+    if(!json_is_object(object) || !json_is_object(other))
+        return -1;
+
+    json_object_foreach(other, key, value) {
+        if(json_object_get(object, key))
+            json_object_set_nocheck(object, key, value);
+    }
+
+    return 0;
+}
+
+int json_object_update_missing(json_t *object, json_t *other)
+{
+    const char *key;
+    json_t *value;
+
+    if(!json_is_object(object) || !json_is_object(other))
+        return -1;
+
+    json_object_foreach(other, key, value) {
+        if(!json_object_get(object, key))
+            json_object_set_nocheck(object, key, value);
+    }
+
+    return 0;
+}
+
+void *json_object_iter(json_t *json)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json))
+        return NULL;
+
+    object = json_to_object(json);
+    return hashtable_iter(&object->hashtable);
+}
+
+void *json_object_iter_at(json_t *json, const char *key)
+{
+    json_object_t *object;
+
+    if(!key || !json_is_object(json))
+        return NULL;
+
+    object = json_to_object(json);
+    return hashtable_iter_at(&object->hashtable, key);
+}
+
+void *json_object_iter_next(json_t *json, void *iter)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json) || iter == NULL)
+        return NULL;
+
+    object = json_to_object(json);
+    return hashtable_iter_next(&object->hashtable, iter);
+}
+
+const char *json_object_iter_key(void *iter)
+{
+    if(!iter)
+        return NULL;
+
+    return hashtable_iter_key(iter);
+}
+
+json_t *json_object_iter_value(void *iter)
+{
+    if(!iter)
+        return NULL;
+
+    return (json_t *)hashtable_iter_value(iter);
+}
+
+int json_object_iter_set_new(json_t *json, void *iter, json_t *value)
+{
+    if(!json_is_object(json) || !iter || !value)
+    {
+        json_decref(value);
+        return -1;
+    }
+
+    hashtable_iter_set(iter, value);
+    return 0;
+}
+
+void *json_object_key_to_iter(const char *key)
+{
+    if(!key)
+        return NULL;
+
+    return hashtable_key_to_iter(key);
+}
+
+static int json_object_equal(const json_t *object1, const json_t *object2)
+{
+    const char *key;
+    const json_t *value1, *value2;
+
+    if(json_object_size(object1) != json_object_size(object2))
+        return 0;
+
+    json_object_foreach((json_t *)object1, key, value1) {
+        value2 = json_object_get(object2, key);
+
+        if(!json_equal(value1, value2))
+            return 0;
+    }
+
+    return 1;
+}
+
+static json_t *json_object_copy(json_t *object)
+{
+    json_t *result;
+
+    const char *key;
+    json_t *value;
+
+    result = json_object();
+    if(!result)
+        return NULL;
+
+    json_object_foreach(object, key, value)
+        json_object_set_nocheck(result, key, value);
+
+    return result;
+}
+
+static json_t *json_object_deep_copy(const json_t *object)
+{
+    json_t *result;
+    void *iter;
+
+    result = json_object();
+    if(!result)
+        return NULL;
+
+    /* Cannot use json_object_foreach because object has to be cast
+       non-const */
+    iter = json_object_iter((json_t *)object);
+    while(iter) {
+        const char *key;
+        const json_t *value;
+        key = json_object_iter_key(iter);
+        value = json_object_iter_value(iter);
+
+        json_object_set_new_nocheck(result, key, json_deep_copy(value));
+        iter = json_object_iter_next((json_t *)object, iter);
+    }
+
+    return result;
+}
+
+
+/*** array ***/
+
+json_t *json_array(void)
+{
+    json_array_t *array = jsonp_malloc(sizeof(json_array_t));
+    if(!array)
+        return NULL;
+    json_init(&array->json, JSON_ARRAY);
+
+    array->entries = 0;
+    array->size = 8;
+
+    array->table = jsonp_malloc(array->size * sizeof(json_t *));
+    if(!array->table) {
+        jsonp_free(array);
+        return NULL;
+    }
+
+    return &array->json;
+}
+
+static void json_delete_array(json_array_t *array)
+{
+    size_t i;
+
+    for(i = 0; i < array->entries; i++)
+        json_decref(array->table[i]);
+
+    jsonp_free(array->table);
+    jsonp_free(array);
+}
+
+size_t json_array_size(const json_t *json)
+{
+    if(!json_is_array(json))
+        return 0;
+
+    return json_to_array(json)->entries;
+}
+
+json_t *json_array_get(const json_t *json, size_t index)
+{
+    json_array_t *array;
+    if(!json_is_array(json))
+        return NULL;
+    array = json_to_array(json);
+
+    if(index >= array->entries)
+        return NULL;
+
+    return array->table[index];
+}
+
+int json_array_set_new(json_t *json, size_t index, json_t *value)
+{
+    json_array_t *array;
+
+    if(!value)
+        return -1;
+
+    if(!json_is_array(json) || json == value)
+    {
+        json_decref(value);
+        return -1;
+    }
+    array = json_to_array(json);
+
+    if(index >= array->entries)
+    {
+        json_decref(value);
+        return -1;
+    }
+
+    json_decref(array->table[index]);
+    array->table[index] = value;
+
+    return 0;
+}
+
+static void array_move(json_array_t *array, size_t dest,
+                       size_t src, size_t count)
+{
+    memmove(&array->table[dest], &array->table[src], count * sizeof(json_t *));
+}
+
+static void array_copy(json_t **dest, size_t dpos,
+                       json_t **src, size_t spos,
+                       size_t count)
+{
+    memcpy(&dest[dpos], &src[spos], count * sizeof(json_t *));
+}
+
+static json_t **json_array_grow(json_array_t *array,
+                                size_t amount,
+                                int copy)
+{
+    size_t new_size;
+    json_t **old_table, **new_table;
+
+    if(array->entries + amount <= array->size)
+        return array->table;
+
+    old_table = array->table;
+
+    new_size = max(array->size + amount, array->size * 2);
+    new_table = jsonp_malloc(new_size * sizeof(json_t *));
+    if(!new_table)
+        return NULL;
+
+    array->size = new_size;
+    array->table = new_table;
+
+    if(copy) {
+        array_copy(array->table, 0, old_table, 0, array->entries);
+        jsonp_free(old_table);
+        return array->table;
+    }
+
+    return old_table;
+}
+
+int json_array_append_new(json_t *json, json_t *value)
+{
+    json_array_t *array;
+
+    if(!value)
+        return -1;
+
+    if(!json_is_array(json) || json == value)
+    {
+        json_decref(value);
+        return -1;
+    }
+    array = json_to_array(json);
+
+    if(!json_array_grow(array, 1, 1)) {
+        json_decref(value);
+        return -1;
+    }
+
+    array->table[array->entries] = value;
+    array->entries++;
+
+    return 0;
+}
+
+int json_array_insert_new(json_t *json, size_t index, json_t *value)
+{
+    json_array_t *array;
+    json_t **old_table;
+
+    if(!value)
+        return -1;
+
+    if(!json_is_array(json) || json == value) {
+        json_decref(value);
+        return -1;
+    }
+    array = json_to_array(json);
+
+    if(index > array->entries) {
+        json_decref(value);
+        return -1;
+    }
+
+    old_table = json_array_grow(array, 1, 0);
+    if(!old_table) {
+        json_decref(value);
+        return -1;
+    }
+
+    if(old_table != array->table) {
+        array_copy(array->table, 0, old_table, 0, index);
+        array_copy(array->table, index + 1, old_table, index,
+                   array->entries - index);
+        jsonp_free(old_table);
+    }
+    else
+        array_move(array, index + 1, index, array->entries - index);
+
+    array->table[index] = value;
+    array->entries++;
+
+    return 0;
+}
+
+int json_array_remove(json_t *json, size_t index)
+{
+    json_array_t *array;
+
+    if(!json_is_array(json))
+        return -1;
+    array = json_to_array(json);
+
+    if(index >= array->entries)
+        return -1;
+
+    json_decref(array->table[index]);
+
+    /* If we're removing the last element, nothing has to be moved */
+    if(index < array->entries - 1)
+        array_move(array, index, index + 1, array->entries - index - 1);
+
+    array->entries--;
+
+    return 0;
+}
+
+int json_array_clear(json_t *json)
+{
+    json_array_t *array;
+    size_t i;
+
+    if(!json_is_array(json))
+        return -1;
+    array = json_to_array(json);
+
+    for(i = 0; i < array->entries; i++)
+        json_decref(array->table[i]);
+
+    array->entries = 0;
+    return 0;
+}
+
+int json_array_extend(json_t *json, json_t *other_json)
+{
+    json_array_t *array, *other;
+    size_t i;
+
+    if(!json_is_array(json) || !json_is_array(other_json))
+        return -1;
+    array = json_to_array(json);
+    other = json_to_array(other_json);
+
+    if(!json_array_grow(array, other->entries, 1))
+        return -1;
+
+    for(i = 0; i < other->entries; i++)
+        json_incref(other->table[i]);
+
+    array_copy(array->table, array->entries, other->table, 0, other->entries);
+
+    array->entries += other->entries;
+    return 0;
+}
+
+static int json_array_equal(const json_t *array1, const json_t *array2)
+{
+    size_t i, size;
+
+    size = json_array_size(array1);
+    if(size != json_array_size(array2))
+        return 0;
+
+    for(i = 0; i < size; i++)
+    {
+        json_t *value1, *value2;
+
+        value1 = json_array_get(array1, i);
+        value2 = json_array_get(array2, i);
+
+        if(!json_equal(value1, value2))
+            return 0;
+    }
+
+    return 1;
+}
+
+static json_t *json_array_copy(json_t *array)
+{
+    json_t *result;
+    size_t i;
+
+    result = json_array();
+    if(!result)
+        return NULL;
+
+    for(i = 0; i < json_array_size(array); i++)
+        json_array_append(result, json_array_get(array, i));
+
+    return result;
+}
+
+static json_t *json_array_deep_copy(const json_t *array)
+{
+    json_t *result;
+    size_t i;
+
+    result = json_array();
+    if(!result)
+        return NULL;
+
+    for(i = 0; i < json_array_size(array); i++)
+        json_array_append_new(result, json_deep_copy(json_array_get(array, i)));
+
+    return result;
+}
+
+/*** string ***/
+
+static json_t *string_create(const char *value, size_t len, int own)
+{
+    char *v;
+    json_string_t *string;
+
+    if(!value)
+        return NULL;
+
+    if(own)
+        v = (char *)value;
+    else {
+        v = jsonp_strndup(value, len);
+        if(!v)
+            return NULL;
+    }
+
+    string = jsonp_malloc(sizeof(json_string_t));
+    if(!string) {
+        if(!own)
+            jsonp_free(v);
+        return NULL;
+    }
+    json_init(&string->json, JSON_STRING);
+    string->value = v;
+    string->length = len;
+
+    return &string->json;
+}
+
+json_t *json_string_nocheck(const char *value)
+{
+    if(!value)
+        return NULL;
+
+    return string_create(value, strlen(value), 0);
+}
+
+json_t *json_stringn_nocheck(const char *value, size_t len)
+{
+    return string_create(value, len, 0);
+}
+
+/* this is private; "steal" is not a public API concept */
+json_t *jsonp_stringn_nocheck_own(const char *value, size_t len)
+{
+    return string_create(value, len, 1);
+}
+
+json_t *json_string(const char *value)
+{
+    if(!value)
+        return NULL;
+
+    return json_stringn(value, strlen(value));
+}
+
+json_t *json_stringn(const char *value, size_t len)
+{
+    if(!value || !utf8_check_string(value, len))
+        return NULL;
+
+    return json_stringn_nocheck(value, len);
+}
+
+const char *json_string_value(const json_t *json)
+{
+    if(!json_is_string(json))
+        return NULL;
+
+    return json_to_string(json)->value;
+}
+
+size_t json_string_length(const json_t *json)
+{
+    if(!json_is_string(json))
+        return 0;
+
+    return json_to_string(json)->length;
+}
+
+int json_string_set_nocheck(json_t *json, const char *value)
+{
+    if(!value)
+        return -1;
+
+    return json_string_setn_nocheck(json, value, strlen(value));
+}
+
+int json_string_setn_nocheck(json_t *json, const char *value, size_t len)
+{
+    char *dup;
+    json_string_t *string;
+
+    if(!json_is_string(json) || !value)
+        return -1;
+
+    dup = jsonp_strndup(value, len);
+    if(!dup)
+        return -1;
+
+    string = json_to_string(json);
+    jsonp_free(string->value);
+    string->value = dup;
+    string->length = len;
+
+    return 0;
+}
+
+int json_string_set(json_t *json, const char *value)
+{
+    if(!value)
+        return -1;
+
+    return json_string_setn(json, value, strlen(value));
+}
+
+int json_string_setn(json_t *json, const char *value, size_t len)
+{
+    if(!value || !utf8_check_string(value, len))
+        return -1;
+
+    return json_string_setn_nocheck(json, value, len);
+}
+
+static void json_delete_string(json_string_t *string)
+{
+    jsonp_free(string->value);
+    jsonp_free(string);
+}
+
+static int json_string_equal(const json_t *string1, const json_t *string2)
+{
+    json_string_t *s1, *s2;
+
+    if(!json_is_string(string1) || !json_is_string(string2))
+        return 0;
+
+    s1 = json_to_string(string1);
+    s2 = json_to_string(string2);
+    return s1->length == s2->length && !memcmp(s1->value, s2->value, s1->length);
+}
+
+static json_t *json_string_copy(const json_t *string)
+{
+    json_string_t *s;
+
+    if(!json_is_string(string))
+        return NULL;
+
+    s = json_to_string(string);
+    return json_stringn_nocheck(s->value, s->length);
+}
+
+json_t *json_vsprintf(const char *fmt, va_list ap) {
+    int length;
+    char *buf;
+    va_list aq;
+    va_copy(aq, ap);
+
+    length = vsnprintf(NULL, 0, fmt, ap);
+    if (length == 0)
+        return json_string("");
+
+    buf = jsonp_malloc(length + 1);
+    if (!buf)
+        return NULL;
+
+    vsnprintf(buf, length + 1, fmt, aq);
+    if (!utf8_check_string(buf, length)) {
+        jsonp_free(buf);
+        return NULL;
+    }
+
+    return jsonp_stringn_nocheck_own(buf, length);
+}
+
+json_t *json_sprintf(const char *fmt, ...) {
+    json_t *result;
+    va_list ap;
+
+    va_start(ap, fmt);
+    result = json_vsprintf(fmt, ap);
+    va_end(ap);
+
+    return result;
+}
+
+
+/*** integer ***/
+
+json_t *json_integer(json_int_t value)
+{
+    json_integer_t *integer = jsonp_malloc(sizeof(json_integer_t));
+    if(!integer)
+        return NULL;
+    json_init(&integer->json, JSON_INTEGER);
+
+    integer->value = value;
+    return &integer->json;
+}
+
+json_int_t json_integer_value(const json_t *json)
+{
+    if(!json_is_integer(json))
+        return 0;
+
+    return json_to_integer(json)->value;
+}
+
+int json_integer_set(json_t *json, json_int_t value)
+{
+    if(!json_is_integer(json))
+        return -1;
+
+    json_to_integer(json)->value = value;
+
+    return 0;
+}
+
+static void json_delete_integer(json_integer_t *integer)
+{
+    jsonp_free(integer);
+}
+
+static int json_integer_equal(const json_t *integer1, const json_t *integer2)
+{
+    return json_integer_value(integer1) == json_integer_value(integer2);
+}
+
+static json_t *json_integer_copy(const json_t *integer)
+{
+    return json_integer(json_integer_value(integer));
+}
+
+
+/*** real ***/
+
+json_t *json_real(double value)
+{
+    json_real_t *real;
+
+    if(isnan(value) || isinf(value))
+        return NULL;
+
+    real = jsonp_malloc(sizeof(json_real_t));
+    if(!real)
+        return NULL;
+    json_init(&real->json, JSON_REAL);
+
+    real->value = value;
+    return &real->json;
+}
+
+double json_real_value(const json_t *json)
+{
+    if(!json_is_real(json))
+        return 0;
+
+    return json_to_real(json)->value;
+}
+
+int json_real_set(json_t *json, double value)
+{
+    if(!json_is_real(json) || isnan(value) || isinf(value))
+        return -1;
+
+    json_to_real(json)->value = value;
+
+    return 0;
+}
+
+static void json_delete_real(json_real_t *real)
+{
+    jsonp_free(real);
+}
+
+static int json_real_equal(const json_t *real1, const json_t *real2)
+{
+    return json_real_value(real1) == json_real_value(real2);
+}
+
+static json_t *json_real_copy(const json_t *real)
+{
+    return json_real(json_real_value(real));
+}
+
+
+/*** number ***/
+
+double json_number_value(const json_t *json)
+{
+    if(json_is_integer(json))
+        return (double)json_integer_value(json);
+    else if(json_is_real(json))
+        return json_real_value(json);
+    else
+        return 0.0;
+}
+
+
+/*** simple values ***/
+
+json_t *json_true(void)
+{
+    static json_t the_true = {JSON_TRUE, (size_t)-1};
+    return &the_true;
+}
+
+
+json_t *json_false(void)
+{
+    static json_t the_false = {JSON_FALSE, (size_t)-1};
+    return &the_false;
+}
+
+
+json_t *json_null(void)
+{
+    static json_t the_null = {JSON_NULL, (size_t)-1};
+    return &the_null;
+}
+
+
+/*** deletion ***/
+
+void json_delete(json_t *json)
+{
+    if (!json)
+        return;
+
+    switch(json_typeof(json)) {
+        case JSON_OBJECT:
+            json_delete_object(json_to_object(json));
+            break;
+        case JSON_ARRAY:
+            json_delete_array(json_to_array(json));
+            break;
+        case JSON_STRING:
+            json_delete_string(json_to_string(json));
+            break;
+        case JSON_INTEGER:
+            json_delete_integer(json_to_integer(json));
+            break;
+        case JSON_REAL:
+            json_delete_real(json_to_real(json));
+            break;
+        default:
+            return;
+    }
+
+    /* json_delete is not called for true, false or null */
+}
+
+
+/*** equality ***/
+
+int json_equal(const json_t *json1, const json_t *json2)
+{
+    if(!json1 || !json2)
+        return 0;
+
+    if(json_typeof(json1) != json_typeof(json2))
+        return 0;
+
+    /* this covers true, false and null as they are singletons */
+    if(json1 == json2)
+        return 1;
+
+    switch(json_typeof(json1)) {
+        case JSON_OBJECT:
+            return json_object_equal(json1, json2);
+        case JSON_ARRAY:
+            return json_array_equal(json1, json2);
+        case JSON_STRING:
+            return json_string_equal(json1, json2);
+        case JSON_INTEGER:
+            return json_integer_equal(json1, json2);
+        case JSON_REAL:
+            return json_real_equal(json1, json2);
+        default:
+            return 0;
+    }
+}
+
+
+/*** copying ***/
+
+json_t *json_copy(json_t *json)
+{
+    if(!json)
+        return NULL;
+
+    switch(json_typeof(json)) {
+        case JSON_OBJECT:
+            return json_object_copy(json);
+        case JSON_ARRAY:
+            return json_array_copy(json);
+        case JSON_STRING:
+            return json_string_copy(json);
+        case JSON_INTEGER:
+            return json_integer_copy(json);
+        case JSON_REAL:
+            return json_real_copy(json);
+        case JSON_TRUE:
+        case JSON_FALSE:
+        case JSON_NULL:
+            return json;
+        default:
+            return NULL;
+    }
+
+    return NULL;
+}
+
+json_t *json_deep_copy(const json_t *json)
+{
+    if(!json)
+        return NULL;
+
+    switch(json_typeof(json)) {
+        case JSON_OBJECT:
+            return json_object_deep_copy(json);
+        case JSON_ARRAY:
+            return json_array_deep_copy(json);
+            /* for the rest of the types, deep copying doesn't differ from
+               shallow copying */
+        case JSON_STRING:
+            return json_string_copy(json);
+        case JSON_INTEGER:
+            return json_integer_copy(json);
+        case JSON_REAL:
+            return json_real_copy(json);
+        case JSON_TRUE:
+        case JSON_FALSE:
+        case JSON_NULL:
+            return (json_t *)json;
+        default:
+            return NULL;
+    }
+
+    return NULL;
+}
-- 
2.39.5

