From: Oleg Moiseenko <olegmsn@gmail.com>
Date: Thu, 2 Nov 2017 12:14:55 +0000 (+0200)
Subject: Merge branch 'master' into 14a_rework3
X-Git-Tag: v3.1.0~133^2~5
X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/commitdiff_plain/378d3406cae2ab5d6f8c43fd933134d5395c4ddb?hp=23207d748f65f97365a608f2a9abfc3ac5997413

Merge branch 'master' into 14a_rework3
---

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 044538c4..60caf413 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ This project uses the changelog in accordance with [keepchangelog](http://keepac
 - `hf mf nested` Check keys after they have found (Merlok)
 - `hf mf chk` Move main cycle to arm (Merlok)
 - Changed proxmark command line parameter `flush` to `-f` or `-flush` (Merlok)
+- Changed `hf 14a reader` to just reqest-anticilission-select sequence (Merlok)
 
 ### Fixed
 - Changed start sequence in Qt mode (fix: short commands hangs main Qt thread) (Merlok)
@@ -32,6 +33,8 @@ This project uses the changelog in accordance with [keepchangelog](http://keepac
 - Added to proxmark command line parameters `w` - wait 20s for serial port (Merlok)
 - Added to proxmark command line parameters `c` and `l` - execute command and lua script from command line (Merlok)
 - Added to proxmark ability to execute commands from stdin (pipe) (Merlok)
+- Added `hf 14a info` and moved there functionality from `hf 14a reader` (Merlok)
+- Added to `hf 14a info` detection of weak prng from Iceman1001 fork (Merlok)
 
 ## [3.0.1][2017-06-08]
 
diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index c39b8a20..5a27e06b 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -1821,7 +1821,7 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u
 	}
 
 	// PICC compilant with iso14443a-4 ---> (SAK & 0x20 != 0)
-  	if( (sak & 0x20) == 0) return 2; 
+	if( (sak & 0x20) == 0) return 2; 
 
 	if (!no_rats) {
 		// Request for answer to select
diff --git a/client/cmdhf14a.c b/client/cmdhf14a.c
index 86cfea2f..1ae63ada 100644
--- a/client/cmdhf14a.c
+++ b/client/cmdhf14a.c
@@ -220,8 +220,10 @@ int CmdHF14AInfo(const char *Cmd)
 	PrintAndLog("ATQA : %02x %02x", card.atqa[1], card.atqa[0]);
 	PrintAndLog(" SAK : %02x [%d]", card.sak, resp.arg[0]);
 
+	bool isMifareClassic = true;
 	switch (card.sak) {
 		case 0x00: 
+			isMifareClassic = false;
 
 			//***************************************test****************
 			// disconnect
@@ -456,6 +458,19 @@ int CmdHF14AInfo(const char *Cmd)
 	// try to see if card responses to "chinese magic backdoor" commands.
 	mfCIdentify();
 	
+	if (isMifareClassic) {		
+		switch(DetectClassicPrng()) {
+		case 0:
+			PrintAndLog("Prng detection: HARDEND (hardnested)");		
+			break;
+		case 1:
+			PrintAndLog("Prng detection: WEAK");
+			break;
+		default:
+			PrintAndLog("Prng detection error.");		
+		}
+	}
+	
 	return select_status;
 }
 
diff --git a/client/mifarehost.c b/client/mifarehost.c
index fe1a8edb..67277b59 100644
--- a/client/mifarehost.c
+++ b/client/mifarehost.c
@@ -903,3 +903,72 @@ int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data,
 	return 0;
 }
 
+/** validate_prng_nonce
+ * Determine if nonce is deterministic. ie: Suspectable to Darkside attack.
+ * returns
+ *   true = weak prng
+ *   false = hardend prng
+ */
+bool validate_prng_nonce(uint32_t nonce) {
+	uint16_t *dist = 0;
+	uint16_t x, i;
+
+	dist = malloc(2 << 16);
+	if(!dist)
+		return -1;
+
+	// init prng table:
+	for (x = i = 1; i; ++i) {
+		dist[(x & 0xff) << 8 | x >> 8] = i;
+		x = x >> 1 | (x ^ x >> 2 ^ x >> 3 ^ x >> 5) << 15;
+	}
+	
+	uint32_t res = (65535 - dist[nonce >> 16] + dist[nonce & 0xffff]) % 65535;
+	
+	free(dist);	
+	return (res == 16);
+}
+
+/* Detect Tag Prng, 
+* function performs a partial AUTH,  where it tries to authenticate against block0, key A, but only collects tag nonce.
+* the tag nonce is check to see if it has a predictable PRNG.
+* @returns 
+*	TRUE if tag uses WEAK prng (ie Now the NACK bug also needs to be present for Darkside attack)
+*   FALSE is tag uses HARDEND prng (ie hardnested attack possible, with known key)
+*/
+int DetectClassicPrng(void){
+
+	UsbCommand resp, respA;	
+	uint8_t cmd[] = {0x60, 0x00}; // MIFARE_AUTH_KEYA
+	uint32_t flags = ISO14A_CONNECT | ISO14A_RAW | ISO14A_APPEND_CRC | ISO14A_NO_RATS;
+	
+	UsbCommand c = {CMD_READER_ISO_14443a, {flags, sizeof(cmd), 0}};
+	memcpy(c.d.asBytes, cmd, sizeof(cmd));
+
+	clearCommandBuffer();
+	SendCommand(&c);
+	if (!WaitForResponseTimeout(CMD_ACK, &resp, 2000)) {
+        PrintAndLog("PRNG UID: Reply timeout.");
+		return -1;
+	}
+	
+	// if select tag failed.
+	if (resp.arg[0] == 0) {
+		PrintAndLog("PRNG error: selecting tag failed, can't detect prng.");
+		return -1;
+	}
+	
+	if (!WaitForResponseTimeout(CMD_ACK, &respA, 5000)) {
+        PrintAndLog("PRNG data: Reply timeout.");
+		return -1;
+	}
+
+	// check respA
+	if (respA.arg[0] != 4) {
+		PrintAndLog("PRNG data error: Wrong length: %d", respA.arg[0]);
+		return -1;
+	}
+
+	uint32_t nonce = bytes_to_num(respA.d.asBytes, respA.arg[0]);
+	return validate_prng_nonce(nonce);
+}
diff --git a/client/mifarehost.h b/client/mifarehost.h
index 118d55cc..031dac1b 100644
--- a/client/mifarehost.h
+++ b/client/mifarehost.h
@@ -60,5 +60,6 @@ extern int saveTraceCard(void);
 extern int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len);
 
 extern int mfCIdentify();
+extern int DetectClassicPrng(void);
 
 #endif
diff --git a/common/crapto1/crapto1.c b/common/crapto1/crapto1.c
index 9398a1f3..1edfca1b 100644
--- a/common/crapto1/crapto1.c
+++ b/common/crapto1/crapto1.c
@@ -426,7 +426,6 @@ int nonce_distance(uint32_t from, uint32_t to)
 	return (65535 + dist[to >> 16] - dist[from >> 16]) % 65535;
 }
 
-
 static uint32_t fastfwd[2][8] = {
 	{ 0, 0x4BC53, 0xECB1, 0x450E2, 0x25E29, 0x6E27A, 0x2B298, 0x60ECB},
 	{ 0, 0x1D962, 0x4BC53, 0x56531, 0xECB1, 0x135D3, 0x450E2, 0x58980}};