Implemented 'hf iclass decrypt <tagdump>'. This performs the 3des decryption of iclas...

diff --git a/client/cmdhficlass.c b/client/cmdhficlass.c
index 6c92893ae9ab1559d983723489ecf2d496dcf5b1..b945e12b4c2b850360113533a8c7bf41f0210c63 100644 (file)
--- a/client/cmdhficlass.c
+++ b/client/cmdhficlass.c
@@ -53,6 +53,21 @@ int CmdHFiClassSnoop(const char *Cmd)
        SendCommand(&c);
        return 0;
 }
+int usage_hf_iclass_sim()
+{
+       PrintAndLog("Usage:  hf iclass sim <option> [CSN]");
+       PrintAndLog("        options");
+       PrintAndLog("                0 <CSN> simulate the given CSN");
+       PrintAndLog("                1       simulate default CSN");
+       PrintAndLog("                2       Reader-attack, gather reader responses to extract elite key");
+       PrintAndLog("                3       Full simulation using emulator memory (see 'hf iclass eload')");
+       PrintAndLog("        example: hf iclass sim 0 031FEC8AF7FF12E0");
+       PrintAndLog("        example: hf iclass sim 2");
+       PrintAndLog("        example: hf iclass eload 'tagdump.bin'");
+       PrintAndLog("                 hf iclass sim 3");
+       return 0;
+}
+
 #define NUM_CSNS 15
 int CmdHFiClassSim(const char *Cmd)
 {
@@ -60,14 +75,7 @@ int CmdHFiClassSim(const char *Cmd)
        uint8_t CSN[8] = {0, 0, 0, 0, 0, 0, 0, 0};
 
        if (strlen(Cmd)<1) {
-               PrintAndLog("Usage:  hf iclass sim [0 <CSN>] | x");
-               PrintAndLog("        options");
-               PrintAndLog("                0 <CSN> simulate the given CSN");
-               PrintAndLog("                1       simulate default CSN");
-               PrintAndLog("                2       iterate CSNs, gather MACs");
-               PrintAndLog("        sample: hf iclass sim 0 031FEC8AF7FF12E0");
-               PrintAndLog("        sample: hf iclass sim 2");
-               return 0;
+               usage_hf_iclass_sim();
        }
 
        simType = param_get8(Cmd, 0);
@@ -76,34 +84,23 @@ int CmdHFiClassSim(const char *Cmd)
        {
                if (param_gethex(Cmd, 1, CSN, 16)) {
                        PrintAndLog("A CSN should consist of 16 HEX symbols");
-                       return 1;
+                       return usage_hf_iclass_sim();
                }
-               PrintAndLog("--simtype:%02x csn:%s", simType, sprint_hex(CSN, 8));
 
+               PrintAndLog("--simtype:%02x csn:%s", simType, sprint_hex(CSN, 8));
        }
-       if(simType > 2)
+       if(simType > 3)
        {
                PrintAndLog("Undefined simptype %d", simType);
-               return 1;
+               return usage_hf_iclass_sim();
        }
-       uint8_t numberOfCSNs=0;
 
+       uint8_t numberOfCSNs=0;
        if(simType == 2)
        {
                UsbCommand c = {CMD_SIMULATE_TAG_ICLASS, {simType,NUM_CSNS}};
                UsbCommand resp = {0};
 
-               /*uint8_t csns[8 * NUM_CSNS] = {
-                        0x00,0x0B,0x0F,0xFF,0xF7,0xFF,0x12,0xE0 ,
-                        0x00,0x13,0x94,0x7e,0x76,0xff,0x12,0xe0 ,
-                        0x2a,0x99,0xac,0x79,0xec,0xff,0x12,0xe0 ,
-                        0x17,0x12,0x01,0xfd,0xf7,0xff,0x12,0xe0 ,
-                        0xcd,0x56,0x01,0x7c,0x6f,0xff,0x12,0xe0 ,
-                        0x4b,0x5e,0x0b,0x72,0xef,0xff,0x12,0xe0 ,
-                        0x00,0x73,0xd8,0x75,0x58,0xff,0x12,0xe0 ,
-                        0x0c,0x90,0x32,0xf3,0x5d,0xff,0x12,0xe0 };
-*/
-
                uint8_t csns[8*NUM_CSNS] = {
                        0x00, 0x0B, 0x0F, 0xFF, 0xF7, 0xFF, 0x12, 0xE0,
                        0x00, 0x04, 0x0E, 0x08, 0xF7, 0xFF, 0x12, 0xE0,
@@ -450,6 +447,102 @@ int CmdHFiClassELoad(const char *Cmd)
        return 0;
 }
 
+int usage_hf_iclass_decrypt()
+{
+       PrintAndLog("Usage: hf iclass decrypt f <tagdump> o ");
+       PrintAndLog("");
+       PrintAndLog("In order to use this function, the file 'iclass_decryptionkey.bin must reside");
+       PrintAndLog("in the working directory. The file should be 16 bytes binary data");
+       PrintAndLog("example: hf iclass decrypt tagdump_12312342343.bin");
+       PrintAndLog("");
+       PrintAndLog("OBS! This is pretty stupid implementation, it tries to decrypt every block after block 5. ");
+       PrintAndLog("Correct behaviour would be to decrypt only the application areas where the key is valid,");
+       PrintAndLog("which is defined by the configuration block.");
+       return 1;
+}
+
+int readKeyfile(const char *filename, size_t len, uint8_t* buffer)
+{
+       FILE *f = fopen(filename, "rb");
+       if(!f) {
+               PrintAndLog("Failed to read from file '%s'", filename);
+               return 1;
+       }
+       fseek(f, 0, SEEK_END);
+       long fsize = ftell(f);
+       fseek(f, 0, SEEK_SET);
+       size_t bytes_read = fread(buffer, 1, len, f);
+       fclose(f);
+       if(fsize != len)
+       {
+               PrintAndLog("Warning, file size is %d, expected %d", fsize, len);
+               return 1;
+       }
+       if(bytes_read != len)
+       {
+               PrintAndLog("Warning, could only read %d bytes, expected %d" ,bytes_read, len);
+               return 1;
+       }
+       return 0;
+}
+
+int CmdHFiClassDecrypt(const char *Cmd)
+{
+       uint8_t key[16] = { 0 };
+       if(readKeyfile("iclass_decryptionkey.bin", 16, key))
+       {
+               usage_hf_iclass_decrypt();
+               return 1;
+       }
+       PrintAndLog("Decryption file found... ");
+       char opt = param_getchar(Cmd, 0);
+       if (strlen(Cmd)<1 || opt == 'h')
+               return usage_hf_iclass_decrypt();
+
+       //Open the tagdump-file
+       FILE *f;
+       char filename[FILE_PATH_SIZE];
+       if(opt == 'f' && param_getstr(Cmd, 1, filename) > 0)
+       {
+               f = fopen(filename, "rb");
+       }else{
+               return usage_hf_iclass_decrypt();
+       }
+
+       fseek(f, 0, SEEK_END);
+       long fsize = ftell(f);
+       fseek(f, 0, SEEK_SET);
+       uint8_t enc_dump[8] = {0};
+       uint8_t *decrypted = malloc(fsize);
+       des3_context ctx = { DES_DECRYPT ,{ 0 } };
+       des3_set2key_dec( &ctx, key);
+       size_t bytes_read = fread(enc_dump, 1, 8, f);
+
+       //Use the first block (CSN) for filename
+       char outfilename[FILE_PATH_SIZE] = { 0 };
+       snprintf(outfilename,FILE_PATH_SIZE,"iclass_tagdump-%02x%02x%02x%02x%02x%02x%02x%02x-decrypted",
+                        enc_dump[0],enc_dump[1],enc_dump[2],enc_dump[3],
+                        enc_dump[4],enc_dump[5],enc_dump[6],enc_dump[7]);
+
+       size_t blocknum =0;
+       while(bytes_read == 8)
+       {
+               if(blocknum < 6)
+               {
+                       memcpy(decrypted+(blocknum*8), enc_dump, 8);
+               }else{
+                       des3_crypt_ecb(&ctx, enc_dump,decrypted +(blocknum*8) );
+               }
+               printvar("decrypted block", decrypted +(blocknum*8), 8);
+               bytes_read = fread(enc_dump, 1, 8, f);
+               blocknum++;
+       }
+       fclose(f);
+
+       saveFile(outfilename,"bin", decrypted, blocknum*8);
+
+       return 0;
+}
 
 int CmdHFiClass_iso14443A_write(const char *Cmd)
 {
@@ -586,6 +679,7 @@ static command_t CommandTable[] =
 //     {"write",       CmdHFiClass_iso14443A_write,    0,      "Authenticate and Write iClass block"},
        {"loclass",     CmdHFiClass_loclass,    1,      "Use loclass to perform bruteforce of reader attack dump"},
        {"eload",   CmdHFiClassELoad,    0,     "[experimental] Load data into iclass emulator memory"},
+       {"decrypt", CmdHFiClassDecrypt,  1,     "Decrypt tagdump" },
        {NULL, NULL, 0, NULL}
 };
 

diff --git a/client/loclass/cipher.c b/client/loclass/cipher.c
index d3b1e7997beb0971319e3a17d3b3d9db1e5102e6..1a77456854f1ca9f4dbe44c87159925ddbc658c6 100644 (file)
--- a/client/loclass/cipher.c
+++ b/client/loclass/cipher.c
@@ -45,7 +45,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <time.h>
-#include "fileutils.h"
+//#include "fileutils.h"
 uint8_t keytable[] = { 0,0,0,0,0,0,0,0};
 
 /**

diff --git a/client/loclass/des.h b/client/loclass/des.h
index 8b8e6a35374936dead9ec38d2a1a25e66fa36421..460beaf0ecd68ddc70369730ea20c70176ed50c1 100644 (file)
--- a/client/loclass/des.h
+++ b/client/loclass/des.h
@@ -78,6 +78,25 @@ typedef struct
        uint32_t sk[96];            /*!<  3DES subkeys      */
 }
 des3_context;
+/*
+ * Triple-DES key schedule (112-bit, encryption)
+ */
+int des3_set2key_enc( des3_context *ctx, const unsigned char key[DES_KEY_SIZE * 2] );
+
+/*
+ * Triple-DES key schedule (112-bit, decryption)
+ */
+int des3_set2key_dec( des3_context *ctx, const unsigned char key[DES_KEY_SIZE * 2] );
+
+/*
+ * Triple-DES key schedule (168-bit, encryption)
+ */
+int des3_set3key_enc( des3_context *ctx, const unsigned char key[DES_KEY_SIZE * 3] );
+
+/*
+ * Triple-DES key schedule (168-bit, decryption)
+ */
+int des3_set3key_dec( des3_context *ctx, const unsigned char key[DES_KEY_SIZE * 3] );
 
 /**
  * \brief          Set key parity on the given key to odd.