added some info from @peterfillmore fork

[proxmark3-svn] / client / mifarehost.c

diff --git a/client/mifarehost.c b/client/mifarehost.c
index ca5d97e13ac1419cbfcac1598ab35d643a9166c7..67277b5904aa3c0f58cf1974808944a869d9cf79 100644 (file)
--- a/client/mifarehost.c
+++ b/client/mifarehost.c
@@ -540,35 +540,10 @@ int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID) {
        return 0;\r
 }\r
 \r
-int mfCIdentify()\r
-{\r
-  UsbCommand c;\r
-//     UsbCommand c = {CMD_READER_ISO_14443a, {ISO14A_CONNECT | ISO14A_NO_DISCONNECT, 0, 0}};\r
-//     SendCommand(&c);\r
-\r
-  UsbCommand resp;\r
-//     WaitForResponse(CMD_ACK,&resp);\r
-\r
-       // iso14a_card_select_t card;\r
-       // memcpy(&card, (iso14a_card_select_t *)resp.d.asBytes, sizeof(iso14a_card_select_t));\r
-\r
-       // uint64_t select_status = resp.arg[0];                // 0: couldn't read, 1: OK, with ATS, 2: OK, no ATS, 3: proprietary Anticollision\r
-\r
-       // if(select_status != 0) {\r
-               // uint8_t rats[] = { 0xE0, 0x80 }; // FSDI=8 (FSD=256), CID=0\r
-               // c.arg[0] = ISO14A_RAW | ISO14A_APPEND_CRC | ISO14A_NO_DISCONNECT;\r
-               // c.arg[1] = 2;\r
-               // c.arg[2] = 0;\r
-               // memcpy(c.d.asBytes, rats, 2);\r
-               // SendCommand(&c);\r
-               // WaitForResponse(CMD_ACK,&resp);\r
-       // }\r
-\r
-       c.cmd = CMD_MIFARE_CIDENT;\r
-       c.arg[0] = 0;\r
-       c.arg[1] = 0;\r
-       c.arg[2] = 0;\r
+int mfCIdentify() {\r
+       UsbCommand c = {CMD_MIFARE_CIDENT, {0, 0, 0}};\r
        SendCommand(&c);\r
+       UsbCommand resp;\r
        WaitForResponse(CMD_ACK,&resp);\r
 \r
        uint8_t isGeneration = resp.arg[0] & 0xff;\r
@@ -578,13 +553,6 @@ int mfCIdentify()
                default: PrintAndLog("No chinese magic backdoor command detected"); break;\r
        }\r
 \r
-       // disconnect\r
-//     c.cmd = CMD_READER_ISO_14443a;\r
-//     c.arg[0] = 0;\r
-//     c.arg[1] = 0;\r
-//     c.arg[2] = 0;\r
-//     SendCommand(&c);\r
-\r
        return (int) isGeneration;\r
 }\r
 \r
@@ -935,3 +903,72 @@ int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data,
        return 0;\r
 }\r
 \r
+/** validate_prng_nonce\r
+ * Determine if nonce is deterministic. ie: Suspectable to Darkside attack.\r
+ * returns\r
+ *   true = weak prng\r
+ *   false = hardend prng\r
+ */\r
+bool validate_prng_nonce(uint32_t nonce) {\r
+       uint16_t *dist = 0;\r
+       uint16_t x, i;\r
+\r
+       dist = malloc(2 << 16);\r
+       if(!dist)\r
+               return -1;\r
+\r
+       // init prng table:\r
+       for (x = i = 1; i; ++i) {\r
+               dist[(x & 0xff) << 8 | x >> 8] = i;\r
+               x = x >> 1 | (x ^ x >> 2 ^ x >> 3 ^ x >> 5) << 15;\r
+       }\r
+       \r
+       uint32_t res = (65535 - dist[nonce >> 16] + dist[nonce & 0xffff]) % 65535;\r
+       \r
+       free(dist);     \r
+       return (res == 16);\r
+}\r
+\r
+/* Detect Tag Prng, \r
+* function performs a partial AUTH,  where it tries to authenticate against block0, key A, but only collects tag nonce.\r
+* the tag nonce is check to see if it has a predictable PRNG.\r
+* @returns \r
+*      TRUE if tag uses WEAK prng (ie Now the NACK bug also needs to be present for Darkside attack)\r
+*   FALSE is tag uses HARDEND prng (ie hardnested attack possible, with known key)\r
+*/\r
+int DetectClassicPrng(void){\r
+\r
+       UsbCommand resp, respA; \r
+       uint8_t cmd[] = {0x60, 0x00}; // MIFARE_AUTH_KEYA\r
+       uint32_t flags = ISO14A_CONNECT | ISO14A_RAW | ISO14A_APPEND_CRC | ISO14A_NO_RATS;\r
+       \r
+       UsbCommand c = {CMD_READER_ISO_14443a, {flags, sizeof(cmd), 0}};\r
+       memcpy(c.d.asBytes, cmd, sizeof(cmd));\r
+\r
+       clearCommandBuffer();\r
+       SendCommand(&c);\r
+       if (!WaitForResponseTimeout(CMD_ACK, &resp, 2000)) {\r
+        PrintAndLog("PRNG UID: Reply timeout.");\r
+               return -1;\r
+       }\r
+       \r
+       // if select tag failed.\r
+       if (resp.arg[0] == 0) {\r
+               PrintAndLog("PRNG error: selecting tag failed, can't detect prng.");\r
+               return -1;\r
+       }\r
+       \r
+       if (!WaitForResponseTimeout(CMD_ACK, &respA, 5000)) {\r
+        PrintAndLog("PRNG data: Reply timeout.");\r
+               return -1;\r
+       }\r
+\r
+       // check respA\r
+       if (respA.arg[0] != 4) {\r
+               PrintAndLog("PRNG data error: Wrong length: %d", respA.arg[0]);\r
+               return -1;\r
+       }\r
+\r
+       uint32_t nonce = bytes_to_num(respA.d.asBytes, respA.arg[0]);\r
+       return validate_prng_nonce(nonce);\r
+}\r