From 799ac5f14ad8975ead235dc6e46fda6cb71da3ed Mon Sep 17 00:00:00 2001 From: Iceman Date: Mon, 26 Jun 2017 21:51:26 +0200 Subject: [PATCH] Update mifarehost.c Add detection of prng --- client/mifarehost.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/client/mifarehost.c b/client/mifarehost.c index 6b5e3ba2..51dd7374 100644 --- a/client/mifarehost.c +++ b/client/mifarehost.c @@ -820,3 +820,33 @@ int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, crypto1_destroy(traceCrypto1); return 0; } +/* 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 Darkside attack possible) +* FALSE is tag uses HARDEND prng (ie hardnested attack possible, with known key) +*/ +bool detect_classic_prng(){ + + UsbCommand resp, respA; + uint8_t cmd[] = {MIFARE_AUTH_KEYA, 0x00}; + uint32_t flags = ISO14A_CONNECT | ISO14A_RAW | ISO14A_APPEND_CRC; + + UsbCommand cAuth = {CMD_READER_ISO_14443a, {flags, sizeof(cmd), 0}}; + memcpy(cAuth.d.asBytes, cmd, sizeof(cmd)); + + clearCommandBuffer(); + SendCommand(&cAuth); + WaitForResponse(CMD_ACK, &resp); + WaitForResponse(CMD_ACK, &respA); + + // if select tag failed. + if ( resp.arg[0] == 0 ) { + printf("Error: selecting tag failed, can't detect prng\n"); + return false; + } + + uint32_t nonce = bytes_to_num(respA.d.asBytes, respA.arg[0]); + return validate_prng_nonce(nonce); +} -- 2.39.5