git.zerfleddert.de Git - proxmark3-svn/blob - common/polarssl/libpcrypto.c

   1 //-----------------------------------------------------------------------------
   2 // Copyright (C) 2018 Merlok
   3 //
   4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   5 // at your option, any later version. See the LICENSE.txt file for the text of
   6 // the license.
   7 //-----------------------------------------------------------------------------
   8 // crypto commands
   9 //-----------------------------------------------------------------------------
  10
  11 #include "polarssl/libpcrypto.h"
  12 #include <polarssl/aes.h>
  13 #include <polarssl/aes_cmac128.h>
  14
  15 // NIST Special Publication 800-38A \97 Recommendation for block cipher modes of operation: methods and techniques, 2001.
  16 int aes_encode(uint8_t *iv, uint8_t *key, uint8_t *input, uint8_t *output, int length){
  17         uint8_t iiv[16] = {0};
  18         if (iv)
  19                 memcpy(iiv, iv, 16);
  20
  21         aes_context aes;
  22         aes_init(&aes);
  23         if (aes_setkey_enc(&aes, key, 128))
  24                 return 1;
  25         if (aes_crypt_cbc(&aes, AES_ENCRYPT, length, iiv, input, output))
  26                 return 2;
  27         aes_free(&aes);
  28
  29         return 0;
  30 }
  31
  32 int aes_decode(uint8_t *iv, uint8_t *key, uint8_t *input, uint8_t *output, int length){
  33         uint8_t iiv[16] = {0};
  34         if (iv)
  35                 memcpy(iiv, iv, 16);
  36
  37         aes_context aes;
  38         aes_init(&aes);
  39         if (aes_setkey_dec(&aes, key, 128))
  40                 return 1;
  41         if (aes_crypt_cbc(&aes, AES_DECRYPT, length, iiv, input, output))
  42                 return 2;
  43         aes_free(&aes);
  44
  45         return 0;
  46 }
  47
  48 //  NIST Special Publication 800-38B \97 Recommendation for block cipher modes of operation: The CMAC mode for authentication.
  49 // https://csrc.nist.gov/CSRC/media/Projects/Cryptographic-Standards-and-Guidelines/documents/examples/AES_CMAC.pdf
  50 int aes_cmac(uint8_t *iv, uint8_t *key, uint8_t *input, uint8_t *mac, int length) {
  51         memset(mac, 0x00, 16);
  52         uint8_t iiv[16] = {0};
  53         if (iv)
  54                 memcpy(iiv, iv, 16);
  55
  56         // padding:  ISO/IEC 9797-1 Message Authentication Codes (MACs) - Part 1: Mechanisms using a block cipher
  57         uint8_t data[2049] = {0}; // length + 16
  58         memcpy(data, input, length);
  59         data[length] = 0x80;
  60         int datalen = (length & 0xfffffff0) + 0x10;
  61
  62         //  NIST 800-38B
  63         aes_cmac128_context ctx;
  64         aes_cmac128_starts(&ctx, key);
  65         aes_cmac128_update(&ctx, data, datalen);
  66         aes_cmac128_final(&ctx, mac);
  67
  68         return 0;
  69 }
  70
  71 int aes_cmac8(uint8_t *iv, uint8_t *key, uint8_t *input, uint8_t *mac, int length) {
  72         uint8_t cmac[16] = {0};
  73         memset(mac, 0x00, 8);
  74
  75         int res = aes_cmac(iv, key, input, cmac, length);
  76         if (res)
  77                 return res;
  78
  79         for(int i = 0; i < 8; i++)
  80                 mac[i] = cmac[i * 2 + 1];
  81
  82         return 0;
  83 }