src/crypto/hmac_sha256.cpp

   1 // Copyright (c) 2014 The Bitcoin Core developers
   2 // Distributed under the MIT software license, see the accompanying
   3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4
   5 #include "crypto/hmac_sha256.h"
   6
   7 #include <string.h>
   8
   9 CHMAC_SHA256::CHMAC_SHA256(const unsigned char* key, size_t keylen)
  10 {
  11     unsigned char rkey[64];
  12     if (keylen <= 64) {
  13         memcpy(rkey, key, keylen);
  14         memset(rkey + keylen, 0, 64 - keylen);
  15     } else {
  16         CSHA256().Write(key, keylen).Finalize(rkey);
  17         memset(rkey + 32, 0, 32);
  18     }
  19
  20     for (int n = 0; n < 64; n++)
  21         rkey[n] ^= 0x5c;
  22     outer.Write(rkey, 64);
  23
  24     for (int n = 0; n < 64; n++)
  25         rkey[n] ^= 0x5c ^ 0x36;
  26     inner.Write(rkey, 64);
  27 }
  28
  29 void CHMAC_SHA256::Finalize(unsigned char hash[OUTPUT_SIZE])
  30 {
  31     unsigned char temp[32];
  32     inner.Finalize(temp);
  33     outer.Write(temp, 32).Finalize(hash);
  34 }