HMAC.cpp

00001 #include "HMAC.h"
00002 #include <string.h>
00003 
00004 HMAC::HMAC(HashAlgorithm *hashAlgo, uint8_t *k, uint32_t kl):
00005 algo(hashAlgo),
00006 keyLength(kl)
00007 {
00008     memcpy(key, k, keyLength);
00009     uint8_t buffer[64];
00010     memcpy(buffer, key, keyLength);
00011     memset(&buffer[keyLength], 0, 64-keyLength);  
00012     
00013     for(int i = 0; i < 64; ++i)
00014         buffer[i] ^= 0x36;
00015         
00016     algo->update(buffer, 64);
00017 }
00018 
00019 HMAC::~HMAC()
00020 {
00021     delete algo;
00022 }
00023 
00024 void HMAC::update(uint8_t *data, uint32_t length)
00025 {
00026     algo->update(data, length);
00027 }
00028 
00029 void HMAC::finalize(uint8_t *hash)
00030 {
00031     uint8_t buffer[64], buffer2[64];
00032     algo->finalize(buffer);
00033     
00034     memcpy(buffer2, key, keyLength);
00035     memset(&buffer2[keyLength], 0, 64-keyLength);
00036     for(int i = 0; i < 64; ++i)
00037         buffer2[i] ^= 0x5C;
00038         
00039     algo->update(buffer2, 64);
00040     algo->update(buffer, algo->outputSize());
00041     algo->finalize(hash);
00042 }
00043