/* LibTomCrypt, modular cryptographic library -- Tom St Denis * * LibTomCrypt is a library that provides various cryptographic * algorithms in a highly modular and flexible manner. * * The library is free for all purposes without any express * guarantee it works. * * Tom St Denis, tomstdenis@iahu.ca, http://libtomcrypt.org *//* Submited by Dobes Vandermeer  (dobes@smartt.com) */#include "mycrypt.h"/*    (1) append zeros to the end of K to create a B byte string        (e.g., if K is of length 20 bytes and B=64, then K will be         appended with 44 zero bytes 0x00)    (2) XOR (bitwise exclusive-OR) the B byte string computed in step        (1) with ipad (ipad = the byte 0x36 repeated B times)    (3) append the stream of data 'text' to the B byte string resulting        from step (2)    (4) apply H to the stream generated in step (3)    (5) XOR (bitwise exclusive-OR) the B byte string computed in        step (1) with opad (opad = the byte 0x5C repeated B times.)    (6) append the H result from step (4) to the B byte string        resulting from step (5)    (7) apply H to the stream generated in step (6) and output        the result*/#ifdef HMAC#define HMAC_BLOCKSIZE hash_descriptor[hash].blocksizeint hmac_done(hmac_state *hmac, unsigned char *hashOut, unsigned long *outlen){    unsigned char buf[MAXBLOCKSIZE];    unsigned char isha[MAXBLOCKSIZE];    unsigned long hashsize, i;    int hash, err;    _ARGCHK(hmac != NULL);    _ARGCHK(hashOut != NULL);    hash = hmac->hash;    if((err = hash_is_valid(hash)) != CRYPT_OK) {        return err;    }    /* get the hash message digest size */    hashsize = hash_descriptor[hash].hashsize;    // Get the hash of the first HMAC vector plus the data    if ((err = hash_descriptor[hash].done(&hmac->md, isha)) != CRYPT_OK) {       return err;    }    // Create the second HMAC vector vector for step (3)    for(i=0; i < HMAC_BLOCKSIZE; i++) {        buf[i] = hmac->key[i] ^ 0x5C;    }    // Now calculate the "outer" hash for step (5), (6), and (7)    hash_descriptor[hash].init(&hmac->md);    hash_descriptor[hash].process(&hmac->md, buf, HMAC_BLOCKSIZE);    hash_descriptor[hash].process(&hmac->md, isha, hashsize);    hash_descriptor[hash].done(&hmac->md, buf);    // copy to output     for (i = 0; i < hashsize && i < *outlen; i++) {        hashOut[i] = buf[i];    }    *outlen = i;#ifdef CLEAN_STACK    zeromem(isha, sizeof(buf));    zeromem(buf,  sizeof(isha));    zeromem(hmac, sizeof(*hmac));#endif    return CRYPT_OK;}#endif