+
−/* 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.
+
− */
+
−#include "tomcrypt.h"
+
−
+
−/**
+
−  @file hmac_done.c
+
−  HMAC support, terminate stream, Tom St Denis/Dobes Vandermeer
+
−*/
+
−
+
−#ifdef LTC_HMAC
+
−
+
−#define LTC_HMAC_BLOCKSIZE hash_descriptor[hash].blocksize
+
−
+
−/**
+
−   Terminate an HMAC session
+
−   @param hmac    The HMAC state
+
−   @param out     [out] The destination of the HMAC authentication tag
+
−   @param outlen  [in/out]  The max size and resulting size of the HMAC authentication tag
+
−   @return CRYPT_OK if successful
+
−*/
+
−int hmac_done(hmac_state *hmac, unsigned char *out, unsigned long *outlen)
+
−{
+
−    unsigned char buf[MAXBLOCKSIZE], isha[MAXBLOCKSIZE];
+
−    unsigned long hashsize, i;
+
−    int hash, err;
+
−
+
−    LTC_ARGCHK(hmac  != NULL);
+
−    LTC_ARGCHK(out   != NULL);
+
−
+
−    /* test hash */
+
−    hash = hmac->hash;
+
−    if((err = hash_is_valid(hash)) != CRYPT_OK) {
+
−        return err;
+
−    }
+
−
+
−    /* get the hash message digest size */
+
−    hashsize = hash_descriptor[hash].hashsize;
+
−
+
−    if ((err = hash_descriptor[hash].done(&hmac->md, isha)) != CRYPT_OK) {
+
−       goto LBL_ERR;
+
−    }
+
−
+
−    /* Create the second HMAC vector vector for step (3) */
+
−    for(i=0; i < LTC_HMAC_BLOCKSIZE; i++) {
+
−        buf[i] = hmac->key[i] ^ 0x5C;
+
−    }
+
−
+
−    /* Now calculate the "outer" hash for step (5), (6), and (7) */
+
−    if ((err = hash_descriptor[hash].init(&hmac->md)) != CRYPT_OK) {
+
−       goto LBL_ERR;
+
−    }
+
−    if ((err = hash_descriptor[hash].process(&hmac->md, buf, LTC_HMAC_BLOCKSIZE)) != CRYPT_OK) {
+
−       goto LBL_ERR;
+
−    }
+
−    if ((err = hash_descriptor[hash].process(&hmac->md, isha, hashsize)) != CRYPT_OK) {
+
−       goto LBL_ERR;
+
−    }
+
−    if ((err = hash_descriptor[hash].done(&hmac->md, buf)) != CRYPT_OK) {
+
−       goto LBL_ERR;
+
−    }
+
−
+
−    /* copy to output  */
+
−    for (i = 0; i < hashsize && i < *outlen; i++) {
+
−        out[i] = buf[i];
+
−    }
+
−    *outlen = i;
+
−
+
−    err = CRYPT_OK;
+
−LBL_ERR:
+
−    XFREE(hmac->key);
+
−#ifdef LTC_CLEAN_STACK
+
−    zeromem(isha, hashsize);
+
−    zeromem(buf,  hashsize);
+
−    zeromem(hmac, sizeof(*hmac));
+
−#endif
+
−
+
−    return err;
+
−}
+
−
+
−#endif
+
−
+
−/* ref:         $Format:%D$ */
+
−/* git commit:  $Format:%H$ */
+
−/* commit time: $Format:%ai$ */