go-sqlcipher/hmac_memory.c

77 lines
2.0 KiB
C

/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
#include "tomcrypt_private.h"
/**
@file hmac_memory.c
HMAC support, process a block of memory, Tom St Denis/Dobes Vandermeer
*/
#ifdef LTC_HMAC
/**
HMAC a block of memory to produce the authentication tag
@param hash The index of the hash to use
@param key The secret key
@param keylen The length of the secret key (octets)
@param in The data to HMAC
@param inlen The length of the data to HMAC (octets)
@param out [out] Destination of the authentication tag
@param outlen [in/out] Max size and resulting size of authentication tag
@return CRYPT_OK if successful
*/
int hmac_memory(int hash,
const unsigned char *key, unsigned long keylen,
const unsigned char *in, unsigned long inlen,
unsigned char *out, unsigned long *outlen)
{
hmac_state *hmac;
int err;
LTC_ARGCHK(key != NULL);
LTC_ARGCHK(in != NULL);
LTC_ARGCHK(out != NULL);
LTC_ARGCHK(outlen != NULL);
/* make sure hash descriptor is valid */
if ((err = hash_is_valid(hash)) != CRYPT_OK) {
return err;
}
/* is there a descriptor? */
if (hash_descriptor[hash].hmac_block != NULL) {
return hash_descriptor[hash].hmac_block(key, keylen, in, inlen, out, outlen);
}
/* nope, so call the hmac functions */
/* allocate ram for hmac state */
hmac = XMALLOC(sizeof(hmac_state));
if (hmac == NULL) {
return CRYPT_MEM;
}
if ((err = hmac_init(hmac, hash, key, keylen)) != CRYPT_OK) {
goto LBL_ERR;
}
if ((err = hmac_process(hmac, in, inlen)) != CRYPT_OK) {
goto LBL_ERR;
}
if ((err = hmac_done(hmac, out, outlen)) != CRYPT_OK) {
goto LBL_ERR;
}
err = CRYPT_OK;
LBL_ERR:
#ifdef LTC_CLEAN_STACK
zeromem(hmac, sizeof(hmac_state));
#endif
XFREE(hmac);
return err;
}
#endif