blob: 7117ae34cc65d5bde484a195ebe9890bbad50280 [file] [log] [blame]
/* 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@gmail.com, http://libtomcrypt.com
*/
#include "tomcrypt.h"
/**
@file omac_file.c
OMAC1 support, process a file, Tom St Denis
*/
#ifdef LTC_OMAC
/**
OMAC a file
@param cipher The index of the cipher desired
@param key The secret key
@param keylen The length of the secret key (octets)
@param filename The name of the file you wish to OMAC
@param out [out] Where the authentication tag is to be stored
@param outlen [in/out] The max size and resulting size of the authentication tag
@return CRYPT_OK if successful, CRYPT_NOP if file support has been disabled
*/
int omac_file(int cipher,
const unsigned char *key, unsigned long keylen,
const char *filename,
unsigned char *out, unsigned long *outlen)
{
#ifdef LTC_NO_FILE
return CRYPT_NOP;
#else
int err, x;
omac_state omac;
FILE *in;
unsigned char buf[512];
LTC_ARGCHK(key != NULL);
LTC_ARGCHK(filename != NULL);
LTC_ARGCHK(out != NULL);
LTC_ARGCHK(outlen != NULL);
in = fopen(filename, "rb");
if (in == NULL) {
return CRYPT_FILE_NOTFOUND;
}
if ((err = omac_init(&omac, cipher, key, keylen)) != CRYPT_OK) {
fclose(in);
return err;
}
do {
x = fread(buf, 1, sizeof(buf), in);
if ((err = omac_process(&omac, buf, x)) != CRYPT_OK) {
fclose(in);
return err;
}
} while (x == sizeof(buf));
fclose(in);
if ((err = omac_done(&omac, out, outlen)) != CRYPT_OK) {
return err;
}
#ifdef LTC_CLEAN_STACK
zeromem(buf, sizeof(buf));
#endif
return CRYPT_OK;
#endif
}
#endif
/* $Source: /cvs/libtom/libtomcrypt/src/mac/omac/omac_file.c,v $ */
/* $Revision: 1.5 $ */
/* $Date: 2006/11/03 00:39:49 $ */