mirror of
https://github.com/Laupetin/OpenAssetTools.git
synced 2025-04-21 16:45:44 +00:00
85 lines
2.1 KiB
C
85 lines
2.1 KiB
C
/* 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 omac_done.c
|
|
OMAC1 support, terminate a stream, Tom St Denis
|
|
*/
|
|
|
|
#ifdef LTC_OMAC
|
|
|
|
/**
|
|
Terminate an OMAC stream
|
|
@param omac The OMAC state
|
|
@param out [out] Destination for the authentication tag
|
|
@param outlen [in/out] The max size and resulting size of the authentication tag
|
|
@return CRYPT_OK if successful
|
|
*/
|
|
int omac_done(omac_state *omac, unsigned char *out, unsigned long *outlen)
|
|
{
|
|
int err, mode;
|
|
unsigned x;
|
|
|
|
LTC_ARGCHK(omac != NULL);
|
|
LTC_ARGCHK(out != NULL);
|
|
LTC_ARGCHK(outlen != NULL);
|
|
if ((err = cipher_is_valid(omac->cipher_idx)) != CRYPT_OK) {
|
|
return err;
|
|
}
|
|
|
|
if ((omac->buflen > (int)sizeof(omac->block)) || (omac->buflen < 0) ||
|
|
(omac->blklen > (int)sizeof(omac->block)) || (omac->buflen > omac->blklen)) {
|
|
return CRYPT_INVALID_ARG;
|
|
}
|
|
|
|
/* figure out mode */
|
|
if (omac->buflen != omac->blklen) {
|
|
/* add the 0x80 byte */
|
|
omac->block[omac->buflen++] = 0x80;
|
|
|
|
/* pad with 0x00 */
|
|
while (omac->buflen < omac->blklen) {
|
|
omac->block[omac->buflen++] = 0x00;
|
|
}
|
|
mode = 1;
|
|
} else {
|
|
mode = 0;
|
|
}
|
|
|
|
/* now xor prev + Lu[mode] */
|
|
for (x = 0; x < (unsigned)omac->blklen; x++) {
|
|
omac->block[x] ^= omac->prev[x] ^ omac->Lu[mode][x];
|
|
}
|
|
|
|
/* encrypt it */
|
|
if ((err = cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->block, omac->block, &omac->key)) != CRYPT_OK) {
|
|
return err;
|
|
}
|
|
cipher_descriptor[omac->cipher_idx].done(&omac->key);
|
|
|
|
/* output it */
|
|
for (x = 0; x < (unsigned)omac->blklen && x < *outlen; x++) {
|
|
out[x] = omac->block[x];
|
|
}
|
|
*outlen = x;
|
|
|
|
#ifdef LTC_CLEAN_STACK
|
|
zeromem(omac, sizeof(*omac));
|
|
#endif
|
|
return CRYPT_OK;
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
/* ref: HEAD -> master, tag: v1.18.2 */
|
|
/* git commit: 7e7eb695d581782f04b24dc444cbfde86af59853 */
|
|
/* commit time: 2018-07-01 22:49:01 +0200 */
|