66 lines
1.5 KiB
C
66 lines
1.5 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.
|
|
*
|
|
* Tom St Denis, tomstdenis@iahu.ca, http://libtomcrypt.org
|
|
*/
|
|
|
|
/* OCB Implementation by Tom St Denis */
|
|
#include "mycrypt.h"
|
|
|
|
#ifdef OCB_MODE
|
|
|
|
int ocb_decrypt_verify_memory(int cipher,
|
|
const unsigned char *key, unsigned long keylen,
|
|
const unsigned char *nonce,
|
|
const unsigned char *ct, unsigned long ctlen,
|
|
unsigned char *pt,
|
|
const unsigned char *tag, unsigned long taglen,
|
|
int *res)
|
|
{
|
|
int err;
|
|
ocb_state *ocb;
|
|
|
|
_ARGCHK(key != NULL);
|
|
_ARGCHK(nonce != NULL);
|
|
_ARGCHK(pt != NULL);
|
|
_ARGCHK(ct != NULL);
|
|
_ARGCHK(tag != NULL);
|
|
_ARGCHK(res != NULL);
|
|
|
|
/* allocate memory */
|
|
ocb = XMALLOC(sizeof(ocb_state));
|
|
if (ocb == NULL) {
|
|
return CRYPT_MEM;
|
|
}
|
|
|
|
if ((err = ocb_init(ocb, cipher, key, keylen, nonce)) != CRYPT_OK) {
|
|
goto __ERR;
|
|
}
|
|
|
|
while (ctlen > (unsigned long)ocb->block_len) {
|
|
if ((err = ocb_decrypt(ocb, ct, pt)) != CRYPT_OK) {
|
|
goto __ERR;
|
|
}
|
|
ctlen -= ocb->block_len;
|
|
pt += ocb->block_len;
|
|
ct += ocb->block_len;
|
|
}
|
|
|
|
err = ocb_done_decrypt(ocb, ct, ctlen, pt, tag, taglen, res);
|
|
__ERR:
|
|
#ifdef CLEAN_STACK
|
|
zeromem(ocb, sizeof(ocb_state));
|
|
#endif
|
|
|
|
XFREE(ocb);
|
|
|
|
return err;
|
|
}
|
|
|
|
#endif
|