63 lines
1.3 KiB
C
63 lines
1.3 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_done_decrypt(ocb_state *ocb,
|
|
const unsigned char *ct, unsigned long ctlen,
|
|
unsigned char *pt,
|
|
const unsigned char *tag, unsigned long taglen, int *res)
|
|
{
|
|
int err;
|
|
unsigned char *tagbuf;
|
|
unsigned long tagbuflen;
|
|
|
|
_ARGCHK(ocb != NULL);
|
|
_ARGCHK(pt != NULL);
|
|
_ARGCHK(ct != NULL);
|
|
_ARGCHK(tag != NULL);
|
|
_ARGCHK(res != NULL);
|
|
|
|
/* default to failed */
|
|
*res = 0;
|
|
|
|
/* allocate memory */
|
|
tagbuf = XMALLOC(MAXBLOCKSIZE);
|
|
if (tagbuf == NULL) {
|
|
return CRYPT_MEM;
|
|
}
|
|
|
|
tagbuflen = MAXBLOCKSIZE;
|
|
if ((err = __ocb_done(ocb, ct, ctlen, pt, tagbuf, &tagbuflen, 1)) != CRYPT_OK) {
|
|
goto __ERR;
|
|
}
|
|
|
|
if (taglen <= tagbuflen && memcmp(tagbuf, tag, taglen) == 0) {
|
|
*res = 1;
|
|
}
|
|
|
|
err = CRYPT_OK;
|
|
__ERR:
|
|
#ifdef CLEAN_STACK
|
|
zeromem(tagbuf, MAXBLOCKSIZE);
|
|
#endif
|
|
|
|
XFREE(tagbuf);
|
|
|
|
return err;
|
|
}
|
|
|
|
#endif
|
|
|