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/* 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.org
*/
/**
@file ocb_encrypt_authenticate_memory.c
OCB implementation, encrypt block of memory, by Tom St Denis
*/
#include "tomcrypt.h"
#ifdef OCB_MODE
/**
Encrypt and generate an authentication code for a buffer of memory
@param cipher The index of the cipher desired
@param key The secret key
@param keylen The length of the secret key (octets)
@param nonce The session nonce (length of the block ciphers block size)
@param pt The plaintext
@param ptlen The length of the plaintext (octets)
@param ct [out] The ciphertext
@param tag [out] The authentication tag
@param taglen [in/out] The max size and resulting size of the authentication tag
@return CRYPT_OK if successful
*/
int ocb_encrypt_authenticate_memory(int cipher,
const unsigned char *key, unsigned long keylen,
const unsigned char *nonce,
const unsigned char *pt, unsigned long ptlen,
unsigned char *ct,
unsigned char *tag, unsigned long *taglen)
{
int err;
ocb_state *ocb;
LTC_ARGCHK(key != NULL);
LTC_ARGCHK(nonce != NULL);
LTC_ARGCHK(pt != NULL);
LTC_ARGCHK(ct != NULL);
LTC_ARGCHK(tag != NULL);
LTC_ARGCHK(taglen != NULL);
/* allocate ram */
ocb = XMALLOC(sizeof(ocb_state));
if (ocb == NULL) {
return CRYPT_MEM;
}
if ((err = ocb_init(ocb, cipher, key, keylen, nonce)) != CRYPT_OK) {
goto LBL_ERR;
}
while (ptlen > (unsigned long)ocb->block_len) {
if ((err = ocb_encrypt(ocb, pt, ct)) != CRYPT_OK) {
goto LBL_ERR;
}
ptlen -= ocb->block_len;
pt += ocb->block_len;
ct += ocb->block_len;
}
err = ocb_done_encrypt(ocb, pt, ptlen, ct, tag, taglen);
LBL_ERR:
#ifdef LTC_CLEAN_STACK
zeromem(ocb, sizeof(ocb_state));
#endif
XFREE(ocb);
return err;
}
#endif
/* $Source: /cvs/libtom/libtomcrypt/src/encauth/ocb/ocb_encrypt_authenticate_memory.c,v $ */
/* $Revision: 1.3 $ */
/* $Date: 2005/05/05 14:35:58 $ */
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