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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 gcm_memory.c
GCM implementation, process a packet, by Tom St Denis
*/
#include "tomcrypt.h"
#ifdef GCM_MODE
/**
Process an entire GCM packet in one call.
@param cipher Index of cipher to use
@param key The secret key
@param keylen The length of the secret key
@param IV The initial vector
@param IVlen The length of the initial vector
@param adata The additional authentication data (header)
@param adatalen The length of the adata
@param pt The plaintext
@param ptlen The length of the plaintext (ciphertext length is the same)
@param ct The ciphertext
@param tag [out] The MAC tag
@param taglen [in/out] The MAC tag length
@param direction Encrypt or Decrypt mode (GCM_ENCRYPT or GCM_DECRYPT)
@return CRYPT_OK on success
*/
int gcm_memory( int cipher,
const unsigned char *key, unsigned long keylen,
const unsigned char *IV, unsigned long IVlen,
const unsigned char *adata, unsigned long adatalen,
unsigned char *pt, unsigned long ptlen,
unsigned char *ct,
unsigned char *tag, unsigned long *taglen,
int direction)
{
gcm_state *gcm;
int err;
if ((err = cipher_is_valid(cipher)) != CRYPT_OK) {
return err;
}
if (cipher_descriptor[cipher].accel_gcm_memory != NULL) {
cipher_descriptor[cipher].accel_gcm_memory
(key, keylen,
IV, IVlen,
adata, adatalen,
pt, ptlen,
ct,
tag, taglen,
direction);
return CRYPT_OK;
}
gcm = XMALLOC(sizeof(*gcm));
if (gcm == NULL) {
return CRYPT_MEM;
}
if ((err = gcm_init(gcm, cipher, key, keylen)) != CRYPT_OK) {
goto LTC_ERR;
}
if ((err = gcm_add_iv(gcm, IV, IVlen)) != CRYPT_OK) {
goto LTC_ERR;
}
if ((err = gcm_add_aad(gcm, adata, adatalen)) != CRYPT_OK) {
goto LTC_ERR;
}
if ((err = gcm_process(gcm, pt, ptlen, ct, direction)) != CRYPT_OK) {
goto LTC_ERR;
}
err = gcm_done(gcm, tag, taglen);
LTC_ERR:
XFREE(gcm);
return err;
}
#endif
/* $Source: /cvs/libtom/libtomcrypt/src/encauth/gcm/gcm_memory.c,v $ */
/* $Revision: 1.19 $ */
/* $Date: 2005/05/05 14:35:58 $ */
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