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data-lite-c/Sources/DataLiteC/libtomcrypt/modes/cbc/cbc_start.c
2025-10-24 19:33:21 +03:00

44 lines
1.1 KiB
C

/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
#include "tomcrypt_private.h"
/**
@file cbc_start.c
CBC implementation, start chain, Tom St Denis
*/
#ifdef LTC_CBC_MODE
/**
Initialize a CBC context
@param cipher The index of the cipher desired
@param IV The initialization vector
@param key The secret key
@param keylen The length of the secret key (octets)
@param num_rounds Number of rounds in the cipher desired (0 for default)
@param cbc The CBC state to initialize
@return CRYPT_OK if successful
*/
int cbc_start(int cipher, const unsigned char *IV, const unsigned char *key,
int keylen, int num_rounds, symmetric_CBC *cbc)
{
int x, err;
LTC_ARGCHK(IV != NULL);
LTC_ARGCHK(key != NULL);
LTC_ARGCHK(cbc != NULL);
/* setup cipher */
if ((err = ecb_start(cipher, key, keylen, num_rounds, &cbc->ecb)) != CRYPT_OK) {
return err;
}
/* copy IV */
for (x = 0; x < cbc->ecb.blocklen; x++) {
cbc->IV[x] = IV[x];
}
return CRYPT_OK;
}
#endif