63 lines
1.5 KiB
C
63 lines
1.5 KiB
C
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
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*
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* LibTomCrypt is a library that provides various cryptographic
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* algorithms in a highly modular and flexible manner.
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*
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* The library is free for all purposes without any express
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* guarantee it works.
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*
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* Tom St Denis, tomstdenis@gmail.com, http://libtom.org
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*/
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#include "tomcrypt.h"
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/**
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@file cbc_start.c
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CBC implementation, start chain, Tom St Denis
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*/
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#ifdef LTC_CBC_MODE
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/**
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Initialize a CBC context
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@param cipher The index of the cipher desired
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@param IV The initial vector
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@param key The secret key
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@param keylen The length of the secret key (octets)
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@param num_rounds Number of rounds in the cipher desired (0 for default)
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@param cbc The CBC state to initialize
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@return CRYPT_OK if successful
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*/
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int cbc_start(int cipher, const unsigned char *IV, const unsigned char *key,
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int keylen, int num_rounds, symmetric_CBC *cbc)
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{
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int x, err;
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LTC_ARGCHK(IV != NULL);
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LTC_ARGCHK(key != NULL);
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LTC_ARGCHK(cbc != NULL);
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/* bad param? */
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if ((err = cipher_is_valid(cipher)) != CRYPT_OK) {
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return err;
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}
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/* setup cipher */
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if ((err = cipher_descriptor[cipher].setup(key, keylen, num_rounds, &cbc->key)) != CRYPT_OK) {
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return err;
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}
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/* copy IV */
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cbc->blocklen = cipher_descriptor[cipher].block_length;
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cbc->cipher = cipher;
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for (x = 0; x < cbc->blocklen; x++) {
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cbc->IV[x] = IV[x];
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}
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return CRYPT_OK;
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}
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#endif
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/* $Source$ */
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/* $Revision$ */
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/* $Date$ */
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