45 lines
945 B
C
45 lines
945 B
C
/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
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/* SPDX-License-Identifier: Unlicense */
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#include "tomcrypt_private.h"
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/**
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@file ctr_setiv.c
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CTR implementation, set IV, Tom St Denis
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*/
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#ifdef LTC_CTR_MODE
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/**
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Set an initialization vector
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@param IV The initialization vector
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@param len The length of the vector (in octets)
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@param ctr The CTR state
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@return CRYPT_OK if successful
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*/
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int ctr_setiv(const unsigned char *IV, unsigned long len, symmetric_CTR *ctr)
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{
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int err;
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LTC_ARGCHK(IV != NULL);
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LTC_ARGCHK(ctr != NULL);
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/* bad param? */
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if ((err = cipher_is_valid(ctr->cipher)) != CRYPT_OK) {
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return err;
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}
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if (len != (unsigned long)ctr->blocklen) {
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return CRYPT_INVALID_ARG;
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}
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/* set IV */
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XMEMCPY(ctr->ctr, IV, len);
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/* force next block */
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ctr->padlen = 0;
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return cipher_descriptor[ctr->cipher].ecb_encrypt(IV, ctr->pad, &ctr->key);
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}
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#endif
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