aes_cbc.c
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上传日期:2020-08-09
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- /* crypto/aes/aes_cbc.c -*- mode:C; c-file-style: "eay" -*- */
- /* ====================================================================
- * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- *
- * 3. All advertising materials mentioning features or use of this
- * software must display the following acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
- *
- * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
- * endorse or promote products derived from this software without
- * prior written permission. For written permission, please contact
- * openssl-core@openssl.org.
- *
- * 5. Products derived from this software may not be called "OpenSSL"
- * nor may "OpenSSL" appear in their names without prior written
- * permission of the OpenSSL Project.
- *
- * 6. Redistributions of any form whatsoever must retain the following
- * acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
- *
- * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
- * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- * ====================================================================
- *
- */
- #ifndef AES_DEBUG
- # ifndef NDEBUG
- # define NDEBUG
- # endif
- #endif
- #include <assert.h>
- #include <openssl/aes.h>
- #include "aes_locl.h"
- void AES_cbc_encrypt(const unsigned char *in, unsigned char *out,
- const unsigned long length, const AES_KEY *key,
- unsigned char *ivec, const int enc) {
- unsigned long n;
- unsigned long len = length;
- unsigned char tmp[AES_BLOCK_SIZE];
- const unsigned char *iv = ivec;
- assert(in && out && key && ivec);
- assert((AES_ENCRYPT == enc)||(AES_DECRYPT == enc));
- if (AES_ENCRYPT == enc) {
- while (len >= AES_BLOCK_SIZE) {
- for(n=0; n < AES_BLOCK_SIZE; ++n)
- out[n] = in[n] ^ iv[n];
- AES_encrypt(out, out, key);
- iv = out;
- len -= AES_BLOCK_SIZE;
- in += AES_BLOCK_SIZE;
- out += AES_BLOCK_SIZE;
- }
- if (len) {
- for(n=0; n < len; ++n)
- out[n] = in[n] ^ iv[n];
- for(n=len; n < AES_BLOCK_SIZE; ++n)
- out[n] = iv[n];
- AES_encrypt(out, out, key);
- iv = out;
- }
- memcpy(ivec,iv,AES_BLOCK_SIZE);
- } else if (in != out) {
- while (len >= AES_BLOCK_SIZE) {
- AES_decrypt(in, out, key);
- for(n=0; n < AES_BLOCK_SIZE; ++n)
- out[n] ^= iv[n];
- iv = in;
- len -= AES_BLOCK_SIZE;
- in += AES_BLOCK_SIZE;
- out += AES_BLOCK_SIZE;
- }
- if (len) {
- AES_decrypt(in,tmp,key);
- for(n=0; n < len; ++n)
- out[n] = tmp[n] ^ iv[n];
- iv = in;
- }
- memcpy(ivec,iv,AES_BLOCK_SIZE);
- } else {
- while (len >= AES_BLOCK_SIZE) {
- memcpy(tmp, in, AES_BLOCK_SIZE);
- AES_decrypt(in, out, key);
- for(n=0; n < AES_BLOCK_SIZE; ++n)
- out[n] ^= ivec[n];
- memcpy(ivec, tmp, AES_BLOCK_SIZE);
- len -= AES_BLOCK_SIZE;
- in += AES_BLOCK_SIZE;
- out += AES_BLOCK_SIZE;
- }
- if (len) {
- memcpy(tmp, in, AES_BLOCK_SIZE);
- AES_decrypt(tmp, out, key);
- for(n=0; n < len; ++n)
- out[n] ^= ivec[n];
- for(n=len; n < AES_BLOCK_SIZE; ++n)
- out[n] = tmp[n];
- memcpy(ivec, tmp, AES_BLOCK_SIZE);
- }
- }
- }