sl@0: /* crypto/aes/aes_cbc.c -*- mode:C; c-file-style: "eay" -*- */
sl@0: /* ====================================================================
sl@0:  * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
sl@0:  *
sl@0:  * Redistribution and use in source and binary forms, with or without
sl@0:  * modification, are permitted provided that the following conditions
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sl@0:  *
sl@0:  * 1. Redistributions of source code must retain the above copyright
sl@0:  *    notice, this list of conditions and the following disclaimer. 
sl@0:  *
sl@0:  * 2. Redistributions in binary form must reproduce the above copyright
sl@0:  *    notice, this list of conditions and the following disclaimer in
sl@0:  *    the documentation and/or other materials provided with the
sl@0:  *    distribution.
sl@0:  *
sl@0:  * 3. All advertising materials mentioning features or use of this
sl@0:  *    software must display the following acknowledgment:
sl@0:  *    "This product includes software developed by the OpenSSL Project
sl@0:  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
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sl@0:  *    openssl-core@openssl.org.
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sl@0:  * 5. Products derived from this software may not be called "OpenSSL"
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sl@0:  * 6. Redistributions of any form whatsoever must retain the following
sl@0:  *    acknowledgment:
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sl@0:  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
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sl@0:  * OF THE POSSIBILITY OF SUCH DAMAGE.
sl@0:  * ====================================================================
sl@0:  *
sl@0:  */
sl@0: 
sl@0: #ifndef AES_DEBUG
sl@0: # ifndef NDEBUG
sl@0: #  define NDEBUG
sl@0: # endif
sl@0: #endif
sl@0: #include <assert.h>
sl@0: 
sl@0: #include <openssl/aes.h>
sl@0: #include "aes_locl.h"
sl@0: 
sl@0: EXPORT_C void AES_cbc_encrypt(const unsigned char *in, unsigned char *out,
sl@0: 		     const unsigned long length, const AES_KEY *key,
sl@0: 		     unsigned char *ivec, const int enc) {
sl@0: 
sl@0: 	unsigned long n;
sl@0: 	unsigned long len = length;
sl@0: 	unsigned char tmp[AES_BLOCK_SIZE];
sl@0: 	const unsigned char *iv = ivec;
sl@0: 
sl@0: 	assert(in && out && key && ivec);
sl@0: 	assert((AES_ENCRYPT == enc)||(AES_DECRYPT == enc));
sl@0: 
sl@0: 	if (AES_ENCRYPT == enc) {
sl@0: 		while (len >= AES_BLOCK_SIZE) {
sl@0: 			for(n=0; n < AES_BLOCK_SIZE; ++n)
sl@0: 				out[n] = in[n] ^ iv[n];
sl@0: 			AES_encrypt(out, out, key);
sl@0: 			iv = out;
sl@0: 			len -= AES_BLOCK_SIZE;
sl@0: 			in += AES_BLOCK_SIZE;
sl@0: 			out += AES_BLOCK_SIZE;
sl@0: 		}
sl@0: 		if (len) {
sl@0: 			for(n=0; n < len; ++n)
sl@0: 				out[n] = in[n] ^ iv[n];
sl@0: 			for(n=len; n < AES_BLOCK_SIZE; ++n)
sl@0: 				out[n] = iv[n];
sl@0: 			AES_encrypt(out, out, key);
sl@0: 			iv = out;
sl@0: 		}
sl@0: 		memcpy(ivec,iv,AES_BLOCK_SIZE);
sl@0: 	} else if (in != out) {
sl@0: 		while (len >= AES_BLOCK_SIZE) {
sl@0: 			AES_decrypt(in, out, key);
sl@0: 			for(n=0; n < AES_BLOCK_SIZE; ++n)
sl@0: 				out[n] ^= iv[n];
sl@0: 			iv = in;
sl@0: 			len -= AES_BLOCK_SIZE;
sl@0: 			in  += AES_BLOCK_SIZE;
sl@0: 			out += AES_BLOCK_SIZE;
sl@0: 		}
sl@0: 		if (len) {
sl@0: 			AES_decrypt(in,tmp,key);
sl@0: 			for(n=0; n < len; ++n)
sl@0: 				out[n] = tmp[n] ^ iv[n];
sl@0: 			iv = in;
sl@0: 		}
sl@0: 		memcpy(ivec,iv,AES_BLOCK_SIZE);
sl@0: 	} else {
sl@0: 		while (len >= AES_BLOCK_SIZE) {
sl@0: 			memcpy(tmp, in, AES_BLOCK_SIZE);
sl@0: 			AES_decrypt(in, out, key);
sl@0: 			for(n=0; n < AES_BLOCK_SIZE; ++n)
sl@0: 				out[n] ^= ivec[n];
sl@0: 			memcpy(ivec, tmp, AES_BLOCK_SIZE);
sl@0: 			len -= AES_BLOCK_SIZE;
sl@0: 			in += AES_BLOCK_SIZE;
sl@0: 			out += AES_BLOCK_SIZE;
sl@0: 		}
sl@0: 		if (len) {
sl@0: 			memcpy(tmp, in, AES_BLOCK_SIZE);
sl@0: 			AES_decrypt(tmp, out, key);
sl@0: 			for(n=0; n < len; ++n)
sl@0: 				out[n] ^= ivec[n];
sl@0: 			for(n=len; n < AES_BLOCK_SIZE; ++n)
sl@0: 				out[n] = tmp[n];
sl@0: 			memcpy(ivec, tmp, AES_BLOCK_SIZE);
sl@0: 		}
sl@0: 	}
sl@0: }