/* crypto/aes/aes_cbc.c -*- mode:C; c-file-style: "eay" -*- */

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 #ifndef AES_DEBUG

 # ifndef NDEBUG

 #  define NDEBUG

 # endif

 #endif

 #include <assert.h>

 #include <openssl/aes.h>

 #include "aes_locl.h"

 EXPORT_C 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);

 		}

 	}

 }