seed_cbc.c

OpenSSL 0.9.8k 最新版OpenSSL

/* crypto/seed/seed_cbc.c -*- mode:C; c-file-style: "eay" -*- */
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 *    notice, this list of conditions and the following disclaimer. 
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 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
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 *    [e-mail].
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 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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#include "seed_locl.h"
#include <string.h>

void SEED_cbc_encrypt(const unsigned char *in, unsigned char *out,
                      size_t len, const SEED_KEY_SCHEDULE *ks,
                      unsigned char ivec[SEED_BLOCK_SIZE], int enc)
	{
	size_t n;
	unsigned char tmp[SEED_BLOCK_SIZE];
	const unsigned char *iv = ivec;

	if (enc)
		{
		while (len >= SEED_BLOCK_SIZE)
			{
			for (n = 0; n < SEED_BLOCK_SIZE; ++n)
				out[n] = in[n] ^ iv[n];
			SEED_encrypt(out, out, ks);
			iv = out;
			len -= SEED_BLOCK_SIZE;
			in  += SEED_BLOCK_SIZE;
			out += SEED_BLOCK_SIZE;
			}
		if (len)
			{
			for (n = 0; n < len; ++n)
				out[n] = in[n] ^ iv[n];
			for (n = len; n < SEED_BLOCK_SIZE; ++n)
				out[n] = iv[n];
			SEED_encrypt(out, out, ks);
			iv = out;
			}
		memcpy(ivec, iv, SEED_BLOCK_SIZE);
		}
	else if (in != out) /* decrypt */
		{
		while (len >= SEED_BLOCK_SIZE)
			{
			SEED_decrypt(in, out, ks);
			for (n = 0; n < SEED_BLOCK_SIZE; ++n)
				out[n] ^= iv[n];
			iv = in;
			len -= SEED_BLOCK_SIZE;
			in  += SEED_BLOCK_SIZE;
			out += SEED_BLOCK_SIZE;
			}
		if (len)
			{
			SEED_decrypt(in, tmp, ks);
			for (n = 0; n < len; ++n)
				out[n] = tmp[n] ^ iv[n];
			iv = in;
			}
		memcpy(ivec, iv, SEED_BLOCK_SIZE);
		}
	else /* decrypt, overlap */
		{
		while (len >= SEED_BLOCK_SIZE)
			{
			memcpy(tmp, in, SEED_BLOCK_SIZE);
			SEED_decrypt(in, out, ks);
			for (n = 0; n < SEED_BLOCK_SIZE; ++n)
				out[n] ^= ivec[n];
			memcpy(ivec, tmp, SEED_BLOCK_SIZE);
			len -= SEED_BLOCK_SIZE;
			in  += SEED_BLOCK_SIZE;
			out += SEED_BLOCK_SIZE;
			}
		if (len)
			{
			memcpy(tmp, in, SEED_BLOCK_SIZE);
			SEED_decrypt(tmp, tmp, ks);
			for (n = 0; n < len; ++n)
				out[n] = tmp[n] ^ ivec[n];
			memcpy(ivec, tmp, SEED_BLOCK_SIZE);
			}
		}
	}