Add more sm4 modes

Not tested yet
2026-05-06 16:36:16 +08:00 · 2024-02-10 15:46:59 +08:00
parent b58ea74f96
commit 8ae03e8105
6 changed files with 533 additions and 2 deletions
--- a/src/sm4_cfb.c
+++ b/src/sm4_cfb.c
@@ -0,0 +1,209 @@
+/*
+ *  Copyright 2014-2024 The GmSSL Project. All Rights Reserved.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the License); you may
+ *  not use this file except in compliance with the License.
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+
+#include <gmssl/sm4.h>
+#include <gmssl/mem.h>
+#include <gmssl/error.h>
+
+
+void sm4_cfb_encrypt(const SM4_KEY *key, size_t sbytes, uint8_t iv[16],
+	const uint8_t *in, size_t inlen, uint8_t *out)
+{
+	uint8_t block[16];
+	size_t len, i;
+
+	// assert(1 <= sbytes && sbytes <= 16);
+
+	while (inlen) {
+		len = inlen < sbytes ? inlen : sbytes;
+		sm4_encrypt(key, iv, block);
+		gmssl_memxor(out, in, block, len);
+
+		// iv = (iv << sbytes) | out
+		for (i = 0; i < 16 - sbytes; i++) {
+			iv[i] = iv[sbytes + i];
+		}
+		memcpy(iv + i, out, len);
+
+		in += len;
+		out += len;
+		inlen -= len;
+	}
+}
+
+void sm4_cfb_decrypt(const SM4_KEY *key, size_t sbytes, uint8_t iv[16],
+	const uint8_t *in, size_t inlen, uint8_t *out)
+{
+	uint8_t block[16];
+	size_t len, i;
+
+	// assert(1 <= sbytes && sbytes <= 16);
+
+	while (inlen) {
+		len = inlen < sbytes ? inlen : sbytes;
+		sm4_encrypt(key, iv, block);
+		gmssl_memxor(out, in, block, len);
+
+		// iv = (iv << sbytes) | in
+		for (i = 0; i < 16 - sbytes; i++) {
+			iv[i] = iv[sbytes + i];
+		}
+		memcpy(iv + i, in, len);
+
+		in += len;
+		out += len;
+		inlen -= len;
+	}
+}
+
+typedef struct {
+	SM4_KEY sm4_key;
+	uint8_t iv[SM4_BLOCK_SIZE];
+	uint8_t block[SM4_BLOCK_SIZE];
+	size_t block_nbytes;
+	size_t sbytes;
+} SM4_CFB_CTX;
+
+int sm4_cfb_encrypt_init(SM4_CFB_CTX *ctx, size_t sbytes,
+	const uint8_t key[SM4_BLOCK_SIZE], const uint8_t iv[SM4_BLOCK_SIZE])
+{
+	if (sbytes < 1 || sbytes > 16) {
+		error_print();
+		return -1;
+	}
+	sm4_set_encrypt_key(&ctx->sm4_key, key);
+	memcpy(ctx->iv, iv, SM4_BLOCK_SIZE);
+	memset(ctx->block, 0, SM4_BLOCK_SIZE);
+	ctx->block_nbytes = 0;
+	ctx->sbytes = sbytes;
+	return 1;
+}
+
+int sm4_cfb_encrypt_update(SM4_CFB_CTX *ctx,
+	const uint8_t *in, size_t inlen, uint8_t *out, size_t *outlen)
+{
+	size_t left;
+	size_t nblocks;
+	size_t len;
+
+	if (ctx->block_nbytes >= ctx->sbytes) {
+		error_print();
+		return -1;
+	}
+	*outlen = 0;
+	if (ctx->block_nbytes) {
+		left = ctx->sbytes - ctx->block_nbytes;
+		if (inlen < left) {
+			memcpy(ctx->block + ctx->block_nbytes, in, inlen);
+			ctx->block_nbytes += inlen;
+			return 1;
+		}
+		memcpy(ctx->block + ctx->block_nbytes, in, left);
+		sm4_cfb_encrypt(&ctx->sm4_key, ctx->sbytes, ctx->iv, ctx->block, ctx->sbytes, out);
+		in += left;
+		inlen -= left;
+		out += ctx->sbytes;
+		*outlen += ctx->sbytes;
+	}
+	if (inlen >= ctx->sbytes) {
+		nblocks = inlen / ctx->sbytes;
+		len = nblocks * ctx->sbytes;
+		sm4_cfb_encrypt(&ctx->sm4_key, ctx->sbytes, ctx->iv, in, len, out);
+		in += len;
+		inlen -= len;
+		out += len;
+		*outlen += len;
+	}
+	if (inlen) {
+		memcpy(ctx->block, in, inlen);
+	}
+	ctx->block_nbytes = inlen;
+	return 1;
+}
+
+int sm4_cfb_encrypt_finish(SM4_CFB_CTX *ctx, uint8_t *out, size_t *outlen)
+{
+	if (ctx->block_nbytes >= ctx->sbytes) {
+		error_print();
+		return -1;
+	}
+	sm4_cfb_encrypt(&ctx->sm4_key, ctx->sbytes, ctx->iv, ctx->block, ctx->block_nbytes, out);
+	*outlen = ctx->block_nbytes;
+	return 1;
+}
+
+int sm4_cfb_decrypt_init(SM4_CFB_CTX *ctx, size_t sbytes,
+	const uint8_t key[SM4_BLOCK_SIZE], const uint8_t iv[SM4_BLOCK_SIZE])
+{
+	if (sbytes < 1 || sbytes > 16) {
+		error_print();
+		return -1;
+	}
+	sm4_set_encrypt_key(&ctx->sm4_key, key);
+	memcpy(ctx->iv, iv, SM4_BLOCK_SIZE);
+	memset(ctx->block, 0, SM4_BLOCK_SIZE);
+	ctx->block_nbytes = 0;
+	ctx->sbytes = sbytes;
+	return 1;
+}
+
+int sm4_cfb_decrypt_update(SM4_CFB_CTX *ctx,
+	const uint8_t *in, size_t inlen, uint8_t *out, size_t *outlen)
+{
+	size_t left;
+	size_t nblocks;
+	size_t len;
+
+	if (ctx->block_nbytes >= ctx->sbytes) {
+		error_print();
+		return -1;
+	}
+	*outlen = 0;
+	if (ctx->block_nbytes) {
+		left = ctx->sbytes - ctx->block_nbytes;
+		if (inlen < left) {
+			memcpy(ctx->block + ctx->block_nbytes, in, inlen);
+			ctx->block_nbytes += inlen;
+			return 1;
+		}
+		memcpy(ctx->block + ctx->block_nbytes, in, left);
+		sm4_cfb_decrypt(&ctx->sm4_key, ctx->sbytes, ctx->iv, ctx->block, ctx->sbytes, out);
+		in += left;
+		inlen -= left;
+		out += ctx->sbytes;
+		*outlen += ctx->sbytes;
+	}
+	if (inlen >= ctx->sbytes) {
+		nblocks = inlen / ctx->sbytes;
+		len = nblocks * ctx->sbytes;
+		sm4_cfb_decrypt(&ctx->sm4_key, ctx->sbytes, ctx->iv, in, len, out);
+		in += len;
+		inlen -= len;
+		out += len;
+		*outlen += len;
+	}
+	if (inlen) {
+		memcpy(ctx->block, in, inlen);
+	}
+	ctx->block_nbytes = inlen;
+	return 1;
+}
+
+int sm4_cfb_decrypt_finish(SM4_CFB_CTX *ctx, uint8_t *out, size_t *outlen)
+{
+	if (ctx->block_nbytes >= ctx->sbytes) {
+		error_print();
+		return -1;
+	}
+	sm4_cfb_decrypt(&ctx->sm4_key, ctx->sbytes, ctx->iv, ctx->block, ctx->block_nbytes, out);
+	*outlen = ctx->block_nbytes;
+	return 1;
+}
+