Let sm4_cbc_encrypt_blocks update iv

If in == out, then after encryptions the input (i.e. iv) is changed

tests/sm4_cbctest.c

@@ -21,15 +21,19 @@
 static int test_sm4_cbc(void)
 {
 	SM4_KEY sm4_key;
-	uint8_t key[16] = {0};
-	uint8_t iv[16] = {0};
+	const uint8_t key[16] = {0};
+	const uint8_t civ[16] = {0};
+	uint8_t iv[16];
 	uint8_t buf1[32] = {0};
 	uint8_t buf2[32] = {0};
 	uint8_t buf3[32] = {0};
 
 	sm4_set_encrypt_key(&sm4_key, key);
+	memcpy(iv, civ, 16);
 	sm4_cbc_encrypt_blocks(&sm4_key, iv, buf1, 2, buf2);
+
 	sm4_set_decrypt_key(&sm4_key, key);
+	memcpy(iv, civ, 16);
 	sm4_cbc_decrypt_blocks(&sm4_key, iv, buf2, 2, buf3);
 
 	if (memcmp(buf1, buf3, sizeof(buf3)) != 0) {
@@ -107,6 +111,7 @@ static int test_sm4_cbc_test_vectors(void)
 		}
 
 		sm4_set_encrypt_key(&sm4_key, key);
+		hex_to_bytes(tests[i].iv, strlen(tests[i].iv), iv, &iv_len);
 		sm4_cbc_encrypt_blocks(&sm4_key, iv, plaintext, plaintext_len/16, encrypted);
 
 		if (memcmp(encrypted, ciphertext, ciphertext_len) != 0) {