openssl: Support sm4

SM4 is formed with <name>-<mode>, different from aes, etc. which is <name>-<key_bits>-<mode>.
See 'openssl list --cipher-algorithms' under new version 3.5.X e.g.

Author: applyforprof

lib/crypto_backend/crypto_openssl.c

@@ -694,7 +694,10 @@ static int _cipher_init(EVP_CIPHER_CTX **hd_enc, EVP_CIPHER_CTX **hd_dec, const
 	if (!strcmp(mode, "xts"))
 		key_bits /= 2;
 
-	r = snprintf(cipher_name, sizeof(cipher_name), "%s-%d-%s", name, key_bits, mode);
+	if ((!strcmp(name, "sm4")) && key_bits == 128)
+		r = snprintf(cipher_name, sizeof(cipher_name), "%s-%s", name, mode);
+	else
+		r = snprintf(cipher_name, sizeof(cipher_name), "%s-%d-%s", name, key_bits, mode);
 	if (r < 0 || (size_t)r >= sizeof(cipher_name))
 		return -EINVAL;