轻装上阵，不调用jar包，用C#写SM4加密算法【卸载IKVM 】

前言

记得之前写了一个文章，是关于java和c#加密不一致导致需要使用ikvm的方式来进行数据加密，主要是ikvm把打包后的jar包打成dll包，然后Nuget引入ikvm，从而实现算法的统一，这几天闲来无事，网上找了一下加密库【BouncyCastle.dll】进行加密,目的是想统一加密。因为ikvm相对重了点，引入一堆dll包。

官方网址

c#入口: https://www.bouncycastle.org/csharp/

java入口: https://www.bouncycastle.org/java.html

（如图所示）在1.8.4中 发现它是支持SM4 加密的，如果你想要使用SM4加密算法，最低版本需要是1.8.4。

Nuget安装（如图所示)

注意事项

这个是针对java和c#的加解密一致性

1.算法要保持一致 均是SM4
2.算法模式要保持一致 （如CBC和ECB 当然还有填充模式）
举个例子：我这边就使用 SM4/CBC/PKCS5Padding
3.编码一致性
如果JAVA 加解密用的UTF8 ，C#加解密用的是GBK 这样肯定不行了
俺们都是Chinese,所以果断选择UTF8了

最后就是代码部分了

java

需要引入bcprov-jdk15on-1.59.jar 和 httpcore-4.4.3.jar

package com.ken.utils;
import java.security.*;
import java.util.Arrays;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.pqc.math.linearalgebra.ByteUtils;public class SM4Util {static {Security.addProvider(new BouncyCastleProvider());}//默认是UTF-8编码//private static final String ENCODING = "UTF-8";public static final String ALGORITHM_NAME = "SM4";// 加密算法/分组加密模式/分组填充方式// PKCS5Padding-以8个字节为一组进行分组加密// 定义分组加密模式使用：PKCS5Paddingpublic static final String ALGORITHM_NAME_ECB_PADDING = "SM4/ECB/PKCS5Padding";// 128 32位16进制  本身SM4默认就是这一种// public static final int DEFAULT_KEY_SIZE = 128;// 这边我默认了密钥public static final String SM4_KEY = "86C63180C2806ED1F47B859DE501215B";/*** 生成ECB暗号* @explain ECB模式（电子密码本模式：Electronic codebook）* @param algorithmName*            算法名称* @param mode*            模式* @param key* @return* @throws Exception*/private static Cipher generateEcbCipher(String algorithmName, int mode, byte[] key) throws Exception {Cipher cipher = Cipher.getInstance(algorithmName, BouncyCastleProvider.PROVIDER_NAME);Key sm4Key = new SecretKeySpec(key, ALGORITHM_NAME);cipher.init(mode, sm4Key);return cipher;}/** 方式一：系统生成密钥* 自动生成密钥* @explain* @return* @throws NoSuchAlgorithmException* @throws NoSuchProviderException*/public static byte[] generateKey() throws Exception {return generateKey(DEFAULT_KEY_SIZE);}/*** @explain* @param keySize* @return* @throws Exception*/public static byte[] generateKey(int keySize) throws Exception {KeyGenerator kg = KeyGenerator.getInstance(ALGORITHM_NAME, BouncyCastleProvider.PROVIDER_NAME);kg.init(keySize, new SecureRandom());return kg.generateKey().getEncoded();}/*** sm4加密* @explain 加密模式：ECB*          密文长度不固定，会随着被加密字符串长度的变化而变化* @param hexKey*            16进制密钥（忽略大小写）* @param paramStr*            待加密字符串* @return 返回16进制的加密字符串* @throws Exception*/public static String encryptEcb(String hexKey, String paramStr) throws Exception {String cipherText = "";// 16进制字符串--&gt;byte[]byte[] keyData = ByteUtils.fromHexString(hexKey);// String--&gt;byte[]byte[] srcData = paramStr.getBytes(ENCODING);// 加密后的数组byte[] cipherArray = encrypt_Ecb_Padding(keyData, srcData);// byte[]--&gt;hexStringcipherText = ByteUtils.toHexString(cipherArray);return cipherText;}/*** 加密模式之Ecb 方法二：自己提供16进制的密钥* @explain* @param key* @param data* @return* @throws Exception*/public static byte[] encrypt_Ecb_Padding(byte[] key, byte[] data) throws Exception {Cipher cipher = generateEcbCipher(ALGORITHM_NAME_ECB_PADDING, Cipher.ENCRYPT_MODE, key);return cipher.doFinal(data);}/*** sm4解密* @explain 解密模式：采用ECB* @param hexKey*            16进制密钥* @param cipherText*            16进制的加密字符串（忽略大小写）* @return 解密后的字符串* @throws Exception*/public static String decryptEcb(String hexKey, String cipherText) throws Exception {// 用于接收解密后的字符串String decryptStr = "";// hexString--&gt;byte[]byte[] keyData = ByteUtils.fromHexString(hexKey);// hexString--&gt;byte[]byte[] cipherData = ByteUtils.fromHexString(cipherText);// 解密byte[] srcData = decrypt_Ecb_Padding(keyData, cipherData);// byte[]--&gt;StringdecryptStr = new String(srcData, ENCODING);return decryptStr;}/*** 解密* @explain* @param key* @param cipherText* @return* @throws Exception*/public static byte[] decrypt_Ecb_Padding(byte[] key, byte[] cipherText) throws Exception {Cipher cipher = generateEcbCipher(ALGORITHM_NAME_ECB_PADDING, Cipher.DECRYPT_MODE, key);return cipher.doFinal(cipherText);}/*** 校验加密前后的字符串是否为同一数据* @explain* @param hexKey*            16进制密钥（忽略大小写）* @param cipherText*            16进制加密后的字符串* @param paramStr*            加密前的字符串* @return 是否为同一数据* @throws Exception*/public static boolean verifyEcb(String hexKey, String cipherText, String paramStr) throws Exception {// 用于接收校验结果boolean flag = false;// hexString--&gt;byte[]byte[] keyData = ByteUtils.fromHexString(hexKey);// 将16进制字符串转换成数组byte[] cipherData = ByteUtils.fromHexString(cipherText);// 解密byte[] decryptData = decrypt_Ecb_Padding(keyData, cipherData);// 将原字符串转换成byte[]byte[] srcData = paramStr.getBytes(ENCODING);// 判断2个数组是否一致flag = Arrays.equals(decryptData, srcData);return flag;}/*** 字符串转化成为16进制字符串* @param s* @return*/public static String strTo16(String s) {String str = "";for (int i = 0; i < s.length(); i++) {int ch = (int) s.charAt(i);String s4 = Integer.toHexString(ch);str = str + s4;}return str;}public static String byteArrayToHexStr(byte[] byteArray) {StringBuilder stringBuilder = new StringBuilder("");if (byteArray == null || byteArray.length <= 0) {return null;}for (int i = 0; i < byteArray.length; i++) {int v = byteArray[i] & 0xFF;String hv = Integer.toHexString(v);if (hv.length() < 2) {stringBuilder.append(0);}stringBuilder.append(hv);}return stringBuilder.toString();}}

C# (Csharp)

using Org.BouncyCastle.Crypto.IO;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Utilities.Encoders;
using System;
using System.IO;
using System.Text;namespace Web.Security.Util
{public static class SM4Util{/// <summary>/// 默认编码/// </summary>private static Encoding DefaultEncoding = Encoding.UTF8;//"GB2312";public const string ALGORITHM_NAME = "SM4";/// <summary>/// ECB模式 [pkcs5padding填充方式]/// </summary>public const string ALGORITHM_NAME_ECB_PADDING = "SM4/ECB/PKCS5Padding";/// <summary>/// CBC模式 [pkcs5padding填充方式]/// </summary>public const string ALGORITHM_NAME_CBC_PADDING = "SM4/CBC/PKCS5Padding";//这个不需要  SM4默认就是128位的密钥//public const int DEFAULT_KEY_SIZE = 128;/// <summary>/// 解密/// </summary>/// <param name="key">密钥</param>/// <param name="passInput"></param>/// <param name="encoding">编码</param>/// <param name="algorithmMode">默认是ECB模式 [pkcs5padding填充方式]</param>/// <returns></returns>public static string DecryptEcb(string key, string passInput, Encoding encoding, string algorithmMode= ALGORITHM_NAME_ECB_PADDING){encoding = encoding??Encoding.UTF8;byte[] keyBytes = Hex.Decode(key);byte[] input = Hex.Decode(passInput);return encoding.GetString(DecryptEcb(keyBytes, input, algorithmMode));}/// <summary>/// 解密/// </summary>/// <param name="key">密钥</param>/// <param name="passInput"></param>/// <param name="algorithmMode">默认是ECB模式 [pkcs5padding填充方式]</param>/// <returns></returns>public static string DecryptEcb(string key, string passInput, string algorithmMode = ALGORITHM_NAME_ECB_PADDING){return DecryptEcb(key, passInput, DefaultEncoding, algorithmMode);}/// <summary>/// 解密/// </summary>/// <param name="keyBytes">密钥</param>/// <param name="passInput"></param>/// <param name="algorithmMode">加密方式</param>/// <returns></returns>/// <exception cref="Exception"></exception>public static byte[] DecryptEcb(byte[] keyBytes, byte[] passInput, string algorithmMode){KeyParameter key = ParameterUtilities.CreateKeyParameter(ALGORITHM_NAME, keyBytes);IBufferedCipher inCipher = CipherUtilities.GetCipher(algorithmMode);//forEncryption位false表示解密inCipher.Init(false, key);MemoryStream bIn = new MemoryStream(passInput, false);CipherStream cIn = new CipherStream(bIn, inCipher, null);byte[] bytes = new byte[passInput.Length];byte[] totalBytes;try{#region 此代码一次性读取解密 可行/*BinaryReader dIn = new BinaryReader(cIn);byte[] extra = dIn.ReadBytes(passInput.Length);Array.Copy(extra, 0, bytes, 0, extra.Length);*/#endregion#region 官方demo 是先处理一半  再处理剩下的 最后把剩下的复制到bytes剩余部分BinaryReader dIn = new BinaryReader(cIn);for (int i = 0; i != passInput.Length / 2; i++){bytes[i] = dIn.ReadByte();}int remaining = bytes.Length - passInput.Length / 2;byte[] extra = dIn.ReadBytes(remaining);//把为了加密补位的部分去掉if (extra.Length < remaining){int len = passInput.Length/2 + extra.Length;totalBytes = new byte[len];Array.Copy(bytes, 0, totalBytes, 0, passInput.Length / 2);extra.CopyTo(totalBytes, passInput.Length / 2);return totalBytes;}else{extra.CopyTo(bytes, passInput.Length / 2);}//throw new EndOfStreamException();#endregion}catch (Exception e){throw new Exception("SM4 failed encryption - " + e, e);}return bytes;}/// <summary>/// 加密/// </summary>/// <param name="key">密钥</param>/// <param name="text"></param>/// <param name="encoding">编码</param>/// <param name="algorithmMode">默认是ECB模式 [pkcs5padding填充方式]</param>/// <returns></returns>public static string EncryptEcb(string key, string text, Encoding encoding,string algorithmMode = ALGORITHM_NAME_ECB_PADDING){encoding = encoding??Encoding.UTF8;byte[] keyBytes = Hex.Decode(key);byte[] input = encoding.GetBytes(text);return Hex.ToHexString(EncryptEcb(keyBytes, input, algorithmMode));}/// <summary>/// 加密/// </summary>/// <param name="key">密钥</param>/// <param name="text"></param>/// <param name="algorithmMode"></param>/// <returns></returns>public static string EncryptEcb(string key, string text, string algorithmMode = ALGORITHM_NAME_ECB_PADDING){return EncryptEcb(key,text, DefaultEncoding, algorithmMode);}/// <summary>/// 加密/// </summary>/// <param name="keyBytes">密钥</param>/// <param name="input"></param>/// <returns></returns>/// <exception cref="Exception"></exception>public static byte[] EncryptEcb(byte[] keyBytes, byte[] input,string algorithmMode){KeyParameter key = ParameterUtilities.CreateKeyParameter(ALGORITHM_NAME, keyBytes);IBufferedCipher outCipher = CipherUtilities.GetCipher(algorithmMode);//forEncryption位true表示加密outCipher.Init(true, key);MemoryStream bOut = new MemoryStream();CipherStream cOut = new CipherStream(bOut, null, outCipher);try{//处理前一半for (int i = 0; i != input.Length / 2; i++){cOut.WriteByte(input[i]);}//处理后一半cOut.Write(input, input.Length / 2, input.Length - input.Length / 2);cOut.Close();}catch (IOException e){throw new Exception("SM4 failed encryption - " + e, e);}byte[] bytes = bOut.ToArray();return bytes;}		}}

密钥生成

java可以使用UUID生成32位的16进制字符串

C#可以使用 GUID生成32位的16进制字符串

密钥格式（示例）: 7A5B5AE03F764358AEAEF0D1B4B2ADAE

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调用方式

string SM4_KEY =“7A5B5AE03F764358AEAEF0D1B4B2ADAE”;

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java

SM4Util.encryptEcb(SM4_KEY, “待加密文本”);SM4Util.decryptEcb(SM4_KEY, “加密后的文本”);

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C#

SM4Util.EncryptEcb(SM4_KEY, “待加密文本”);
SM4Util.DecryptEcb(SM4_KEY, “加密后的文本”)

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ps: java版本的，如果数据量超过5000，不建议全部加密，会比较耗时。c# 2万条依旧扛得住。

这个我试过虽然加密的结果两者（java和C#）是不一样的，但解密的结果都是一样的，如果你对此不放心 也可以把java版的改成使用统一版本的BouncyCastle。