JAVA集成国密SM4加解密
国密算法概述：https://blog.csdn.net/qq_38254635/article/details/131801527
SM4对称算法
SM4 无线局域网标准的分组数据算法。对称加密，密钥长度和分组长度均为128位
一、pom配置
<!-- 国密 --><dependency><groupId>org.bouncycastle</groupId><artifactId>bcprov-jdk15to18</artifactId><version>1.66</version></dependency>二、代码集成
2.1、目录结构
2.2、源码
ConfigBean.java
package com.secret.sm4;public class ConfigBean { public static final int SM4_KEY_SIZE = 128; public static final String ALGORITHM_NAME = "SM4"; public static final byte[] SM4_KEY_IV = { 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31 }; public static final String ALGORITHM_ECB_PADDING = "SM4/ECB/PKCS5Padding"; public static final String ALGORITHM_CBC_PADDING = "SM4/CBC/PKCS5Padding";}ProviderSingleton.java
package com.secret.sm4;import org.bouncycastle.jce.provider.BouncyCastleProvider;public class ProviderSingleton { private static BouncyCastleProvider instance = null; private ProviderSingleton() { } private static synchronized void syncInit() { if (instance == null) { instance = new BouncyCastleProvider(); } } public static BouncyCastleProvider getInstance() { if (instance == null) { syncInit(); } return instance; }}SecretCommon.java
package com.secret.sm4;import org.apache.tomcat.util.codec.binary.Base64;import org.bouncycastle.jce.provider.BouncyCastleProvider;import org.bouncycastle.pqc.math.linearalgebra.ByteUtils;import javax.crypto.BadPaddingException;import javax.crypto.Cipher;import javax.crypto.IllegalBlockSizeException;import javax.crypto.KeyGenerator;import javax.crypto.NoSuchPaddingException;import javax.crypto.spec.IvParameterSpec;import javax.crypto.spec.SecretKeySpec;import java.nio.charset.StandardCharsets;import java.security.InvalidAlgorithmParameterException;import java.security.InvalidKeyException;import java.security.NoSuchAlgorithmException;import java.security.NoSuchProviderException;import java.security.SecureRandom;import java.security.Security;public class SecretCommon { static { Security.addProvider(new BouncyCastleProvider()); } public static String generateKey() throws NoSuchAlgorithmException { return ByteUtils.toHexString(generateKeyByte(ConfigBean.SM4_KEY_SIZE, ProviderSingleton.getInstance())); } public static String generateKeyBC() throws NoSuchProviderException, NoSuchAlgorithmException { return ByteUtils.toHexString(generateKeyByte(ConfigBean.SM4_KEY_SIZE, BouncyCastleProvider.PROVIDER_NAME)); } public static byte[] generateKeyByte(int keySize, String var) throws NoSuchAlgorithmException, NoSuchProviderException { KeyGenerator keyGenerator = KeyGenerator.getInstance(ConfigBean.ALGORITHM_NAME, var); keyGenerator.init(keySize, new SecureRandom()); return keyGenerator.generateKey().getEncoded(); } public static byte[] generateKeyByte(int keySize, BouncyCastleProvider var) throws NoSuchAlgorithmException { KeyGenerator keyGenerator = KeyGenerator.getInstance(ConfigBean.ALGORITHM_NAME, var); keyGenerator.init(keySize, new SecureRandom()); return keyGenerator.generateKey().getEncoded(); } public static String encryptECB(String plainText, String keyText) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { return Base64.encodeBase64String(cipherECB(Cipher.ENCRYPT_MODE, plainText.getBytes(StandardCharsets.UTF_8), keyText.getBytes())); } public static String decryptECB(String cipherText, String keyText) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { return new String(cipherECB(Cipher.DECRYPT_MODE, Base64.decodeBase64(cipherText), keyText.getBytes())); } public static byte[] cipherECB(int mode, byte[] plainByte, byte[] keyByte) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { Cipher cipher = Cipher.getInstance(ConfigBean.ALGORITHM_ECB_PADDING, ProviderSingleton.getInstance()); cipher.init(mode, new SecretKeySpec(keyByte, ConfigBean.ALGORITHM_NAME)); return cipher.doFinal(plainByte); } public static String encryptCBC(String plainText, String keyText) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { return Base64.encodeBase64String(cipherCBC(Cipher.ENCRYPT_MODE, plainText.getBytes(StandardCharsets.UTF_8), keyText.getBytes())); } public static String decryptCBC(String cipherText, String keyText) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { return new String(cipherCBC(Cipher.DECRYPT_MODE, Base64.decodeBase64(cipherText), keyText.getBytes())); } public static byte[] cipherCBC(int mode, byte[] plainByte, byte[] keyByte) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { Cipher cipher = Cipher.getInstance(ConfigBean.ALGORITHM_CBC_PADDING, ProviderSingleton.getInstance()); cipher.init(mode, new SecretKeySpec(keyByte, ConfigBean.ALGORITHM_NAME), new IvParameterSpec(ConfigBean.SM4_KEY_IV)); return cipher.doFinal(plainByte); }}Utils.java
package com.secret.sm4;import javax.crypto.BadPaddingException;import javax.crypto.IllegalBlockSizeException;import javax.crypto.NoSuchPaddingException;import java.security.InvalidAlgorithmParameterException;import java.security.InvalidKeyException;import java.security.NoSuchAlgorithmException;public class Utils { public static String generateKey() throws NoSuchAlgorithmException { return SecretCommon.generateKey().substring(0, 16); } public static String encrypt(String plainText, String keyText) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { return encryptECB(plainText, keyText); } public static String decrypt(String cipherText, String keyText) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { return decryptECB(cipherText, keyText); } public static String encryptECB(String plainText, String keyText) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { return SecretCommon.encryptECB(plainText, keyText); } public static String decryptECB(String cipherText, String keyText) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { return SecretCommon.decryptECB(cipherText, keyText); } public static String encryptCBC(String plainText, String keyText) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { return SecretCommon.encryptCBC(plainText, keyText); } public static String decryptCBC(String cipherText, String keyText) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { return SecretCommon.decryptCBC(cipherText, keyText); }}测试类：Test.java
package com.secret.sm4;public class Test { public static void main(String[] args) throws Exception{ String key = Utils.generateKey(); System.out.println("生成SM4秘钥：" + key); String plainText = "Believe in yourself, you are the best"; String ECBText = Utils.encrypt(plainText, key); System.out.println("ECB默认加密后密文：" + ECBText); System.out.println("ECB默认解密后明文：" + Utils.decrypt(ECBText, key)); String CBCText = Utils.encryptCBC(plainText, key); System.out.println("CBC加密后密文：" + CBCText); System.out.println("CBC解密后明文：" + Utils.decryptCBC(CBCText, key)); }}2.3、测试
使用方法参考测试类即可。
三、遇到的坑
3.1、秘钥长度
使用KeyGenerator构建的秘钥长度太长无法使用，会提示：
秘钥取16位即可使用。
3.2、转码问题
在使用 ECB模式 时，加解密都会报错，头大。
加密报错如下：
Exception in thread "main" java.lang.IllegalArgumentException: Last encoded character (before the paddings if any) is a valid base 64 alphabet but not a possible value. Expected the discarded bits to be zero.at org.apache.tomcat.util.codec.binary.Base64.validateCharacter(Base64.java:429)at org.apache.tomcat.util.codec.binary.Base64.decode(Base64.java:671)at org.apache.tomcat.util.codec.binary.BaseNCodec.decode(BaseNCodec.java:362)at org.apache.tomcat.util.codec.binary.BaseNCodec.decode(BaseNCodec.java:353)at org.apache.tomcat.util.codec.binary.BaseNCodec.decode(BaseNCodec.java:379)at org.apache.tomcat.util.codec.binary.Base64.decodeBase64(Base64.java:172)at com.secret.sm4.SecretCommon.encryptECB(SecretCommon.java:64)at com.secret.sm4.Utils.encryptECB(Utils.java:39)at com.secret.sm4.Utils.encrypt(Utils.java:23)at com.secret.sm4.Test.main(Test.java:10)
解密报错如下：
Exception in thread "main" javax.crypto.BadPaddingException: pad block corruptedat org.bouncycastle.jcajce.provider.symmetric.util.BaseBlockCipher$BufferedGenericBlockCipher.doFinal(Unknown Source)at org.bouncycastle.jcajce.provider.symmetric.util.BaseBlockCipher.engineDoFinal(Unknown Source)at javax.crypto.Cipher.doFinal(Cipher.java:2165)at com.secret.sm4.SecretCommon.cipherECB(SecretCommon.java:85)at com.secret.sm4.SecretCommon.decryptECB(SecretCommon.java:73)at com.secret.sm4.Utils.decryptECB(Utils.java:48)at com.secret.sm4.Utils.decrypt(Utils.java:30)at com.secret.sm4.Test.main(Test.java:12)
查阅了资料才发现，是转byte[]数组的问题。
String plainText = "Believe in yourself, you are the best";byte[] byte1 = plainText.getBytes();byte[] byte2 = plainText.getBytes(StandardCharsets.UTF_8);byte[] byte3 = Base64.decodeBase64(plainText);byte[] byte4 = Hex.decode(plainText);Base64.encodeBase64String()new String()测试的时候发现，同样是转byte[]，不同的方法，可能结果会不一样，可以自行尝试验证。
加密的时候：
入参直接使用 getBytes()获取byte数组，返回参数使用 Base64.encodeBase64String()即可。
解密的时候：
入参使用 Base64.decodeBase64()获取byte数组，返回参数直接new String() 即可。
四、相关链接
国密算法概述：https://blog.csdn.net/qq_38254635/article/details/131801527
JAVA集成国密SM2：https://blog.csdn.net/qq_38254635/article/details/131810661
JAVA集成国密SM3：https://blog.csdn.net/qq_38254635/article/details/131810696
单例模式及多线程并发在单例模式中的影响：https://blog.csdn.net/qq_38254635/article/details/119888843
来源地址：https://blog.csdn.net/qq_38254635/article/details/131810715
