SM4 对称加密算法

import org.apache.commons.codec.binary.Hex; import org.bouncycastle.jce.provider.BouncyCastleProvider; import org.bouncycastle.pqc.math.linearalgebra.ByteUtils; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.spec.SecretKeySpec; import java.security.Key; import java.security.SecureRandom; import java.security.Security; import java.util.Arrays; public class Sm4Util { static { Security.addProvider(new BouncyCastleProvider()); } 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：PKCS5Padding public static final String ALGORITHM_NAME_ECB_PADDING = "SM4/ECB/PKCS5Padding"; // 128-32位16进制；256-64位16进制 public static final int DEFAULT_KEY_SIZE = 128; /** * 自动生成密钥 * * @return * @explain */ public static String generateKey() throws Exception { return new String(Hex.encodeHex(generateKey(DEFAULT_KEY_SIZE), false)); } /** * @param keySize * @return * @throws Exception * @explain */ 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(); } /** * 生成ECB暗号 * * @param algorithmName 算法名称 * @param mode 模式 * @param key * @return * @throws Exception * @explain ECB模式（电子密码本模式：Electronic codebook） */ 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; } /** * sm4加密 * * @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 * @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 */ public static String encryptEcb(String hexKey, String paramStr) { try { String cipherText = ""; // 16进制字符串-->byte[] byte[] keyData = ByteUtils.fromHexString(hexKey); // String-->byte[] byte[] srcData = paramStr.getBytes(ENCODING); // 加密后的数组 byte[] cipherArray = encrypt_Ecb_Padding(keyData, srcData); // byte[]-->hexString cipherText = ByteUtils.toHexString(cipherArray); return cipherText; } catch (Exception e) { return paramStr; } } /** * 加密模式之Ecb * * @param key * @param data * @return * @throws Exception * @explain */ 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 * * @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 * @explain 解密模式：采用ECB */ public static String decryptEcb(String hexKey, String cipherText) { // 用于接收解密后的字符串 String decryptStr = ""; // hexString-->byte[] byte[] keyData = ByteUtils.fromHexString(hexKey); // hexString-->byte[] byte[] cipherData = ByteUtils.fromHexString(cipherText); // 解密 byte[] srcData = new byte[0]; try { srcData = decrypt_Ecb_Padding(keyData, cipherData); // byte[]-->String decryptStr = new String(srcData, ENCODING); } catch (Exception e) { e.printStackTrace(); /*解密失败，返回原报文*/ return cipherText; } return decryptStr; } /** * 解密 * * @param key * @param cipherText * @return * @throws Exception * @explain */ 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 * * @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 * @explain */ public static boolean verifyEcb(String hexKey, String cipherText, String paramStr) throws Exception { // 用于接收校验结果 boolean flag = false; // hexString-->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; } }