sm4加解密以及随机生成密钥

本文主要是介绍sm4加解密以及随机生成密钥，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

字节数组处理工具类

public class ByteUtils {private static final char[] HEX_CHARS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e','f' };private ByteUtils() {// Utility class}public static byte[] fromHexString(String s) {int len = s.length();//// // Data length must be even// if (len % 2 != 0) {// throw new IllegalArgumentException("Hex string has an odd number of// characters");// }byte[] data = new byte[len / 2];for (int i = 0; i < len; i += 2) {data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4) + Character.digit(s.charAt(i + 1), 16));}return data;}public static String toHexString(byte[] input) {StringBuilder sb = new StringBuilder();for (byte b : input) {sb.append(HEX_CHARS[(b >>> 4) & 0x0f]);sb.append(HEX_CHARS[b & 0x0f]);}return sb.toString();}public static String toHexString(byte[] input, String prefix, String separator) {StringBuilder sb = new StringBuilder(prefix);for (int i = 0; i < input.length; i++) {sb.append(HEX_CHARS[(input[i] >>> 4) & 0x0f]);sb.append(HEX_CHARS[input[i] & 0x0f]);if (i < input.length - 1) {sb.append(separator);}}return sb.toString();}
}

随机生成十六进制密钥

// 生成 SM4 密钥的方法public static String generateSM4Key() {// 定义一个 128 位的字节数组byte[] keyBytes = new byte[16];// 使用 SecureRandom 生成随机密钥SecureRandom secureRandom = new SecureRandom();secureRandom.nextBytes(keyBytes);// 将字节数组转换为十六进制字符串StringBuilder sb = new StringBuilder();for (byte b : keyBytes) {// 使用 Integer.toHexString() 方法将字节转换为十六进制字符串sb.append(String.format("%02x", b & 0xff));}// 返回生成的密钥return sb.toString();}//    public static void main(String[] args) {
//        // 生成 SM4 密钥并打印
//        String sm4Key = generateSM4Key();
//        System.out.println("Generated SM4 Key: " + sm4Key);
//    }

sm4工具类

public class Sm4Utils {static {Security.addProvider(new BouncyCastleProvider());}private static final String ENCODING = "UTF-8";public static final String ALGORIGTHM_NAME = "SM4";public static final String ALGORITHM_NAME_ECB_PADDING = "SM4/ECB/PKCS7Padding";public static final int DEFAULT_KEY_SIZE = 128;private static Cipher generateEcbCipher(String algorithmName, int mode, byte[] key) throws Exception {Cipher cipher = Cipher.getInstance(algorithmName, "BC");Key sm4Key = new SecretKeySpec(key, ALGORIGTHM_NAME);cipher.init(mode, sm4Key);return cipher;}public static byte[] generateKey(String keyString) throws Exception {// Use SHA-256 to hash the string and then take first 128 bits (16 bytes)MessageDigest digest = MessageDigest.getInstance("SHA-256");byte[] hash = digest.digest(keyString.getBytes(StandardCharsets.UTF_8));byte[] key = new byte[16];System.arraycopy(hash, 0, key, 0, 16);return key;}public static String encryptEcb(String key, String paramStr, String charset) throws Exception {String cipherText = "";if (null != paramStr && !"".equals(paramStr)) {byte[] keyData = generateKey(key);charset = charset.trim();if (charset.length() <= 0) {charset = ENCODING;}byte[] srcData = paramStr.getBytes(charset);byte[] cipherArray = encryptEcbPadding(keyData, srcData);cipherText = ByteUtils.toHexString(cipherArray);}return cipherText;}public static byte[] encryptEcbPadding(byte[] key, byte[] data) throws Exception {Cipher cipher = generateEcbCipher("SM4/ECB/PKCS7Padding", Cipher.ENCRYPT_MODE, key);byte[] bs = cipher.doFinal(data);return bs;}public static String decryptEcb(String key, String cipherText, String charset) throws Exception {String decryptStr = "";byte[] keyData = generateKey(key);byte[] cipherData = ByteUtils.fromHexString(cipherText);byte[] srcData = decryptEcbPadding(keyData, cipherData);charset = charset.trim();if (charset.length() <= 0) {charset = ENCODING;}decryptStr = new String(srcData, charset);return decryptStr;}public static byte[] decryptEcbPadding(byte[] key, byte[] cipherText) throws Exception {Cipher cipher = generateEcbCipher("SM4/ECB/PKCS7Padding", Cipher.DECRYPT_MODE, key);return cipher.doFinal(cipherText);}//测试加解密public static void main(String[] args) {try {String enpwd = "";//已加密数据String json = "";//需要加密数据String key = "";//这里填生成的十六进制密钥
//            String cipher = encryptEcb(key, json, ENCODING);//加密
//            System.out.println(cipher);System.out.println(decryptEcb(key, enpwd, ENCODING));//解密} catch (Exception var5) {var5.printStackTrace();}}
}

pom

<dependency><groupId>org.bouncycastle</groupId><artifactId>bcprov-jdk15to18</artifactId><version>1.68</version>//可根据情况修改
</dependency>

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