1、算法定义:SM4算法是一种分组密码算法。其分组长度为128bit,密钥长度也为128bit。加密算法与密钥扩展算法均采用32轮非线性迭代结构,以字(32位)为单位进行加密运算,每一次迭代运算均为一轮变换函数F。SM4算法加/解密算法的结构相同,只是使用轮密钥相反,其中解密轮密钥是加密轮密钥的逆序。
2、
基本运算
⊕ 异或
<<<i 循环左移i位
3.算法实现
即首先执行32次轮函数迭代运算,然后在对最后一轮数据反序变换并得到密文输出
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;
import java.security.*;
import java.util.Arrays;
/**
* packageName com.utils
*
* @author
* @version JDK 8
* @className Sm4Util
* @date 2024/5/8 0008
* @description 国产SM4数据加密和解密
*/
@Slf4j
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_PADDING5 = "SM4/ECB/PKCS5Padding";
public static final String ALGORITHM_NAME_ECB_PADDING7 = "SM4/ECB/PKCS7Padding";
// 64-16位16进制;128-32位16进制;256-64位16进制
public static final int DEFAULT_KEY_SIZE = 128;
//16进制密钥(忽略大小写)
private static String hexKey = "86C63180C2806ED1";
/**
* 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;
}
// 产生密钥
/**
* 自动生成密钥
*
* @return
* @throws NoSuchAlgorithmException
* @throws NoSuchProviderException
* @explain
*/
public static byte[] generateKey() throws Exception {
return generateKey(DEFAULT_KEY_SIZE);
}
/**
* @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();
}
/**
* sm4加密
*
* @param hexKey 16进制密钥(忽略大小写)--可以自定义key
* @param paramStr 待加密字符串
* @return 返回16进制的加密字符串
* @throws Exception
* @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) {
String cipherText = "";
try {
// 16进制字符串-->byte[]
//byte[] keyData = ByteUtils.fromHexString(hexKey);
byte[] keyData = hexKey.getBytes(ENCODING);
// 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);
cipherText = Base64.encodeBase64String(cipherArray);
log.info("SM4加密成功:{}",cipherText);
} catch (Exception e) {
log.error("sm4加密失败:"+e.getMessage());
}
return cipherText;
}
/**
* sm4加密-不用传key
* @param paramStr 待加密字符串
* @return 返回16进制的加密字符串
* 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 paramStr) {
String cipherText = "";
try {
// 16进制字符串-->byte[]
//byte[] keyData = ByteUtils.fromHexString(hexKey);
byte[] keyData = hexKey.getBytes(ENCODING);
// 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);
cipherText = Base64.encodeBase64String(cipherArray);
log.info("SM4加密成功:{}",cipherText);
} catch (Exception e) {
log.error("sm4加密失败:"+e.getMessage());
}
return cipherText;
}
/**
* 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_PADDING7, Cipher.ENCRYPT_MODE, key);
return cipher.doFinal(data);
}
/**
* sm4解密
*
* @param hexKey 16进制密钥-可以自定义key
* @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) {
try {
// 用于接收解密后的字符串
String decryptStr = "";
// hexString-->byte[]
//byte[] keyData = ByteUtils.fromHexString(hexKey);
byte[] keyData = hexKey.getBytes(ENCODING);
// hexString-->byte[]
//byte[] cipherData = ByteUtils.fromHexString(cipherText);
byte[] cipherData =Base64.decodeBase64(cipherText);
// 解密
byte[] srcData = decrypt_Ecb_Padding(keyData, cipherData);
// byte[]-->String
decryptStr = new String(srcData, ENCODING);
log.info("SM4数据解密成功:{}",decryptStr);
return decryptStr;
} catch (Exception e) {
log.error("SM4数据解密失败",e.getMessage());
}
return null;
}
/**
* sm4解密--不用传key,默认key
* @param cipherText 16进制的加密字符串(忽略大小写)
* @return 解密后的字符串
* @explain 解密模式:采用ECB
*/
public static String decryptEcb(String cipherText) {
try {
// 用于接收解密后的字符串
String decryptStr = "";
// hexString-->byte[]
//byte[] keyData = ByteUtils.fromHexString(hexKey);
byte[] keyData = hexKey.getBytes(ENCODING);
// hexString-->byte[]
//byte[] cipherData = ByteUtils.fromHexString(cipherText);
byte[] cipherData =Base64.decodeBase64(cipherText);
// 解密
byte[] srcData = decrypt_Ecb_Padding(keyData, cipherData);
// byte[]-->String
decryptStr = new String(srcData, ENCODING);
log.info("SM4数据解密成功:{}",decryptStr);
return decryptStr;
} catch (Exception e) {
log.error("SM4数据解密失败",e.getMessage());
}
return null;
}
/**
* 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_PADDING7, 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);
byte[] keyData = hexKey.getBytes(ENCODING);
// 将16进制字符串转换成数组
//byte[] cipherData = ByteUtils.fromHexString(cipherText);
byte[] cipherData = Base64.decodeBase64(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;
}
/**
* 校验加密前后的字符串是否为同一数据
*
* @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 cipherText, String paramStr) throws Exception {
// 用于接收校验结果
boolean flag = false;
// hexString-->byte[]
//byte[] keyData = ByteUtils.fromHexString(hexKey);
byte[] keyData = hexKey.getBytes(ENCODING);
// 将16进制字符串转换成数组
//byte[] cipherData = ByteUtils.fromHexString(cipherText);
byte[] cipherData = Base64.decodeBase64(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;
}
public static void main(String[] args) {
try {
String json = "{\"name\":\"Marydon\",\"website\":\"http://www.cnblogs.com/Marydon20170307\"}";
json = "1234567890abcdefghijklmnopqrstuvwxyz";
// 自定义的16位16进制密钥,key的字符长度智能是16位
String key = "86C63180C2806ED1";
String cipher = Sm4Util.encryptEcb(key, json);
System.out.println("国密SM4加密解密:\r\n密钥:" + key + " \n加密内容:" + json + " \n加密后:" + cipher);
//System.out.println(cipher);
//比对加密解密信息
// String cipher = "Ub+KDfcDkHwJYdKn82b4c4mVehDAcy7yLh1/+Yfy1nABHwqvcgwbLimrnLOnUstN";
System.out.println(Sm4Util.verifyEcb(key, cipher, json));// true
json = Sm4Util.decryptEcb(key, cipher);
System.out.println("国密SM4加密解密:\n密钥:" + key + " \n加密内容:" + cipher + " \n解密后:" + json);
//System.out.println(json);
} catch (Exception e) {
e.printStackTrace();
}
}
}
以上代码亲测有效,有任何疑问欢迎留言。