A friend is outsourcing work in a bank. Since he can't access the Internet, it is troublesome to use his mobile phone to check the information. He asked me to help me find the algorithm about the national secret SM4S. After comparing with other people's writings on Baidu, I summed up the best algorithm I think, main The use of encryption and decryption in the method is clear at a glance. The source code is attached below.
import java.util.Arrays;
public class SMS4 {
private static final int ENCRYPT = 1;
private static final int DECRYPT = 0;
public static final int ROUND = 32;
private static final int BLOCK = 16;
private byte[] Sbox = { (byte) 0xd6, (byte) 0x90, (byte) 0xe9, (byte) 0xfe,
(byte) 0xcc, (byte) 0xe1, 0x3d, (byte) 0xb7, 0x16, (byte) 0xb6,
0x14, (byte) 0xc2, 0x28, (byte) 0xfb, 0x2c, 0x05, 0x2b, 0x67,
(byte) 0x9a, 0x76, 0x2a, (byte) 0xbe, 0x04, (byte) 0xc3,
(byte) 0xaa, 0x44, 0x13, 0x26, 0x49, (byte) 0x86, 0x06,
(byte) 0x99, (byte) 0x9c, 0x42, 0x50, (byte) 0xf4, (byte) 0x91,
(byte) 0xef, (byte) 0x98, 0x7a, 0x33, 0x54, 0x0b, 0x43,
(byte) 0xed, (byte) 0xcf, (byte) 0xac, 0x62, (byte) 0xe4,
(byte) 0xb3, 0x1c, (byte) 0xa9, (byte) 0xc9, 0x08, (byte) 0xe8,
(byte) 0x95, (byte) 0x80, (byte) 0xdf, (byte) 0x94, (byte) 0xfa,
0x75, (byte) 0x8f, 0x3f, (byte) 0xa6, 0x47, 0x07, (byte) 0xa7,
(byte) 0xfc, (byte) 0xf3, 0x73, 0x17, (byte) 0xba, (byte) 0x83,
0x59, 0x3c, 0x19, (byte) 0xe6, (byte) 0x85, 0x4f, (byte) 0xa8,
0x68, 0x6b, (byte) 0x81, (byte) 0xb2, 0x71, 0x64, (byte) 0xda,
(byte) 0x8b, (byte) 0xf8, (byte) 0xeb, 0x0f, 0x4b, 0x70, 0x56,
(byte) 0x9d, 0x35, 0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, (byte) 0xd1,
(byte) 0xa2, 0x25, 0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, (byte) 0x87,
(byte) 0xd4, 0x00, 0x46, 0x57, (byte) 0x9f, (byte) 0xd3, 0x27,
0x52, 0x4c, 0x36, 0x02, (byte) 0xe7, (byte) 0xa0, (byte) 0xc4,
(byte) 0xc8, (byte) 0x9e, (byte) 0xea, (byte) 0xbf, (byte) 0x8a,
(byte) 0xd2, 0x40, (byte) 0xc7, 0x38, (byte) 0xb5, (byte) 0xa3,
(byte) 0xf7, (byte) 0xf2, (byte) 0xce, (byte) 0xf9, 0x61, 0x15,
(byte) 0xa1, (byte) 0xe0, (byte) 0xae, 0x5d, (byte) 0xa4,
(byte) 0x9b, 0x34, 0x1a, 0x55, (byte) 0xad, (byte) 0x93, 0x32,
0x30, (byte) 0xf5, (byte) 0x8c, (byte) 0xb1, (byte) 0xe3, 0x1d,
(byte) 0xf6, (byte) 0xe2, 0x2e, (byte) 0x82, 0x66, (byte) 0xca,
0x60, (byte) 0xc0, 0x29, 0x23, (byte) 0xab, 0x0d, 0x53, 0x4e, 0x6f,
(byte) 0xd5, (byte) 0xdb, 0x37, 0x45, (byte) 0xde, (byte) 0xfd,
(byte) 0x8e, 0x2f, 0x03, (byte) 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b,
0x51, (byte) 0x8d, 0x1b, (byte) 0xaf, (byte) 0x92, (byte) 0xbb,
(byte) 0xdd, (byte) 0xbc, 0x7f, 0x11, (byte) 0xd9, 0x5c, 0x41,
0x1f, 0x10, 0x5a, (byte) 0xd8, 0x0a, (byte) 0xc1, 0x31,
(byte) 0x88, (byte) 0xa5, (byte) 0xcd, 0x7b, (byte) 0xbd, 0x2d,
0x74, (byte) 0xd0, 0x12, (byte) 0xb8, (byte) 0xe5, (byte) 0xb4,
(byte) 0xb0, (byte) 0x89, 0x69, (byte) 0x97, 0x4a, 0x0c,
(byte) 0x96, 0x77, 0x7e, 0x65, (byte) 0xb9, (byte) 0xf1, 0x09,
(byte) 0xc5, 0x6e, (byte) 0xc6, (byte) 0x84, 0x18, (byte) 0xf0,
0x7d, (byte) 0xec, 0x3a, (byte) 0xdc, 0x4d, 0x20, 0x79,
(byte) 0xee, 0x5f, 0x3e, (byte) 0xd7, (byte) 0xcb, 0x39, 0x48 };
private int[] CK = { 0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9, 0xe0e7eef5,
0xfc030a11, 0x181f262d, 0x343b4249, 0x50575e65, 0x6c737a81,
0x888f969d, 0xa4abb2b9, 0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d,
0x141b2229, 0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209, 0x10171e25,
0x2c333a41, 0x484f565d, 0x646b7279 };
private int Rotl(int x, int y) {
return x << y | x >>> (32 - y);
}
private int ByteSub(int A) {
return (Sbox[A >>> 24 & 0xFF] & 0xFF) << 24
| (Sbox[A >>> 16 & 0xFF] & 0xFF) << 16
| (Sbox[A >>> 8 & 0xFF] & 0xFF) << 8 | (Sbox[A & 0xFF] & 0xFF);
}
private int L1(int B) {
return B ^ Rotl(B, 2) ^ Rotl(B, 10) ^ Rotl(B, 18) ^ Rotl(B, 24);
// return B^(B<<2|B>>>30)^(B<<10|B>>>22)^(B<<18|B>>>14)^(B<<24|B>>>8);
}
private int L2(int B) {
return B ^ Rotl(B, 13) ^ Rotl(B, 23);
// return B^(B<<13|B>>>19)^(B<<23|B>>>9);
}
void SMS4Crypt(byte[] Input, byte[] Output, int[] rk) {
int r, mid, x0, x1, x2, x3;
int[] x = new int[4];
int[] tmp = new int[4];
for (int i = 0; i < 4; i++) {
tmp[0] = Input[0 + 4 * i] & 0xff;
tmp[1] = Input[1 + 4 * i] & 0xff;
tmp[2] = Input[2 + 4 * i] & 0xff;
tmp[3] = Input[3 + 4 * i] & 0xff;
x[i] = tmp[0] << 24 | tmp[1] << 16 | tmp[2] << 8 | tmp[3];
// x[i]=(Input[0+4*i]<<24|Input[1+4*i]<<16|Input[2+4*i]<<8|Input[3+4*i]);
}
for (r = 0; r < 32; r += 4) {
mid = x[1] ^ x[2] ^ x[3] ^ rk[r + 0];
mid = ByteSub(mid);
x[0] = x[0] ^ L1(mid); // x4
mid = x[2] ^ x[3] ^ x[0] ^ rk[r + 1];
mid = ByteSub(mid);
x[1] = x[1] ^ L1(mid); // x5
mid = x[3] ^ x[0] ^ x[1] ^ rk[r + 2];
mid = ByteSub(mid);
x[2] = x[2] ^ L1(mid); // x6
mid = x[0] ^ x[1] ^ x[2] ^ rk[r + 3];
mid = ByteSub(mid);
x[3] = x[3] ^ L1(mid); // x7
}
// Reverse
for (int j = 0; j < 16; j += 4) {
Output[j] = (byte) (x[3 - j / 4] >>> 24 & 0xFF);
Output[j + 1] = (byte) (x[3 - j / 4] >>> 16 & 0xFF);
Output[j + 2] = (byte) (x[3 - j / 4] >>> 8 & 0xFF);
Output[j + 3] = (byte) (x[3 - j / 4] & 0xFF);
}
}
private void SMS4KeyExt(byte[] Key, int[] rk, int CryptFlag) {
int r, mid;
int[] x = new int[4];
int[] tmp = new int[4];
for (int i = 0; i < 4; i++) {
tmp[0] = Key[0 + 4 * i] & 0xFF;
tmp[1] = Key[1 + 4 * i] & 0xff;
tmp[2] = Key[2 + 4 * i] & 0xff;
tmp[3] = Key[3 + 4 * i] & 0xff;
x[i] = tmp[0] << 24 | tmp[1] << 16 | tmp[2] << 8 | tmp[3];
// x[i]=Key[0+4*i]<<24|Key[1+4*i]<<16|Key[2+4*i]<<8|Key[3+4*i];
}
x[0] ^= 0xa3b1bac6;
x[1] ^= 0x56aa3350;
x[2] ^= 0x677d9197;
x[3] ^= 0xb27022dc;
for (r = 0; r < 32; r += 4) {
mid = x[1] ^ x[2] ^ x[3] ^ CK[r + 0];
mid = ByteSub(mid);
rk[r + 0] = x[0] ^= L2(mid); // rk0=K4
mid = x[2] ^ x[3] ^ x[0] ^ CK[r + 1];
mid = ByteSub(mid);
rk[r + 1] = x[1] ^= L2(mid); // rk1=K5
mid = x[3] ^ x[0] ^ x[1] ^ CK[r + 2];
mid = ByteSub(mid);
rk[r + 2] = x[2] ^= L2(mid); // rk2=K6
mid = x[0] ^ x[1] ^ x[2] ^ CK[r + 3];
mid = ByteSub(mid);
rk[r + 3] = x[3] ^= L2(mid); // rk3=K7
}
// 解密时轮密钥使用顺序：rk31,rk30,...,rk0
if (CryptFlag == DECRYPT) {
for (r = 0; r < 16; r++) {
mid = rk[r];
rk[r] = rk[31 - r];
rk[31 - r] = mid;
}
}
}
public int sms4(byte[] in, int inLen, byte[] key, byte[] out, int CryptFlag) {
int point = 0;
int[] round_key = new int[ROUND];
// int[] round_key={0};
SMS4KeyExt(key, round_key, CryptFlag);
byte[] input = new byte[16];
byte[] output = new byte[16];
while (inLen >= BLOCK) {
input = Arrays.copyOfRange(in, point, point + 16);
// output=Arrays.copyOfRange(out, point, point+16);
SMS4Crypt(input, output, round_key);
System.arraycopy(output, 0, out, point, BLOCK);
inLen -= BLOCK;
point += BLOCK;
}
return 0;
}
public static byte[] encodeSMS4(String plaintext, byte[] key) {
if (plaintext == null || plaintext.equals("")) {
return null;
}
for (int i = plaintext.getBytes().length % 16; i < 16; i++) {
plaintext += '\0';
} return SMS4.encodeSMS4(plaintext.getBytes(), key); } /** * 不限明文长度的SMS4加密 * * @param plaintext * @param key * @return */
public static byte[] encodeSMS4(byte[] plaintext, byte[] key) {
byte[] ciphertext = new byte[plaintext.length]; int k = 0; int plainLen = plaintext.length; while (k + 16 <= plainLen) { byte[] cellPlain = new byte[16]; for (int i = 0; i < 16; i++) { cellPlain[i] = plaintext[k + i]; } byte[] cellCipher = encode16(cellPlain, key); for (int i = 0; i < cellCipher.length; i++) { ciphertext[k + i] = cellCipher[i]; } k += 16; } return ciphertext; } /** * 不限明文长度的SMS4解密 *
* @param ciphertext
* @param key
* @return
*/
public static byte[] decodeSMS4(byte[] ciphertext, byte[] key) {
byte[] plaintext = new byte[ciphertext.length]; int k = 0; int cipherLen = ciphertext.length; while (k + 16 <= cipherLen) { byte[] cellCipher = new byte[16]; for (int i = 0; i < 16; i++) { cellCipher[i] = ciphertext[k + i]; } byte[] cellPlain = decode16(cellCipher, key); for (int i = 0; i < cellPlain.length; i++) { plaintext[k + i] = cellPlain[i]; } k += 16; }
return plaintext;
} /** * 解密，获得明文字符串 * @param ciphertext * @param key * @return */ public static String decodeSMS4toString(byte[] ciphertext, byte[] key) { byte[] plaintext = new byte[ciphertext.length]; plaintext = decodeSMS4(ciphertext, key); return new String(plaintext); } /** * 只加密16位明文 * * @param plaintext * @param key * @return */ private static byte[] encode16(byte[] plaintext, byte[] key) { byte[] cipher = new byte[16]; SMS4 sm4 = new SMS4();
sm4.sms4(plaintext, 16, key, cipher, ENCRYPT); return cipher; } /** * 只解密16位密文 * * @param plaintext * @param key * @return */ private static byte[] decode16(byte[] ciphertext, byte[] key) { byte[] plain = new byte[16]; SMS4 sm4 = new SMS4(); sm4.sms4(ciphertext, 16, key, plain, DECRYPT); return plain;
}
//This method converts the encrypted hexadecimal byte array into a String string
if (byteArray == null || byteArray.length < 1)
throw new IllegalArgumentException("this byteArray must not be null or empty"); final StringBuilder hexString = new StringBuilder(); for (int i = 0; i < byteArray.length; i++) { if ((byteArray[i] & 0xff) < 0x10)//0~F前面不零 hexString.append("0"); hexString.append(Integer.toHexString(0xFF & byteArray[i])); } return hexString.toString().toLowerCase(); } public static void main(String[] args) { String key = "kxlyzjyw_zh_jrqs"; String input= "123456"; byte[] enOut = SMS4.encodeSMS4(input, key.getBytes());
System.out.println("Encryption result: ");
System.out.println(toHexString(enOut));
}
}
operation result
