SMS4簡介：

本算法是一個分組算法。該算法的分組長度為128比特，密鑰長度為128比特，也就是16個字節。加密算法與密鑰擴展算法都采用32輪非線性迭代結構。解密算法與加密算法的結構相同，只是輪密鑰的使用順序相反，解密輪密鑰是加密輪密鑰的逆序。所有在SMS4的基礎類中，你會看到加密和解密的基礎函數是同一個，只是需要一個int型的標志位來判斷是加密還是解密。

SMS4加密算法基礎類：

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); // x4mid = x[2] ^ x[3] ^ x[0] ^ rk[r + 1];mid = ByteSub(mid);x[1] = x[1] ^ L1(mid); // x5mid = x[3] ^ x[0] ^ x[1] ^ rk[r + 2];mid = ByteSub(mid);x[2] = x[2] ^ L1(mid); // x6mid = x[0] ^ x[1] ^ x[2] ^ rk[r + 3];mid = ByteSub(mid);x[3] = x[3] ^ L1(mid); // x7}// Reversefor (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=K4mid = x[2] ^ x[3] ^ x[0] ^ CK[r + 1];mid = ByteSub(mid);rk[r + 1] = x[1] ^= L2(mid); // rk1=K5mid = x[3] ^ x[0] ^ x[1] ^ CK[r + 2];mid = ByteSub(mid);rk[r + 2] = x[2] ^= L2(mid); // rk2=K6mid = x[0] ^ x[1] ^ x[2] ^ CK[r + 3];mid = ByteSub(mid);rk[r + 3] = x[3] ^= L2(mid); // rk3=K7}// 解密時輪密鑰使用順序：rk31,rk30,...,rk0if (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;} }

封裝對外接口：

基于這個基本類，對其進行封裝接口，主要接口如下：

private static byte[] encode16(byte[] plain, byte[] key); private static byte[] decode16(byte[] cipher, byte[] key); private static byte[] encode32(byte[] plain, byte[] key); private static byte[] decode32(byte[] cipher, byte[] key); public static byte[] encodeSMS4(byte[] plain, byte[] key); public static byte[] decodeSMS4(byte[] cipher, byte[] key); public static String decodeSMS4toString(byte[] cipher, byte[] key);
encode16(byte[], byte[])是針對16位明文和16位密鑰進行加密的接口；
private static byte[] decode16(byte[] cipher, byte[] key)：是針對16位密文和16位密鑰進行解密的接口；
private static byte[] encode32(byte[] plain, byte[] key)：是針對32位明文和16位密鑰進行加密的接口；
private static byte[] decode32(byte[] cipher, byte[] key)：是針對32位密文和16位密鑰進行解密的接口；
public static byte[] encodeSMS4(byte[] plain, byte[] key)：是針對不限字節數的明文和16位密鑰進行加密的接口；
public static byte[] decodeSMS4(byte[] cipher, byte[] key)：是針對不限字節數的密文和16位密鑰進行解密的接口；
public static String decodeSMS4toString(byte[] cipher, byte[] key)：是針對不限字節數的密文和16位密鑰進行解密的接口；

接口方法代碼：

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);}/*** 不限明文長度的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;}/*** 不限明文長度的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，獲得明文字符串* @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;} 只對32位明文加密這里不做介紹，與只對16位明文的方法很類似。

而不限明文長度的加密和解密的基本算法就是基于這個只對16位進行加密和解密的基礎之上的。對超過16位的明文，這里采用的是分組加密。而如果遇到像30位這樣的不能被16整除長度的明文，這里采用一個補位的方式，就是將其補到對被16整除為止。原則上是只補到最小的一個能被16整除的數，當然如果你高興，補大一些也沒關系，因為補的是結束符'\0'。

分組加密是要把每一個16位明文加密一次，再把這些加密過的16位密文重新組合成一個新的密文。在解密的過程中也是先拆分成單個16位，再把這些解密后的若干明文重新組合成新的明文。

使用示范：

// 密鑰byte[] key = { 0x01, 0x23, 0x45, 0x67, (byte) 0x89, (byte) 0xab,(byte) 0xcd, (byte) 0xef, (byte) 0xfe, (byte) 0xdc,(byte) 0xba, (byte) 0x98, 0x76, 0x54, 0x32, 0x10 };String newString = "Coding，你好！"; // 明文byte[] enOut = SMS4.encodeSMS4(newString, key);if (enOut == null) {return;}System.out.println("加密結果：");printBit(enOut);byte[] deOut = SMS4.decodeSMS4(enOut, key);System.out.println("\n解密結果(return byte[])：");printBit(deOut);String deOutStr = SMS4.decodeSMS4toString(enOut, key);System.out.println("\n解密結果(return String)：\n" + deOutStr);

示例Demo連接：

http://download.csdn.net/detail/u013761665/8357917

總結

以上是生活随笔為你收集整理的Java版SMS4加密算法的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。