文章来源:https://www.jianshu.com/p/5ec8464b0a1b
一、简介
-
与DES和AES算法类似,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。
二、原理
首先,将明文转化为字节,由于SM4加密算法按照128个位进行分组,所以很大几率会出现最后一个分组不够128位的情况,需要进行填充,填充方式有很多,比如ZeroPadding、PKCS7Padding、PKCS5Padding,不管使用哪种方式,最后每个分组都是128位。然后对每个分组执行上面的操作,每个分组按照32位一个字分成四个字,根据一定的规则计算出下一轮的结果。进行32轮的计算,最后将加密的结果逆序之后就可以了。
解密时只是将轮密钥的使用顺序进行逆向进行。
三、ECB模式与CBC模式
1、ECB模式
- 电子密码本模式,最古老,最简单的模式,将加密的数据分成若干组,每组的大小跟加密密钥相同。不足的部分进行填充。
- 按照顺序将计算所得的数据连在一起即可,各段数据之间互不影响。
•优点:
•简单
•有利于并行计算
•误差不会被传递
•缺点:
•不能隐藏明文的模式
•可能对明文进行主动攻击
2、CBC模式
- 密文分组链接模式,也需要进行分组,不足的部分按照指定的数据进行填充。
- 需要一个初始化向量,每个分组数据与上一个分组数据加密的结果进行异或运算,最后再进行加密。将所有分组加密的结果连接起来就形成了最终的结果。
•优点:
•不容易进行主动攻击
•安全性好于ECB
•缺点:
•不利于并行计算
•误差传递
•需要初始化向量
四、三种填充方式的比较
某些加密算法要求明文需要按一定长度对齐,叫做块大小(BlockSize),比如16字节,那么对于一段任意的数据,加密前需要对最后一个块填充到16 字节,解密后需要删除掉填充的数据。
ZeroPadding,数据长度不对齐时使用0填充,否则不填充。
PKCS7Padding,假设数据长度需要填充n(n>0)个字节才对齐,那么填充n个字节,每个字节都是n;如果数据本身就已经对齐了,则填充一块长度为块大小的数据,每个字节都是块大小。
PKCS5Padding,PKCS7Padding的子集,块大小固定为8字节。
由于使用PKCS7Padding/PKCS5Padding填充时,最后一个字节肯定为填充数据的长度,所以在解密后可以准确删除填充的数据,而使用ZeroPadding填充时,没办法区分真实数据与填充数据,所以只适合以\0结尾的字符串加解密。
五、代码实现
SM4.java
import Util;import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Arrays;public class SM4 {public static final int SM4_ENCRYPT = 1;public static final int SM4_DECRYPT = 0;private long GET_ULONG_BE(byte[] b, int i) {long n = (long) (b[i] & 0xff) << 24 | (long) ((b[i + 1] & 0xff) << 16) | (long) ((b[i + 2] & 0xff) << 8) | (long) (b[i + 3] & 0xff) & 0xffffffffL;return n;}private void PUT_ULONG_BE(long n, byte[] b, int i) {b[i] = (byte) (int) (0xFF & n >> 24);b[i + 1] = (byte) (int) (0xFF & n >> 16);b[i + 2] = (byte) (int) (0xFF & n >> 8);b[i + 3] = (byte) (int) (0xFF & n);}private long SHL(long x, int n) {return (x & 0xFFFFFFFF) << n;}private long ROTL(long x, int n) {return SHL(x, n) | x >> (32 - n);}private void SWAP(long[] sk, int i) {long t = sk[i];sk[i] = sk[(31 - i)];sk[(31 - i)] = t;}public static final byte[] SboxTable = {(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};public static final int[] FK = {0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc};public static final 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 byte sm4Sbox(byte inch) {int i = inch & 0xFF;byte retVal = SboxTable[i];return retVal;}private long sm4Lt(long ka) {long bb = 0L;long c = 0L;byte[] a = new byte[4];byte[] b = new byte[4];PUT_ULONG_BE(ka, a, 0);b[0] = sm4Sbox(a[0]);b[1] = sm4Sbox(a[1]);b[2] = sm4Sbox(a[2]);b[3] = sm4Sbox(a[3]);bb = GET_ULONG_BE(b, 0);c = bb ^ ROTL(bb, 2) ^ ROTL(bb, 10) ^ ROTL(bb, 18) ^ ROTL(bb, 24);return c;}private long sm4F(long x0, long x1, long x2, long x3, long rk) {return x0 ^ sm4Lt(x1 ^ x2 ^ x3 ^ rk);}private long sm4CalciRK(long ka) {long bb = 0L;long rk = 0L;byte[] a = new byte[4];byte[] b = new byte[4];PUT_ULONG_BE(ka, a, 0);b[0] = sm4Sbox(a[0]);b[1] = sm4Sbox(a[1]);b[2] = sm4Sbox(a[2]);b[3] = sm4Sbox(a[3]);bb = GET_ULONG_BE(b, 0);rk = bb ^ ROTL(bb, 13) ^ ROTL(bb, 23);return rk;}private void sm4_setkey(long[] SK, byte[] key) {long[] MK = new long[4];long[] k = new long[36];int i = 0;MK[0] = GET_ULONG_BE(key, 0);MK[1] = GET_ULONG_BE(key, 4);MK[2] = GET_ULONG_BE(key, 8);MK[3] = GET_ULONG_BE(key, 12);k[0] = MK[0] ^ (long) FK[0];k[1] = MK[1] ^ (long) FK[1];k[2] = MK[2] ^ (long) FK[2];k[3] = MK[3] ^ (long) FK[3];for (; i < 32; i++) {k[(i + 4)] = (k[i] ^ sm4CalciRK(k[(i + 1)] ^ k[(i + 2)] ^ k[(i + 3)] ^ (long) CK[i]));SK[i] = k[(i + 4)];}}private void sm4_one_round(long[] sk, byte[] input, byte[] output) {int i = 0;long[] ulbuf = new long[36];ulbuf[0] = GET_ULONG_BE(input, 0);ulbuf[1] = GET_ULONG_BE(input, 4);ulbuf[2] = GET_ULONG_BE(input, 8);ulbuf[3] = GET_ULONG_BE(input, 12);while (i < 32) {ulbuf[(i + 4)] = sm4F(ulbuf[i], ulbuf[(i + 1)], ulbuf[(i + 2)], ulbuf[(i + 3)], sk[i]);i++;}PUT_ULONG_BE(ulbuf[35], output, 0);PUT_ULONG_BE(ulbuf[34], output, 4);PUT_ULONG_BE(ulbuf[33], output, 8);PUT_ULONG_BE(ulbuf[32], output, 12);}public static byte[] PKCS5Padding(byte[] inputByte) {// 获字节长度int length = inputByte.length;// 补齐位数int leftLength = 16 - (length % 16);// 定义新字节byte[] arrayReturn = new byte[length + leftLength];// 定义填充字节byte[] plusbyte = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,0x0f,0x10 };// 是否满足为16字节倍数//if (leftLength < 16) {// 不满足16倍数自动填充for (int i = 0; i < length + leftLength; i++) {if (i < length) {// 赋值arrayReturn[i] = inputByte[i];} else {// 补齐位数arrayReturn[i] = (byte)leftLength;}}// System.out.println("填充的字节:"+plusbyte[leftLength]);
// } else {
// for (int i = 0; i < length + 16; i++) {
// if (i < length) {
// // 赋值
// arrayReturn[i] = inputByte[i];
// } else {
// // 补齐位数
// arrayReturn[i] = (byte)16;
// }
// }
// }return arrayReturn;}public static byte[] PKCS7PaddingRestore(byte[] paramArray) throws Exception {//try {// 定义是否需要消除填充数据//boolean needRestore = true;int length = paramArray.length;// 获取字节长度// 拆分并获取最后一组16倍数数值byte[] paramByteLast = Arrays.copyOfRange(paramArray, length - 16, length);// 获取最后一个字节byte byteLast = paramByteLast[paramByteLast.length - 1];return Arrays.copyOfRange(paramArray,0,length-byteLast);
// // 开始填充字节位置
// int paddingNum = paramByteLast.length - byteLast;
// if (paddingNum > 0) {
// // 判断数组字节位数的字节是否与最后字节相等
// for (int i = paddingNum; i < paramByteLast.length; i++) {
// byte paramSon = paramByteLast[i];
// if (byteLast != paramSon) {
// needRestore = false;
// }
// }
// } else {
// needRestore = false;
// }
// if (needRestore) {
// // 组合新数组并返回
// byte[] resultArray = Arrays.copyOfRange(paramArray, 0, length - byteLast);
// return resultArray;
// }
// return paramArray;
// } catch (Exception e) {
// throw new Exception("数据异常,字节填充还原错误,异常抛出!" + e.getMessage());
// }}//修改了填充模式,为模式private byte[] padding(byte[] input, int mode) {byte[] ret = (byte[]) null;if (mode == SM4_ENCRYPT) {//填充:hex必须是32的整数倍填充 ,填充的是80 00 00 00
// int p = 16 - input.length % 16;
// String inputHex = Util.byteToHex(input)+ "80";
// StringBuffer stringBuffer =new StringBuffer(inputHex);
// for (int i = 0; i <p-1 ; i++) {
// stringBuffer.append("00");
// }
// ret= Util.hexToByte(stringBuffer.toString());try {ret = PKCS5Padding(input);} catch (Exception e) {e.printStackTrace();}//ret = new byte[input.length + p];/*System.arraycopy(input, 0, ret, 0, input.length);for (int i = 0; i < p; i++) {ret[input.length + i] = (byte) '�';}*/} else {/*int p = input[input.length - 1];ret = new byte[input.length - p];System.arraycopy(input, 0, ret, 0, input.length - p);*/// String inputHex =Util.byteToHex(input);
// int i = inputHex.lastIndexOf("80");
// String substring = inputHex.substring(0, i);
// ret= Util.hexToByte(substring);try {ret = PKCS7PaddingRestore(input);} catch (Exception e) {e.printStackTrace();}}return ret;}public void sm4_setkey_enc(SM4_Context ctx, byte[] key) throws Exception {if (ctx == null) {throw new Exception("ctx is null!");}if (key == null || key.length != 16) {throw new Exception("key error!");}ctx.mode = SM4_ENCRYPT;sm4_setkey(ctx.sk, key);}public void sm4_setkey_dec(SM4_Context ctx, byte[] key) throws Exception {if (ctx == null) {throw new Exception("ctx is null!");}if (key == null || key.length != 16) {throw new Exception("key error!");}int i = 0;ctx.mode = SM4_DECRYPT;sm4_setkey(ctx.sk, key);for (i = 0; i < 16; i++) {SWAP(ctx.sk, i);}}public byte[] sm4_crypt_ecb(SM4_Context ctx, byte[] input) throws Exception {if (input == null) {throw new Exception("input is null!");}if ((ctx.isPadding) && (ctx.mode == SM4_ENCRYPT)) {input = padding(input, SM4_ENCRYPT);}int length = input.length;ByteArrayInputStream bins = new ByteArrayInputStream(input);ByteArrayOutputStream bous = new ByteArrayOutputStream();for (; length > 0; length -= 16) {byte[] in = new byte[16];byte[] out = new byte[16];bins.read(in);sm4_one_round(ctx.sk, in, out);bous.write(out);}byte[] output = bous.toByteArray();if (ctx.isPadding && ctx.mode == SM4_DECRYPT) {output = padding(output, SM4_DECRYPT);}bins.close();bous.close();return output;}public byte[] sm4_crypt_cbc(SM4_Context ctx, byte[] iv, byte[] input) throws Exception {if (iv == null || iv.length != 16) {throw new Exception("iv error!");}if (input == null) {throw new Exception("input is null!");}if (ctx.isPadding && ctx.mode == SM4_ENCRYPT) {input = padding(input, SM4_ENCRYPT);}int i = 0;int length = input.length;ByteArrayInputStream bins = new ByteArrayInputStream(input);ByteArrayOutputStream bous = new ByteArrayOutputStream();if (ctx.mode == SM4_ENCRYPT) {for (; length > 0; length -= 16) {byte[] in = new byte[16];byte[] out = new byte[16];byte[] out1 = new byte[16];bins.read(in);for (i = 0; i < 16; i++) {out[i] = ((byte) (in[i] ^ iv[i]));}sm4_one_round(ctx.sk, out, out1);System.arraycopy(out1, 0, iv, 0, 16);bous.write(out1);}} else {byte[] temp = new byte[16];for (; length > 0; length -= 16) {byte[] in = new byte[16];byte[] out = new byte[16];byte[] out1 = new byte[16];bins.read(in);System.arraycopy(in, 0, temp, 0, 16);sm4_one_round(ctx.sk, in, out);for (i = 0; i < 16; i++) {out1[i] = ((byte) (out[i] ^ iv[i]));}System.arraycopy(temp, 0, iv, 0, 16);bous.write(out1);}}byte[] output = bous.toByteArray();if (ctx.isPadding && ctx.mode == SM4_DECRYPT) {output = padding(output, SM4_DECRYPT);}bins.close();bous.close();return output;}
}
SM4_Context.java
/*** Created by $(USER) on $(DATE)*/
public class SM4_Context {public int mode;public long[] sk;public boolean isPadding;public SM4_Context(){this.mode = 1;this.isPadding = true;this.sk = new long[32];}
}
Util.java
package cn.xjfme.encrypt.utils;import java.math.BigInteger;public class Util {/*** 整形转换成网络传输的字节流(字节数组)型数据** @param num 一个整型数据* @return 4个字节的自己数组*/public static byte[] intToBytes(int num) {byte[] bytes = new byte[4];bytes[0] = (byte) (0xff & (num >> 0));bytes[1] = (byte) (0xff & (num >> 8));bytes[2] = (byte) (0xff & (num >> 16));bytes[3] = (byte) (0xff & (num >> 24));return bytes;}/*** 四个字节的字节数据转换成一个整形数据** @param bytes 4个字节的字节数组* @return 一个整型数据*/public static int byteToInt(byte[] bytes) {int num = 0;int temp;temp = (0x000000ff & (bytes[0])) << 0;num = num | temp;temp = (0x000000ff & (bytes[1])) << 8;num = num | temp;temp = (0x000000ff & (bytes[2])) << 16;num = num | temp;temp = (0x000000ff & (bytes[3])) << 24;num = num | temp;return num;}/*** 长整形转换成网络传输的字节流(字节数组)型数据** @param num 一个长整型数据* @return 4个字节的自己数组*/public static byte[] longToBytes(long num) {byte[] bytes = new byte[8];for (int i = 0; i < 8; i++) {bytes[i] = (byte) (0xff & (num >> (i * 8)));}return bytes;}/*** 大数字转换字节流(字节数组)型数据** @param n* @return*/public static byte[] byteConvert32Bytes(BigInteger n) {byte tmpd[] = (byte[]) null;if (n == null) {return null;}if (n.toByteArray().length == 33) {tmpd = new byte[32];System.arraycopy(n.toByteArray(), 1, tmpd, 0, 32);} else if (n.toByteArray().length == 32) {tmpd = n.toByteArray();} else {tmpd = new byte[32];for (int i = 0; i < 32 - n.toByteArray().length; i++) {tmpd[i] = 0;}System.arraycopy(n.toByteArray(), 0, tmpd, 32 - n.toByteArray().length, n.toByteArray().length);}return tmpd;}/*** 换字节流(字节数组)型数据转大数字** @param b* @return*/public static BigInteger byteConvertInteger(byte[] b) {if (b[0] < 0) {byte[] temp = new byte[b.length + 1];temp[0] = 0;System.arraycopy(b, 0, temp, 1, b.length);return new BigInteger(temp);}return new BigInteger(b);}/*** 根据字节数组获得值(十六进制数字)** @param bytes* @return*/public static String getHexString(byte[] bytes) {return getHexString(bytes, true);}/*** 根据字节数组获得值(十六进制数字)** @param bytes* @param upperCase* @return*/public static String getHexString(byte[] bytes, boolean upperCase) {String ret = "";for (int i = 0; i < bytes.length; i++) {ret += Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1);}return upperCase ? ret.toUpperCase() : ret;}/*** 打印十六进制字符串** @param bytes*/public static void printHexString(byte[] bytes) {for (int i = 0; i < bytes.length; i++) {String hex = Integer.toHexString(bytes[i] & 0xFF);if (hex.length() == 1) {hex = '0' + hex;}System.out.print("0x" + hex.toUpperCase() + ",");}System.out.println("");}/*** Convert hex string to byte[]** @param hexString the hex string* @return byte[]*/public static byte[] hexStringToBytes(String hexString) {if (hexString == null || hexString.equals("")) {return null;}hexString = hexString.toUpperCase();int length = hexString.length() / 2;char[] hexChars = hexString.toCharArray();byte[] d = new byte[length];for (int i = 0; i < length; i++) {int pos = i * 2;d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));}return d;}/*** Convert char to byte** @param c char* @return byte*/public static byte charToByte(char c) {return (byte) "0123456789ABCDEF".indexOf(c);}/*** 用于建立十六进制字符的输出的小写字符数组*/private static final char[] DIGITS_LOWER = {'0', '1', '2', '3', '4', '5','6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};/*** 用于建立十六进制字符的输出的大写字符数组*/private static final char[] DIGITS_UPPER = {'0', '1', '2', '3', '4', '5','6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};/*** 将字节数组转换为十六进制字符数组** @param data byte[]* @return 十六进制char[]*/public static char[] encodeHex(byte[] data) {return encodeHex(data, true);}/*** 将字节数组转换为十六进制字符数组** @param data byte[]* @param toLowerCase <code>true</code> 传换成小写格式 , <code>false</code> 传换成大写格式* @return 十六进制char[]*/public static char[] encodeHex(byte[] data, boolean toLowerCase) {return encodeHex(data, toLowerCase ? DIGITS_LOWER : DIGITS_UPPER);}/*** 将字节数组转换为十六进制字符数组** @param data byte[]* @param toDigits 用于控制输出的char[]* @return 十六进制char[]*/protected static char[] encodeHex(byte[] data, char[] toDigits) {int l = data.length;char[] out = new char[l << 1];// two characters form the hex value.for (int i = 0, j = 0; i < l; i++) {out[j++] = toDigits[(0xF0 & data[i]) >>> 4];out[j++] = toDigits[0x0F & data[i]];}return out;}/*** 将字节数组转换为十六进制字符串** @param data byte[]* @return 十六进制String*/public static String encodeHexString(byte[] data) {return encodeHexString(data, true);}/*** 将字节数组转换为十六进制字符串** @param data byte[]* @param toLowerCase <code>true</code> 传换成小写格式 , <code>false</code> 传换成大写格式* @return 十六进制String*/public static String encodeHexString(byte[] data, boolean toLowerCase) {return encodeHexString(data, toLowerCase ? DIGITS_LOWER : DIGITS_UPPER);}/*** 将字节数组转换为十六进制字符串** @param data byte[]* @param toDigits 用于控制输出的char[]* @return 十六进制String*/protected static String encodeHexString(byte[] data, char[] toDigits) {return new String(encodeHex(data, toDigits));}/*** 将十六进制字符数组转换为字节数组** @param data 十六进制char[]* @return byte[]* @throws RuntimeException 如果源十六进制字符数组是一个奇怪的长度,将抛出运行时异常*/public static byte[] decodeHex(char[] data) {int len = data.length;if ((len & 0x01) != 0) {throw new RuntimeException("Odd number of characters.");}byte[] out = new byte[len >> 1];// two characters form the hex value.for (int i = 0, j = 0; j < len; i++) {int f = toDigit(data[j], j) << 4;j++;f = f | toDigit(data[j], j);j++;out[i] = (byte) (f & 0xFF);}return out;}/*** 将十六进制字符转换成一个整数** @param ch 十六进制char* @param index 十六进制字符在字符数组中的位置* @return 一个整数* @throws RuntimeException 当ch不是一个合法的十六进制字符时,抛出运行时异常*/protected static int toDigit(char ch, int index) {int digit = Character.digit(ch, 16);if (digit == -1) {throw new RuntimeException("Illegal hexadecimal character " + ch+ " at index " + index);}return digit;}/*** 数字字符串转ASCII码字符串** @param String 字符串* @return ASCII字符串*/public static String StringToAsciiString(String content) {String result = "";int max = content.length();for (int i = 0; i < max; i++) {char c = content.charAt(i);String b = Integer.toHexString(c);result = result + b;}return result;}/*** 十六进制转字符串** @param hexString 十六进制字符串* @param encodeType 编码类型4:Unicode,2:普通编码* @return 字符串*/public static String hexStringToString(String hexString, int encodeType) {String result = "";int max = hexString.length() / encodeType;for (int i = 0; i < max; i++) {char c = (char) hexStringToAlgorism(hexString.substring(i * encodeType, (i + 1) * encodeType));result += c;}return result;}/*** 十六进制字符串装十进制** @param hex 十六进制字符串* @return 十进制数值*/public static int hexStringToAlgorism(String hex) {hex = hex.toUpperCase();int max = hex.length();int result = 0;for (int i = max; i > 0; i--) {char c = hex.charAt(i - 1);int algorism = 0;if (c >= '0' && c <= '9') {algorism = c - '0';} else {algorism = c - 55;}result += Math.pow(16, max - i) * algorism;}return result;}/*** 十六转二进制** @param hex 十六进制字符串* @return 二进制字符串*/public static String hexStringToBinary(String hex) {hex = hex.toUpperCase();String result = "";int max = hex.length();for (int i = 0; i < max; i++) {char c = hex.charAt(i);switch (c) {case '0':result += "0000";break;case '1':result += "0001";break;case '2':result += "0010";break;case '3':result += "0011";break;case '4':result += "0100";break;case '5':result += "0101";break;case '6':result += "0110";break;case '7':result += "0111";break;case '8':result += "1000";break;case '9':result += "1001";break;case 'A':result += "1010";break;case 'B':result += "1011";break;case 'C':result += "1100";break;case 'D':result += "1101";break;case 'E':result += "1110";break;case 'F':result += "1111";break;}}return result;}/*** ASCII码字符串转数字字符串** @param String ASCII字符串* @return 字符串*/public static String AsciiStringToString(String content) {String result = "";int length = content.length() / 2;for (int i = 0; i < length; i++) {String c = content.substring(i * 2, i * 2 + 2);int a = hexStringToAlgorism(c);char b = (char) a;String d = String.valueOf(b);result += d;}return result;}/*** 将十进制转换为指定长度的十六进制字符串** @param algorism int 十进制数字* @param maxLength int 转换后的十六进制字符串长度* @return String 转换后的十六进制字符串*/public static String algorismToHexString(int algorism, int maxLength) {String result = "";result = Integer.toHexString(algorism);if (result.length() % 2 == 1) {result = "0" + result;}return patchHexString(result.toUpperCase(), maxLength);}/*** 字节数组转为普通字符串(ASCII对应的字符)** @param bytearray byte[]* @return String*/public static String byteToString(byte[] bytearray) {String result = "";char temp;int length = bytearray.length;for (int i = 0; i < length; i++) {temp = (char) bytearray[i];result += temp;}return result;}/*** 二进制字符串转十进制** @param binary 二进制字符串* @return 十进制数值*/public static int binaryToAlgorism(String binary) {int max = binary.length();int result = 0;for (int i = max; i > 0; i--) {char c = binary.charAt(i - 1);int algorism = c - '0';result += Math.pow(2, max - i) * algorism;}return result;}/*** 十进制转换为十六进制字符串** @param algorism int 十进制的数字* @return String 对应的十六进制字符串*/public static String algorismToHEXString(int algorism) {String result = "";result = Integer.toHexString(algorism);if (result.length() % 2 == 1) {result = "0" + result;}result = result.toUpperCase();return result;}/*** HEX字符串前补0,主要用于长度位数不足。** @param str String 需要补充长度的十六进制字符串* @param maxLength int 补充后十六进制字符串的长度* @return 补充结果*/static public String patchHexString(String str, int maxLength) {String temp = "";for (int i = 0; i < maxLength - str.length(); i++) {temp = "0" + temp;}str = (temp + str).substring(0, maxLength);return str;}/*** 将一个字符串转换为int** @param s String 要转换的字符串* @param defaultInt int 如果出现异常,默认返回的数字* @param radix int 要转换的字符串是什么进制的,如16 8 10.* @return int 转换后的数字*/public static int parseToInt(String s, int defaultInt, int radix) {int i = 0;try {i = Integer.parseInt(s, radix);} catch (NumberFormatException ex) {i = defaultInt;}return i;}/*** 将一个十进制形式的数字字符串转换为int** @param s String 要转换的字符串* @param defaultInt int 如果出现异常,默认返回的数字* @return int 转换后的数字*/public static int parseToInt(String s, int defaultInt) {int i = 0;try {i = Integer.parseInt(s);} catch (NumberFormatException ex) {i = defaultInt;}return i;}/*** 十六进制串转化为byte数组** @return the array of byte*/public static byte[] hexToByte(String hex)throws IllegalArgumentException {if (hex.length() % 2 != 0) {throw new IllegalArgumentException();}char[] arr = hex.toCharArray();byte[] b = new byte[hex.length() / 2];for (int i = 0, j = 0, l = hex.length(); i < l; i++, j++) {String swap = "" + arr[i++] + arr[i];int byteint = Integer.parseInt(swap, 16) & 0xFF;b[j] = new Integer(byteint).byteValue();}return b;}/*** 字节数组转换为十六进制字符串** @param b byte[] 需要转换的字节数组* @return String 十六进制字符串*/public static String byteToHex(byte b[]) {if (b == null) {throw new IllegalArgumentException("Argument b ( byte array ) is null! ");}String hs = "";String stmp = "";for (int n = 0; n < b.length; n++) {stmp = Integer.toHexString(b[n] & 0xff);if (stmp.length() == 1) {hs = hs + "0" + stmp;} else {hs = hs + stmp;}}return hs.toLowerCase();//return hs.toUpperCase();}public static byte[] subByte(byte[] input, int startIndex, int length) {byte[] bt = new byte[length];for (int i = 0; i < length; i++) {bt[i] = input[i + startIndex];}return bt;}
}
SM4Utils.java
import Util;
import org.apache.commons.codec.binary.Base64;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;public class SM4Utils {public String secretKey = "";public String iv = "";public boolean hexString = false;public SM4Utils() {}public String encryptData_ECB(String plainText) {try {SM4_Context ctx = new SM4_Context();ctx.isPadding = true;ctx.mode = SM4.SM4_ENCRYPT;byte[] keyBytes;if (hexString) {keyBytes = Util.hexStringToBytes(secretKey);} else {//keyBytes = secretKey.getBytes();keyBytes = Util.hexStringToBytes(secretKey);}SM4 sm4 = new SM4();sm4.sm4_setkey_enc(ctx, keyBytes);byte[] encrypted = sm4.sm4_crypt_ecb(ctx, plainText.getBytes("UTF-8"));return Util.byteToHex(encrypted);} catch (Exception e) {e.printStackTrace();return null;}}public String decryptData_ECB(String cipherText) {try {byte[] encrypted = Util.hexToByte(cipherText);cipherText=Base64.encodeBase64String(encrypted);;//cipherText = new BASE64Encoder().encode(encrypted);if (cipherText != null && cipherText.trim().length() > 0) {Pattern p = Pattern.compile("\\s*|\t|\r|\n");Matcher m = p.matcher(cipherText);cipherText = m.replaceAll("");}SM4_Context ctx = new SM4_Context();ctx.isPadding = true;ctx.mode = SM4.SM4_DECRYPT;byte[] keyBytes;if (hexString) {keyBytes = Util.hexStringToBytes(secretKey);} else {keyBytes = secretKey.getBytes();}SM4 sm4 = new SM4();sm4.sm4_setkey_dec(ctx, keyBytes);byte[] decrypted = sm4.sm4_crypt_ecb(ctx, Base64.decodeBase64(cipherText));//byte[] decrypted = sm4.sm4_crypt_ecb(ctx, new BASE64Decoder().decodeBuffer(cipherText));return new String(decrypted, "UTF-8");} catch (Exception e) {e.printStackTrace();return null;}}public String encryptData_CBC(String plainText) {try {SM4_Context ctx = new SM4_Context();ctx.isPadding = true;ctx.mode = SM4.SM4_ENCRYPT;byte[] keyBytes;byte[] ivBytes;if (hexString) {keyBytes = Util.hexStringToBytes(secretKey);ivBytes = Util.hexStringToBytes(iv);} else {keyBytes = secretKey.getBytes();ivBytes = iv.getBytes();}SM4 sm4 = new SM4();sm4.sm4_setkey_enc(ctx, keyBytes);byte[] encrypted = sm4.sm4_crypt_cbc(ctx, ivBytes, plainText.getBytes("UTF-8"));return Util.byteToHex(encrypted);} catch (Exception e) {e.printStackTrace();return null;}}public String decryptData_CBC(String cipherText) {try {byte[] encrypted = Util.hexToByte(cipherText);cipherText=Base64.encodeBase64String(encrypted);;//cipherText = new BASE64Encoder().encode(encrypted);if (cipherText != null && cipherText.trim().length() > 0) {Pattern p = Pattern.compile("\\s*|\t|\r|\n");Matcher m = p.matcher(cipherText);cipherText = m.replaceAll("");}SM4_Context ctx = new SM4_Context();ctx.isPadding = true;ctx.mode = SM4.SM4_DECRYPT;byte[] keyBytes;byte[] ivBytes;if (hexString) {keyBytes = Util.hexStringToBytes(secretKey);ivBytes = Util.hexStringToBytes(iv);} else {keyBytes = secretKey.getBytes();ivBytes = iv.getBytes();}SM4 sm4 = new SM4();sm4.sm4_setkey_dec(ctx, keyBytes);//byte[] decrypted = sm4.sm4_crypt_cbc(ctx, ivBytes, new BASE64Decoder().decodeBuffer(cipherText));byte[] decrypted = sm4.sm4_crypt_cbc(ctx, ivBytes, Base64.decodeBase64(cipherText));/*String text = new String(decrypted, "UTF-8");return text.substring(0,text.length()-1);*/return new String(decrypted, "UTF-8");} catch (Exception e) {e.printStackTrace();return null;}}public static void main(String[] args) throws IOException {String plainText = "I Love You Every Day";String s = Util.byteToHex(plainText.getBytes());System.out.println("原文" + s);SM4Utils sm4 = new SM4Utils();//sm4.secretKey = "JeF8U9wHFOMfs2Y8";sm4.secretKey = "64EC7C763AB7BF64E2D75FF83A319918";sm4.hexString = true;System.out.println("ECB模式加密");String cipherText = sm4.encryptData_ECB(plainText);System.out.println("密文: " + cipherText);System.out.println("");String plainText2 = sm4.decryptData_ECB(cipherText);System.out.println("明文: " + plainText2);System.out.println("");System.out.println("CBC模式加密");sm4.iv = "31313131313131313131313131313131";String cipherText2 = sm4.encryptData_CBC(plainText);System.out.println("加密密文: " + cipherText2);System.out.println("");String plainText3 = sm4.decryptData_CBC(cipherText2);System.out.println("解密明文: " + plainText3);}
}
我上面是自己实现的方式,基本没有依赖第三方包。有一个加密包:BouncyCastle可以很方便的实现加密与解密。