1.对于即时通讯的消息对话加密采用SM2还是SM4更合适?
对于即时通讯的消息对话加密，建议采用SM4对称加密算法，而不是SM2非对称加密算法。
SM2主要用于数字签名和密钥交换，其加密速度比SM4慢，而且SM2不太适合对长消息进行加密，因为它只能对比较短的数据块进行加密，这对于即时通讯中的大量数据传输是不够高效的。
相比之下，SM4对称加密算法可以更好地适应即时通讯的消息对话加密需求。SM4具有较高的安全性和较快的加解密速度，适合用于加密较长的消息和文件，并且能够适应即时通讯中快速传输和处理数据的要求。同时，SM4也具有较好的自主可控性，适合用于保护国家机密和重要数据的安全。
因此，综合考虑，建议采用SM4对称加密算法来实现即时通讯的消息对话加密。
2.SM2和SM4的优缺点对比?
SM2和SM4都是中国密码领域的国家密码算法，但是它们的设计目的和使用场景不同，因此它们的优缺点也有所不同。
SM2是一种非对称加密算法，主要用于数字签名和密钥交换。相对于其他非对称加密算法，如RSA和ECC，SM2具有以下优点：
优点：
安全性高：SM2采用的是椭圆曲线加密算法，比RSA和ECC更难破解。
效率高：SM2的加解密速度较快，尤其是在小设备上表现优异，因为SM2使用的参数相对较小，计算量相对较少。
自主可控：SM2是由中国密码学专家自主设计的，没有涉及外部专家，因此具有自主可控性。
缺点：
兼容性差：SM2与其他非对称加密算法不兼容，因此不能与其他算法进行密钥交换。
适用性受限：SM2适用于数字签名和密钥交换，但不适用于对称加密和身份认证等领域。
SM4是一种对称加密算法，主要用于数据加密和保护。相对于其他对称加密算法，如AES和DES，SM4具有以下优点：
优点：
安全性高：SM4采用的是32轮Feistel结构，具有较高的安全性。
效率高：SM4的加解密速度较快，尤其是在小设备上表现优异，因为SM4使用的参数相对较小，计算量相对较少。
自主可控：SM4是由中国密码学专家自主设计的，没有涉及外部专家，因此具有自主可控性。
缺点：
算法公开度低：SM4的算法细节没有完全公开，因此可能存在安全风险。
受限的国际认可度：SM4在国际上的认可度较低，受到限制。
SM4.java
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
public class SM4 {
public static final int SM4_ENCRYPT = 1;
public static final int SM4_DECRYPT = 0;
private int GET_ULONG_BE(byte[] b, int i) {
int n = (int) (b[i] & 0xff) << 24 | (int) ((b[i + 1] & 0xff) << 16) | (int) ((b[i + 2] & 0xff) << 8) | (int) (b[i + 3] & 0xff) & 0xffffffff;
return n;
}
private void PUT_ULONG_BE(int 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 int SHL(int x, int n) {
return (x & 0xFFFFFFFF) << n;
}
private int ROTL(int x, int n) {
return SHL(x, n) | x >> (32 - n);
}
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 int sm4Lt(int ka) {
int bb = 0;
int c = 0;
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 int sm4F(int x0, int x1, int x2, int x3, int rk) {
return x0 ^ sm4Lt(x1 ^ x2 ^ x3 ^ rk);
}
private int sm4CalciRK(int ka) {
int bb = 0;
int rk = 0;
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(int[] SK, byte[] key) {
int[] MK = new int[4];
int[] k = new int[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] ^ (int) FK[0];
k[1] = MK[1] ^ (int) FK[1];
k[2] = MK[2] ^ (int) FK[2];
k[3] = MK[3] ^ (int) FK[3];
for (; i < 32; i++) {
k[(i + 4)] = (k[i] ^ sm4CalciRK(k[(i + 1)] ^ k[(i + 2)] ^ k[(i + 3)] ^ (int) CK[i]));
SK[i] = k[(i + 4)];
}
}
private void sm4_one_round(int[] sk, byte[] input, byte[] output) {
int i = 0;
int[] ulbuf = new int[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);
}
private byte[] padding(byte[] input, int mode) {
if (input == null) {
return null;
}
byte[] ret = (byte[]) null;
if (mode == SM4_ENCRYPT) {
int p = 16 - input.length % 16;
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) p;
}
} else {
int p = input[input.length - 1];
ret = new byte[input.length - p];
System.arraycopy(input, 0, ret, 0, input.length - p);
}
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 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 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);
}
}
private void SWAP(int[] sk, int i) {
int t = sk[i];
sk[i] = sk[(31 - i)];
sk[(31 - i)] = t;
}
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;
}
}Util.java
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.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;
}
}SM4_Context.java
public class SM4_Context {
public int mode;
public int[] sk;
public boolean isPadding;
public SM4_Context() {
this.mode = 1;
this.isPadding = true;
this.sk = new int[32];
}
}SM4Utils.java
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
public class SM4Utils {
private String secretKey = "";
private String iv = "";
private 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;
keyBytes = secretKey.getBytes();
SM4 sm4 = new SM4();
sm4.sm4_setkey_enc(ctx, keyBytes);
byte[] encrypted = sm4.sm4_crypt_ecb(ctx, plainText.getBytes("UTF-8"));
String 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("");
}
return cipherText;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
public String decryptData_ECB(String cipherText) {
try {
SM4_Context ctx = new SM4_Context();
ctx.isPadding = true;
ctx.mode = SM4.SM4_DECRYPT;
byte[] keyBytes;
keyBytes = secretKey.getBytes();
SM4 sm4 = new SM4();
sm4.sm4_setkey_dec(ctx, keyBytes);
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;
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"));
String 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("");
}
return cipherText;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
public String decryptData_CBC(String cipherText) {
try {
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));
return new String(decrypted, "UTF-8");
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
public static void main(String[] args) throws IOException {
String plainText = "东临碣石，以观沧海";
SM4Utils sm4 = new SM4Utils();
sm4.secretKey = "11HDESaAhiHHugDz";
plainText.getBytes("UTF-8");
System.out.println("ECB模式");
String cipherText = sm4.encryptData_ECB(plainText);
System.out.println("密文: " + cipherText);
System.out.println("");
plainText = sm4.decryptData_ECB(cipherText);
System.out.println("明文: " + plainText);
System.out.println("");
System.out.println("CBC模式");
sm4.iv = "UISwD9fW6cFh9SNS";
cipherText = sm4.encryptData_CBC(plainText);
System.out.println("密文: " + cipherText);
System.out.println("");
plainText = sm4.decryptData_CBC(cipherText);
System.out.println("明文: " + plainText);
}
}ECB模式
密文: wtpCqJK/zKfwff38IfCmaxnABddcH5wC1p8eNXbX5q4=
明文: 东临碣石，以观沧海
CBC模式
密文: uLwJVA/DbXwkrTcDEQfpIWYfB8GLmoD8d2wI4mh6EUg=
明文: 东临碣石，以观沧海
文章来源：https://www.toymoban.com/news/detail-472281.html
文章来源地址https://www.toymoban.com/news/detail-472281.html
到了这里，关于java实现国密SM4的加密和解密方式(即时通讯的消息对话加密采用SM2还是SM4)的文章就介绍完了。如果您还想了解更多内容，请在右上角搜索TOY模板网以前的文章或继续浏览下面的相关文章，希望大家以后多多支持TOY模板网！
