非对称加解密算法SM2

原文链接：https://blog.csdn.net/TurboAnho/article/details/126647410

SM2是国家密码管理局于2010年12月17日发布的椭圆曲线公钥密码算法。

SM2算法和RSA算法都是公钥密码算法，SM2算法是一种更先进安全的算法，在我们国家商用密码体系中被用来替换RSA算法。

随着密码技术和计算机技术的发展，目前常用的1024位RSA算法面临严重的安全威胁，我们国家密码管理部门经过研究，决定采用SM2椭圆曲线算法替换RSA算法。

SM2算法和RSA算法比较
SM2性能更优更安全：密码复杂度高、处理速度快、机器性能消耗更小

SM2 RSA
算法结构

基本椭圆曲线（ECC）

基于特殊的可逆模幂运算

计算复杂度

完全指数级

亚指数级

存储空间

192-256bit

2048-4096bit

秘钥生成速度

较RSA算法快百倍以上

慢

解密加密速度

较快

一般

工具类如下：
Cipher.java

import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.math.ec.ECPoint;

import java.math.BigInteger;

public class Cipher {
private int ct;
private ECPoint p2;
private SM3Digest sm3keybase;
private SM3Digest sm3c3;
private byte key[];
private byte keyOff;

public Cipher()
{
this.ct = 1;
this.key = new byte[32];
this.keyOff = 0;
}

private void Reset()
{
this.sm3keybase = new SM3Digest();
this.sm3c3 = new SM3Digest();

byte p[] = Util.byteConvert32Bytes(p2.getX().toBigInteger());
this.sm3keybase.update(p, 0, p.length);
this.sm3c3.update(p, 0, p.length);

p = Util.byteConvert32Bytes(p2.getY().toBigInteger());
this.sm3keybase.update(p, 0, p.length);
this.ct = 1;
NextKey();
}

private void NextKey()
{
SM3Digest sm3keycur = new SM3Digest(this.sm3keybase);
sm3keycur.update((byte) (ct >> 24 & 0xff));
sm3keycur.update((byte) (ct >> 16 & 0xff));
sm3keycur.update((byte) (ct >> 8 & 0xff));
sm3keycur.update((byte) (ct & 0xff));
sm3keycur.doFinal(key, 0);
this.keyOff = 0;
this.ct++;
}

public ECPoint Init_enc(SM2 sm2, ECPoint userKey)
{
AsymmetricCipherKeyPair key = sm2.ecc_key_pair_generator.generateKeyPair();
ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters) key.getPrivate();
ECPublicKeyParameters ecpub = (ECPublicKeyParameters) key.getPublic();
BigInteger k = ecpriv.getD();
ECPoint c1 = ecpub.getQ();
this.p2 = userKey.multiply(k);
Reset();
return c1;
}

public void Encrypt(byte data[])
{
this.sm3c3.update(data, 0, data.length);
for (int i = 0; i < data.length; i++)
{
if (keyOff == key.length)
{
NextKey();
}
data[i] ^= key[keyOff++];
}
}

public void Init_dec(BigInteger userD, ECPoint c1)
{
this.p2 = c1.multiply(userD);
Reset();
}

public void Decrypt(byte data[])
{
for (int i = 0; i < data.length; i++)
{
if (keyOff == key.length)
{
NextKey();
}
data[i] ^= key[keyOff++];
}

this.sm3c3.update(data, 0, data.length);
}

public void Dofinal(byte c3[])
{
byte p[] = Util.byteConvert32Bytes(p2.getY().toBigInteger());
this.sm3c3.update(p, 0, p.length);
this.sm3c3.doFinal(c3, 0);
Reset();
}
}
SM2.java

import org.bouncycastle.crypto.generators.ECKeyPairGenerator;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.crypto.params.ECKeyGenerationParameters;
import org.bouncycastle.math.ec.ECCurve;
import org.bouncycastle.math.ec.ECFieldElement;
import org.bouncycastle.math.ec.ECFieldElement.Fp;
import org.bouncycastle.math.ec.ECPoint;

import java.math.BigInteger;
import java.security.SecureRandom;

public class SM2 {

//正式参数
public static String[] ecc_param = {
"FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFF",
"FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFC",
"28E9FA9E9D9F5E344D5A9E4BCF6509A7F39789F515AB8F92DDBCBD414D940E93",
"FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123",
"32C4AE2C1F1981195F9904466A39C9948FE30BBFF2660BE1715A4589334C74C7",
"BC3736A2F4F6779C59BDCEE36B692153D0A9877CC62A474002DF32E52139F0A0"
};

public static SM2 Instance()
{
return new SM2();
}

public final BigInteger ecc_p;
public final BigInteger ecc_a;
public final BigInteger ecc_b;
public final BigInteger ecc_n;
public final BigInteger ecc_gx;
public final BigInteger ecc_gy;
public final ECCurve ecc_curve;
public final ECPoint ecc_point_g;
public final ECDomainParameters ecc_bc_spec;
public final ECKeyPairGenerator ecc_key_pair_generator;
public final ECFieldElement ecc_gx_fieldelement;
public final ECFieldElement ecc_gy_fieldelement;

public SM2()
{
this.ecc_p = new BigInteger(ecc_param[0], 16);
this.ecc_a = new BigInteger(ecc_param[1], 16);
this.ecc_b = new BigInteger(ecc_param[2], 16);
this.ecc_n = new BigInteger(ecc_param[3], 16);
this.ecc_gx = new BigInteger(ecc_param[4], 16);
this.ecc_gy = new BigInteger(ecc_param[5], 16);

this.ecc_gx_fieldelement = new Fp(this.ecc_p, this.ecc_gx);
this.ecc_gy_fieldelement = new Fp(this.ecc_p, this.ecc_gy);

this.ecc_curve = new ECCurve.Fp(this.ecc_p, this.ecc_a, this.ecc_b);
this.ecc_point_g = new ECPoint.Fp(this.ecc_curve, this.ecc_gx_fieldelement, this.ecc_gy_fieldelement);

this.ecc_bc_spec = new ECDomainParameters(this.ecc_curve, this.ecc_point_g, this.ecc_n);

ECKeyGenerationParameters ecc_ecgenparam;
ecc_ecgenparam = new ECKeyGenerationParameters(this.ecc_bc_spec, new SecureRandom());

this.ecc_key_pair_generator = new ECKeyPairGenerator();
this.ecc_key_pair_generator.init(ecc_ecgenparam);
}
}
SM2Utils.java

import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.math.ec.ECPoint;

import java.io.IOException;
import java.math.BigInteger;
import java.util.Arrays;

public class SM2Utils {

//生成随机秘钥对
public static void generateKeyPair(){
SM2 sm2 = SM2.Instance();
AsymmetricCipherKeyPair key = sm2.ecc_key_pair_generator.generateKeyPair();
ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters) key.getPrivate();
ECPublicKeyParameters ecpub = (ECPublicKeyParameters) key.getPublic();
BigInteger privateKey = ecpriv.getD();
ECPoint publicKey = ecpub.getQ();

System.out.println("公钥: " + Util.byteToHex(publicKey.getEncoded()));
System.out.println("私钥: " + Util.byteToHex(privateKey.toByteArray()));
}
// 国密规范正式私钥
private static String prik = "00C27C803367F9D6CFEC4B346E029DF63EEBF470036543D459A62E36C5C1A86925";
// 国密规范正式公钥
private static String pubk = "04BDF955A37EFAC70111B533F0DBFBB368C50B9015213C31359BA3FB3B600D0BD8A1BD2F152180AAB7448EB281C8CE3938CF1BE005D664950E6A9CCF3B10C61E52";
//数据加密
public static String encrypt(byte[] data) throws IOException
{
byte[] publicKey =Util.hexToByte(pubk);
if (data == null || data.length == 0)
{
return null;
}

byte[] source = new byte[data.length];
System.arraycopy(data, 0, source, 0, data.length);

Cipher cipher = new Cipher();
SM2 sm2 = SM2.Instance();
ECPoint userKey = sm2.ecc_curve.decodePoint(publicKey);

ECPoint c1 = cipher.Init_enc(sm2, userKey);
cipher.Encrypt(source);
byte[] c3 = new byte[32];
cipher.Dofinal(c3);

//C1 C2 C3拼装成加密字串
return Util.byteToHex(c1.getEncoded()) + Util.byteToHex(source) + Util.byteToHex(c3);

}

//数据解密
public static byte[] decrypt( byte[] encryptedData) throws IOException
{
byte[] privateKey=Util.hexToByte(prik);
if (encryptedData == null || encryptedData.length == 0)
{
return null;
}
//加密字节数组转换为十六进制的字符串 长度变为encryptedData.length * 2
String data = Util.byteToHex(encryptedData);
/***分解加密字串
* （C1 = C1标志位2位 + C1实体部分128位 = 130）
* （C3 = C3实体部分64位 = 64）
* （C2 = encryptedData.length * 2 - C1长度 - C2长度）
*/
byte[] c1Bytes = Util.hexToByte(data.substring(0,130));
int c2Len = encryptedData.length - 97;
byte[] c2 = Util.hexToByte(data.substring(130,130 + 2 * c2Len));
byte[] c3 = Util.hexToByte(data.substring(130 + 2 * c2Len,194 + 2 * c2Len));

SM2 sm2 = SM2.Instance();
BigInteger userD = new BigInteger(1, privateKey);

//通过C1实体字节来生成ECPoint
ECPoint c1 = sm2.ecc_curve.decodePoint(c1Bytes);
Cipher cipher = new Cipher();
cipher.Init_dec(userD, c1);
cipher.Decrypt(c2);
cipher.Dofinal(c3);

//返回解密结果
return c2;
}

public static void main(String[] args) throws Exception
{
//生成公钥私钥
// generateKeyPair();
//加解密测试
String a = "saassa";
String j = SM2Utils.encrypt( a.getBytes());
System.out.println("加密 = " + j);
System.out.println("解密 = " + new String(SM2Utils.decrypt( Util.hexToByte(j))));
}
}
SM3.java

public class SM3 {
public static final byte[] iv = { 0x73, (byte) 0x80, 0x16, 0x6f, 0x49,
0x14, (byte) 0xb2, (byte) 0xb9, 0x17, 0x24, 0x42, (byte) 0xd7,
(byte) 0xda, (byte) 0x8a, 0x06, 0x00, (byte) 0xa9, 0x6f, 0x30,
(byte) 0xbc, (byte) 0x16, 0x31, 0x38, (byte) 0xaa, (byte) 0xe3,
(byte) 0x8d, (byte) 0xee, 0x4d, (byte) 0xb0, (byte) 0xfb, 0x0e,
0x4e };

public static int[] Tj = new int[64];

static
{
for (int i = 0; i < 16; i++)
{
Tj[i] = 0x79cc4519;
}

for (int i = 16; i < 64; i++)
{
Tj[i] = 0x7a879d8a;
}
}

public static byte[] CF(byte[] V, byte[] B)
{
int[] v, b;
v = convert(V);
b = convert(B);
return convert(CF(v, b));
}

private static int[] convert(byte[] arr)
{
int[] out = new int[arr.length / 4];
byte[] tmp = new byte[4];
for (int i = 0; i < arr.length; i += 4)
{
System.arraycopy(arr, i, tmp, 0, 4);
out[i / 4] = bigEndianByteToInt(tmp);
}
return out;
}

private static byte[] convert(int[] arr)
{
byte[] out = new byte[arr.length * 4];
byte[] tmp = null;
for (int i = 0; i < arr.length; i++)
{
tmp = bigEndianIntToByte(arr[i]);
System.arraycopy(tmp, 0, out, i * 4, 4);
}
return out;
}

public static int[] CF(int[] V, int[] B)
{
int a, b, c, d, e, f, g, h;
int ss1, ss2, tt1, tt2;
a = V[0];
b = V[1];
c = V[2];
d = V[3];
e = V[4];
f = V[5];
g = V[6];
h = V[7];

int[][] arr = expand(B);
int[] w = arr[0];
int[] w1 = arr[1];

for (int j = 0; j < 64; j++)
{
ss1 = (bitCycleLeft(a, 12) + e + bitCycleLeft(Tj[j], j));
ss1 = bitCycleLeft(ss1, 7);
ss2 = ss1 ^ bitCycleLeft(a, 12);
tt1 = FFj(a, b, c, j) + d + ss2 + w1[j];
tt2 = GGj(e, f, g, j) + h + ss1 + w[j];
d = c;
c = bitCycleLeft(b, 9);
b = a;
a = tt1;
h = g;
g = bitCycleLeft(f, 19);
f = e;
e = P0(tt2);

}

int[] out = new int[8];
out[0] = a ^ V[0];
out[1] = b ^ V[1];
out[2] = c ^ V[2];
out[3] = d ^ V[3];
out[4] = e ^ V[4];
out[5] = f ^ V[5];
out[6] = g ^ V[6];
out[7] = h ^ V[7];

return out;
}

private static int[][] expand(int[] B)
{
int W[] = new int[68];
int W1[] = new int[64];
for (int i = 0; i < B.length; i++)
{
W[i] = B[i];
}

for (int i = 16; i < 68; i++)
{
W[i] = P1(W[i - 16] ^ W[i - 9] ^ bitCycleLeft(W[i - 3], 15))
^ bitCycleLeft(W[i - 13], 7) ^ W[i - 6];
}

for (int i = 0; i < 64; i++)
{
W1[i] = W[i] ^ W[i + 4];
}

int arr[][] = new int[][] { W, W1 };
return arr;
}

private static byte[] bigEndianIntToByte(int num)
{
return back(Util.intToBytes(num));
}

private static int bigEndianByteToInt(byte[] bytes)
{
return Util.byteToInt(back(bytes));
}

private static int FFj(int X, int Y, int Z, int j)
{
if (j >= 0 && j <= 15)
{
return FF1j(X, Y, Z);
}
else
{
return FF2j(X, Y, Z);
}
}

private static int GGj(int X, int Y, int Z, int j)
{
if (j >= 0 && j <= 15)
{
return GG1j(X, Y, Z);
}
else
{
return GG2j(X, Y, Z);
}
}

// 逻辑位运算函数
private static int FF1j(int X, int Y, int Z)
{
int tmp = X ^ Y ^ Z;
return tmp;
}

private static int FF2j(int X, int Y, int Z)
{
int tmp = ((X & Y) | (X & Z) | (Y & Z));
return tmp;
}

private static int GG1j(int X, int Y, int Z)
{
int tmp = X ^ Y ^ Z;
return tmp;
}

private static int GG2j(int X, int Y, int Z)
{
int tmp = (X & Y) | (~X & Z);
return tmp;
}

private static int P0(int X)
{
int y = rotateLeft(X, 9);
y = bitCycleLeft(X, 9);
int z = rotateLeft(X, 17);
z = bitCycleLeft(X, 17);
int t = X ^ y ^ z;
return t;
}

private static int P1(int X)
{
int t = X ^ bitCycleLeft(X, 15) ^ bitCycleLeft(X, 23);
return t;
}

/**
* 对最后一个分组字节数据padding
*
* @param in
* @param bLen
* 分组个数
* @return
*/
public static byte[] padding(byte[] in, int bLen)
{
int k = 448 - (8 * in.length + 1) % 512;
if (k < 0)
{
k = 960 - (8 * in.length + 1) % 512;
}
k += 1;
byte[] padd = new byte[k / 8];
padd[0] = (byte) 0x80;
long n = in.length * 8 + bLen * 512;
byte[] out = new byte[in.length + k / 8 + 64 / 8];
int pos = 0;
System.arraycopy(in, 0, out, 0, in.length);
pos += in.length;
System.arraycopy(padd, 0, out, pos, padd.length);
pos += padd.length;
byte[] tmp = back(Util.longToBytes(n));
System.arraycopy(tmp, 0, out, pos, tmp.length);
return out;
}

/**
* 字节数组逆序
*
* @param in
* @return
*/
private static byte[] back(byte[] in)
{
byte[] out = new byte[in.length];
for (int i = 0; i < out.length; i++)
{
out[i] = in[out.length - i - 1];
}

return out;
}

public static int rotateLeft(int x, int n)
{
return (x << n) | (x >> (32 - n));
}

private static int bitCycleLeft(int n, int bitLen)
{
bitLen %= 32;
byte[] tmp = bigEndianIntToByte(n);
int byteLen = bitLen / 8;
int len = bitLen % 8;
if (byteLen > 0)
{
tmp = byteCycleLeft(tmp, byteLen);
}

if (len > 0)
{
tmp = bitSmall8CycleLeft(tmp, len);
}

return bigEndianByteToInt(tmp);
}

private static byte[] bitSmall8CycleLeft(byte[] in, int len)
{
byte[] tmp = new byte[in.length];
int t1, t2, t3;
for (int i = 0; i < tmp.length; i++)
{
t1 = (byte) ((in[i] & 0x000000ff) << len);
t2 = (byte) ((in[(i + 1) % tmp.length] & 0x000000ff) >> (8 - len));
t3 = (byte) (t1 | t2);
tmp[i] = (byte) t3;
}

return tmp;
}

private static byte[] byteCycleLeft(byte[] in, int byteLen)
{
byte[] tmp = new byte[in.length];
System.arraycopy(in, byteLen, tmp, 0, in.length - byteLen);
System.arraycopy(in, 0, tmp, in.length - byteLen, byteLen);
return tmp;
}
}
SM3Digest.java

import org.bouncycastle.util.encoders.Hex;

public class SM3Digest {
/** SM3值的长度 */
private static final int BYTE_LENGTH = 32;

/** SM3分组长度 */
private static final int BLOCK_LENGTH = 64;

/** 缓冲区长度 */
private static final int BUFFER_LENGTH = BLOCK_LENGTH * 1;

/** 缓冲区 */
private byte[] xBuf = new byte[BUFFER_LENGTH];

/** 缓冲区偏移量 */
private int xBufOff;

/** 初始向量 */
private byte[] V = SM3.iv.clone();

private int cntBlock = 0;

public SM3Digest() {
}

public SM3Digest(SM3Digest t)
{
System.arraycopy(t.xBuf, 0, this.xBuf, 0, t.xBuf.length);
this.xBufOff = t.xBufOff;
System.arraycopy(t.V, 0, this.V, 0, t.V.length);
}

/**
* SM3结果输出
*
* @param out 保存SM3结构的缓冲区
* @param outOff 缓冲区偏移量
* @return
*/
public int doFinal(byte[] out, int outOff)
{
byte[] tmp = doFinal();
System.arraycopy(tmp, 0, out, 0, tmp.length);
return BYTE_LENGTH;
}

public void reset()
{
xBufOff = 0;
cntBlock = 0;
V = SM3.iv.clone();
}

/**
* 明文输入
*
* @param in
* 明文输入缓冲区
* @param inOff
* 缓冲区偏移量
* @param len
* 明文长度
*/
public void update(byte[] in, int inOff, int len)
{
int partLen = BUFFER_LENGTH - xBufOff;
int inputLen = len;
int dPos = inOff;
if (partLen < inputLen)
{
System.arraycopy(in, dPos, xBuf, xBufOff, partLen);
inputLen -= partLen;
dPos += partLen;
doUpdate();
while (inputLen > BUFFER_LENGTH)
{
System.arraycopy(in, dPos, xBuf, 0, BUFFER_LENGTH);
inputLen -= BUFFER_LENGTH;
dPos += BUFFER_LENGTH;
doUpdate();
}
}

System.arraycopy(in, dPos, xBuf, xBufOff, inputLen);
xBufOff += inputLen;
}

private void doUpdate()
{
byte[] B = new byte[BLOCK_LENGTH];
for (int i = 0; i < BUFFER_LENGTH; i += BLOCK_LENGTH)
{
System.arraycopy(xBuf, i, B, 0, B.length);
doHash(B);
}
xBufOff = 0;
}

private void doHash(byte[] B)
{
byte[] tmp = SM3.CF(V, B);
System.arraycopy(tmp, 0, V, 0, V.length);
cntBlock++;
}

private byte[] doFinal()
{
byte[] B = new byte[BLOCK_LENGTH];
byte[] buffer = new byte[xBufOff];
System.arraycopy(xBuf, 0, buffer, 0, buffer.length);
byte[] tmp = SM3.padding(buffer, cntBlock);
for (int i = 0; i < tmp.length; i += BLOCK_LENGTH)
{
System.arraycopy(tmp, i, B, 0, B.length);
doHash(B);
}
return V;
}

public void update(byte in)
{
byte[] buffer = new byte[] { in };
update(buffer, 0, 1);
}

public int getDigestSize()
{
return BYTE_LENGTH;
}

public static void main(String[] args)
{
byte[] md = new byte[32];
byte[] msg1 = "ererfeiisgod".getBytes();
SM3Digest sm3 = new SM3Digest();
sm3.update(msg1, 0, msg1.length);
sm3.doFinal(md, 0);
String s = new String(Hex.encode(md));
System.out.println(s.toUpperCase());
}
}
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;
}
}