SM2密钥交换算法的java语言实现

考虑到网上大多数SM2密钥交换协议均是C语言实现，没有找到java实现的版本，所以参考了网上SM2加密算法实现的代码，自行写出了Java版本的密钥交换算法。
本文中的SM2.java SM3.java SM3Digest.java Util.java来源于CSDN博客：https://blog.csdn.net/ErErFei/article/details/50998162
本文程序均在命令行窗口运行通过。由于密钥对不断随机产生，所以运行结果和本文是不相同的。
SM2.java文件

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

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.ECPoint;
import org.bouncycastle.math.ec.ECFieldElement.Fp;

public class SM2 {
//测试参数
// public static final String[] ecc_param = {
// "8542D69E4C044F18E8B92435BF6FF7DE457283915C45517D722EDB8B08F1DFC3",
// "787968B4FA32C3FD2417842E73BBFEFF2F3C848B6831D7E0EC65228B3937E498",
// "63E4C6D3B23B0C849CF84241484BFE48F61D59A5B16BA06E6E12D1DA27C5249A",
// "8542D69E4C044F18E8B92435BF6FF7DD297720630485628D5AE74EE7C32E79B7",
// "421DEBD61B62EAB6746434EBC3CC315E32220B3BADD50BDC4C4E6C147FEDD43D",
// "0680512BCBB42C07D47349D2153B70C4E5D7FDFCBFA36EA1A85841B9E46E09A2"
// };

//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;//素数p  
public final BigInteger ecc_a;//系数a  
public final BigInteger ecc_b;//系数b  
public final BigInteger ecc_n;//生成元G的阶n  
public final BigInteger ecc_gx;  //生成元G是椭圆曲线的一个点，该点的横坐标x
public final BigInteger ecc_gy;  //G的纵坐标
public final ECCurve ecc_curve;  //椭圆曲线
public final ECPoint ecc_point_g;  //点G
public final int ecc_w;
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_w = 127;
    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);  //生成椭圆曲线
    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);  
}  

}

SM2_Exchange.java

import java.math.BigInteger;
import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.math.ec.ECPoint;
import ren_sm3.Util;
import ren_sm3.SM3Digest;
public class SM2_Exchange
{
private byte[] pubKey;
private byte[] priKey;
//生成密钥对
public void generateKeyPair(){
SM2 sm2 = SM2.Instance(); //生成SM2实例
AsymmetricCipherKeyPair key = sm2.ecc_key_pair_generator.generateKeyPair(); //生成公私密钥对
ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters) key.getPrivate(); //从密钥对中提取私钥参数
ECPublicKeyParameters ecpub = (ECPublicKeyParameters) key.getPublic(); //从密钥对中提取公钥参数
BigInteger privateKey = ecpriv.getD(); //私钥是个大整数
ECPoint publicKey = ecpub.getQ(); //公钥是个点

    pubKey = publicKey.getEncoded();  //将椭圆曲线点转化为字节数组
    priKey = privateKey.toByteArray();  //将大整数转化为字节数组
	System.out.println(Util.getHexString(priKey));
}
//获取公钥
public byte[] getPubKey()
{
	return pubKey;
}
//获取私钥
public byte[] getPriKey()
{
	return priKey;
}
/**
* 计算Z值
* @param ID  身份标识
* @param Z   存储32字节杂凑值的字节数组
*/
public void computeZ(String ID,byte[] Z)throws Exception
{
	SM3Digest sm3=new SM3Digest();
	byte[] ENTL = new byte[]{0x00,(byte)0x80};
	byte[] byte_ID = ID.getBytes("US-ASCII");//将字符串以ASCII格式编码为字节数组
	sm3.update(ENTL,0,ENTL.length);
	sm3.update(byte_ID,0,byte_ID.length);
	SM2 sm2 = SM2.Instance();
	byte[] a = Util.hexToByte(sm2.ecc_a.toString(16));//将椭圆曲线的参数a大整数格式转化为字节数组
	byte[] b = Util.hexToByte(sm2.ecc_b.toString(16));//将椭圆曲线的参数b大整数格式转化为字节数组
	sm3.update(a,0,a.length);
	sm3.update(b,0,b.length);
	byte[] gx = Util.hexToByte(sm2.ecc_gx.toString(16));//将椭圆曲线的参数gx大整数格式转化为字节数组
	byte[] gy = Util.hexToByte(sm2.ecc_gy.toString(16));//将椭圆曲线的参数gy大整数格式转化为字节数组
	sm3.update(gx,0,gx.length);
	sm3.update(gy,0,gy.length);
	sm3.update(pubKey,1,pubKey.length-1);//将公钥的横坐标和纵坐标导入缓冲区
	sm3.doFinal(Z,0);
}
public static void main(String[] args)throws Exception
{
	SM2_Exchange A = new SM2_Exchange();
	SM2_Exchange B = new SM2_Exchange();
	A.generateKeyPair();//产生A的公私钥对
	B.generateKeyPair();//产生B的公私钥对
	
	byte[] pubK_A = A.getPubKey();//获取A的公钥
	byte[] pubK_B = B.getPubKey();//获取B的公钥
	byte[] priK_A = A.getPriKey();//获取A的私钥
	byte[] priK_B = B.getPriKey();//获取B的私钥
	
	
	byte[] ZA =new byte[32];
	A.computeZ("[email protected]",ZA);//根据输入的标识计算ZA值
	
	byte [] ZB =new byte[32];
	B.computeZ("[email protected]",ZB);//根据输入的标识计算ZB值
	
	Exch A_EX = new Exch();
	Exch B_EX = new Exch();
	A_EX.Init(priK_A);//产生rA,RA,x_1,tA
	B_EX.Init(priK_B);//产生rB,RB,x_2,tB
	
	ECPoint R_A = A_EX.R1;//获取A产生的RA
	ECPoint R_B = B_EX.R1;//获取B产生的RB
	
	SM2 sm2 = new SM2();
	ECPoint pubA = sm2.ecc_curve.decodePoint(pubK_A);//将A公钥的字节数组格式转化为椭圆曲线点
	ECPoint pubB = sm2.ecc_curve.decodePoint(pubK_B);//将B公钥的字节数组格式转化为椭圆曲线点

	A_EX.computeKey(pubB,R_B,ZA,ZB);//A计算x_2,UA,KA
	B_EX.computeKey(pubA,R_A,ZA,ZB);//B计算X_1,UB,KB
}

}

Exch.java

import org.bouncycastle.math.ec.ECPoint;
import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import java.math.BigInteger;
import ren_sm3.SM3Digest;
import ren_sm3.Util;
import org.bouncycastle.math.ec.ECFieldElement;
import org.bouncycastle.math.ec.ECFieldElement.Fp;
public class Exch
{
private BigInteger t;
public ECPoint R1;
private byte[] ux;//椭圆曲线点U的横坐标
private byte[] uy;//椭圆曲线点U的纵坐标
public int w;

/**
* @param priKey 私钥
*/
public void Init(byte[] priKey) 
{
	SM2 sm2 = SM2.Instance();
	w= sm2.ecc_w;
	AsymmetricCipherKeyPair key = sm2.ecc_key_pair_generator.generateKeyPair();  
    ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters) key.getPrivate();  
    ECPublicKeyParameters ecpub = (ECPublicKeyParameters) key.getPublic();
	BigInteger r = ecpriv.getD();  //随机数r，在这是用临时私钥代替
    R1 = ecpub.getQ();  //临时私钥对应的临时公钥，也就是R1
	BigInteger x1 = R1.getX().toBigInteger();//取出R1的横坐标x1		
	BigInteger x_1 = computeX(w,x1);		
	compute_t(priKey,x_1,r);//计算t		
}
public BigInteger computeX(int Y,BigInteger x1)
{
	BigInteger a = new BigInteger(binaryToBig(Y,"0"),2);
	BigInteger b = new BigInteger(binaryToBig(Y-1,"1"),2);
	BigInteger c = x1.and(b);
	return a.add(c);
}
public String binaryToBig(int Y,String s)
{	
	String st="1";
	for(int i =0;i> 24 & 0xff));//此时已经把第一个64字节分组扩展压缩完，然后将ct导入缓冲区  
    kdf.update((byte) (ct>> 16 & 0xff));  
    kdf.update((byte) (ct >> 8 & 0xff));  
    kdf.update((byte) (ct& 0xff));
	kdf.doFinal(key, 0);
}
public ECPoint computePoint(BigInteger x,ECPoint pubKey,ECPoint R)
{
	SM2 sm2 = SM2.Instance();
	BigInteger ecc_gx = pubKey.getX().toBigInteger();  
    BigInteger ecc_gy = pubKey.getY().toBigInteger();  
    ECFieldElement ecc_gx_fieldelement = new Fp(sm2.ecc_p, ecc_gx);  
    ECFieldElement ecc_gy_fieldelement = new Fp(sm2.ecc_p, ecc_gy); 
	ECPoint a = R.multiply(x);
	ECPoint c = new ECPoint.Fp(sm2.ecc_curve,ecc_gx_fieldelement,ecc_gy_fieldelement);
	ECPoint b = c.add(a);
	
	return b.multiply(t);
}

}

SM3.java文件
package ren_sm3;
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);

        /*System.out.print(j+" ");
        System.out.print(Integer.toHexString(a)+" ");
        System.out.print(Integer.toHexString(b)+" ");
        System.out.print(Integer.toHexString(c)+" ");
        System.out.print(Integer.toHexString(d)+" ");
        System.out.print(Integer.toHexString(e)+" ");
        System.out.print(Integer.toHexString(f)+" ");
        System.out.print(Integer.toHexString(g)+" ");
        System.out.print(Integer.toHexString(h)+" ");
        System.out.println("");*/
    }

// System.out.println("");

    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文件
package ren_sm3;
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 = "你好啊我是任雄鹏，任我行的任，英雄的雄，朋友的朋，再加上一只鸟".getBytes();
	byte[] msg1 = {0x61,0x62,0x63};
	//Util util = new Util();
    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());
	System.out.print(Util.getHexString(md,true));
}

}

Util.java
package ren_sm3;
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 true 传换成小写格式 ， false 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 true 传换成小写格式 ， false 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 content
 *            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 content
 *            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;
}

}

运行结果如下：