- public class MD5 {
- /*
- * 四个链接变量
- */
- private final int A=0x67452301;
- private final int B=0xefcdab89;
- private final int C=0x98badcfe;
- private final int D=0x10325476;
- /*
- * ABCD的临时变量
- */
- private int Atemp,Btemp,Ctemp,Dtemp;
- /*
- * 常量ti
- * 公式:floor(abs(sin(i + 1)) × (2 pow 32)
- */
- private final int K[] = {
- 0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
- 0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501, 0x698098d8,
- 0x8b44f7af, 0xffff5bb1, 0x895cd7be, 0x6b901122, 0xfd987193,
- 0xa679438e, 0x49b40821, 0xf61e2562, 0xc040b340, 0x265e5a51,
- 0xe9b6c7aa, 0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
- 0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed, 0xa9e3e905,
- 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a, 0xfffa3942, 0x8771f681,
- 0x6d9d6122, 0xfde5380c, 0xa4beea44, 0x4bdecfa9, 0xf6bb4b60,
- 0xbebfbc70, 0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05,
- 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665, 0xf4292244,
- 0x432aff97, 0xab9423a7, 0xfc93a039, 0x655b59c3, 0x8f0ccc92,
- 0xffeff47d, 0x85845dd1, 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314,
- 0x4e0811a1, 0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391 };
- /*
- * 向左位移数,计算方法未知
- */
- private final int s[] = { 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7,
- 12, 17, 22, 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20,
- 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 6, 10,
- 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21 };
- /*
- * 初始化函数
- */
- private void init(){
- Atemp=A;
- Btemp=B;
- Ctemp=C;
- Dtemp=D;
- }
- /*
- * 移动一定位数
- */
- private int shift(int a,int s){
- return (a<<s)|(a>>>(32-s));//右移的时候,高位一定要补零,而不是补充符号位
- }
- /*
- * 主循环
- */
- private void MainLoop(int M[]){
- int F,g;
- int a=Atemp;
- int b=Btemp;
- int c=Ctemp;
- int d=Dtemp;
- for(int i=0;i<64;i++){
- if(i<16){
- F=(b&c)|((~b)&d);
- g=i;
- }
- else if(i<32){
- F=(d&b)|((~d)&c);
- g=(5*i+1)%16;
- }
- else if(i<48){
- F=b^c^d;
- g=(3*i+5)%16;
- }
- else{
- F=c^(b|(~d));
- g=(7*i)%16;
- }
- int tmp=d;
- d=c;
- c=b;
- b=b+shift(a+F+K[i]+M[g],s[i]);
- a=tmp;
- }
- Atemp=a+Atemp;
- Btemp=b+Btemp;
- Ctemp=c+Ctemp;
- Dtemp=d+Dtemp;
- }
- /*
- * 填充函数
- * 处理后应满足bits ≡ 448 (mod 512),字节就是bytes ≡ 56(mode64)
- * 填充方式为先加一个0,其它位补零
- * 最后加上64位的原来长度
- */
- private int[] add(String str){
- int num=((str.length()+8)/64)+1;//以512位,64个字节为一组
- int strByte[]=new int[num*16];//64/4=16,所以有16个整数
- for(int i=0;i<num*16;i++){//全部初始化0
- strByte[i]=0;
- }
- int i;
- for(i=0;i<str.length();i++){
- strByte[i>>2]|=str.charAt(i)<<((i%4)*8);//一个整数存储四个字节,小端序
- }
- strByte[i>>2]|=0x80<<((i%4)*8);//尾部添加1
- /*
- * 添加原长度,长度指位的长度,所以要乘8,然后是小端序,所以放在倒数第二个,这里长度只用了32位
- */
- strByte[num*16-2]=str.length() * 8;
- return strByte;
- }
- /*
- * 调用函数
- */
- public String getMD5(String source){
- init();
- int strByte[]=add(source);
- for(int i=0;i<strByte.length/16;i+=16){
- int num[]=new int[16];
- for(int j=0;j<16;j++){
- num[j]=strByte[i*16+j];
- }
- MainLoop(num);
- }
- return changeHex(Atemp)+changeHex(Btemp)+changeHex(Ctemp)+changeHex(Dtemp);
- }
- /*
- * 整数变成16进制字符串
- */
- private String changeHex(int a){
- String str="";
- for(int i=0;i<4;i++){
- str+=Integer.toHexString(((a>>i*8)%(1<<8))&0xff);
- }
- return str;
- }
- /*
- * 单例
- */
- private static MD5 instance;
- public static MD5 getInstance(){
- if(instance==null){
- instance=new MD5();
- }
- return instance;
- }
- private MD5(){};
- }
- import tools.com.edu.hdu.MD5;
- public class Test {
- public static void main(String[] args) {
- String str=MD5.getInstance().getMD5("");
- System.out.println(str);
- }
- }
来源: http://www.phpxs.com/code/1002853/