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public class md5
{
/*
* a java implementation of the rsa data security, inc. md5 message
* digest algorithm, as defined in rfc 1321.
* based on the javascript implementation of paul johnston
* copyright (c) paul johnston 1999 – 2000.
* see http://pajhome.org.uk/site/legal.html for details.
* java version by thomas weber (orange interactive gmbh)
*/
/*
* convert a 32-bit number to a hex string with ls-byte first
*/
string hex_chr = "0123456789abcdef";
private string rhex(int num)
{
string str = "";
for(int j = 0; j <= 3; j++)
str = str + hex_chr.charat((num >> (j * 8 + 4)) & 0x0f) + hex_chr.charat((num >> (j * 8)) & 0x0f);
return str;
}
/*
* convert a string to a sequence of 16-word blocks, stored as an array.
* append padding bits and the length, as described in the md5 standard.
*/
private int[] str2blks_md5(string str)
{
int nblk = ((str.length() + 8) >> 6) + 1;
int[] blks = new int[nblk * 16];
int i = 0;
for(i = 0; i < nblk * 16; i++) {
blks[i] = 0;
}
for(i = 0; i < str.length(); i++) {
blks[i >> 2] |= str.charat(i) << ((i % 4) * 8);
}
blks[i >> 2] |= 0x80 << ((i % 4) * 8);
blks[nblk * 16 – 2] = str.length()*8;
return blks;
}
/*
* add integers, wrapping at 2^32
*/
private int add(int x, int y)
{
return ((x&0x7fffffff) + (y&0x7fffffff)) ^ (x&0x80000000) ^ (y&0x80000000);
}
/*
* bitwise rotate a 32-bit number to the left
*/
private int rol(int num, int cnt)
{
return (num << cnt) | (num >>> (32 – cnt));
}
/*
* these functions implement the basic operation for each round of the
* algorithm.
*/
private int cmn(int q, int a, int b, int x, int s, int t)
{
return add(rol(add(add(a, q), add(x, t)), s), b);
}
private int ff(int a, int b, int c, int d, int x, int s, int t)
{
return cmn((b & c) | ((~b) & d), a, b, x, s, t);
}
private int gg(int a, int b, int c, int d, int x, int s, int t)
{
return cmn((b & d) | (c & (~d)), a, b, x, s, t);
}
private int hh(int a, int b, int c, int d, int x, int s, int t)
{
return cmn(b ^ c ^ d, a, b, x, s, t);
}
private int ii(int a, int b, int c, int d, int x, int s, int t)
{
return cmn(c ^ (b | (~d)), a, b, x, s, t);
}
/*
* take a string and return the hex representation of its md5.
*/
public string calcmd5(string str)
{
int[] x = str2blks_md5(str);
int a = 0x67452301;
int b = 0xefcdab89;
int c = 0x98badcfe;
int d = 0x10325476;
for(int i = 0; i < x.length; i += 16)
{
int olda = a;
int oldb = b;
int oldc = c;
int oldd = d;
a = ff(a, b, c, d, x[i+ 0], 7 , 0xd76aa478);
d = ff(d, a, b, c, x[i+ 1], 12, 0xe8c7b756);
c = ff(c, d, a, b, x[i+ 2], 17, 0x242070db);
b = ff(b, c, d, a, x[i+ 3], 22, 0xc1bdceee);
a = ff(a, b, c, d, x[i+ 4], 7 , 0xf57c0faf);
d = ff(d, a, b, c, x[i+ 5], 12, 0x4787c62a);
c = ff(c, d, a, b, x[i+ 6], 17, 0xa8304613);
b = ff(b, c, d, a, x[i+ 7], 22, 0xfd469501);
a = ff(a, b, c, d, x[i+ 8], 7 , 0x698098d8);
d = ff(d, a, b, c, x[i+ 9], 12, 0x8b44f7af);
c = ff(c, d, a, b, x[i+10], 17, 0xffff5bb1);
b = ff(b, c, d, a, x[i+11], 22, 0x895cd7be);
a = ff(a, b, c, d, x[i+12], 7 , 0x6b901122);
d = ff(d, a, b, c, x[i+13], 12, 0xfd987193);
c = ff(c, d, a, b, x[i+14], 17, 0xa679438e);
b = ff(b, c, d, a, x[i+15], 22, 0x49b40821);
a = gg(a, b, c, d, x[i+ 1], 5 , 0xf61e2562);
d = gg(d, a, b, c, x[i+ 6], 9 , 0xc040b340);
c = gg(c, d, a, b, x[i+11], 14, 0x265e5a51);
b = gg(b, c, d, a, x[i+ 0], 20, 0xe9b6c7aa);
a = gg(a, b, c, d, x[i+ 5], 5 , 0xd62f105d);
d = gg(d, a, b, c, x[i+10], 9 , 0x02441453);
c = gg(c, d, a, b, x[i+15], 14, 0xd8a1e681);
b = gg(b, c, d, a, x[i+ 4], 20, 0xe7d3fbc8);
a = gg(a, b, c, d, x[i+ 9], 5 , 0x21e1cde6);
d = gg(d, a, b, c, x[i+14], 9 , 0xc33707d6);
c = gg(c, d, a, b, x[i+ 3], 14, 0xf4d50d87);
b = gg(b, c, d, a, x[i+ 8], 20, 0x455a14ed);
a = gg(a, b, c, d, x[i+13], 5 , 0xa9e3e905);
d = gg(d, a, b, c, x[i+ 2], 9 , 0xfcefa3f8);
c = gg(c, d, a, b, x[i+ 7], 14, 0x676f02d9);
b = gg(b, c, d, a, x[i+12], 20, 0x8d2a4c8a);
a = hh(a, b, c, d, x[i+ 5], 4 , 0xfffa3942);
d = hh(d, a, b, c, x[i+ 8], 11, 0x8771f681);
c = hh(c, d, a, b, x[i+11], 16, 0x6d9d6122);
b = hh(b, c, d, a, x[i+14], 23, 0xfde5380c);
a = hh(a, b, c, d, x[i+ 1], 4 , 0xa4beea44);
d = hh(d, a, b, c, x[i+ 4], 11, 0x4bdecfa9);
c = hh(c, d, a, b, x[i+ 7], 16, 0xf6bb4b60);
b = hh(b, c, d, a, x[i+10], 23, 0xbebfbc70);
a = hh(a, b, c, d, x[i+13], 4 , 0x289b7ec6);
d = hh(d, a, b, c, x[i+ 0], 11, 0xeaa127fa);
c = hh(c, d, a, b, x[i+ 3], 16, 0xd4ef3085);
b = hh(b, c, d, a, x[i+ 6], 23, 0x04881d05);
a = hh(a, b, c, d, x[i+ 9], 4 , 0xd9d4d039);
d = hh(d, a, b, c, x[i+12], 11, 0xe6db99e5);
c = hh(c, d, a, b, x[i+15], 16, 0x1fa27cf8);
b = hh(b, c, d, a, x[i+ 2], 23, 0xc4ac5665);
a = ii(a, b, c, d, x[i+ 0], 6 , 0xf4292244);
d = ii(d, a, b, c, x[i+ 7], 10, 0x432aff97);
c = ii(c, d, a, b, x[i+14], 15, 0xab9423a7);
b = ii(b, c, d, a, x[i+ 5], 21, 0xfc93a039);
a = ii(a, b, c, d, x[i+12], 6 , 0x655b59c3);
d = ii(d, a, b, c, x[i+ 3], 10, 0x8f0ccc92);
c = ii(c, d, a, b, x[i+10], 15, 0xffeff47d);
b = ii(b, c, d, a, x[i+ 1], 21, 0x85845dd1);
a = ii(a, b, c, d, x[i+ 8], 6 , 0x6fa87e4f);
d = ii(d, a, b, c, x[i+15], 10, 0xfe2ce6e0);
c = ii(c, d, a, b, x[i+ 6], 15, 0xa3014314);
b = ii(b, c, d, a, x[i+13], 21, 0x4e0811a1);
a = ii(a, b, c, d, x[i+ 4], 6 , 0xf7537e82);
d = ii(d, a, b, c, x[i+11], 10, 0xbd3af235);
c = ii(c, d, a, b, x[i+ 2], 15, 0x2ad7d2bb);
b = ii(b, c, d, a, x[i+ 9], 21, 0xeb86d391);
a = add(a, olda);
b = add(b, oldb);
c = add(c, oldc);
d = add(d, oldd);
}
return rhex(a) + rhex(b) + rhex(c) + rhex(d);
}
}
