md5.cpp

VC 实 现 MD5 加 解 密 算 法,

#include "MD5.h"



		const CString hex_chr="0123456789abcdef";
	CString	MD5::rhex(int num)
	{
		CString str = "";
        for (int j = 0; j <= 3; j++) {
            str = str + hex_chr.GetAt((num >> (j * 8 + 4)) & 0x0F) +
                  hex_chr.GetAt((num >> (j * 8)) & 0x0F);
        }
        return str;
	}
	int* MD5::str2blks_MD5(CString str)
	{
		int nblk = ((str.GetLength() + 8) >> 6) + 1;
		arrLen=nblk * 16;
        int *blks = new int[arrLen];
        int i = 0;
        for (i = 0; i < nblk * 16; i++) {
            blks[i] = 0;
        }
        for (i = 0; i < str.GetLength(); i++) {
            blks[i >> 2] |= str.GetAt(i) << ((i % 4) * 8);
        }
        blks[i >> 2] |= 0x80 << ((i % 4) * 8);
        blks[nblk * 16 - 2] = str.GetLength() * 8;

        return blks;
	}
	int MD5::add(int x, int y)
	{
		return ((x & 0x7FFFFFFF) + (y & 0x7FFFFFFF)) ^ (x & 0x80000000) ^
                (y & 0x80000000);
	}
	int MD5::rol(int num, int cnt)
	{
		return (num << cnt) | (((unsigned int)num) >> (32 - cnt));
	}
	int MD5::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);
	}
	int MD5::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);
	}
	int MD5::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);
	}
	int MD5::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);
	}	
	int MD5::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);
	}
	CString MD5::calcMD5(CString str) {
        int *x = str2blks_MD5(str);
        int a = 0x67452301;
        int b = 0xEFCDAB89;
        int c = 0x98BADCFE;
        int d = 0x10325476;

        for (int i = 0; i < arrLen; 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);
    }