MD5 encrypted JavaScript Implementation example

/* MD5 message-digest Algorithm-javascript
' Modification HISTORY:
' 1.0 16-feb-2001-phil Fresle (sales@frez.co.uk)-Initial Version (vb/asp code)
' 1.0 21-feb-2001-enrico Mosanghini (erik504@yahoo.com)-JavaScript porting
*/
function MD5 (smessage) {
function Rotateleft (LValue, ishiftbits) {return (lvalue<<ishiftbits) | (Lvalue>>> (32-ishiftbits)); }
function addunsigned (lx,ly) {
var Lx4,ly4,lx8,ly8,lresult;
LX8 = (LX & 0x80000000);
LY8 = (LY & 0x80000000);
LX4 = (LX & 0x40000000);
LY4 = (LY & 0x40000000);
LRESULT = (LX & 0x3fffffff) + (LY & 0X3FFFFFFF);
if (LX4 & lY4) return (lresult ^ 0x80000000 ^ lX8 ^ lY8);
if (lX4 | lY4) {
if (Lresult & 0x40000000) return (lresult ^ 0xc0000000 ^ lX8 ^ lY8);
else return (lresult ^ 0x40000000 ^ lX8 ^ lY8);
else return (lresult ^ lX8 ^ lY8);
}
function F (x,y,z) {return (x & y) | ((~x) & Z); }
function G (x,y,z) {return (X & Z) | (Y & (~z)); }
function H (x,y,z) {return (x ^ y ^ z);}
function I (x,y,z) {return (y ^ (x | (~z))); }
function FF (A,B,C,D,X,S,AC) {
A = addunsigned (A, addunsigned (addunsigned (F (b, C, D), x), AC);
Return addunsigned (Rotateleft (A, s), b);
}
function GG (A,B,C,D,X,S,AC) {
A = addunsigned (A, addunsigned (addunsigned (G (b, C, D), x), AC);
Return addunsigned (Rotateleft (A, s), b);
}
function HH (A,B,C,D,X,S,AC) {
A = addunsigned (A, addunsigned (addunsigned (H (b, C, D), x), AC);
Return addunsigned (Rotateleft (A, s), b);
}
function II (A,B,C,D,X,S,AC) {
A = addunsigned (A, addunsigned (addunsigned (I (b, C, D), x), AC);
Return addunsigned (Rotateleft (A, s), b);
}
function Converttowordarray (smessage) {
var Lwordcount;
var lmessagelength = smessage.length;
var lnumberofwords_temp1=lmessagelength + 8;
var lnumberofwords_temp2= (lnumberofwords_temp1-(lnumberofwords_temp1% 64))/64;
var lnumberofwords = (lnumberofwords_temp2+1) *16;
var lwordarray=array (lNumberOfWords-1);
var lbyteposition = 0;
var lbytecount = 0;
while (Lbytecount < lmessagelength) {
Lwordcount = (lbytecount-(lbytecount% 4))/4;
lbyteposition = (lbytecount% 4) *8;
Lwordarray[lwordcount] = (Lwordarray[lwordcount] | (Smessage.charcodeat (Lbytecount) <<lbyteposition));
lbytecount++;
}
Lwordcount = (lbytecount-(lbytecount% 4))/4;
lbyteposition = (lbytecount% 4) *8;
Lwordarray[lwordcount] = Lwordarray[lwordcount] | (0x80<<lbyteposition);
Lwordarray[lnumberofwords-2] = lmessagelength<<3;
LWORDARRAY[LNUMBEROFWORDS-1] = lmessagelength>>>29;
return lwordarray;
}
function Wordtohex (lValue) {
var wordtohexvalue= "", wordtohexvalue_temp= "", Lbyte,lcount;
for (Lcount = 0;lcount<=3;lcount++) {
Lbyte = (lvalue>>> (lcount*8)) & 255;
Wordtohexvalue_temp = "0" + lbyte.tostring (16);
Wordtohexvalue = Wordtohexvalue + wordtohexvalue_temp.substr (wordtohexvalue_temp.length-2,2);
}
return wordtohexvalue;
}
var x=array ();
var k,aa,bb,cc,dd,a,b,c,d
var s11=7, s12=12, s13=17, s14=22;
var s21=5, s22=9, s23=14, s24=20;
var s31=4, s32=11, s33=16, s34=23;
var s41=6, s42=10, s43=15, s44=21;
Steps 1 and 2. Append padding bits and length and convert to words
x = Converttowordarray (smessage);
Step 3. Initialise
A = 0x67452301; b = 0xefcdab89; c = 0x98badcfe; D = 0x10325476;
Step 4. Process the message in 16-word blocks
for (k=0;k<x.length;k+=16) {
Aa=a; Bb=b; Cc=c; Dd=d;
A=FF (a,b,c,d,x[k+0], s11,0xd76aa478);
D=FF (d,a,b,c,x[k+1], s12,0xe8c7b756);
C=FF (c,d,a,b,x[k+2], s13,0x242070db);
B=FF (b,c,d,a,x[k+3], s14,0xc1bdceee);
A=FF (A,b,c,d,x[k+4], S11,0XF57C0FAF);
D=FF (d,a,b,c,x[k+5], s12,0x4787c62a);
C=FF (C,d,a,b,x[k+6], s13,0xa8304613);
B=FF (B,c,d,a,x[k+7], s14,0xfd469501);
A=FF (A,b,c,d,x[k+8], s11,0x698098d8);
D=FF (d,a,b,c,x[k+9], S12,0X8B44F7AF);
C=FF (C,D,A,B,X[K+10],S13,0XFFFF5BB1);
B=FF (B,C,D,A,X[K+11],S14,0X895CD7BE);
A=FF (a,b,c,d,x[k+12],s11,0x6b901122);
D=FF (d,a,b,c,x[k+13],s12,0xfd987193);
C=FF (c,d,a,b,x[k+14],s13,0xa679438e);
B=FF (b,c,d,a,x[k+15],s14,0x49b40821);
A=gg (a,b,c,d,x[k+1], s21,0xf61e2562);
D=gg (D,a,b,c,x[k+6], s22,0xc040b340);
C=gg (C,D,A,B,X[K+11],S23,0X265E5A51);
B=gg (b,c,d,a,x[k+0], S24,0XE9B6C7AA);
A=gg (a,b,c,d,x[k+5], s21,0xd62f105d);
D=gg (d,a,b,c,x[k+10],s22,0x2441453);
C=gg (c,d,a,b,x[k+15],s23,0xd8a1e681);
B=gg (B,c,d,a,x[k+4], S24,0XE7D3FBC8);
A=gg (a,b,c,d,x[k+9], s21,0x21e1cde6);
D=gg (D,A,B,C,X[K+14],S22,0XC33707D6);
C=gg (c,d,a,b,x[k+3], s23,0xf4d50d87);
B=gg (B,c,d,a,x[k+8], s24,0x455a14ed);
A=gg (a,b,c,d,x[k+13],s21,0xa9e3e905);
D=gg (d,a,b,c,x[k+2], s22,0xfcefa3f8);
C=gg (C,d,a,b,x[k+7], s23,0x676f02d9);
B=gg (B,C,D,A,X[K+12],S24,0X8D2A4C8A);
A=HH (a,b,c,d,x[k+5], s31,0xfffa3942);
D=HH (D,a,b,c,x[k+8], s32,0x8771f681);
C=HH (c,d,a,b,x[k+11],s33,0x6d9d6122);
B=HH (b,c,d,a,x[k+14],s34,0xfde5380c);
A=HH (a,b,c,d,x[k+1], s31,0xa4beea44);
D=HH (D,a,b,c,x[k+4], s32,0x4bdecfa9);
C=HH (C,d,a,b,x[k+7], s33,0xf6bb4b60);
B=HH (B,C,D,A,X[K+10],S34,0XBEBFBC70);
A=HH (A,B,C,D,X[K+13],S31,0X289B7EC6);
D=HH (d,a,b,c,x[k+0], S32,0XEAA127FA);
C=HH (c,d,a,b,x[k+3], s33,0xd4ef3085);
B=HH (B,c,d,a,x[k+6], s34,0x4881d05);
A=HH (a,b,c,d,x[k+9], s31,0xd9d4d039);
D=HH (D,A,B,C,X[K+12],S32,0XE6DB99E5);
C=HH (C,D,A,B,X[K+15],S33,0X1FA27CF8);
B=HH (b,c,d,a,x[k+2], s34,0xc4ac5665);
A=ii (a,b,c,d,x[k+0], s41,0xf4292244);
D=ii (D,a,b,c,x[k+7], s42,0x432aff97);
C=ii (C,D,A,B,X[K+14],S43,0XAB9423A7);
B=ii (b,c,d,a,x[k+5], s44,0xfc93a039);
A=ii (A,B,C,D,X[K+12],S41,0X655B59C3);
D=ii (d,a,b,c,x[k+3], s42,0x8f0ccc92);
C=ii (c,d,a,b,x[k+10],s43,0xffeff47d);
B=ii (b,c,d,a,x[k+1], S44,0X85845DD1);
A=ii (A,b,c,d,x[k+8], s41,0x6fa87e4f);
D=ii (D,A,B,C,X[K+15],S42,0XFE2CE6E0);
C=ii (C,d,a,b,x[k+6], s43,0xa3014314);
B=ii (B,C,D,A,X[K+13],S44,0X4E0811A1);
A=ii (A,b,c,d,x[k+4], s41,0xf7537e82);
D=ii (d,a,b,c,x[k+11],s42,0xbd3af235);
C=ii (c,d,a,b,x[k+2], S43,0X2AD7D2BB);
B=ii (b,c,d,a,x[k+9], s44,0xeb86d391);
A=addunsigned (A,AA); B=addunsigned (B,BB); C=addunsigned (C,CC); D=addunsigned (D,DD);
}
Step 5. Output the 128 bit digest
var temp= wordtohex (a) +wordtohex (b) +wordtohex (c) +wordtohex (d);
return Temp.tolowercase ();
}