/** 
 * 
 *  Secure Hash Algorithm (SHA1) 
 *  http://www.webtoolkit.info/ 
 * 
 **/  
   
 function SHA1(msg) {  
   
     function rotate_left(n,s) {  
         var t4 = ( n<<s ) | (n>>>(32-s));  
         return t4;  
     };  
   
     function lsb_hex(val) {  
         var str="";  
         var i;  
         var vh;  
         var vl;  
   
         for( i=0; i<=6; i+=2 ) {  
             vh = (val>>>(i*4+4))&0x0f;  
             vl = (val>>>(i*4))&0x0f;  
             str += vh.toString(16) + vl.toString(16);  
         }  
         return str;  
     };  
   
     function cvt_hex(val) {  
         var str="";  
         var i;  
         var v;  
   
         for( i=7; i>=0; i-- ) {  
             v = (val>>>(i*4))&0x0f;  
             str += v.toString(16);  
         }  
         return str;  
     };  
   
   
     function Utf8Encode(string) {  
         string = string.replace(/\r\n/g,"\n");  
         var utftext = "";  
   
         for (var n = 0; n < string.length; n++) {  
   
             var c = string.charCodeAt(n);  
   
             if (c < 128) {  
                 utftext += String.fromCharCode(c);  
             }  
             else if((c > 127) && (c < 2048)) {  
                 utftext += String.fromCharCode((c >> 6) | 192);  
                 utftext += String.fromCharCode((c & 63) | 128);  
             }  
             else {  
                 utftext += String.fromCharCode((c >> 12) | 224);  
                 utftext += String.fromCharCode(((c >> 6) & 63) | 128);  
                 utftext += String.fromCharCode((c & 63) | 128);  
             }  
   
         }  
   
         return utftext;  
     };  
   
     var blockstart;  
     var i, j;  
     var W = new Array(80);  
     var H0 = 0x67452301;  
     var H1 = 0xEFCDAB89;  
     var H2 = 0x98BADCFE;  
     var H3 = 0x10325476;  
     var H4 = 0xC3D2E1F0;  
     var A, B, C, D, E;  
     var temp;  
   
     msg = Utf8Encode(msg);  
   
     var msg_len = msg.length;  
   
     var word_array = new Array();  
     for( i=0; i<msg_len-3; i+=4 ) {  
         j = msg.charCodeAt(i)<<24 | msg.charCodeAt(i+1)<<16 |  
         msg.charCodeAt(i+2)<<8 | msg.charCodeAt(i+3);  
         word_array.push( j );  
     }  
   
     switch( msg_len % 4 ) {  
         case 0:  
             i = 0x080000000;  
         break;  
         case 1:  
             i = msg.charCodeAt(msg_len-1)<<24 | 0x0800000;  
         break;  
   
         case 2:  
             i = msg.charCodeAt(msg_len-2)<<24 | msg.charCodeAt(msg_len-1)<<16 | 0x08000;  
         break;  
   
         case 3:  
             i = msg.charCodeAt(msg_len-3)<<24 | msg.charCodeAt(msg_len-2)<<16 | msg.charCodeAt(msg_len-1)<<8  | 0x80;  
         break;  
     }  
   
     word_array.push( i );  
   
     while( (word_array.length % 16) != 14 ) word_array.push( 0 );  
   
     word_array.push( msg_len>>>29 );  
     word_array.push( (msg_len<<3)&0x0ffffffff );  
   
   
     for ( blockstart=0; blockstart<word_array.length; blockstart+=16 ) {  
   
         for( i=0; i<16; i++ ) W[i] = word_array[blockstart+i];  
         for( i=16; i<=79; i++ ) W[i] = rotate_left(W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16], 1);  
   
         A = H0;  
         B = H1;  
         C = H2;  
         D = H3;  
         E = H4;  
   
         for( i= 0; i<=19; i++ ) {  
             temp = (rotate_left(A,5) + ((B&C) | (~B&D)) + E + W[i] + 0x5A827999) & 0x0ffffffff;  
             E = D;  
             D = C;  
             C = rotate_left(B,30);  
             B = A;  
             A = temp;  
         }  
   
         for( i=20; i<=39; i++ ) {  
             temp = (rotate_left(A,5) + (B ^ C ^ D) + E + W[i] + 0x6ED9EBA1) & 0x0ffffffff;  
             E = D;  
             D = C;  
             C = rotate_left(B,30);  
             B = A;  
             A = temp;  
         }  
   
         for( i=40; i<=59; i++ ) {  
             temp = (rotate_left(A,5) + ((B&C) | (B&D) | (C&D)) + E + W[i] + 0x8F1BBCDC) & 0x0ffffffff;  
             E = D;  
             D = C;  
             C = rotate_left(B,30);  
             B = A;  
             A = temp;  
         }  
   
         for( i=60; i<=79; i++ ) {  
             temp = (rotate_left(A,5) + (B ^ C ^ D) + E + W[i] + 0xCA62C1D6) & 0x0ffffffff;  
             E = D;  
             D = C;  
             C = rotate_left(B,30);  
             B = A;  
             A = temp;  
         }  
   
         H0 = (H0 + A) & 0x0ffffffff;  
         H1 = (H1 + B) & 0x0ffffffff;  
         H2 = (H2 + C) & 0x0ffffffff;  
         H3 = (H3 + D) & 0x0ffffffff;  
         H4 = (H4 + E) & 0x0ffffffff;  
   
     }  
   
     var temp = cvt_hex(H0) + cvt_hex(H1) + cvt_hex(H2) + cvt_hex(H3) + cvt_hex(H4);  
   
     return temp.toLowerCase();  
   
 }