Skip to content

Instantly share code, notes, and snippets.

@lpf23

lpf23/SHA1 JavaScript Demo

Created May 21, 2014 19:26
Show Gist options
  • Save lpf23/ec798ff1c73f882dfeae to your computer and use it in GitHub Desktop.
Save lpf23/ec798ff1c73f882dfeae to your computer and use it in GitHub Desktop.
Download ZIP
Demo HTML page that runs a string through SHA1
Raw
SHA1 JavaScript Demo
<html>
<script type="text/javascript">
/**
* 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();
}
function enterString() {
var x;
var string = prompt("Enter value to run through SHA1...");
if (string != null) {
document.getElementById("convertedString").innerHTML =
"String: <b><font color=red>" + string + "</font></b><br> Hash: <b><font color=blue>" + SHA1(string) + "</font></b>";
}
}
</script>
<body>
<button onclick="enterString()">Click to enter string</button>
<p id="convertedString"></p>
</body>
</html>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment