2019-09-21 16:11:55 +02:00

90 lines
2.3 KiB
JavaScript

// Adapted from Chris Veness' SHA1 code at
// http://www.movable-type.co.uk/scripts/sha1.html
'use strict';
function f(s, x, y, z) {
switch (s) {
case 0: return (x & y) ^ (~x & z);
case 1: return x ^ y ^ z;
case 2: return (x & y) ^ (x & z) ^ (y & z);
case 3: return x ^ y ^ z;
}
}
function ROTL(x, n) {
return (x << n) | (x>>> (32 - n));
}
function sha1(bytes) {
var K = [0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6];
var H = [0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0xc3d2e1f0];
if (typeof(bytes) == 'string') {
var msg = unescape(encodeURIComponent(bytes)); // UTF8 escape
bytes = new Array(msg.length);
for (var i = 0; i < msg.length; i++) bytes[i] = msg.charCodeAt(i);
}
bytes.push(0x80);
var l = bytes.length/4 + 2;
var N = Math.ceil(l/16);
var M = new Array(N);
for (var i=0; i<N; i++) {
M[i] = new Array(16);
for (var j=0; j<16; j++) {
M[i][j] =
bytes[i * 64 + j * 4] << 24 |
bytes[i * 64 + j * 4 + 1] << 16 |
bytes[i * 64 + j * 4 + 2] << 8 |
bytes[i * 64 + j * 4 + 3];
}
}
M[N - 1][14] = ((bytes.length - 1) * 8) /
Math.pow(2, 32); M[N - 1][14] = Math.floor(M[N - 1][14]);
M[N - 1][15] = ((bytes.length - 1) * 8) & 0xffffffff;
for (var i=0; i<N; i++) {
var W = new Array(80);
for (var t=0; t<16; t++) W[t] = M[i][t];
for (var t=16; t<80; t++) {
W[t] = ROTL(W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16], 1);
}
var a = H[0];
var b = H[1];
var c = H[2];
var d = H[3];
var e = H[4];
for (var t=0; t<80; t++) {
var s = Math.floor(t/20);
var T = ROTL(a, 5) + f(s, b, c, d) + e + K[s] + W[t] >>> 0;
e = d;
d = c;
c = ROTL(b, 30) >>> 0;
b = a;
a = T;
}
H[0] = (H[0] + a) >>> 0;
H[1] = (H[1] + b) >>> 0;
H[2] = (H[2] + c) >>> 0;
H[3] = (H[3] + d) >>> 0;
H[4] = (H[4] + e) >>> 0;
}
return [
H[0] >> 24 & 0xff, H[0] >> 16 & 0xff, H[0] >> 8 & 0xff, H[0] & 0xff,
H[1] >> 24 & 0xff, H[1] >> 16 & 0xff, H[1] >> 8 & 0xff, H[1] & 0xff,
H[2] >> 24 & 0xff, H[2] >> 16 & 0xff, H[2] >> 8 & 0xff, H[2] & 0xff,
H[3] >> 24 & 0xff, H[3] >> 16 & 0xff, H[3] >> 8 & 0xff, H[3] & 0xff,
H[4] >> 24 & 0xff, H[4] >> 16 & 0xff, H[4] >> 8 & 0xff, H[4] & 0xff
];
}
module.exports = sha1;