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// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
// Copyright 2014-2017 browserify-aes contributors. All rights reserved. MIT license.
// Copyright 2013 Maxwell Krohn. All rights reserved. MIT license.
// Copyright 2009-2013 Jeff Mott. All rights reserved. MIT license.
// Copyright 2009-2015, Emily Stark, Mike Hamburg and Dan Boneh at Stanford University. All rights reserved.
// deno-lint-ignore-file no-var
import { Buffer } from "internal:deno_node/polyfills/buffer.ts";
var ZEROES = Buffer.alloc(16, 0);
function toArray(buf) {
return [
buf.readUInt32BE(0),
buf.readUInt32BE(4),
buf.readUInt32BE(8),
buf.readUInt32BE(12),
];
}
function fromArray(out) {
var buf = Buffer.allocUnsafe(16);
buf.writeUInt32BE(out[0] >>> 0, 0);
buf.writeUInt32BE(out[1] >>> 0, 4);
buf.writeUInt32BE(out[2] >>> 0, 8);
buf.writeUInt32BE(out[3] >>> 0, 12);
return buf;
}
export function GHASH(key) {
this.h = key;
this.state = Buffer.alloc(16, 0);
this.cache = Buffer.allocUnsafe(0);
}
// from http://bitwiseshiftleft.github.io/sjcl/doc/symbols/src/core_gcm.js.html
// by Juho Vähä-Herttua
GHASH.prototype.ghash = function (block) {
var i = -1;
while (++i < block.length) {
this.state[i] ^= block[i];
}
this._multiply();
};
GHASH.prototype._multiply = function () {
var Vi = toArray(this.h);
var Zi = [0, 0, 0, 0];
var j, xi, lsbVi;
var i = -1;
while (++i < 128) {
xi = (this.state[~~(i / 8)] & (1 << (7 - (i % 8)))) !== 0;
if (xi) {
// Z_i+1 = Z_i ^ V_i
Zi[0] ^= Vi[0];
Zi[1] ^= Vi[1];
Zi[2] ^= Vi[2];
Zi[3] ^= Vi[3];
}
// Store the value of LSB(V_i)
lsbVi = (Vi[3] & 1) !== 0;
// V_i+1 = V_i >> 1
for (j = 3; j > 0; j--) {
Vi[j] = (Vi[j] >>> 1) | ((Vi[j - 1] & 1) << 31);
}
Vi[0] = Vi[0] >>> 1;
// If LSB(V_i) is 1, V_i+1 = (V_i >> 1) ^ R
if (lsbVi) {
Vi[0] = Vi[0] ^ (0xe1 << 24);
}
}
this.state = fromArray(Zi);
};
GHASH.prototype.update = function (buf) {
this.cache = Buffer.concat([this.cache, buf]);
var chunk;
while (this.cache.length >= 16) {
chunk = this.cache.slice(0, 16);
this.cache = this.cache.slice(16);
this.ghash(chunk);
}
};
GHASH.prototype.final = function (abl, bl) {
if (this.cache.length) {
this.ghash(Buffer.concat([this.cache, ZEROES], 16));
}
this.ghash(fromArray([0, abl, 0, bl]));
return this.state;
};
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