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> Monorepo of isomorphic utility functions
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JavaScript
;
Object.defineProperty(exports, '__esModule', { value: true });
var binary = require('./binary-ac8e39e2.cjs');
/**
* @module sha256
* Spec: https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.180-4.pdf
* Resources:
* - https://web.archive.org/web/20150315061807/http://csrc.nist.gov/groups/STM/cavp/documents/shs/sha256-384-512.pdf
*/
/**
* @param {number} w - a 32bit uint
* @param {number} shift
*/
const rotr = (w, shift) => (w >>> shift) | (w << (32 - shift));
/**
* Helper for SHA-224 & SHA-256. See 4.1.2.
* @param {number} x
*/
const sum0to256 = x => rotr(x, 2) ^ rotr(x, 13) ^ rotr(x, 22);
/**
* Helper for SHA-224 & SHA-256. See 4.1.2.
* @param {number} x
*/
const sum1to256 = x => rotr(x, 6) ^ rotr(x, 11) ^ rotr(x, 25);
/**
* Helper for SHA-224 & SHA-256. See 4.1.2.
* @param {number} x
*/
const sigma0to256 = x => rotr(x, 7) ^ rotr(x, 18) ^ x >>> 3;
/**
* Helper for SHA-224 & SHA-256. See 4.1.2.
* @param {number} x
*/
const sigma1to256 = x => rotr(x, 17) ^ rotr(x, 19) ^ x >>> 10;
// @todo don't init these variables globally
/**
* See 4.2.2: Constant for sha256 & sha224
* These words represent the first thirty-two bits of the fractional parts of
* the cube roots of the first sixty-four prime numbers. In hex, these constant words are (from left to
* right)
*/
const K = new Uint32Array([
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
]);
/**
* See 5.3.3. Initial hash value.
*
* These words were obtained by taking the first thirty-two bits of the fractional parts of the
* square roots of the first eight prime numbers.
*
* @todo shouldn't be a global variable
*/
const HINIT = new Uint32Array([
0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
]);
// time to beat: (large value < 4.35s)
class Hasher {
constructor () {
const buf = new ArrayBuffer(64 + 64 * 4);
// Init working variables using a single arraybuffer
this._H = new Uint32Array(buf, 0, 8);
this._H.set(HINIT);
// "Message schedule" - a working variable
this._W = new Uint32Array(buf, 64, 64);
}
_updateHash () {
const H = this._H;
const W = this._W;
for (let t = 16; t < 64; t++) {
W[t] = sigma1to256(W[t - 2]) + W[t - 7] + sigma0to256(W[t - 15]) + W[t - 16];
}
let a = H[0];
let b = H[1];
let c = H[2];
let d = H[3];
let e = H[4];
let f = H[5];
let g = H[6];
let h = H[7];
for (let tt = 0, T1, T2; tt < 64; tt++) {
T1 = (h + sum1to256(e) + ((e & f) ^ (~e & g)) + K[tt] + W[tt]) >>> 0;
T2 = (sum0to256(a) + ((a & b) ^ (a & c) ^ (b & c))) >>> 0;
h = g;
g = f;
f = e;
e = (d + T1) >>> 0;
d = c;
c = b;
b = a;
a = (T1 + T2) >>> 0;
}
H[0] += a;
H[1] += b;
H[2] += c;
H[3] += d;
H[4] += e;
H[5] += f;
H[6] += g;
H[7] += h;
}
/**
* @param {Uint8Array} data
*/
digest (data) {
let i = 0;
for (; i + 56 <= data.length;) {
// write data in big endianess
let j = 0;
for (; j < 16 && i + 3 < data.length; j++) {
this._W[j] = data[i++] << 24 | data[i++] << 16 | data[i++] << 8 | data[i++];
}
if (i % 64 !== 0) { // there is still room to write partial content and the ending bit.
this._W.fill(0, j, 16);
while (i < data.length) {
this._W[j] |= data[i] << ((3 - (i % 4)) * 8);
i++;
}
this._W[j] |= binary.BIT8 << ((3 - (i % 4)) * 8);
}
this._updateHash();
}
// same check as earlier - the ending bit has been written
const isPaddedWith1 = i % 64 !== 0;
this._W.fill(0, 0, 16);
let j = 0;
for (; i < data.length; j++) {
for (let ci = 3; ci >= 0 && i < data.length; ci--) {
this._W[j] |= data[i++] << (ci * 8);
}
}
// Write padding of the message. See 5.1.2.
if (!isPaddedWith1) {
this._W[j - (i % 4 === 0 ? 0 : 1)] |= binary.BIT8 << ((3 - (i % 4)) * 8);
}
// write length of message (size in bits) as 64 bit uint
// @todo test that this works correctly
this._W[14] = data.byteLength / binary.BIT30; // same as data.byteLength >>> 30 - but works on floats
this._W[15] = data.byteLength * 8;
this._updateHash();
// correct H endianness to use big endiannes and return a Uint8Array
const dv = new Uint8Array(32);
for (let i = 0; i < this._H.length; i++) {
for (let ci = 0; ci < 4; ci++) {
dv[i * 4 + ci] = this._H[i] >>> (3 - ci) * 8;
}
}
return dv
}
}
/**
* @param {Uint8Array} data
*/
const digest = data => new Hasher().digest(data);
exports.digest = digest;
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