sha256-universal
Version:
Sha256 hashing algorithm in both WASM and pure JS
236 lines (187 loc) • 6.18 kB
JavaScript
const assert = require('nanoassert')
const b4a = require('b4a')
module.exports = Sha256
const SHA256_BYTES = module.exports.SHA256_BYTES = 32
const BLOCKSIZE = 64
const K = [
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
]
function expand (a, b, c, d) {
var b_ = (((a >>> 17) | (a << 15)) ^ ((a >>> 19) | (a << 13)) ^ (a >>> 10)) + b
var d_ = (((c >>> 7) | (c << 25)) ^ ((c >>> 18) | (c << 14)) ^ (c >>> 3)) + d
return (b_ + d_) << 0
}
function compress (state, words) {
// initialise registers
var ch, maj, s0, s1, T1, T2
var [a, b, c, d, e, f, g, h] = state
// expand message schedule
const w = new Uint32Array(64)
for (let i = 0; i < 16; i++) w[i] = bswap(words[i])
for (let i = 16; i < 64; i++) w[i] = expand(w[i - 2], w[i - 7], w[i - 15], w[i - 16])
for (let i = 0; i < 64; i += 4) round(i)
state[0] = state[0] + a
state[1] = state[1] + b
state[2] = state[2] + c
state[3] = state[3] + d
state[4] = state[4] + e
state[5] = state[5] + f
state[6] = state[6] + g
state[7] = state[7] + h
function round (n) {
ch = (e & f) ^ (~e & g)
maj = (a & b) ^ (a & c) ^ (b & c)
s0 = ((a >>> 2) | (a << 30)) ^ ((a >>> 13) | (a << 19)) ^ ((a >>> 22) | (a << 10))
s1 = ((e >>> 6) | (e << 26)) ^ ((e >>> 11) | (e << 21)) ^ ((e >>> 25) | (e << 7))
T1 = h + ch + s1 + w[n] + K[n]
T2 = s0 + maj
h = d + T1
d = T1 + T2
ch = (h & e) ^ (~h & f)
maj = (d & a) ^ (d & b) ^ (a & b)
s0 = ((d >>> 2) | (d << 30)) ^ ((d >>> 13) | (d << 19)) ^ ((d >>> 22) | (d << 10))
s1 = ((h >>> 6) | (h << 26)) ^ ((h >>> 11) | (h << 21)) ^ ((h >>> 25) | (h << 7))
T1 = g + ch + s1 + w[n + 1] + K[n + 1]
T2 = s0 + maj
g = c + T1
c = T1 + T2
ch = (g & h) ^ (~g & e)
maj = (c & d) ^ (c & a) ^ (d & a)
s0 = ((c >>> 2) | (c << 30)) ^ ((c >>> 13) | (c << 19)) ^ ((c >>> 22) | (c << 10))
s1 = ((g >>> 6) | (g << 26)) ^ ((g >>> 11) | (g << 21)) ^ ((g >>> 25) | (g << 7))
T1 = f + ch + s1 + w[n + 2] + K[n + 2]
T2 = s0 + maj
f = b + T1
b = T1 + T2
ch = (f & g) ^ (~f & h)
maj = (b & c) ^ (b & d) ^ (c & d)
s0 = ((b >>> 2) | (b << 30)) ^ ((b >>> 13) | (b << 19)) ^ ((b >>> 22) | (b << 10))
s1 = ((f >>> 6) | (f << 26)) ^ ((f >>> 11) | (f << 21)) ^ ((f >>> 25) | (f << 7))
T1 = e + ch + s1 + w[n + 3] + K[n + 3]
T2 = s0 + maj
e = a + T1
a = T1 + T2
}
}
function Sha256 () {
if (!(this instanceof Sha256)) return new Sha256()
this.buffer = new ArrayBuffer(64)
this.bytesRead = 0
this.pos = 0
this.digestLength = SHA256_BYTES
this.finalised = false
this.load = new Uint8Array(this.buffer)
this.words = new Uint32Array(this.buffer)
this.state = new Uint32Array([
0x6a09e667,
0xbb67ae85,
0x3c6ef372,
0xa54ff53a,
0x510e527f,
0x9b05688c,
0x1f83d9ab,
0x5be0cd19
])
return this
}
Sha256.prototype.update = function (input, enc) {
assert(this.finalised === false, 'Hash instance finalised')
var [inputBuf, len] = formatInput(input, enc)
var i = 0
this.bytesRead += len
while (len > 0) {
this.load.set(inputBuf.subarray(i, i + BLOCKSIZE - this.pos), this.pos)
i += BLOCKSIZE - this.pos
len -= BLOCKSIZE - this.pos
if (len < 0) break
this.pos = 0
compress(this.state, this.words)
}
this.pos = this.bytesRead & 0x3f
this.load.fill(0, this.pos)
return this
}
Sha256.prototype.digest = function (enc, offset = 0) {
assert(this.finalised === false, 'Hash instance finalised')
this.finalised = true
this.load.fill(0, this.pos)
this.load[this.pos] = 0x80
if (this.pos > 55) {
compress(this.state, this.words)
this.words.fill(0)
this.pos = 0
}
const view = new DataView(this.buffer)
view.setUint32(56, this.bytesRead / 2 ** 29)
view.setUint32(60, this.bytesRead << 3)
compress(this.state, this.words)
const resultBuf = new Uint8Array(this.state.map(bswap).buffer)
if (!enc) {
return new Uint8Array(resultBuf)
}
if (typeof enc === 'string') {
return b4a.toString(resultBuf, enc)
}
assert(enc instanceof Uint8Array, 'input must be Uint8Array or Buffer')
assert(enc.byteLength >= this.digestLength + offset, 'input not large enough for digest')
for (let i = 0; i < this.digestLength; i++) {
enc[i + offset] = resultBuf[i]
}
return enc
}
function HMAC (key) {
if (!(this instanceof HMAC)) return new HMAC(key)
this.pad = b4a.alloc(64)
this.inner = Sha256()
this.outer = Sha256()
const keyhash = b4a.alloc(32)
if (key.byteLength > 64) {
Sha256().update(key).digest(keyhash)
key = keyhash
}
this.pad.fill(0x36)
for (let i = 0; i < key.byteLength; i++) {
this.pad[i] ^= key[i]
}
this.inner.update(this.pad)
this.pad.fill(0x5c)
for (let i = 0; i < key.byteLength; i++) {
this.pad[i] ^= key[i]
}
this.outer.update(this.pad)
this.pad.fill(0)
keyhash.fill(0)
}
HMAC.prototype.update = function (input, enc) {
this.inner.update(input, enc)
return this
}
HMAC.prototype.digest = function (enc, offset = 0) {
this.outer.update(this.inner.digest())
return this.outer.digest(enc, offset)
}
Sha256.HMAC = HMAC
function formatInput (input, enc) {
var result = b4a.from(input, enc)
return [result, result.byteLength]
}
function bswap (a) {
var r = ((a & 0x00ff00ff) >>> 8) | ((a & 0x00ff00ff) << 24)
var l = ((a & 0xff00ff00) << 8) | ((a & 0xff00ff00) >>> 24)
return r | l
}