blossom-cloudron/public/lib/@noble/hashes/_md.js

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2024-11-04 15:09:32 +00:00
import { exists, output } from './_assert.js';
import { Hash, createView, toBytes } from './utils.js';
// Polyfill for Safari 14
function setBigUint64(view, byteOffset, value, isLE) {
if (typeof view.setBigUint64 === 'function')
return view.setBigUint64(byteOffset, value, isLE);
const _32n = BigInt(32);
const _u32_max = BigInt(0xffffffff);
const wh = Number((value >> _32n) & _u32_max);
const wl = Number(value & _u32_max);
const h = isLE ? 4 : 0;
const l = isLE ? 0 : 4;
view.setUint32(byteOffset + h, wh, isLE);
view.setUint32(byteOffset + l, wl, isLE);
}
// Choice: a ? b : c
export const Chi = (a, b, c) => (a & b) ^ (~a & c);
// Majority function, true if any two inpust is true
export const Maj = (a, b, c) => (a & b) ^ (a & c) ^ (b & c);
/**
* Merkle-Damgard hash construction base class.
* Could be used to create MD5, RIPEMD, SHA1, SHA2.
*/
export class HashMD extends Hash {
constructor(blockLen, outputLen, padOffset, isLE) {
super();
this.blockLen = blockLen;
this.outputLen = outputLen;
this.padOffset = padOffset;
this.isLE = isLE;
this.finished = false;
this.length = 0;
this.pos = 0;
this.destroyed = false;
this.buffer = new Uint8Array(blockLen);
this.view = createView(this.buffer);
}
update(data) {
exists(this);
const { view, buffer, blockLen } = this;
data = toBytes(data);
const len = data.length;
for (let pos = 0; pos < len;) {
const take = Math.min(blockLen - this.pos, len - pos);
// Fast path: we have at least one block in input, cast it to view and process
if (take === blockLen) {
const dataView = createView(data);
for (; blockLen <= len - pos; pos += blockLen)
this.process(dataView, pos);
continue;
}
buffer.set(data.subarray(pos, pos + take), this.pos);
this.pos += take;
pos += take;
if (this.pos === blockLen) {
this.process(view, 0);
this.pos = 0;
}
}
this.length += data.length;
this.roundClean();
return this;
}
digestInto(out) {
exists(this);
output(out, this);
this.finished = true;
// Padding
// We can avoid allocation of buffer for padding completely if it
// was previously not allocated here. But it won't change performance.
const { buffer, view, blockLen, isLE } = this;
let { pos } = this;
// append the bit '1' to the message
buffer[pos++] = 0b10000000;
this.buffer.subarray(pos).fill(0);
// we have less than padOffset left in buffer, so we cannot put length in
// current block, need process it and pad again
if (this.padOffset > blockLen - pos) {
this.process(view, 0);
pos = 0;
}
// Pad until full block byte with zeros
for (let i = pos; i < blockLen; i++)
buffer[i] = 0;
// Note: sha512 requires length to be 128bit integer, but length in JS will overflow before that
// You need to write around 2 exabytes (u64_max / 8 / (1024**6)) for this to happen.
// So we just write lowest 64 bits of that value.
setBigUint64(view, blockLen - 8, BigInt(this.length * 8), isLE);
this.process(view, 0);
const oview = createView(out);
const len = this.outputLen;
// NOTE: we do division by 4 later, which should be fused in single op with modulo by JIT
if (len % 4)
throw new Error('_sha2: outputLen should be aligned to 32bit');
const outLen = len / 4;
const state = this.get();
if (outLen > state.length)
throw new Error('_sha2: outputLen bigger than state');
for (let i = 0; i < outLen; i++)
oview.setUint32(4 * i, state[i], isLE);
}
digest() {
const { buffer, outputLen } = this;
this.digestInto(buffer);
const res = buffer.slice(0, outputLen);
this.destroy();
return res;
}
_cloneInto(to) {
to || (to = new this.constructor());
to.set(...this.get());
const { blockLen, buffer, length, finished, destroyed, pos } = this;
to.length = length;
to.pos = pos;
to.finished = finished;
to.destroyed = destroyed;
if (length % blockLen)
to.buffer.set(buffer);
return to;
}
}
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