v0.4.10 - api

node_modules/@noble/hashes/src/_sha2.ts

@@ -0,0 +1,118 @@
+import assert from './_assert.js';
+import { Hash, createView, Input, toBytes } from './utils.js';
+
+// Polyfill for Safari 14
+function setBigUint64(view: DataView, byteOffset: number, value: bigint, isLE: boolean): void {
+  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);
+}
+
+// Base SHA2 class (RFC 6234)
+export abstract class SHA2<T extends SHA2<T>> extends Hash<T> {
+  protected abstract process(buf: DataView, offset: number): void;
+  protected abstract get(): number[];
+  protected abstract set(...args: number[]): void;
+  abstract destroy(): void;
+  protected abstract roundClean(): void;
+  // For partial updates less than block size
+  protected buffer: Uint8Array;
+  protected view: DataView;
+  protected finished = false;
+  protected length = 0;
+  protected pos = 0;
+  protected destroyed = false;
+
+  constructor(
+    readonly blockLen: number,
+    public outputLen: number,
+    readonly padOffset: number,
+    readonly isLE: boolean
+  ) {
+    super();
+    this.buffer = new Uint8Array(blockLen);
+    this.view = createView(this.buffer);
+  }
+  update(data: Input): this {
+    assert.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: Uint8Array) {
+    assert.exists(this);
+    assert.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?: T): T {
+    to ||= new (this.constructor as any)() as T;
+    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;
+  }
+}