807 lines
28 KiB
JavaScript
807 lines
28 KiB
JavaScript
/**
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* Utilities for hex, bytes, CSPRNG.
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* @module
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*/
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/*! noble-ciphers - MIT License (c) 2023 Paul Miller (paulmillr.com) */
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/**
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* Checks if something is Uint8Array. Be careful: nodejs Buffer will return true.
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* @param a - Value to inspect.
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* @returns `true` when the value is a Uint8Array view, including Node's `Buffer`.
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* @example
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* Guards a value before treating it as raw key material.
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*
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* ```ts
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* isBytes(new Uint8Array());
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* ```
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*/
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export function isBytes(a) {
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// Plain `instanceof Uint8Array` is too strict for some Buffer / proxy /
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// cross-realm cases. The fallback still requires a real ArrayBuffer view
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// so plain JSON-deserialized `{ constructor: ... }`
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// spoofing is rejected, and `BYTES_PER_ELEMENT === 1` keeps the fallback on byte-oriented views.
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return (a instanceof Uint8Array ||
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(ArrayBuffer.isView(a) &&
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a.constructor.name === 'Uint8Array' &&
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'BYTES_PER_ELEMENT' in a &&
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a.BYTES_PER_ELEMENT === 1));
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}
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/**
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* Asserts something is boolean.
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* @param b - Value to validate.
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* @throws On wrong argument types. {@link TypeError}
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* @example
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* Validates a boolean option before branching on it.
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*
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* ```ts
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* abool(true);
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* ```
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*/
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export function abool(b) {
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if (typeof b !== 'boolean')
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throw new TypeError(`boolean expected, not ${b}`);
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}
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/**
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* Asserts something is a non-negative safe integer.
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* @param n - Value to validate.
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* @throws On wrong argument types. {@link TypeError}
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* @throws On wrong argument ranges or values. {@link RangeError}
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* @example
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* Validates a non-negative length or counter.
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*
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* ```ts
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* anumber(1);
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* ```
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*/
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export function anumber(n) {
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if (typeof n !== 'number')
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throw new TypeError('number expected, got ' + typeof n);
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if (!Number.isSafeInteger(n) || n < 0)
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throw new RangeError('positive integer expected, got ' + n);
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}
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/**
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* Asserts something is Uint8Array.
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* @param value - Value to validate.
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* @param length - Expected byte length.
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* @param title - Optional label used in error messages.
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* @returns The validated byte array.
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* On Node, `Buffer` is accepted too because it is a Uint8Array view.
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* @throws On wrong argument types. {@link TypeError}
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* @throws On wrong argument lengths. {@link RangeError}
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* @example
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* Validates a fixed-length nonce or key buffer.
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*
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* ```ts
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* abytes(new Uint8Array([1, 2]), 2);
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* ```
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*/
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export function abytes(value, length, title = '') {
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const bytes = isBytes(value);
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const len = value?.length;
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const needsLen = length !== undefined;
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if (!bytes || (needsLen && len !== length)) {
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const prefix = title && `"${title}" `;
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const ofLen = needsLen ? ` of length ${length}` : '';
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const got = bytes ? `length=${len}` : `type=${typeof value}`;
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const message = prefix + 'expected Uint8Array' + ofLen + ', got ' + got;
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if (!bytes)
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throw new TypeError(message);
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throw new RangeError(message);
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}
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return value;
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}
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/**
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* Asserts a hash- or MAC-like instance has not been destroyed or finished.
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* @param instance - Stateful instance to validate.
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* @param checkFinished - Whether to reject finished instances.
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* When `false`, only `destroyed` is checked.
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* @throws If the hash instance has already been destroyed or finalized. {@link Error}
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* @example
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* Guards against calling `update()` or `digest()` on a finished hash.
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*
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* ```ts
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* aexists({ destroyed: false, finished: false });
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* ```
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*/
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export function aexists(instance, checkFinished = true) {
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if (instance.destroyed)
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throw new Error('Hash instance has been destroyed');
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if (checkFinished && instance.finished)
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throw new Error('Hash#digest() has already been called');
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}
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/**
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* Asserts output is a properly-sized byte array.
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* @param out - Output buffer to validate.
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* @param instance - Hash-like instance providing `outputLen`.
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* This is the relaxed `digestInto()`-style contract: output must be at least `outputLen`,
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* unlike one-shot cipher helpers elsewhere in the repo that often require exact lengths.
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* @throws On wrong argument types. {@link TypeError}
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* @param onlyAligned - Whether `out` must be 4-byte aligned for zero-allocation word views.
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* @throws On wrong output buffer lengths. {@link RangeError}
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* @throws On wrong output buffer alignment. {@link Error}
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* @example
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* Verifies that a caller-provided output buffer is large enough.
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*
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* ```ts
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* aoutput(new Uint8Array(16), { outputLen: 16 });
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* ```
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*/
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export function aoutput(out, instance, onlyAligned = false) {
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abytes(out, undefined, 'output');
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const min = instance.outputLen;
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if (out.length < min) {
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throw new RangeError('digestInto() expects output buffer of length at least ' + min);
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}
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if (onlyAligned && !isAligned32(out))
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throw new Error('invalid output, must be aligned');
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}
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/**
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* Casts a typed-array view to Uint8Array.
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* @param arr - Typed-array view to reinterpret.
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* @returns Uint8Array view over the same bytes.
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* @example
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* Views 32-bit words as raw bytes without copying.
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*
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* ```ts
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* u8(new Uint32Array([1]));
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* ```
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*/
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export function u8(arr) {
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return new Uint8Array(arr.buffer, arr.byteOffset, arr.byteLength);
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}
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/**
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* Casts a typed-array view to Uint32Array.
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* @param arr - Typed-array view to reinterpret.
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* @returns Uint32Array view over the same bytes. Callers are expected to provide a
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* 4-byte-aligned offset; trailing `1..3` bytes are silently dropped.
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* @example
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* Views a byte buffer as 32-bit words for block processing.
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*
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* ```ts
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* u32(new Uint8Array(4));
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* ```
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*/
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export function u32(arr) {
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return new Uint32Array(arr.buffer, arr.byteOffset, Math.floor(arr.byteLength / 4));
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}
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/**
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* Zeroizes typed arrays in place.
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* Warning: JS provides no guarantees.
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* @param arrays - Arrays to wipe.
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* @example
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* Wipes a temporary key buffer after use.
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*
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* ```ts
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* const bytes = new Uint8Array([1]);
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* clean(bytes);
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* ```
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*/
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export function clean(...arrays) {
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for (let i = 0; i < arrays.length; i++) {
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arrays[i].fill(0);
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}
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}
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/**
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* Creates a DataView for byte-level manipulation.
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* @param arr - Typed-array view to wrap.
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* @returns DataView over the same bytes.
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* @example
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* Creates an endian-aware view for length encoding.
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*
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* ```ts
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* createView(new Uint8Array(4));
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* ```
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*/
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export function createView(arr) {
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return new DataView(arr.buffer, arr.byteOffset, arr.byteLength);
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}
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/**
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* Whether the current platform is little-endian.
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* Most are; some IBM systems are not.
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*/
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export const isLE = /* @__PURE__ */ (() => new Uint8Array(new Uint32Array([0x11223344]).buffer)[0] === 0x44)();
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/**
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* Reverses byte order of one 32-bit word.
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* @param word - Unsigned 32-bit word to swap.
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* @returns The same word with bytes reversed.
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* @example
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* Swaps a big-endian word into little-endian byte order.
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*
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* ```ts
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* byteSwap(0x11223344);
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* ```
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*/
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export const byteSwap = (word) => ((word << 24) & 0xff000000) |
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((word << 8) & 0xff0000) |
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((word >>> 8) & 0xff00) |
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((word >>> 24) & 0xff);
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/**
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* Normalizes one 32-bit word to the little-endian representation expected by cipher cores.
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* @param n - Unsigned 32-bit word to normalize.
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* @returns Little-endian normalized word on big-endian hosts, else the input word unchanged.
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* @example
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* Normalizes a host-endian word before passing it into an ARX/AES core.
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*
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* ```ts
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* swap8IfBE(0x11223344);
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* ```
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*/
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export const swap8IfBE = isLE
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? (n) => n
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: (n) => byteSwap(n) >>> 0;
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/**
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* Byte-swaps every word of a Uint32Array in place.
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* @param arr - Uint32Array whose words should be swapped.
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* @returns The same array after in-place byte swapping.
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* @example
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* Swaps every 32-bit word in a word-view buffer.
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*
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* ```ts
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* byteSwap32(new Uint32Array([0x11223344]));
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* ```
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*/
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export const byteSwap32 = (arr) => {
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for (let i = 0; i < arr.length; i++)
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arr[i] = byteSwap(arr[i]);
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return arr;
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};
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/**
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* Normalizes a Uint32Array view to the little-endian representation expected by cipher cores.
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* @param u - Word view to normalize in place.
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* @returns Little-endian normalized word view.
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* @example
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* Normalizes a word-view buffer before block processing.
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*
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* ```ts
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* swap32IfBE(new Uint32Array([0x11223344]));
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* ```
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*/
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export const swap32IfBE = isLE
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? (u) => u
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: byteSwap32;
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// Built-in hex conversion:
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// {@link https://caniuse.com/mdn-javascript_builtins_uint8array_fromhex | caniuse entry}
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const hasHexBuiltin = /* @__PURE__ */ (() =>
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// @ts-ignore
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typeof Uint8Array.from([]).toHex === 'function' && typeof Uint8Array.fromHex === 'function')();
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// Array where index 0xf0 (240) is mapped to string 'f0'
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const hexes = /* @__PURE__ */ Array.from({ length: 256 }, (_, i) => i.toString(16).padStart(2, '0'));
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/**
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* Convert byte array to hex string. Uses built-in function, when available.
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* @param bytes - Bytes to encode.
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* @returns Lowercase hexadecimal string.
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* @throws On wrong argument types. {@link TypeError}
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* @example
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* Formats ciphertext bytes for logs or test vectors.
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*
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* ```ts
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* bytesToHex(Uint8Array.from([0xca, 0xfe, 0x01, 0x23])); // 'cafe0123'
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* ```
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*/
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export function bytesToHex(bytes) {
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abytes(bytes);
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// @ts-ignore
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if (hasHexBuiltin)
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return bytes.toHex();
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// pre-caching improves the speed 6x
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let hex = '';
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for (let i = 0; i < bytes.length; i++) {
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hex += hexes[bytes[i]];
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}
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return hex;
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}
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// We use optimized technique to convert hex string to byte array
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const asciis = { _0: 48, _9: 57, A: 65, F: 70, a: 97, f: 102 };
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function asciiToBase16(ch) {
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if (ch >= asciis._0 && ch <= asciis._9)
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return ch - asciis._0; // '2' => 50-48
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if (ch >= asciis.A && ch <= asciis.F)
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return ch - (asciis.A - 10); // 'B' => 66-(65-10)
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if (ch >= asciis.a && ch <= asciis.f)
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return ch - (asciis.a - 10); // 'b' => 98-(97-10)
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return;
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}
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/**
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* Convert hex string to byte array. Uses built-in function, when available.
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* @param hex - Hexadecimal string to decode.
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* @returns Decoded bytes.
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* @throws On wrong argument types. {@link TypeError}
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* @throws On malformed hexadecimal input. {@link RangeError}
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* @example
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* Parses a hex test vector into bytes.
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*
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* ```ts
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* hexToBytes('cafe0123'); // Uint8Array.from([0xca, 0xfe, 0x01, 0x23])
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* ```
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*/
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export function hexToBytes(hex) {
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if (typeof hex !== 'string')
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throw new TypeError('hex string expected, got ' + typeof hex);
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if (hasHexBuiltin) {
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try {
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return Uint8Array.fromHex(hex);
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}
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catch (error) {
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if (error instanceof SyntaxError)
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throw new RangeError(error.message);
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throw error;
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}
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}
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const hl = hex.length;
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const al = hl / 2;
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if (hl % 2)
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throw new RangeError('hex string expected, got unpadded hex of length ' + hl);
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const array = new Uint8Array(al);
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for (let ai = 0, hi = 0; ai < al; ai++, hi += 2) {
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const n1 = asciiToBase16(hex.charCodeAt(hi));
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const n2 = asciiToBase16(hex.charCodeAt(hi + 1));
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if (n1 === undefined || n2 === undefined) {
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const char = hex[hi] + hex[hi + 1];
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throw new RangeError('hex string expected, got non-hex character "' + char + '" at index ' + hi);
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}
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array[ai] = n1 * 16 + n2; // multiply first octet, e.g. 'a3' => 10*16+3 => 160 + 3 => 163
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}
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return array;
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}
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// Used in micro
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/**
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* Converts a big-endian hex string into bigint.
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* @param hex - Hexadecimal string without `0x`.
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* @returns Parsed bigint value. The empty string is treated as `0n`.
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* @throws On wrong argument types. {@link TypeError}
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* @example
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* Parses a big-endian field element or counter from hex.
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*
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* ```ts
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* hexToNumber('ff');
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* ```
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*/
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export function hexToNumber(hex) {
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if (typeof hex !== 'string')
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throw new TypeError('hex string expected, got ' + typeof hex);
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return BigInt(hex === '' ? '0' : '0x' + hex); // Big Endian
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}
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// Used in ff1
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// BE: Big Endian, LE: Little Endian
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/**
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* Converts big-endian bytes into bigint.
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* @param bytes - Big-endian bytes.
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* @returns Parsed bigint value. Empty input is treated as `0n`.
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* @throws On invalid byte input passed to the internal hex conversion. {@link TypeError}
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* @example
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* Reads a big-endian integer from serialized bytes.
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*
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* ```ts
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* bytesToNumberBE(new Uint8Array([1, 0]));
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* ```
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*/
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export function bytesToNumberBE(bytes) {
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return hexToNumber(bytesToHex(bytes));
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}
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// Used in micro, ff1
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/**
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* Converts a number into big-endian bytes of fixed length.
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* @param n - Number to encode.
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* @param len - Output length in bytes.
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* @returns Big-endian bytes padded to `len`.
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* Validation is indirect through `hexToBytes(...)`, so negative values, `len = 0`,
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* and values that do not fit surface through the downstream hex parser instead of a
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* dedicated range guard here.
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* @throws On wrong argument types. {@link TypeError}
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* @throws If the requested output length cannot represent the encoded value. {@link RangeError}
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* @example
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* Encodes a counter as fixed-width big-endian bytes.
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*
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* ```ts
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* numberToBytesBE(1, 2);
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* ```
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*/
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export function numberToBytesBE(n, len) {
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// Reject coercible non-numeric inputs before string/hex conversion changes behavior.
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if (typeof n === 'number')
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anumber(n);
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else if (typeof n !== 'bigint')
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throw new TypeError(`number or bigint expected, got ${typeof n}`);
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anumber(len);
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return hexToBytes(n.toString(16).padStart(len * 2, '0'));
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}
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/**
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* Converts string to bytes using UTF8 encoding.
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* @param str - String to encode.
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* @returns UTF-8 bytes in a detached fresh Uint8Array copy.
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* @throws On wrong argument types. {@link TypeError}
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* @example
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* Encodes application text before encryption or MACing.
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*
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* ```ts
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* utf8ToBytes('abc'); // new Uint8Array([97, 98, 99])
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* ```
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*/
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export function utf8ToBytes(str) {
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if (typeof str !== 'string')
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throw new TypeError('string expected');
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return new Uint8Array(new TextEncoder().encode(str)); // {@link https://bugzil.la/1681809 | Firefox bug 1681809}
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}
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/**
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* Converts bytes to string using UTF8 encoding.
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* @param bytes - UTF-8 bytes.
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* @returns Decoded string. Input validation is delegated to `TextDecoder`, and malformed
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* UTF-8 is replacement-decoded instead of rejected.
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* @example
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* Decodes UTF-8 plaintext back into a string.
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*
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* ```ts
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* bytesToUtf8(new Uint8Array([97, 98, 99])); // 'abc'
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* ```
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*/
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export function bytesToUtf8(bytes) {
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return new TextDecoder().decode(bytes);
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}
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/**
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* Checks if two U8A use same underlying buffer and overlaps.
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* This is invalid and can corrupt data.
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* @param a - First byte view.
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* @param b - Second byte view.
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* @returns `true` when the views overlap in memory.
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* @example
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* Detects whether two slices alias the same backing buffer.
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*
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* ```ts
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* overlapBytes(new Uint8Array(4), new Uint8Array(4));
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* ```
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*/
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export function overlapBytes(a, b) {
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// Zero-length views cannot overwrite anything, even if their offset sits inside another range.
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if (!a.byteLength || !b.byteLength)
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return false;
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return (a.buffer === b.buffer && // best we can do, may fail with an obscure Proxy
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a.byteOffset < b.byteOffset + b.byteLength && // a starts before b end
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b.byteOffset < a.byteOffset + a.byteLength // b starts before a end
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);
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}
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/**
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* If input and output overlap and input starts before output, we will overwrite end of input before
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* we start processing it, so this is not supported for most ciphers
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* (except chacha/salsa, which were designed for this)
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* @param input - Input bytes.
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* @param output - Output bytes.
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* @throws If the output view would overwrite unread input bytes. {@link Error}
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* @example
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* Rejects an in-place layout that would overwrite unread input bytes.
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*
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* ```ts
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* complexOverlapBytes(new Uint8Array(4), new Uint8Array(4));
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* ```
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*/
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export function complexOverlapBytes(input, output) {
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|
// This is very cursed. It works somehow, but I'm completely unsure,
|
|
// reasoning about overlapping aligned windows is very hard.
|
|
if (overlapBytes(input, output) && input.byteOffset < output.byteOffset)
|
|
throw new Error('complex overlap of input and output is not supported');
|
|
}
|
|
/**
|
|
* Copies several Uint8Arrays into one.
|
|
* @param arrays - Byte arrays to concatenate.
|
|
* @returns Combined byte array.
|
|
* @throws On wrong argument types inside the byte-array list. {@link TypeError}
|
|
* @example
|
|
* Builds a `nonce || ciphertext` style buffer.
|
|
*
|
|
* ```ts
|
|
* concatBytes(new Uint8Array([1]), new Uint8Array([2]));
|
|
* ```
|
|
*/
|
|
export function concatBytes(...arrays) {
|
|
let sum = 0;
|
|
for (let i = 0; i < arrays.length; i++) {
|
|
const a = arrays[i];
|
|
abytes(a);
|
|
sum += a.length;
|
|
}
|
|
const res = new Uint8Array(sum);
|
|
for (let i = 0, pad = 0; i < arrays.length; i++) {
|
|
const a = arrays[i];
|
|
res.set(a, pad);
|
|
pad += a.length;
|
|
}
|
|
return res;
|
|
}
|
|
/**
|
|
* Merges user options into defaults.
|
|
* @param defaults - Default option values.
|
|
* @param opts - User-provided overrides.
|
|
* @returns Combined options object.
|
|
* The merge mutates `defaults` in place and returns the same object.
|
|
* @throws If options are missing or not an object. {@link Error}
|
|
* @example
|
|
* Applies user overrides to the default cipher options.
|
|
*
|
|
* ```ts
|
|
* checkOpts({ rounds: 20 }, { rounds: 8 });
|
|
* ```
|
|
*/
|
|
export function checkOpts(defaults, opts) {
|
|
if (opts == null || typeof opts !== 'object')
|
|
throw new Error('options must be defined');
|
|
const merged = Object.assign(defaults, opts);
|
|
return merged;
|
|
}
|
|
/**
|
|
* Compares two byte arrays in kinda constant time once lengths already match.
|
|
* @param a - First byte array.
|
|
* @param b - Second byte array.
|
|
* @returns `true` when the arrays contain the same bytes. Different lengths still return early.
|
|
* @example
|
|
* Compares an expected authentication tag with the received one.
|
|
*
|
|
* ```ts
|
|
* equalBytes(new Uint8Array([1]), new Uint8Array([1]));
|
|
* ```
|
|
*/
|
|
export function equalBytes(a, b) {
|
|
if (a.length !== b.length)
|
|
return false;
|
|
let diff = 0;
|
|
for (let i = 0; i < a.length; i++)
|
|
diff |= a[i] ^ b[i];
|
|
return diff === 0;
|
|
}
|
|
/**
|
|
* Wraps a keyed MAC constructor into a one-shot helper with `.create()`.
|
|
* @param keyLen - Valid probe-key length used to read static metadata once.
|
|
* The probe key is only used for `outputLen` / `blockLen`, so callers with several valid key sizes
|
|
* can pass any representative size as long as those values stay fixed.
|
|
* @param macCons - Keyed MAC constructor or factory.
|
|
* @param fromMsg - Optional adapter that derives extra constructor args from the one-shot message.
|
|
* @returns Callable MAC helper with `.create()`.
|
|
*/
|
|
export function wrapMacConstructor(keyLen, macCons, fromMsg) {
|
|
const mac = macCons;
|
|
const getArgs = (fromMsg || (() => []));
|
|
const macC = (msg, key) => mac(key, ...getArgs(msg))
|
|
.update(msg)
|
|
.digest();
|
|
const tmp = mac(new Uint8Array(keyLen), ...getArgs(new Uint8Array(0)));
|
|
macC.outputLen = tmp.outputLen;
|
|
macC.blockLen = tmp.blockLen;
|
|
macC.create = (key, ...args) => mac(key, ...args);
|
|
return macC;
|
|
}
|
|
/**
|
|
* Wraps a cipher: validates args, ensures encrypt() can only be called once.
|
|
* Used internally by the exported cipher constructors.
|
|
* Output-buffer support is inferred from the wrapped `encrypt` / `decrypt`
|
|
* arity (`fn.length === 2`), and tag-bearing constructors are expected to use
|
|
* `args[1]` for optional AAD.
|
|
* @__NO_SIDE_EFFECTS__
|
|
* @param params - Static cipher metadata. See {@link CipherParams}.
|
|
* @param constructor - Cipher constructor.
|
|
* @returns Wrapped constructor with validation.
|
|
*/
|
|
export const wrapCipher = (params, constructor) => {
|
|
function wrappedCipher(key, ...args) {
|
|
// Validate key
|
|
abytes(key, undefined, 'key');
|
|
// Validate nonce if nonceLength is present
|
|
if (params.nonceLength !== undefined) {
|
|
const nonce = args[0];
|
|
abytes(nonce, params.varSizeNonce ? undefined : params.nonceLength, 'nonce');
|
|
}
|
|
// Validate AAD if tagLength present
|
|
const tagl = params.tagLength;
|
|
if (tagl && args[1] !== undefined)
|
|
abytes(args[1], undefined, 'AAD');
|
|
const cipher = constructor(key, ...args);
|
|
const checkOutput = (fnLength, output) => {
|
|
if (output !== undefined) {
|
|
if (fnLength !== 2)
|
|
throw new Error('cipher output not supported');
|
|
abytes(output, undefined, 'output');
|
|
}
|
|
};
|
|
// Create wrapped cipher with validation and single-use encryption
|
|
let called = false;
|
|
const wrCipher = {
|
|
encrypt(data, output) {
|
|
if (called)
|
|
throw new Error('cannot encrypt() twice with same key + nonce');
|
|
called = true;
|
|
abytes(data);
|
|
checkOutput(cipher.encrypt.length, output);
|
|
return cipher.encrypt(data, output);
|
|
},
|
|
decrypt(data, output) {
|
|
abytes(data);
|
|
if (tagl && data.length < tagl)
|
|
throw new Error('"ciphertext" expected length bigger than tagLength=' + tagl);
|
|
checkOutput(cipher.decrypt.length, output);
|
|
return cipher.decrypt(data, output);
|
|
},
|
|
};
|
|
return wrCipher;
|
|
}
|
|
Object.assign(wrappedCipher, params);
|
|
return wrappedCipher;
|
|
};
|
|
/**
|
|
* By default, returns u8a of length.
|
|
* When out is available, it checks it for validity and uses it.
|
|
* @param expectedLength - Required output length.
|
|
* @param out - Optional destination buffer.
|
|
* @param onlyAligned - Whether `out` must be 4-byte aligned.
|
|
* @returns Output buffer ready for writing.
|
|
* @throws On wrong argument types. {@link TypeError}
|
|
* @throws If the provided output buffer has the wrong size or alignment. {@link Error}
|
|
* @example
|
|
* Reuses a caller-provided output buffer when lengths match.
|
|
*
|
|
* ```ts
|
|
* getOutput(16, new Uint8Array(16));
|
|
* ```
|
|
*/
|
|
export function getOutput(expectedLength, out, onlyAligned = true) {
|
|
if (out === undefined)
|
|
return new Uint8Array(expectedLength);
|
|
// Keep Buffer/cross-realm Uint8Array support here instead of trusting a shape-compatible object.
|
|
abytes(out, undefined, 'output');
|
|
if (out.length !== expectedLength)
|
|
throw new Error('"output" expected Uint8Array of length ' + expectedLength + ', got: ' + out.length);
|
|
if (onlyAligned && !isAligned32(out))
|
|
throw new Error('invalid output, must be aligned');
|
|
return out;
|
|
}
|
|
/**
|
|
* Encodes data and AAD bit lengths into a 16-byte buffer.
|
|
* @param dataLength - Data length in bits.
|
|
* @param aadLength - AAD length in bits.
|
|
* The serialized block is still `aadLength || dataLength`, matching GCM/Poly1305
|
|
* conventions even though the helper parameter order is `(dataLength, aadLength)`.
|
|
* @param isLE - Whether to encode lengths as little-endian.
|
|
* @returns 16-byte length block.
|
|
* @throws On wrong argument types passed to the endian validator. {@link TypeError}
|
|
* @throws On wrong argument ranges or values. {@link RangeError}
|
|
* @example
|
|
* Builds the length block appended by GCM and Poly1305.
|
|
*
|
|
* ```ts
|
|
* u64Lengths(16, 8, true);
|
|
* ```
|
|
*/
|
|
export function u64Lengths(dataLength, aadLength, isLE) {
|
|
// Reject coercible non-number lengths like '10' and true before BigInt(...) accepts them.
|
|
anumber(dataLength);
|
|
anumber(aadLength);
|
|
abool(isLE);
|
|
const num = new Uint8Array(16);
|
|
const view = createView(num);
|
|
view.setBigUint64(0, BigInt(aadLength), isLE);
|
|
view.setBigUint64(8, BigInt(dataLength), isLE);
|
|
return num;
|
|
}
|
|
/**
|
|
* Checks whether a byte array is aligned to a 4-byte offset.
|
|
* @param bytes - Byte array to inspect.
|
|
* @returns `true` when the view is 4-byte aligned.
|
|
* @example
|
|
* Checks whether a buffer can be safely viewed as Uint32Array.
|
|
*
|
|
* ```ts
|
|
* isAligned32(new Uint8Array(4));
|
|
* ```
|
|
*/
|
|
export function isAligned32(bytes) {
|
|
return bytes.byteOffset % 4 === 0;
|
|
}
|
|
/**
|
|
* Copies bytes into a new Uint8Array.
|
|
* @param bytes - Bytes to copy.
|
|
* @returns Copied byte array.
|
|
* @throws On wrong argument types. {@link TypeError}
|
|
* @example
|
|
* Copies input into an aligned Uint8Array before block processing.
|
|
*
|
|
* ```ts
|
|
* copyBytes(new Uint8Array([1, 2]));
|
|
* ```
|
|
*/
|
|
export function copyBytes(bytes) {
|
|
// `Uint8Array.from(...)` would also accept arrays / other typed arrays. Keep this helper strict
|
|
// because callers use it at byte-validation boundaries before mutating the detached copy.
|
|
return Uint8Array.from(abytes(bytes));
|
|
}
|
|
/**
|
|
* Cryptographically secure PRNG.
|
|
* Uses internal OS-level `crypto.getRandomValues`.
|
|
* @param bytesLength - Number of bytes to produce.
|
|
* Validation is delegated to `Uint8Array(bytesLength)` and `getRandomValues`, so
|
|
* non-integers, negative lengths, and oversize requests surface backend/runtime errors.
|
|
* @returns Random byte array.
|
|
* @throws On wrong argument types. {@link TypeError}
|
|
* @throws On wrong argument ranges or values. {@link RangeError}
|
|
* @throws If the runtime does not expose `crypto.getRandomValues`. {@link Error}
|
|
* @example
|
|
* Generates a fresh nonce or key.
|
|
*
|
|
* ```ts
|
|
* randomBytes(16);
|
|
* ```
|
|
*/
|
|
export function randomBytes(bytesLength = 32) {
|
|
// Validate upfront so fractional / coercible lengths do not silently
|
|
// truncate through Uint8Array().
|
|
anumber(bytesLength);
|
|
const cr = typeof globalThis === 'object' ? globalThis.crypto : null;
|
|
if (typeof cr?.getRandomValues !== 'function')
|
|
throw new Error('crypto.getRandomValues must be defined');
|
|
return cr.getRandomValues(new Uint8Array(bytesLength));
|
|
}
|
|
/**
|
|
* Uses CSPRNG for nonce, nonce injected in ciphertext.
|
|
* For `encrypt`, a `nonceBytes`-length buffer is fetched from CSPRNG and
|
|
* prepended to encrypted ciphertext. For `decrypt`, first `nonceBytes` of ciphertext
|
|
* are treated as nonce. The wrapper always allocates a fresh `nonce || ciphertext`
|
|
* buffer on encrypt and intentionally does not support caller-provided destination buffers.
|
|
* Too-short decrypt inputs are split into short/empty nonce views and then delegated
|
|
* to the wrapped cipher instead of being rejected here first.
|
|
*
|
|
* NOTE: Under the same key, using random nonces (e.g. `managedNonce`) with AES-GCM and ChaCha
|
|
* should be limited to `2**23` (8M) messages to get a collision chance of
|
|
* `2**-50`. Stretching to `2**32` (4B) messages would raise that chance to
|
|
* `2**-33`, still negligible but creeping up.
|
|
* @param fn - Cipher constructor that expects a nonce.
|
|
* @param randomBytes_ - Random-byte source used for nonce generation.
|
|
* @returns Cipher constructor that prepends the nonce to ciphertext.
|
|
* @throws On wrong argument types. {@link TypeError}
|
|
* @throws On invalid nonce lengths observed at wrapper construction or use. {@link RangeError}
|
|
* @example
|
|
* Prepends a fresh random nonce to every ciphertext.
|
|
*
|
|
* ```ts
|
|
* import { gcm } from '@noble/ciphers/aes.js';
|
|
* import { managedNonce, randomBytes } from '@noble/ciphers/utils.js';
|
|
* const wrapped = managedNonce(gcm);
|
|
* const key = randomBytes(16);
|
|
* const ciphertext = wrapped(key).encrypt(new Uint8Array([1, 2, 3]));
|
|
* wrapped(key).decrypt(ciphertext);
|
|
* ```
|
|
*/
|
|
export function managedNonce(fn, randomBytes_ = randomBytes) {
|
|
const { nonceLength } = fn;
|
|
anumber(nonceLength);
|
|
const addNonce = (nonce, ciphertext, plaintext) => {
|
|
const out = concatBytes(nonce, ciphertext);
|
|
// Wrapped ciphers may alias caller plaintext on encrypt(); never zero
|
|
// caller-owned buffers here.
|
|
if (!overlapBytes(plaintext, ciphertext))
|
|
ciphertext.fill(0);
|
|
return out;
|
|
};
|
|
// NOTE: we cannot support DST here, it would be mistake:
|
|
// - we don't know how much dst length cipher requires
|
|
// - nonce may unalign dst and break everything
|
|
// - we create new u8a anyway (concatBytes)
|
|
// - previously we passed all args to cipher, but that was mistake!
|
|
const res = ((key, ...args) => ({
|
|
encrypt(plaintext) {
|
|
abytes(plaintext);
|
|
const nonce = randomBytes_(nonceLength);
|
|
const encrypted = fn(key, nonce, ...args).encrypt(plaintext);
|
|
// @ts-ignore
|
|
if (encrypted instanceof Promise)
|
|
return encrypted.then((ct) => addNonce(nonce, ct, plaintext));
|
|
return addNonce(nonce, encrypted, plaintext);
|
|
},
|
|
decrypt(ciphertext) {
|
|
abytes(ciphertext);
|
|
const nonce = ciphertext.subarray(0, nonceLength);
|
|
const decrypted = ciphertext.subarray(nonceLength);
|
|
return fn(key, nonce, ...args).decrypt(decrypted);
|
|
},
|
|
}));
|
|
// Auto-nonce wrappers still preserve the wrapped payload geometry.
|
|
if ('blockSize' in fn)
|
|
res.blockSize = fn.blockSize;
|
|
if ('tagLength' in fn)
|
|
res.tagLength = fn.tagLength;
|
|
return res;
|
|
}
|
|
//# sourceMappingURL=utils.js.map
|