BLAKE3

BLAKE3 running in JavaScript (node.js and browsers) via native bindings, where available, or WebAssembly.

npm install blake3

Additionally, there's a flavor of the package which is identical except that it will not download native Node.js bindings and use only WebAssembly:

npm install blake3-wasm

Quickstart
API
- Node.js
- Browser
Speed
Other (JS) Implementations
Contributing
- Publishing

Quickstart

If you're on Node, import the module via

const blake3 = require('blake3');

blake3.hash('foo'); // => Buffer

If you're in the browser, import blake3/browser. This includes a WebAssembly binary, so you probably want to import it asynchronously, like so:

import('blake3/browser').then((blake3) => {
  blake3.hash('foo'); // => Uint8Array
});

The API is very similar in Node.js and browsers, but Node supports and returns Buffers and a wider range of input and output encoding.

More complete example:

const { hash, createHash } = require('blake3');

hash('some string'); // => hash a string to a uint8array

// Update incrementally (Node and Browsers):
const hash = createHash();
stream.on('data', (d) => hash.update(d));
stream.on('error', (err) => {
  // hashes use unmanaged memory in WebAssembly, always free them if you don't digest()!
  hash.dispose();
  throw err;
});
stream.on('end', () => finishedHash(hash.digest()));

// Or, in Node, it's also a transform stream:
createReadStream('file.txt')
  .pipe(createHash())
  .on('data', (hash) => console.log(hash.toString('hex')));

API

Node.js

The Node API can be imported via require('blake3').

`hash(data: BinaryLike, options?: { length: number }): Buffer`

Returns a hash for the given data. The data can be a string, buffer, typedarray, array buffer, or array. By default, it generates the first 32 bytes of the hash for the data, but this is configurable. It returns a Buffer.

`keyedHash(key: BinaryLike, data: BinaryLike, options?: { length: number }): Buffer`

Returns keyed a hash for the given data. The key must be exactly 32 bytes. The data can be a string, buffer, typedarray, array buffer, or array. By default, it generates the first 32 bytes of the hash for the data, but this is configurable. It returns a Buffer.

For more information, see the blake3 docs.

`deriveKey(context: BinaryLike, material: BinaryLike, options?: { length: number }): Buffer`

The key derivation function. The data can be a string, buffer, typedarray, array buffer, or array. By default, it generates the first 32 bytes of the hash for the data, but this is configurable. It returns a Buffer.

For more information, see the blake3 docs.

Hasher

The hasher is a type that lets you incrementally build a hash. It's compatible with Node's crypto hash instance. For instance, it implements a transform stream, so you could do something like:

createReadStream('file.txt')
  .pipe(createHash())
  .on('data', (hash) => console.log(hash.toString('hex')));

`createHash(): Hasher`

Creates a new hasher instance using the standard hash function.

`createKeyed(key: BinaryLike): Hasher`

Creates a new hasher instance for a keyed hash. For more information, see the blake3 docs.

`createDeriveKey(context: BinaryLike): Hasher`

Creates a new hasher instance for the key derivation function. For more information, see the blake3 docs.

`hasher.update(data: BinaryLike): this`

Adds data to a hash. The data can be a string, buffer, typedarray, array buffer, or array.

`hasher.digest(encoding?: string, options?: { length: number })): Buffer | string`

Returns the hash of the data. If an encoding is given, a string will be returned. Otherwise, a Buffer is returned. Optionally, you can specify the requested byte length of the hash.

`hasher.reader(): HashReader`

Returns a HashReader for the current hash.

`hasher.dispose()`

This is a no-op for Node.js.

HashReader

The hash reader can be returned from hashing functions. Up to 264-1 bytes of data can be read from BLAKE3 hashes; this structure lets you read those. Note that, like hash, this is an object which needs to be manually disposed of.

`reader.position: bigint`

A property which gets or sets the position of the reader in the output stream. A RangeError is thrown if setting this to a value less than 0 or greater than 264-1. Note that this is a bigint, not a standard number.

reader.position += 32n; // advance the reader 32 bytes

`reader.readInto(target: Uint8Array): number`

Reads bytes into the target array, filling it up and advancing the reader's position. It returns the number of bytes written, which may be less then the size of the target buffer if position 264-1 is reached.

`reader.read(bytes: number): Buffer`

Reads and returns the given number of bytes from the reader, and advances the position. A RangeError is thrown if reading this data puts the reader past 264-1 bytes.

`reader.view(target: Buffer): Readonly<Uint8Array>`

Returns a view of the given number of bytes from the reader. The view can be used synchronously, but must not be reused later. This is more efficient when using the webassembly version of the module.

Fewer bytes may be returned than requested, if the number is large (>1MB).

`reader[Symbol.iterator]`

The reader is an Iterable of Readonly<Uint8Array>s. Like the view method, the iterated arrays will be reused internally on the next iteration, so if you need data, you should copy it out of the iterated array.

Browser

The browser API can be imported via import('blake3/browser'), which works well with Webpack.

Note that you must call the load() method before using any function in the module.

import * as blake3 from 'blake3/browser-async';

blake3.load().then(() => {
  console.log(blake3.hash('hello world'));
});

`hash(data: BinaryLike, options?: { length: number }): Hash`

Returns a hash for the given data. The data can be a string, typedarray, array buffer, or array. By default, it generates the first 32 bytes of the hash for the data, but this is configurable. It returns a Hash instance.

Blake3

Install / Use

README