tweetnacl
TweetNaCl.js
Port of TweetNaCl / NaCl to JavaScript for modern browsers and Node.js. Public domain.
Demo: https://tweetnacl.js.org
⚠️ The library is stable and API is frozen, however it has not been independently reviewed. If you can help reviewing it, please contact me.
Documentation
Overview
The primary goal of this project is to produce a translation of TweetNaCl to JavaScript which is as close as possible to the original C implementation, plus a thin layer of idiomatic high-level API on top of it.
There are two versions, you can use either of them:
nacl.jsis the port of TweetNaCl with minimum differences from the original + high-level API.nacl-fast.jsis likenacl.js, but with some functions replaced with faster versions.
Installation
You can install TweetNaCl.js via a package manager:
NPM:
Usage
All API functions accept and return bytes as Uint8Arrays. If you need to encode or decode strings, use functions from https://github.com/dchest/tweetnacl-util-js or one of the more robust codec packages.
In Node.js v4 and later Buffer objects are backed by Uint8Arrays, so you can freely pass them to TweetNaCl.js functions as arguments. The returned objects are still Uint8Arrays, so if you need Buffers, you'll have to convert them manually; make sure to convert using copying: new Buffer(array), instead of sharing: new Buffer(array.buffer), because some functions return subarrays of their buffers.
Public-key authenticated encryption (box)
Implements curve25519-xsalsa20-poly1305.
nacl.box.keyPair()
Generates a new random key pair for box and returns it as an object with publicKey and secretKey members:
nacl.box.keyPair.fromSecretKey(secretKey)
Returns a key pair for box with public key corresponding to the given secret key.
nacl.box(message, nonce, theirPublicKey, mySecretKey)
Encrypt and authenticates message using peer's public key, our secret key, and the given nonce, which must be unique for each distinct message for a key pair.
Returns an encrypted and authenticated message, which is nacl.box.overheadLength longer than the original message.
nacl.box.open(box, nonce, theirPublicKey, mySecretKey)
Authenticates and decrypts the given box with peer's public key, our secret key, and the given nonce.
Returns the original message, or false if authentication fails.
nacl.box.before(theirPublicKey, mySecretKey)
Returns a precomputed shared key which can be used in nacl.box.after and nacl.box.open.after.
nacl.box.after(message, nonce, sharedKey)
Same as nacl.box, but uses a shared key precomputed with nacl.box.before.
nacl.box.open.after(box, nonce, sharedKey)
Same as nacl.box.open, but uses a shared key precomputed with nacl.box.before.
nacl.box.publicKeyLength = 32
Length of public key in bytes.
nacl.box.secretKeyLength = 32
Length of secret key in bytes.
nacl.box.sharedKeyLength = 32
Length of precomputed shared key in bytes.
nacl.box.nonceLength = 24
Length of nonce in bytes.
nacl.box.overheadLength = 16
Length of overhead added to box compared to original message.
Secret-key authenticated encryption (secretbox)
Implements xsalsa20-poly1305.
nacl.secretbox(message, nonce, key)
Encrypt and authenticates message using the key and the nonce. The nonce must be unique for each distinct message for this key.
Returns an encrypted and authenticated message, which is nacl.secretbox.overheadLength longer than the original message.
nacl.secretbox.open(box, nonce, key)
Authenticates and decrypts the given secret box using the key and the nonce.
Returns the original message, or false if authentication fails.
nacl.secretbox.keyLength = 32
Length of key in bytes.
nacl.secretbox.nonceLength = 24
Length of nonce in bytes.
nacl.secretbox.overheadLength = 16
Length of overhead added to secret box compared to original message.
Scalar multiplication
Implements curve25519.
nacl.scalarMult(n, p)
Multiplies an integer n by a group element p and returns the resulting group element.
nacl.scalarMult.base(n)
Multiplies an integer n by a standard group element and returns the resulting group element.
nacl.scalarMult.scalarLength = 32
Length of scalar in bytes.
nacl.scalarMult.groupElementLength = 32
Length of group element in bytes.
Signatures
Implements ed25519.
nacl.sign.keyPair()
Generates new random key pair for signing and returns it as an object with publicKey and secretKey members:
nacl.sign.keyPair.fromSecretKey(secretKey)
Returns a signing key pair with public key corresponding to the given 64-byte secret key. The secret key must have been generated by nacl.sign.keyPair or nacl.sign.keyPair.fromSeed.
nacl.sign.keyPair.fromSeed(seed)
Returns a new signing key pair generated deterministically from a 32-byte seed. The seed must contain enough entropy to be secure. This method is not recommended for general use: instead, use nacl.sign.keyPair to generate a new key pair from a random seed.
nacl.sign(message, secretKey)
Signs the message using the secret key and returns a signed message.
nacl.sign.open(signedMessage, publicKey)
Verifies the signed message and returns the message without signature.
Returns null if verification failed.
nacl.sign.detached(message, secretKey)
Signs the message using the secret key and returns a signature.
nacl.sign.detached.verify(message, signature, publicKey)
Verifies the signature for the message and returns true if verification succeeded or false if it failed.
nacl.sign.publicKeyLength = 32
Length of signing public key in bytes.
nacl.sign.secretKeyLength = 64
Length of signing secret key in bytes.
nacl.sign.seedLength = 32
Length of seed for nacl.sign.keyPair.fromSeed in bytes.
nacl.sign.signatureLength = 64
Length of signature in bytes.
Hashing
Implements SHA-512.
nacl.hash(message)
Returns SHA-512 hash of the message.
nacl.hash.hashLength = 64
Length of hash in bytes.
Random bytes generation
nacl.randomBytes(length)
Returns a Uint8Array of the given length containing random bytes of cryptographic quality.
Implementation note
TweetNaCl.js uses the following methods to generate random bytes, depending on the platform it runs on:
window.crypto.getRandomValues(WebCrypto standard)window.msCrypto.getRandomValues(Internet Explorer 11)crypto.randomBytes(Node.js)
If the platform doesn't provide a suitable PRNG, the following functions, which require random numbers, will throw exception:
nacl.randomBytesnacl.box.keyPairnacl.sign.keyPair
Other functions are deterministic and will continue working.
If a platform you are targeting doesn't implement secure random number generator, but you somehow have a cryptographically-strong source of entropy (not Math.random!), and you know what you are doing, you can plug it into TweetNaCl.js like this:
Note that nacl.setPRNG completely replaces internal random byte generator with the one provided.
Constant-time comparison
nacl.verify(x, y)
Compares x and y in constant time and returns true if their lengths are non-zero and equal, and their contents are equal.
Returns false if either of the arguments has zero length, or arguments have different lengths, or their contents differ.
System requirements
TweetNaCl.js supports modern browsers that have a cryptographically secure pseudorandom number generator and typed arrays, including the latest versions of:
Chrome
Firefox
Safari (Mac, iOS)
Internet Explorer 11
Other systems:
Node.js
Development and testing
Install NPM modules needed for development:
To build minified versions:
Tests use minified version, so make sure to rebuild it every time you change nacl.js or nacl-fast.js.
Testing
To run tests in Node.js:
By default all tests described here work on nacl.min.js. To test other versions, set environment variable NACL_SRC to the file name you want to test. For example, the following command will test fast minified version:
To run full suite of tests in Node.js, including comparing outputs of JavaScript port to outputs of the original C version:
To prepare tests for browsers:
and then open test/browser/test.html (or test/browser/test-fast.html) to run them.
To run headless browser tests with tape-run (powered by Electron):
(If you get Error: spawn ENOENT, install xvfb: sudo apt-get install xvfb.)
To run tests in both Node and Electron:
Benchmarking
To run benchmarks in Node.js:
To run benchmarks in a browser, open test/benchmark/bench.html (or test/benchmark/bench-fast.html).
Benchmarks
For reference, here are benchmarks from MacBook Pro (Retina, 13-inch, Mid 2014) laptop with 2.6 GHz Intel Core i5 CPU (Intel) in Chrome 53/OS X and Xiaomi Redmi Note 3 smartphone with 1.8 GHz Qualcomm Snapdragon 650 64-bit CPU (ARM) in Chrome 52/Android:
salsa20
1.3 MB/s
128 MB/s
0.4 MB/s
43 MB/s
poly1305
13 MB/s
171 MB/s
4 MB/s
52 MB/s
hash
4 MB/s
34 MB/s
0.9 MB/s
12 MB/s
secretbox 1K
1113 op/s
57583 op/s
334 op/s
14227 op/s
box 1K
145 op/s
718 op/s
37 op/s
368 op/s
scalarMult
171 op/s
733 op/s
56 op/s
380 op/s
sign
77 op/s
200 op/s
20 op/s
61 op/s
sign.open
39 op/s
102 op/s
11 op/s
31 op/s
(You can run benchmarks on your devices by clicking on the links at the bottom of the home page).
In short, with nacl-fast.js and 1024-byte messages you can expect to encrypt and authenticate more than 57000 messages per second on a typical laptop or more than 14000 messages per second on a $170 smartphone, sign about 200 and verify 100 messages per second on a laptop or 60 and 30 messages per second on a smartphone, per CPU core (with Web Workers you can do these operations in parallel), which is good enough for most applications.
Contributors
See AUTHORS.md file.
Third-party libraries based on TweetNaCl.js
forward-secrecy — Axolotl ratchet implementation
nacl-stream - streaming encryption
tweetnacl-auth-js — implementation of
crypto_authchloride - unified API for various NaCl modules
Who uses it
Some notable users of TweetNaCl.js:
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