node-saltpack

our standard saltpack implementation in JS

Features

• Full implementation of the saltpack spec (https://saltpack.org)
• Written for streaming (composable with standard node streams)
• Browser-ready

Encrypting and decrypting

First, you'll need to obtain keys somehow. See our NaCl library for info on how to do that. If you just want random keys for testing, there's an alice_and_bob function that returns two keypairs in lib/util.js.

Once you have keys for the encryptor and the public keys of each recipient:

var saltpack = require("saltpack");

//get some testing keys, create encrypt/decrypt streams
var alice, bob;
{alice, bob} = saltpack.lowlevel.util.alice_and_bob();

//to specify anonymous recipients, simply add an "anonymized_recipients" argument
//to the dict, with "null" in place of a public key for each recipient you want to hide.
var es = new saltpack.stream.EncryptStream({
    encryptor: alice,
    do_armoring: true,
    recipients: [bob.publicKey]
})
var ds = new saltpack.stream.DecryptStream({decryptor: bob, do_armoring: true})

//register error listeners
es.on('error', (err) -> throw err)
ds.on('error', (err) -> throw err)

//encrypt from stdin, write to a file
var fs = require("fs");
var file = fs.createWriteStream("/path/to/file");

//pipe the EncryptStream into the file
process.stdin.pipe(es);
//currently, it's not possible to chain pipe calls with {Encrypt,Decrypt}Streams, i.e.
//process.stdin.pipe(es).pipe(file) - this change may come down the line,
//but for now we just have to use the extra line.
es.pipe(file);
file.on('close', () -> es.end())

//decrypt from a file, write to stdout
file = fs.createReadStream("/path/to/file");
file.pipe(ds)
ds.pipe(process.stdin)
file.on('close', () -> ds.end())

Stream interface

EncryptStream and DecryptStream mimic the NodeJS stream API as closely as possible. Accordingly, you can watch for the following events:

• Writable side (input):
  • drain
  • pipe
  • unpipe
• Readable side (output):
  • close
  • data
  • end
  • finish
  • readable The events are propagated up to the caller by the wrapped stream classes. Additionally, 'error' events emitted by any stream in the pipeline will propagate up to the caller.

EncryptStream and DecryptStream also provide three stream-interface methods:

• .write(chunk)
• .pipe(dest)
• .end()

Unfortunately, at this time it is not possibe to chain .pipe() calls, as explained above. Other than this you can treat EncryptStream and DecryptStream as standard NodeJS streams.