rsa-stream

encrypt/decrypt rsa with streams

This module is a bit silly unless you are using it as a wrapper because you shouldn't encrypt too many bytes with asymmetric crypto. Instead, encrypt a key for a symmetric cipher in a short header and then switch to symmetric crypto for the payload.

You should probably be using hybrid-rsa-stream instead.

example

encrypt

var rsa = require('rsa-stream');
var fs = require('fs');
var pubkey = fs.readFileSync(process.argv[2], 'utf8');
 
var enc = rsa.encrypt(pubkey, { encoding: 'base64' });
process.stdin.pipe(enc).pipe(process.stdout);

output:

$ echo beep boop | node enc.js ~/.ssh/id_rsa.pub
t1Lytqy7CoONohuzIDxoGpErAK4vN9xKWWO/IK4yH/2PvAOIldSAdNg/HhiAWg5PAPwCTSIfINYlpNSQgkw3kK/GtaeEIpAdRnlHh6wNzBcbT7L7R+EZthWzPKpPE9IO0tPM5kBpN8SDr16Z6PC0OxK5ArJAqmbv8hiWzjS384dMYcyYrK6Z0cUawkC2oeZhBf5z6ev1OLTesPF71evJSTIFD3XlbksziAgYIS4CAG+Gwx0avmHwJHnHuvAr/wY3FcVYc4788tmS1YVmRAPrqg/0UoGglnLaSR1DdOJNgw5y/oErlBxXtMV6jEjWLi8XK2hZiKk/ecA921Fx+483zw==

decrypt

var rsa = require('rsa-stream');
var fs = require('fs');
var privkey = fs.readFileSync(process.argv[2], 'utf8');
 
var dec = rsa.decrypt(privkey, { encoding: 'base64' });
process.stdin.pipe(dec).pipe(process.stdout);

output:

$ echo beep boop | node enc.js ~/.ssh/id_rsa.pub | node dec.js ~/.ssh/id_rsa
Enter PEM pass phrase:
beep boop

methods

var rsa = require('rsa-stream')

var enc = rsa.encrypt(publicKey, opts)

Return an encryption stream enc that will encrypt the data written to it with the given publicKey and output the encrypted stream with opts.encoding ('binary' buffers by default).

publicKey should be a string or buffer with PEM key data or the openssh-style public keys typically found in ~/.ssh that begin with /^ssh-rsa\b/

If more than opts.limit bytes are written, an error is thrown. The default number of bytes is 100, which you should only raise to maximally n/8-11 for an n-bit RSA key.

var dec = rsa.decrypt(privateKey, opts)

Return a decryption stream dec that will decrypt the data written to it in opts.encoding format with the given privateKey.

privateKey should be a string or buffer with PEM or openssh-style /^ssh-rsa\b/ data.

install

To get the library, with npm do:

npm install rsa-stream

license

MIT