react-native-rsa

React native rsa crypto lib

The use case

Initially this was created for encrypted messaging

Client would generate RSA key pairs and store private key locally and share the public key.

How to use

npm install react-native-rsa

Generate RSA keys

var RSAKey = require('react-native-rsa');
const bits = 1024;
const exponent = '10001'; // must be a string
var rsa = new RSAKey();
var r = rsa.generate(bits, exponent);
var publicKey = rsa.RSAGetPublicString(); // return json encoded string
var privateKey = rsa.RSAGetPrivateString(); // return json encoded string

Encrypt

var rsa = new RSAKey();
rsa.setPublicString(publicKey);
var originText = 'sample String Value';
var encrypted = rsa.encrypt(originText);

Decrypt

rsa.setPrivateString(privateKey);
var decrypted = rsa.decrypt(encrypted); // decrypted == originText

Credits

This lib uses Tom Wu's jsbn http://www-cs-students.stanford.edu/~tjw/jsbn/

TODO: Still missing export to DER/PEM format

Known issues:

• RSA encryption/decryption with this lib doesn't work well with other RSA libs (such as Node RSA). I have to use the same lib on both client and server to make it work
• In the future, consider to fix this issue and let it work with standard openssl lib.
• Node js may complain about 'window' is not defined. I just commented out the 'window' related codes in rng.js and it worked. (It look like just adding some extra randomness. Should still work without that part)