react-native-rsa work with ursa

gistfile1.txt

// In URSA

var crt = ursa.createPublicKeyFromComponents(new Buffer(publicKey.n, 'hex'), new Buffer(publicKey.e, 'hex'));
var textToEncrypt = 'sampleText';
var encryptedCipher = crt.encrypt(textToEncrypt, 'utf8', 'base64', DEFAULT_RSA_PADDING);

// In react-native
// convert a base64 string to hex

function b64tohex(s) {
    var ret = "";
    var i;
    var k = 0; // b64 state, 0-3
    var slop;
    for (i = 0; i < s.length; ++i) {
        if (s.charAt(i) == b64padchar) break;
        v = b64map.indexOf(s.charAt(i));
        if (v < 0) continue;
        if (k == 0) {
            ret += int2char(v >> 2);
            slop = v & 3;
            k = 1;
        } else if (k == 1) {
            ret += int2char((slop << 2) | (v >> 4));
            slop = v & 0xf;
            k = 2;
        } else if (k == 2) {
            ret += int2char(slop);
            ret += int2char(v >> 2);
            slop = v & 3;
            k = 3;
        } else {
            ret += int2char((slop << 2) | (v >> 4));
            ret += int2char(v & 0xf);
            k = 0;
        }
    }
    if (k == 1)
        ret += int2char(slop << 2);
    return ret;
}
function decryptRSA(encrypted, format) {
    format = format || 'base64';
    if (format == 'base64') {
        encrypted = b64tohex(encrypted);
    }
    this.rsa = this.rsa || new ReactNativeRSA();
    return this.rsa.decrypt(encrypted);
}
decryptRSA(encryptedCipher);

//Make sure the text length is smaller than the size of your RSA key size.