RSA encrypt using jsencrypt and decrypt using boun

Question

Right I've a small problem. I'm using a Javascript library (jsencrypt) to encrypt a message in a browser. This message is then sent to the backend where it is decrypted using a Java library (bouncycastle). My problem is although I can encrypt and decrypt messages using both libraries they don't seem to want to work together. So when I encrypt my message in a browser and send it to the backend I end up getting garbled gibberish. Does anyone have any idea what's going on here?

JSENCRYPT

var text = "This is another msg!";
var pubkey = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwyTZf5gRWJdEevtK7sJSz14lhs1Jw7+aFhGtr4cbDGxdiXH8J+BwuYmBc6QFMhRw7AeYcgkx9zPb3SICzr+oK17RMA6T66dH+GPXp75LFUmfONfk2JdSeO80mMODGctSuefWDvoQ24Cq0Bz+ysrhP7hRqvJso5a0GMNPwt8ErtWfz4HZjSsaaZ7gXga2h5dq1OTcGNfevkDN9CJtFW/0Wwb/F6cnXngVHE41rsN4POUB3IWcX2CrCGxSraa+xsT/P7AJ8HRJ4wcjl9G2K/rlHJ8ZXZKlIuWwEzx0/F0IjE+S93tLpDgt6YJxjWqYqjL2uuJAGmEU323+PWA3jFTC+QIDAQAB";        

var encrypt = new JSEncrypt();
encrypt.setPublicKey(pubkey);
var ciphertext = encrypt.encrypt(text);
console.log("ciphertext  : " + ciphertext);

var decrypt = new JSEncrypt();
decrypt.setPrivateKey($("#privkey").val());
var plaintext = decrypt.decrypt(ciphertext);
console.log("plaintext  : " + plaintext);

BOUNCYCASTLE

String cipherText = "jQ/I+oyyIfG5ARIHZsa6MfxwHciCt+3p6l+bLh4NPinq2s8eDjbO9O8abhVt2xuBQQcPAIaqbiP3Y3vRFYLOD2O+inKWiL1SpSBxvUb0XlWMgLmOqWUL6w6sL2iEla3i5EbdlrkK0uLA7QOUc6/fGVyLVe8VL7Vv4BGlo/cxR2FN74HK4MtLFRNaLKejwD6WbCNQoz4sIMA/Ez8GRSVEMyeYVZoWELShvyIRCqVADboAeuEP5l+oFlzgQfW6HFdpPnX+9TnHrbezdWhXiuJiD1Mq4VTicsya50MNcXJuPDV7NINYZs72UCS8NTYvfVkFc2lO7EUlDvvJ7Ns4wWuuWQ==";

PemReader pemReader = new PemReader(new InputStreamReader(new FileInputStream("priv.pem")));
PemObject pemObject = null;

try 
{
    pemObject = pemReader.readPemObject();

} finally {

    pemReader.close();
}

PrivateKey privateKey = EncryptionUtil.generatePrivateKey(pemObject.getContent());
byte[] plainText = EncryptionUtil.asymDecrypt(privateKey, cipherText.getBytes());
System.out.println(new String(plainText));

Answer 1

@EbbeM.Pedersen

You are properly getting different default padding modes. Keywords like RSA-OAEP padding & PKCS#1 padding comes to mind.

This was indeed the issue. I changed the default padding in bouncycastle to PKCS#1 and it all works now.

Thanks a million.