Android create RSA 1024 .NET compatible keys

I am developing an Android Application and I need to generate some RSA private and public keys to use for secure communication with web services. To do this I need to have the public key in a .NET compatible form. Like:

<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent></RSAKeyValue>

So far I managed to to this:

  keyGen = KeyPairGenerator.getInstance("RSA");开发者_Python百科
  keyGen.initialize(1024);
  keypair = keyGen.genKeyPair();
  privateKey = keypair.getPrivate();
  publicKey = keypair.getPublic();

  // Get the bytes of the public and private keys
  byte[] privateKeyBytes = privateKey.getEncoded();
  byte[] publicKeyBytes = publicKey.getEncoded();

I've got no clue how to continue. Could you please provide some help ?

For anybody else interested, a very good tutorial can be found in here

http://www.codeproject.com/KB/security/porting_java_public_key.aspx?msg=3407475

If you need Base64 encoding/decoding, because it's not included in Android (at least in API 4) you could use the class from here: iharder.sourceforge.net/current/java/base64/

You don't show the type publicKey. If is not already, you should cast to an RSAPublicKey, then use the getPublicExponent() and getModulus() methods to extract the BigInteger. Then simply use standard Java IO, e.q. PrintStream.println() or printf() to generate the XML components.