Java: Different results when decoding base64 string with java.util.Base64 vs android.util.Base64

Question

I'm working on a client/server system and I'm trying to do some basic encryption. When I connect to the server, I send a public key as an escaped string across the socket. I've verified that the string is identical on both ends, newlines and all.

On the client (Android), I'm able to use the public/private keys to successfully encrypt and decrypt a secret key (for testing purposes). However, the server fails right out of the gate when trying to decode the public key from a String to a byte[], with:

 java.lang.IllegalArgumentException: Illegal base64 character a 

which seems preposterous, as 'a' is absolutely a base64 character, if I understand correctly. The client and server use a shared library to handle all encryption, so the code is nearly identical. The only difference is encoding/decoding base64 Strings, since java.util.Base64 is unavailable on Android.

Shared class

public abstract class EasyCrypt {  ...      public PublicKey loadPublicKey(String key64) throws GeneralSecurityException {          byte[] data = decode(key64); //Calls abstract methods, shown below          X509EncodedKeySpec spec = new X509EncodedKeySpec(data);         KeyFactory fact = KeyFactory.getInstance("RSA");         return fact.generatePublic(spec);     }  ...  } 

Client (Android) methods

import android.util.Base64;  public class ClientCrypt extends EasyCrypt {     @Override     protected byte[] decode(String s) {         return Base64.decode(s.getBytes(), Base64.DEFAULT); //Works perfectly     }      @Override     protected String encode(byte[] bytes) {         return Base64.encodeToString(bytes, Base64.DEFAULT);     } 

}

Server (Linux) methods

import java.util.Base64;  public class ServerCrypt extends EasyCrypt{     @Override     public byte[] decode(String str){         return Base64.getDecoder().decode(str); //Throws IllegalArgumentException     }      @Override     public String encode(byte[] bytes){         return Base64.getEncoder().encodeToString(bytes);     } 

}

Answer 1

On android, Use Base64.NO_WRAP instead of Base64.DEFAULT

@Override protected String encode(byte[] bytes) {     return Base64.encodeToString(bytes, Base64.NO_WRAP); }