Convert byte[] to String Java Android Encryption

Question

I am using the JNCryptor library to encrypt a string before sending it to my server as an encrypted string. Here is my code:

    String teststring = "Hello World";
    JNCryptor cryptor = new AES256JNCryptor();
    byte[] plaintext = teststring.getBytes();
    String password = "test";

    try {
        byte[] ciphertext = cryptor.encryptData(plaintext, password.toCharArray());

        String a = new String(ciphertext);
        return a;


    } catch (CryptorException e) {
        // Something went wrong
        e.printStackTrace();

        return "0";
    }

However, when I send my string "a" to the server, it has a bunch of unrecognizable characters. I read an explanation regarding this:

String is not a suitable container for binary data and ciphertext is binary data. For any given character encoding not all bytes and byte sequences represents characters and when an un-representable byte or sequence is found it is converted to some error character. Obviously this error character cannot be converted back to a unique byte or byte sequence (it is a many->one mapping).

Is this advice correct? In that case, how do I convert the byte[] to a string correctly? So that I can readably store it on my server?

The advice is correct. Failure to heed it will lead to tears. — President James K. Polk
– President James K. Polk, Commented Jul 22, 2014 at 22:29

JBires · Accepted Answer · 2014-07-22 17:58:48Z

4

There is no standard way for converting from a byte array to a string. You have to encode the byte array. A common way to do this is base64 encoding. For an explanation of how base64 encoding works: http://en.wikipedia.org/wiki/Base64

Then once it gets to your server, base64 decode it back into your original byte array and store it, done!

answered Jul 22, 2014 at 17:58

JBires

4413 silver badges11 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

President James K. Polk Over a year ago

On Android this is accessible in the android.util.Base64 class. I don't know iOS.

Collectives™ on Stack Overflow

Convert byte[] to String Java Android Encryption

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related