Android™

Poly1305 MAC

See more Encryption Examples

Demonstrates the Poly1305 Message Authentication Code. (Introduced in Chilkat v9.5.0.55) This example duplicates the results of Test Vector #4 for Poly1305 in RFC 7539. Android™

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    boolean success = false;

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkCrypt2 crypt = new CkCrypt2();

    // Set the MAC algorithm to poly1305
    crypt.put_MacAlgorithm("poly1305");

    // EncodingMode specifies the encoding of the output for
    // encryption, and the input for decryption.
    // Valid modes are (case insensitive) "Base64", "modBase64", "Base32", "Base58", "UU", 
    // "QP" (for quoted-printable), "URL" (for url-encoding), "Hex", 
    // "Q", "B", "url_oauth", "url_rfc1738", "url_rfc2396", and "url_rfc3986".
    crypt.put_EncodingMode("hex");

    // Poly1305 always uses a 32-byte (256-bit) MAC key.
    String keyHex = "1c9240a5eb55d38af333888604f6b5f0473917c1402b80099dca5cbc207075c0";
    success = crypt.SetMacKeyEncoded(keyHex,"hex");

    String plainText = "'Twas brillig, and the slithy toves\nDid gyre and gimble in the wabe:\nAll mimsy were the borogoves,\nAnd the mome raths outgrabe.";

    // The computed tag should match the Tag shown below.
    // (Note: hexidecimal encoding is case insensitive.)
    String encTag = crypt.macStringENC(plainText);
    Log.i(TAG, encTag);

    // Here is the Test Vector data copied from RFC 7539

    //  Test Vector #4:
    //  ==============
    // 
    //  One-time Poly1305 Key:
    //  000  1c 92 40 a5 eb 55 d3 8a f3 33 88 86 04 f6 b5 f0  ..@..U...3......
    //  016  47 39 17 c1 40 2b 80 09 9d ca 5c bc 20 70 75 c0  G9..@+....\. pu.
    // 
    //  Text to MAC:
    //  000  27 54 77 61 73 20 62 72 69 6c 6c 69 67 2c 20 61  'Twas brillig, a
    //  016  6e 64 20 74 68 65 20 73 6c 69 74 68 79 20 74 6f  nd the slithy to
    //  032  76 65 73 0a 44 69 64 20 67 79 72 65 20 61 6e 64  ves.Did gyre and
    //  048  20 67 69 6d 62 6c 65 20 69 6e 20 74 68 65 20 77   gimble in the w
    //  064  61 62 65 3a 0a 41 6c 6c 20 6d 69 6d 73 79 20 77  abe:.All mimsy w
    //  080  65 72 65 20 74 68 65 20 62 6f 72 6f 67 6f 76 65  ere the borogove
    //  096  73 2c 0a 41 6e 64 20 74 68 65 20 6d 6f 6d 65 20  s,.And the mome
    //  112  72 61 74 68 73 20 6f 75 74 67 72 61 62 65 2e     raths outgrabe.
    // 
    //  Tag:
    //  000  45 41 66 9a 7e aa ee 61 e7 08 dc 7c bc c5 eb 62  EAf.~..a...|...

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}