(Android™) Hash Binary Data (SHA256 and other hash algorithms)

Demonstrates how to hash binary bytes using SHA256, SHA384, SHA512, MD2, MD5, HAVAL, RIPEMD, etc.

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// 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);

    // This example requires the Chilkat Crypt API to have been previously unlocked.
    // See Unlock Chilkat Crypt for sample code.

    // Let's load a binary file to get the bytes..
    CkBinData jpgData = new CkBinData();
    boolean success = jpgData.LoadFile("qa_data/jpg/starfish.jpg");
    if (success != true) {
        Log.i(TAG, "Failed to load file.");
        return;
        }

    CkByteData jpgBytes = new CkByteData();
    success = jpgData.GetBinary(jpgBytes);

    CkCrypt2 crypt = new CkCrypt2();

    // Choose the hash algorithm.
    // Can be  "sha1", "sha256", "sha384", "sha512", "md2", "md5", "haval", "ripemd128", "ripemd160","ripemd256", or "ripemd320".
    crypt.put_HashAlgorithm("sha256");

    CkByteData hashBytes = new CkByteData();
    success = crypt.HashBytes(jpgBytes,hashBytes);

    // Let's examine the hash as a hex string.
    CkStringBuilder sb = new CkStringBuilder();
    sb.AppendEncoded(hashBytes,"hex");
    Log.i(TAG, "SHA256 hash = " + sb.getAsString());

    // We could alternatively hash the bytes and receive the hex result directly:
    crypt.put_EncodingMode("hex");
    String hashHexStr = crypt.hashBytesENC(jpgBytes);
    Log.i(TAG, "SHA256 hash = " + hashHexStr);

  }

  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."
  }
}