(Android™) Generate RSA SSH Key

See more SSH Key Examples

Generates an RSA SSH key and saves to various public and private key file formats (OpenSSH and PuTTY).

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);

    CkSshKey key = new CkSshKey();

    // numBits may range from 384 to 4096.  Typical values are
    // 1024 or 2048.  (must be a multiple of 64)
    // A good choice for the exponent is 65537.  Chilkat recommends
    // always using this value.
    int numBits = 2048;
    int exponent = 65537;
    boolean success = key.GenerateRsaKey(numBits,exponent);
    if (success != true) {
        Log.i(TAG, "Bad params passed to RSA key generation method.");
        return;
        }

    // Note: Generating a public/private key pair is CPU intensive
    // and may take a short amount of time (more than few seconds,
    // but less than a minute).

    String exportedKey;
    boolean exportEncrypted;

    // Export the RSA private key to OpenSSH, PuTTY, and XML and save. 
    exportEncrypted = false;
    exportedKey = key.toOpenSshPrivateKey(exportEncrypted);
    // Chilkat provides a SaveText method for convenience...
    success = key.SaveText(exportedKey,"privkey_openssh_unencrypted.pem");

    // Export with encryption to OpenSSH private key format:
    key.put_Password("secret");
    exportEncrypted = true;
    exportedKey = key.toOpenSshPrivateKey(exportEncrypted);
    success = key.SaveText(exportedKey,"privkey_openssh_encrypted.pem");

    // Export the RSA private key to unencrypted PuTTY format:
    exportEncrypted = false;
    exportedKey = key.toPuttyPrivateKey(exportEncrypted);
    success = key.SaveText(exportedKey,"privkey_putty_unencrypted.ppk");

    // Export the RSA private key to encrypted PuTTY format:
    key.put_Password("secret");
    exportEncrypted = true;
    exportedKey = key.toPuttyPrivateKey(exportEncrypted);
    success = key.SaveText(exportedKey,"privkey_putty_encrypted.ppk");

    // Export private key to XML:
    exportedKey = key.toXml();
    success = key.SaveText(exportedKey,"privkey.xml");

    // ----------------------------------------------------
    // Now for the public key....
    // ----------------------------------------------------

    // The Secure Shell (SSH) Public Key File Format
    // is documented in RFC 4716.
    exportedKey = key.toRfc4716PublicKey();
    success = key.SaveText(exportedKey,"pubkey_rfc4716.pub");

    // OpenSSH has a separate public-key file format, which 
    // is also supported by Chilkat SshKey:
    exportedKey = key.toOpenSshPublicKey();
    success = key.SaveText(exportedKey,"pubkey_openSsh.pub");

    Log.i(TAG, "Finished.");

  }

  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."
  }
}