// SMSLib for Java v3
// A Java API library for sending and receiving SMS via a GSM modem
// or other supported gateways.
// Web Site: http://www.smslib.org
//
// Copyright (C) 2002-2012, Thanasis Delenikas, Athens/GREECE.
// SMSLib is distributed under the terms of the Apache License version 2.0
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package org.smslib.crypto;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.HashMap;
import javax.crypto.BadPaddingException;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import org.smslib.SMSLibException;
/**
* The KeyManager class handles the association of a number (originator or
* recipient) with a cryptographic key.
*/
public class KeyManager
{
static private KeyManager _instance = null;
HashMap<String, AKey> keys;
private KeyManager()
{
this.keys = new HashMap<String, AKey>();
}
static public KeyManager getInstance()
{
if (_instance == null) _instance = new KeyManager();
return _instance;
}
/**
* Associates a mobile number with an encryption key.
*
* @param mobileNumber
* The mobile number which will be associated with the encryption
* key.
* @param key
* The encryption key.
* @see AKey
* @see #registerKey(String, AKey)
* @see #unregisterAllKeys()
*/
public void registerKey(String mobileNumber, AKey key)
{
this.keys.put((mobileNumber.charAt(0) == '+' ? mobileNumber.substring(1) : mobileNumber), key);
}
/**
* Removes the association of a mobile number with a key.
*
* @param mobileNumber
* The mobile number which will be removed from the key
* associations.
* @return The encryption key which was associated with the specific mobile
* number.
* @see AKey
* @see #registerKey(String, AKey)
*/
public AKey unregisterKey(String mobileNumber)
{
return this.keys.remove((mobileNumber.charAt(0) == '+' ? mobileNumber.substring(1) : mobileNumber));
}
/**
* Removes all associations of mobile numbers and encryption keys.
*/
public void unregisterAllKeys()
{
this.keys.clear();
}
/**
* Returns the encryption key of the specified mobile number. Returns null
* if there is no association.
*
* @param mobileNumber
* The mobile number to look for.
* @return The encryption key, null if no key was previously associated.
*/
public AKey getKey(String mobileNumber)
{
if (mobileNumber == null) return null;
return this.keys.get((mobileNumber.charAt(0) == '+' ? mobileNumber.substring(1) : mobileNumber));
}
/**
* Encrypts the specified message with the encryption key already associated
* with the specified mobile number.
*
* @param mobileNumber
* The mobile number which the message will be send to / received
* from.
* @param message
* The decrypted message.
* @return The encrypted message.
* @throws SMSLibException
* @throws InvalidKeyException
* @throws IllegalBlockSizeException
* @throws BadPaddingException
* @throws NoSuchPaddingException
* @throws NoSuchAlgorithmException
*/
public byte[] encrypt(String mobileNumber, byte[] message) throws SMSLibException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException, NoSuchPaddingException, NoSuchAlgorithmException
{
AKey k = getKey(mobileNumber);
if (k == null) throw new SMSLibException("Could not find Encryption Key for the specific number.");
else if (k instanceof ASymmetricKey) return ((ASymmetricKey) k).encrypt(message);
else return new byte[0];
}
/**
* Decrypts the specified message with the encryption key already associated
* with the specified mobile number.
*
* @param mobileNumber
* The mobile number which the message received from.
* @param message
* The encrypted message.
* @return The decrypted message.
* @throws SMSLibException
* @throws InvalidKeyException
* @throws IllegalBlockSizeException
* @throws BadPaddingException
* @throws NoSuchPaddingException
* @throws NoSuchAlgorithmException
*/
public byte[] decrypt(String mobileNumber, byte[] message) throws SMSLibException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException, NoSuchPaddingException, NoSuchAlgorithmException
{
AKey k = getKey(mobileNumber);
if (k == null) throw new SMSLibException("Could not find Encryption Key for the specific number.");
else if (k instanceof ASymmetricKey) return ((ASymmetricKey) k).decrypt(message);
else return new byte[0];
}
}