Smack/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/internal/OmemoAesCipher.java

100 lines
4.3 KiB
Java

/**
*
* Copyright 2017 Paul Schaub, 2019-2021 Florian Schmaus
*
* 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.jivesoftware.smackx.omemo.internal;
import java.nio.charset.StandardCharsets;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import org.jivesoftware.smack.util.RandomUtil;
import org.jivesoftware.smackx.omemo.util.OmemoConstants;
import org.jivesoftware.smackx.omemo.util.OmemoMessageBuilder;
public class OmemoAesCipher {
static {
byte[] iv = OmemoMessageBuilder.generateIv();
byte[] key = new byte[16];
RandomUtil.fillWithSecureRandom(key);
try {
encryptAesGcmNoPadding("This is just a test", key, iv);
} catch (InvalidKeyException | NoSuchAlgorithmException | NoSuchPaddingException
| InvalidAlgorithmParameterException | IllegalBlockSizeException | BadPaddingException e) {
String message = "Unable to perform " + OmemoConstants.Crypto.CIPHERMODE
+ " operation requires by OMEMO. Ensure that a suitable crypto provider for is available."
+ " For example Bouncycastle on Android (BouncyCastleProvider)";
throw new AssertionError(message);
}
}
private enum CipherOpmode {
encrypt(Cipher.ENCRYPT_MODE),
decrypt(Cipher.DECRYPT_MODE),
;
public final int opmodeInt;
CipherOpmode(int opmodeInt) {
this.opmodeInt = opmodeInt;
}
}
private static byte[] performCipherOperation(CipherOpmode opmode, byte[] input, byte[] key,
byte[] initializationVector)
throws IllegalBlockSizeException, BadPaddingException, NoSuchAlgorithmException,
NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException {
SecretKey secretKey = new SecretKeySpec(key, OmemoConstants.Crypto.KEYTYPE);
IvParameterSpec ivSpec = new IvParameterSpec(initializationVector);
Cipher cipher = Cipher.getInstance(OmemoConstants.Crypto.CIPHERMODE);
cipher.init(opmode.opmodeInt, secretKey, ivSpec);
byte[] ciphertext = cipher.doFinal(input);
return ciphertext;
}
public static byte[] decryptAesGcmNoPadding(byte[] ciphertext, byte[] key, byte[] initializationVector)
throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException,
NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException {
return performCipherOperation(CipherOpmode.decrypt, ciphertext, key, initializationVector);
}
public static byte[] encryptAesGcmNoPadding(byte[] plaintext, byte[] key, byte[] initializationVector)
throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException,
InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException {
return performCipherOperation(CipherOpmode.encrypt, plaintext, key, initializationVector);
}
public static byte[] encryptAesGcmNoPadding(String plaintext, byte[] key, byte[] initializationVector)
throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException,
InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException {
byte[] plaintextBytes = plaintext.getBytes(StandardCharsets.UTF_8);
return encryptAesGcmNoPadding(plaintextBytes, key, initializationVector);
}
}