org.bitcoinj.crypto.KeyCrypter Maven / Gradle / Ivy
/*
* Copyright 2013 Jim Burton.
*
* Licensed under the MIT license (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://opensource.org/licenses/mit-license.php
*
* 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.bitcoinj.crypto;
import org.bitcoinj.wallet.Protos.Wallet.EncryptionType;
import org.bouncycastle.crypto.params.KeyParameter;
import java.io.Serializable;
/**
* A KeyCrypter can be used to encrypt and decrypt a message. The sequence of events to encrypt and then decrypt
* a message are as follows:
*
* (1) Ask the user for a password. deriveKey() is then called to create an KeyParameter. This contains the AES
* key that will be used for encryption.
* (2) Encrypt the message using encrypt(), providing the message bytes and the KeyParameter from (1). This returns
* an EncryptedData which contains the encryptedPrivateKey bytes and an initialisation vector.
* (3) To decrypt an EncryptedData, repeat step (1) to get a KeyParameter, then call decrypt().
*
* There can be different algorithms used for encryption/ decryption so the getUnderstoodEncryptionType is used
* to determine whether any given KeyCrypter can understand the type of encrypted data you have.
*/
public interface KeyCrypter extends Serializable {
/**
* Return the EncryptionType enum value which denotes the type of encryption/ decryption that this KeyCrypter
* can understand.
*/
EncryptionType getUnderstoodEncryptionType();
/**
* Create a KeyParameter (which typically contains an AES key)
* @param password
* @return KeyParameter The KeyParameter which typically contains the AES key to use for encrypting and decrypting
* @throws KeyCrypterException
*/
KeyParameter deriveKey(CharSequence password) throws KeyCrypterException;
/**
* Decrypt the provided encrypted bytes, converting them into unencrypted bytes.
*
* @throws KeyCrypterException if decryption was unsuccessful.
*/
byte[] decrypt(EncryptedData encryptedBytesToDecode, KeyParameter aesKey) throws KeyCrypterException;
/**
* Encrypt the supplied bytes, converting them into ciphertext.
*
* @return encryptedPrivateKey An encryptedPrivateKey containing the encrypted bytes and an initialisation vector.
* @throws KeyCrypterException if encryption was unsuccessful
*/
EncryptedData encrypt(byte[] plainBytes, KeyParameter aesKey) throws KeyCrypterException;
}