pgpainless/pgpainless-core/src/main/java/org/pgpainless/s2k/SessionKey.java

67 lines
1.8 KiB
Java

// SPDX-FileCopyrightText: 2021 Paul Schaub <vanitasvitae@fsfe.org>
//
// SPDX-License-Identifier: Apache-2.0
package org.pgpainless.s2k;
import javax.annotation.Nonnull;
import org.bouncycastle.openpgp.PGPSessionKey;
import org.bouncycastle.util.encoders.Hex;
import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
/**
* A {@link SessionKey} is the symmetric key that is used to encrypt/decrypt an OpenPGP message.
* The OpenPGP message header contains a copy of the session key, encrypted for the public key of each recipient.
*/
public class SessionKey {
private final SymmetricKeyAlgorithm algorithm;
private final byte[] key;
/**
* Constructor to create a session key from a BC {@link PGPSessionKey} object.
*
* @param sessionKey BC session key
*/
public SessionKey(@Nonnull PGPSessionKey sessionKey) {
this(SymmetricKeyAlgorithm.requireFromId(sessionKey.getAlgorithm()), sessionKey.getKey());
}
/**
* Create a session key object from an algorithm and a key.
*
* @param algorithm algorithm
* @param key key
*/
public SessionKey(@Nonnull SymmetricKeyAlgorithm algorithm, @Nonnull byte[] key) {
this.algorithm = algorithm;
this.key = key;
}
/**
* Return the symmetric key algorithm.
*
* @return algorithm
*/
public SymmetricKeyAlgorithm getAlgorithm() {
return algorithm;
}
/**
* Return the bytes of the key.
*
* @return key
*/
public byte[] getKey() {
byte[] copy = new byte[key.length];
System.arraycopy(key, 0, copy, 0, copy.length);
return copy;
}
@Override
public String toString() {
return "" + getAlgorithm().getAlgorithmId() + ":" + Hex.toHexString(getKey());
}
}