KeyRingBuilder.java
/*
* Copyright 2018 Paul Schaub.
*
* 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.pgpainless.key.generation;
import javax.annotation.Nonnull;
import java.nio.charset.Charset;
import java.security.InvalidAlgorithmParameterException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.bouncycastle.bcpg.sig.KeyFlags;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.openpgp.PGPEncryptedData;
import org.bouncycastle.openpgp.PGPException;
import org.bouncycastle.openpgp.PGPKeyPair;
import org.bouncycastle.openpgp.PGPKeyRingGenerator;
import org.bouncycastle.openpgp.PGPPublicKeyRing;
import org.bouncycastle.openpgp.PGPSecretKeyRing;
import org.bouncycastle.openpgp.PGPSignature;
import org.bouncycastle.openpgp.PGPSignatureSubpacketVector;
import org.bouncycastle.openpgp.operator.PBESecretKeyEncryptor;
import org.bouncycastle.openpgp.operator.PGPContentSignerBuilder;
import org.bouncycastle.openpgp.operator.PGPDigestCalculator;
import org.bouncycastle.openpgp.operator.jcajce.JcaPGPContentSignerBuilder;
import org.bouncycastle.openpgp.operator.jcajce.JcaPGPDigestCalculatorProviderBuilder;
import org.bouncycastle.openpgp.operator.jcajce.JcaPGPKeyPair;
import org.bouncycastle.openpgp.operator.jcajce.JcePBESecretKeyEncryptorBuilder;
import org.pgpainless.algorithm.HashAlgorithm;
import org.pgpainless.algorithm.KeyFlag;
import org.pgpainless.key.collection.PGPKeyRing;
import org.pgpainless.key.generation.type.ECDH;
import org.pgpainless.key.generation.type.ECDSA;
import org.pgpainless.key.generation.type.KeyType;
import org.pgpainless.key.generation.type.RSA_GENERAL;
import org.pgpainless.key.generation.type.curve.EllipticCurve;
import org.pgpainless.key.generation.type.length.RsaLength;
import org.pgpainless.util.KeyRingSubKeyFix;
import org.pgpainless.util.Passphrase;
public class KeyRingBuilder implements KeyRingBuilderInterface {
private final Charset UTF8 = Charset.forName("UTF-8");
private List<KeySpec> keySpecs = new ArrayList<>();
private String userId;
private Passphrase passphrase;
/**
* Creates a simple RSA KeyPair of length {@code length} with user-id {@code userId}.
* The KeyPair consists of a single RSA master key which is used for signing, encryption and certification.
*
* @param userId user id.
* @param length length in bits.
* @return {@link PGPSecretKeyRing} containing the KeyPair.
* @throws PGPException
* @throws NoSuchAlgorithmException
* @throws NoSuchProviderException
* @throws InvalidAlgorithmParameterException
*/
public PGPKeyRing simpleRsaKeyRing(@Nonnull String userId, @Nonnull RsaLength length)
throws PGPException, NoSuchAlgorithmException, NoSuchProviderException, InvalidAlgorithmParameterException {
return withMasterKey(
KeySpec.getBuilder(RSA_GENERAL.withLength(length))
.withDefaultKeyFlags()
.withDefaultAlgorithms())
.withPrimaryUserId(userId)
.withoutPassphrase()
.build();
}
/**
* Creates a key ring consisting of an ECDSA master key and an ECDH sub-key.
* The ECDSA master key is used for signing messages and certifying the sub key.
* The ECDH sub-key is used for encryption of messages.
*
* @param userId user-id
* @return {@link PGPSecretKeyRing} containing the key pairs.
* @throws PGPException
* @throws NoSuchAlgorithmException
* @throws NoSuchProviderException
* @throws InvalidAlgorithmParameterException
*/
public PGPKeyRing simpleEcKeyRing(@Nonnull String userId)
throws PGPException, NoSuchAlgorithmException, NoSuchProviderException, InvalidAlgorithmParameterException {
return withSubKey(
KeySpec.getBuilder(ECDH.fromCurve(EllipticCurve._P256))
.withKeyFlags(KeyFlag.ENCRYPT_STORAGE, KeyFlag.ENCRYPT_COMMS)
.withDefaultAlgorithms())
.withMasterKey(
KeySpec.getBuilder(ECDSA.fromCurve(EllipticCurve._P256))
.withKeyFlags(KeyFlag.AUTHENTICATION, KeyFlag.CERTIFY_OTHER, KeyFlag.SIGN_DATA)
.withDefaultAlgorithms())
.withPrimaryUserId(userId)
.withoutPassphrase()
.build();
}
@Override
public KeyRingBuilderInterface withSubKey(@Nonnull KeySpec type) {
KeyRingBuilder.this.keySpecs.add(type);
return this;
}
@Override
public WithPrimaryUserId withMasterKey(@Nonnull KeySpec spec) {
if ((spec.getSubpackets().getKeyFlags() & KeyFlags.CERTIFY_OTHER) == 0) {
throw new IllegalArgumentException("Certification Key MUST have KeyFlag CERTIFY_OTHER");
}
KeyRingBuilder.this.keySpecs.add(0, spec);
return new WithPrimaryUserIdImpl();
}
class WithPrimaryUserIdImpl implements WithPrimaryUserId {
@Override
public WithPassphrase withPrimaryUserId(@Nonnull String userId) {
KeyRingBuilder.this.userId = userId;
return new WithPassphraseImpl();
}
@Override
public WithPassphrase withPrimaryUserId(@Nonnull byte[] userId) {
return withPrimaryUserId(new String(userId, UTF8));
}
}
class WithPassphraseImpl implements WithPassphrase {
@Override
public Build withPassphrase(@Nonnull Passphrase passphrase) {
KeyRingBuilder.this.passphrase = passphrase;
return new BuildImpl();
}
@Override
public Build withoutPassphrase() {
KeyRingBuilder.this.passphrase = null;
return new BuildImpl();
}
class BuildImpl implements Build {
@Override
public PGPKeyRing build() throws NoSuchAlgorithmException, PGPException, NoSuchProviderException,
InvalidAlgorithmParameterException {
// Hash Calculator
PGPDigestCalculator calculator = new JcaPGPDigestCalculatorProviderBuilder()
.setProvider(BouncyCastleProvider.PROVIDER_NAME)
.build()
.get(HashAlgorithm.SHA1.getAlgorithmId());
// Encryptor for encrypting secret keys
PBESecretKeyEncryptor encryptor = passphrase == null ?
null : // unencrypted key pair, otherwise AES-256 encrypted
new JcePBESecretKeyEncryptorBuilder(PGPEncryptedData.AES_256, calculator)
.setProvider(BouncyCastleProvider.PROVIDER_NAME)
.build(passphrase != null ? passphrase.getChars() : null);
if (passphrase != null) {
passphrase.clear();
}
// First key is the Master Key
KeySpec certKeySpec = keySpecs.get(0);
// Remove master key, so that we later only add sub keys.
keySpecs.remove(0);
// Generate Master Key
PGPKeyPair certKey = generateKeyPair(certKeySpec);
// Signer for creating self-signature
PGPContentSignerBuilder signer = new JcaPGPContentSignerBuilder(
certKey.getPublicKey().getAlgorithm(), HashAlgorithm.SHA512.getAlgorithmId())
.setProvider(BouncyCastleProvider.PROVIDER_NAME);
PGPSignatureSubpacketVector hashedSubPackets = certKeySpec.getSubpackets();
// Generator which the user can get the key pair from
PGPKeyRingGenerator ringGenerator = new PGPKeyRingGenerator(
PGPSignature.POSITIVE_CERTIFICATION, certKey,
userId, calculator,
hashedSubPackets, null, signer, encryptor);
for (KeySpec subKeySpec : keySpecs) {
PGPKeyPair subKey = generateKeyPair(subKeySpec);
if (subKeySpec.isInheritedSubPackets()) {
ringGenerator.addSubKey(subKey);
} else {
ringGenerator.addSubKey(subKey, subKeySpec.getSubpackets(), null);
}
}
PGPPublicKeyRing publicKeys = ringGenerator.generatePublicKeyRing();
PGPSecretKeyRing secretKeys = ringGenerator.generateSecretKeyRing();
// TODO: Remove once BC 1.61 is released
secretKeys = KeyRingSubKeyFix.repairSubkeyPackets(secretKeys, null, null);
return new PGPKeyRing(publicKeys, secretKeys);
}
private PGPKeyPair generateKeyPair(KeySpec spec)
throws NoSuchProviderException, NoSuchAlgorithmException, PGPException,
InvalidAlgorithmParameterException {
KeyType type = spec.getKeyType();
KeyPairGenerator certKeyGenerator = KeyPairGenerator.getInstance(
type.getName(), BouncyCastleProvider.PROVIDER_NAME);
certKeyGenerator.initialize(type.getAlgorithmSpec());
// Create raw Key Pair
KeyPair keyPair = certKeyGenerator.generateKeyPair();
// Form PGP key pair
PGPKeyPair pgpKeyPair = new JcaPGPKeyPair(type.getAlgorithm().getAlgorithmId(),
keyPair, new Date());
return pgpKeyPair;
}
}
}
}