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Kotlin conversion: EncryptionOptions

This commit is contained in:
Paul Schaub 2023-09-03 17:55:46 +02:00
parent ef9ead1a71
commit 903b3f9658
Signed by: vanitasvitae
GPG key ID: 62BEE9264BF17311
3 changed files with 300 additions and 476 deletions

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// SPDX-FileCopyrightText: 2021 Paul Schaub <vanitasvitae@fsfe.org>
//
// SPDX-License-Identifier: Apache-2.0
package org.pgpainless.encryption_signing;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import javax.annotation.Nonnull;
import org.bouncycastle.openpgp.PGPPublicKey;
import org.bouncycastle.openpgp.PGPPublicKeyRing;
import org.bouncycastle.openpgp.PGPPublicKeyRingCollection;
import org.bouncycastle.openpgp.operator.PBEKeyEncryptionMethodGenerator;
import org.bouncycastle.openpgp.operator.PGPKeyEncryptionMethodGenerator;
import org.bouncycastle.openpgp.operator.PublicKeyKeyEncryptionMethodGenerator;
import org.pgpainless.algorithm.EncryptionPurpose;
import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
import org.pgpainless.authentication.CertificateAuthenticity;
import org.pgpainless.authentication.CertificateAuthority;
import org.pgpainless.exception.KeyException;
import org.pgpainless.implementation.ImplementationFactory;
import org.pgpainless.key.OpenPgpFingerprint;
import org.pgpainless.key.SubkeyIdentifier;
import org.pgpainless.key.info.KeyAccessor;
import org.pgpainless.key.info.KeyRingInfo;
import org.pgpainless.util.Passphrase;
/**
* Options for the encryption process.
* This class can be used to set encryption parameters, like encryption keys and passphrases, algorithms etc.
* <p>
* A typical use might look like follows:
* <pre>
* {@code
* EncryptionOptions opt = new EncryptionOptions();
* opt.addRecipient(aliceKey, "Alice <alice@wonderland.lit>");
* opt.addPassphrase(Passphrase.fromPassword("AdditionalDecryptionPassphrase123"));
* }
* </pre>
*<p>
* To use a custom symmetric encryption algorithm, use {@link #overrideEncryptionAlgorithm(SymmetricKeyAlgorithm)}.
* This will cause PGPainless to use the provided algorithm for message encryption, instead of negotiating an algorithm
* by inspecting the provided recipient keys.
* <p>
* By default, PGPainless will encrypt to all suitable, encryption capable subkeys on each recipient's certificate.
* This behavior can be changed per recipient, e.g. by calling
* <pre>
* {@code
* opt.addRecipient(aliceKey, EncryptionOptions.encryptToFirstSubkey());
* }
* </pre>
* when adding the recipient key.
*/
public class EncryptionOptions {
private final EncryptionPurpose purpose;
private final Set<PGPKeyEncryptionMethodGenerator> encryptionMethods = new LinkedHashSet<>();
private final Set<SubkeyIdentifier> encryptionKeys = new LinkedHashSet<>();
private final Map<SubkeyIdentifier, KeyRingInfo> keyRingInfo = new HashMap<>();
private final Map<SubkeyIdentifier, KeyAccessor> keyViews = new HashMap<>();
private final EncryptionKeySelector encryptionKeySelector = encryptToAllCapableSubkeys();
private boolean allowEncryptionWithMissingKeyFlags = false;
private Date evaluationDate = new Date();
private SymmetricKeyAlgorithm encryptionAlgorithmOverride = null;
/**
* Encrypt to keys both carrying the key flag {@link org.pgpainless.algorithm.KeyFlag#ENCRYPT_COMMS}
* or {@link org.pgpainless.algorithm.KeyFlag#ENCRYPT_STORAGE}.
*/
public EncryptionOptions() {
this(EncryptionPurpose.ANY);
}
public EncryptionOptions(@Nonnull EncryptionPurpose purpose) {
this.purpose = purpose;
}
/**
* Factory method to create an {@link EncryptionOptions} object which will encrypt for keys
* which carry either the {@link org.pgpainless.algorithm.KeyFlag#ENCRYPT_COMMS} or
* {@link org.pgpainless.algorithm.KeyFlag#ENCRYPT_STORAGE} flag.
* <p>
* Use this if you are not sure.
*
* @return encryption options
*/
public static EncryptionOptions get() {
return new EncryptionOptions();
}
/**
* Override the evaluation date for recipient keys with the given date.
*
* @param evaluationDate new evaluation date
* @return this
*/
public EncryptionOptions setEvaluationDate(@Nonnull Date evaluationDate) {
this.evaluationDate = evaluationDate;
return this;
}
/**
* Factory method to create an {@link EncryptionOptions} object which will encrypt for keys
* which carry the flag {@link org.pgpainless.algorithm.KeyFlag#ENCRYPT_COMMS}.
*
* @return encryption options
*/
public static EncryptionOptions encryptCommunications() {
return new EncryptionOptions(EncryptionPurpose.COMMUNICATIONS);
}
/**
* Factory method to create an {@link EncryptionOptions} object which will encrypt for keys
* which carry the flag {@link org.pgpainless.algorithm.KeyFlag#ENCRYPT_STORAGE}.
*
* @return encryption options
*/
public static EncryptionOptions encryptDataAtRest() {
return new EncryptionOptions(EncryptionPurpose.STORAGE);
}
/**
* Identify authenticatable certificates for the given user-ID by querying the {@link CertificateAuthority} for
* identifiable bindings.
* Add all acceptable bindings, whose trust amount is larger or equal to the target amount to the list of recipients.
* @param userId userId
* @param email if true, treat the user-ID as an email address and match all user-IDs containing the mail address
* @param authority certificate authority
* @return encryption options
*/
public EncryptionOptions addAuthenticatableRecipients(String userId, boolean email, CertificateAuthority authority) {
return addAuthenticatableRecipients(userId, email, authority, 120);
}
/**
* Identify authenticatable certificates for the given user-ID by querying the {@link CertificateAuthority} for
* identifiable bindings.
* Add all acceptable bindings, whose trust amount is larger or equal to the target amount to the list of recipients.
* @param userId userId
* @param email if true, treat the user-ID as an email address and match all user-IDs containing the mail address
* @param authority certificate authority
* @param targetAmount target amount (120 = fully authenticated, 240 = doubly authenticated,
* 60 = partially authenticated...)
* @return encryption options
*/
public EncryptionOptions addAuthenticatableRecipients(String userId, boolean email, CertificateAuthority authority, int targetAmount) {
List<CertificateAuthenticity> identifiedCertificates = authority.lookupByUserId(userId, email, evaluationDate, targetAmount);
boolean foundAcceptable = false;
for (CertificateAuthenticity candidate : identifiedCertificates) {
if (candidate.isAuthenticated()) {
addRecipient(candidate.getCertificate());
foundAcceptable = true;
}
}
if (!foundAcceptable) {
throw new IllegalArgumentException("Could not identify any trust-worthy certificates for '" + userId + "' and target trust amount " + targetAmount);
}
return this;
}
/**
* Add all key rings in the provided {@link Iterable} (e.g. {@link PGPPublicKeyRingCollection}) as recipients.
*
* @param keys keys
* @return this
*/
public EncryptionOptions addRecipients(@Nonnull Iterable<PGPPublicKeyRing> keys) {
if (!keys.iterator().hasNext()) {
throw new IllegalArgumentException("Set of recipient keys cannot be empty.");
}
for (PGPPublicKeyRing key : keys) {
addRecipient(key);
}
return this;
}
/**
* Add all key rings in the provided {@link Iterable} (e.g. {@link PGPPublicKeyRingCollection}) as recipients.
* Per key ring, the selector is applied to select one or more encryption subkeys.
*
* @param keys keys
* @param selector encryption key selector
* @return this
*/
public EncryptionOptions addRecipients(@Nonnull Iterable<PGPPublicKeyRing> keys, @Nonnull EncryptionKeySelector selector) {
if (!keys.iterator().hasNext()) {
throw new IllegalArgumentException("Set of recipient keys cannot be empty.");
}
for (PGPPublicKeyRing key : keys) {
addRecipient(key, selector);
}
return this;
}
/**
* Add a recipient by providing a key and recipient user-id.
* The user-id is used to determine the recipients preferences (algorithms etc.).
*
* @param key key ring
* @param userId user id
* @return this
*/
public EncryptionOptions addRecipient(@Nonnull PGPPublicKeyRing key, @Nonnull CharSequence userId) {
return addRecipient(key, userId, encryptionKeySelector);
}
/**
* Add a recipient by providing a key and recipient user-id, as well as a strategy for selecting one or multiple
* encryption capable subkeys from the key.
*
* @param key key
* @param userId user-id
* @param encryptionKeySelectionStrategy strategy to select one or more encryption subkeys to encrypt to
* @return this
*/
public EncryptionOptions addRecipient(@Nonnull PGPPublicKeyRing key,
@Nonnull CharSequence userId,
@Nonnull EncryptionKeySelector encryptionKeySelectionStrategy) {
KeyRingInfo info = new KeyRingInfo(key, evaluationDate);
List<PGPPublicKey> encryptionSubkeys = encryptionKeySelectionStrategy
.selectEncryptionSubkeys(info.getEncryptionSubkeys(userId.toString(), purpose));
if (encryptionSubkeys.isEmpty()) {
throw new KeyException.UnacceptableEncryptionKeyException(OpenPgpFingerprint.of(key));
}
for (PGPPublicKey encryptionSubkey : encryptionSubkeys) {
SubkeyIdentifier keyId = new SubkeyIdentifier(key, encryptionSubkey.getKeyID());
keyRingInfo.put(keyId, info);
keyViews.put(keyId, new KeyAccessor.ViaUserId(info, keyId, userId.toString()));
addRecipientKey(key, encryptionSubkey, false);
}
return this;
}
/**
* Add a recipient by providing a key.
*
* @param key key ring
* @return this
*/
public EncryptionOptions addRecipient(@Nonnull PGPPublicKeyRing key) {
return addRecipient(key, encryptionKeySelector);
}
/**
* Add a recipient by providing a key and an encryption key selection strategy.
*
* @param key key ring
* @param encryptionKeySelectionStrategy strategy used to select one or multiple encryption subkeys.
* @return this
*/
public EncryptionOptions addRecipient(@Nonnull PGPPublicKeyRing key,
@Nonnull EncryptionKeySelector encryptionKeySelectionStrategy) {
return addAsRecipient(key, encryptionKeySelectionStrategy, false);
}
/**
* Add a certificate as hidden recipient.
* The recipients key-id will be obfuscated by setting a wildcard key ID.
*
* @param key recipient key
* @return this
*/
public EncryptionOptions addHiddenRecipient(@Nonnull PGPPublicKeyRing key) {
return addHiddenRecipient(key, encryptionKeySelector);
}
/**
* Add a certificate as hidden recipient, using the provided {@link EncryptionKeySelector} to select recipient subkeys.
* The recipients key-ids will be obfuscated by setting a wildcard key ID instead.
*
* @param key recipient key
* @param encryptionKeySelectionStrategy strategy to select recipient (sub) keys.
* @return this
*/
public EncryptionOptions addHiddenRecipient(PGPPublicKeyRing key, EncryptionKeySelector encryptionKeySelectionStrategy) {
return addAsRecipient(key, encryptionKeySelectionStrategy, true);
}
private EncryptionOptions addAsRecipient(PGPPublicKeyRing key, EncryptionKeySelector encryptionKeySelectionStrategy, boolean wildcardKeyId) {
KeyRingInfo info = new KeyRingInfo(key, evaluationDate);
Date primaryKeyExpiration;
try {
primaryKeyExpiration = info.getPrimaryKeyExpirationDate();
} catch (NoSuchElementException e) {
throw new KeyException.UnacceptableSelfSignatureException(OpenPgpFingerprint.of(key));
}
if (primaryKeyExpiration != null && primaryKeyExpiration.before(evaluationDate)) {
throw new KeyException.ExpiredKeyException(OpenPgpFingerprint.of(key), primaryKeyExpiration);
}
List<PGPPublicKey> encryptionSubkeys = encryptionKeySelectionStrategy
.selectEncryptionSubkeys(info.getEncryptionSubkeys(purpose));
// There are some legacy keys around without key flags.
// If we allow encryption for those keys, we add valid keys without any key flags, if they are
// capable of encryption by means of their algorithm
if (encryptionSubkeys.isEmpty() && allowEncryptionWithMissingKeyFlags) {
List<PGPPublicKey> validSubkeys = info.getValidSubkeys();
for (PGPPublicKey validSubkey : validSubkeys) {
if (!validSubkey.isEncryptionKey()) {
continue;
}
// only add encryption keys with no key flags.
if (info.getKeyFlagsOf(validSubkey.getKeyID()).isEmpty()) {
encryptionSubkeys.add(validSubkey);
}
}
}
if (encryptionSubkeys.isEmpty()) {
throw new KeyException.UnacceptableEncryptionKeyException(OpenPgpFingerprint.of(key));
}
for (PGPPublicKey encryptionSubkey : encryptionSubkeys) {
SubkeyIdentifier keyId = new SubkeyIdentifier(key, encryptionSubkey.getKeyID());
keyRingInfo.put(keyId, info);
keyViews.put(keyId, new KeyAccessor.ViaKeyId(info, keyId));
addRecipientKey(key, encryptionSubkey, wildcardKeyId);
}
return this;
}
private void addRecipientKey(@Nonnull PGPPublicKeyRing keyRing,
@Nonnull PGPPublicKey key,
boolean wildcardKeyId) {
encryptionKeys.add(new SubkeyIdentifier(keyRing, key.getKeyID()));
PublicKeyKeyEncryptionMethodGenerator encryptionMethod = ImplementationFactory
.getInstance().getPublicKeyKeyEncryptionMethodGenerator(key);
encryptionMethod.setUseWildcardKeyID(wildcardKeyId);
addEncryptionMethod(encryptionMethod);
}
/**
* Add a symmetric passphrase which the message will be encrypted to.
*
* @param passphrase passphrase
* @return this
*/
public EncryptionOptions addPassphrase(@Nonnull Passphrase passphrase) {
if (passphrase.isEmpty()) {
throw new IllegalArgumentException("Passphrase must not be empty.");
}
PBEKeyEncryptionMethodGenerator encryptionMethod = ImplementationFactory
.getInstance().getPBEKeyEncryptionMethodGenerator(passphrase);
return addEncryptionMethod(encryptionMethod);
}
/**
* Add an {@link PGPKeyEncryptionMethodGenerator} which will be used to encrypt the message.
* Method generators are either {@link PBEKeyEncryptionMethodGenerator} (passphrase)
* or {@link PGPKeyEncryptionMethodGenerator} (public key).
*
* This method is intended for advanced users to allow encryption for specific subkeys.
* This can come in handy for example if data needs to be encrypted to a subkey that's ignored by PGPainless.
*
* @param encryptionMethod encryption method
* @return this
*/
public EncryptionOptions addEncryptionMethod(@Nonnull PGPKeyEncryptionMethodGenerator encryptionMethod) {
encryptionMethods.add(encryptionMethod);
return this;
}
Set<PGPKeyEncryptionMethodGenerator> getEncryptionMethods() {
return new HashSet<>(encryptionMethods);
}
Map<SubkeyIdentifier, KeyRingInfo> getKeyRingInfo() {
return new HashMap<>(keyRingInfo);
}
Set<SubkeyIdentifier> getEncryptionKeyIdentifiers() {
return new HashSet<>(encryptionKeys);
}
Map<SubkeyIdentifier, KeyAccessor> getKeyViews() {
return new HashMap<>(keyViews);
}
SymmetricKeyAlgorithm getEncryptionAlgorithmOverride() {
return encryptionAlgorithmOverride;
}
/**
* Override the used symmetric encryption algorithm.
* The symmetric encryption algorithm is used to encrypt the message itself,
* while the used symmetric key will be encrypted to all recipients using public key
* cryptography.
*
* If the algorithm is not overridden, a suitable algorithm will be negotiated.
*
* @param encryptionAlgorithm encryption algorithm override
* @return this
*/
public EncryptionOptions overrideEncryptionAlgorithm(@Nonnull SymmetricKeyAlgorithm encryptionAlgorithm) {
if (encryptionAlgorithm == SymmetricKeyAlgorithm.NULL) {
throw new IllegalArgumentException("Plaintext encryption can only be used to denote unencrypted secret keys.");
}
this.encryptionAlgorithmOverride = encryptionAlgorithm;
return this;
}
/**
* If this method is called, subsequent calls to {@link #addRecipient(PGPPublicKeyRing)} will allow encryption
* for subkeys that do not carry any {@link org.pgpainless.algorithm.KeyFlag} subpacket.
* This is a workaround for dealing with legacy keys that have no key flags subpacket but rely on the key algorithm
* type to convey the subkeys use.
*
* @return this
*/
public EncryptionOptions setAllowEncryptionWithMissingKeyFlags() {
this.allowEncryptionWithMissingKeyFlags = true;
return this;
}
/**
* Return <pre>true</pre> iff the user specified at least one encryption method,
* <pre>false</pre> otherwise.
*
* @return encryption methods is not empty
*/
public boolean hasEncryptionMethod() {
return !encryptionMethods.isEmpty();
}
public interface EncryptionKeySelector {
List<PGPPublicKey> selectEncryptionSubkeys(@Nonnull List<PGPPublicKey> encryptionCapableKeys);
}
/**
* Only encrypt to the first valid encryption capable subkey we stumble upon.
*
* @return encryption key selector
*/
public static EncryptionKeySelector encryptToFirstSubkey() {
return new EncryptionKeySelector() {
@Override
public List<PGPPublicKey> selectEncryptionSubkeys(@Nonnull List<PGPPublicKey> encryptionCapableKeys) {
return encryptionCapableKeys.isEmpty() ? Collections.emptyList() : Collections.singletonList(encryptionCapableKeys.get(0));
}
};
}
/**
* Encrypt to any valid, encryption capable subkey on the key ring.
*
* @return encryption key selector
*/
public static EncryptionKeySelector encryptToAllCapableSubkeys() {
return new EncryptionKeySelector() {
@Override
public List<PGPPublicKey> selectEncryptionSubkeys(@Nonnull List<PGPPublicKey> encryptionCapableKeys) {
return encryptionCapableKeys;
}
};
}
// TODO: Create encryptToBestSubkey() method
}

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package org.pgpainless.encryption_signing
import org.bouncycastle.openpgp.PGPPublicKey
import org.bouncycastle.openpgp.PGPPublicKeyRing
import org.bouncycastle.openpgp.operator.PGPKeyEncryptionMethodGenerator
import org.pgpainless.algorithm.EncryptionPurpose
import org.pgpainless.algorithm.SymmetricKeyAlgorithm
import org.pgpainless.authentication.CertificateAuthority
import org.pgpainless.exception.KeyException
import org.pgpainless.exception.KeyException.*
import org.pgpainless.implementation.ImplementationFactory
import org.pgpainless.key.OpenPgpFingerprint
import org.pgpainless.key.SubkeyIdentifier
import org.pgpainless.key.info.KeyAccessor
import org.pgpainless.key.info.KeyRingInfo
import org.pgpainless.util.Passphrase
import java.util.*
import javax.annotation.Nonnull
class EncryptionOptions(
private val purpose: EncryptionPurpose
) {
private val _encryptionMethods: MutableSet<PGPKeyEncryptionMethodGenerator> = mutableSetOf()
private val _encryptionKeyIdentifiers: MutableSet<SubkeyIdentifier> = mutableSetOf()
private val _keyRingInfo: MutableMap<SubkeyIdentifier, KeyRingInfo> = mutableMapOf()
private val _keyViews: MutableMap<SubkeyIdentifier, KeyAccessor> = mutableMapOf()
private val encryptionKeySelector: EncryptionKeySelector = encryptToAllCapableSubkeys()
private var allowEncryptionWithMissingKeyFlags = false
private var evaluationDate = Date()
private var _encryptionAlgorithmOverride: SymmetricKeyAlgorithm? = null
val encryptionMethods
get() = _encryptionMethods.toSet()
val encryptionKeyIdentifiers
get() = _encryptionKeyIdentifiers.toSet()
val keyRingInfo
get() = _keyRingInfo.toMap()
val keyViews
get() = _keyViews.toMap()
val encryptionAlgorithmOverride
get() = _encryptionAlgorithmOverride
constructor(): this(EncryptionPurpose.ANY)
/**
* Factory method to create an {@link EncryptionOptions} object which will encrypt for keys
* which carry the flag {@link org.pgpainless.algorithm.KeyFlag#ENCRYPT_COMMS}.
*
* @return encryption options
*/
fun setEvaluationDate(evaluationDate: Date) = apply {
this.evaluationDate = evaluationDate
}
/**
* Identify authenticatable certificates for the given user-ID by querying the {@link CertificateAuthority} for
* identifiable bindings.
* Add all acceptable bindings, whose trust amount is larger or equal to the target amount to the list of recipients.
* @param userId userId
* @param email if true, treat the user-ID as an email address and match all user-IDs containing the mail address
* @param authority certificate authority
* @param targetAmount target amount (120 = fully authenticated, 240 = doubly authenticated,
* 60 = partially authenticated...)
* @return encryption options
*/
@JvmOverloads
fun addAuthenticatableRecipients(userId: String, email: Boolean, authority: CertificateAuthority, targetAmount: Int = 120) = apply {
var foundAcceptable = false
authority.lookupByUserId(userId, email, evaluationDate, targetAmount)
.filter { it.isAuthenticated() }
.forEach { addRecipient(it.certificate)
.also {
foundAcceptable = true
}
}
require(foundAcceptable) {
"Could not identify any trust-worthy certificates for '$userId' and target trust amount $targetAmount."
}
}
/**
* Add all key rings in the provided {@link Iterable} (e.g. {@link PGPPublicKeyRingCollection}) as recipients.
*
* @param keys keys
* @return this
*/
fun addRecipients(keys: Iterable<PGPPublicKeyRing>) = apply {
keys.toList().let {
require(it.isNotEmpty()) {
"Set of recipient keys cannot be empty."
}
it.forEach { key -> addRecipient(key) }
}
}
/**
* Add all key rings in the provided {@link Iterable} (e.g. {@link PGPPublicKeyRingCollection}) as recipients.
* Per key ring, the selector is applied to select one or more encryption subkeys.
*
* @param keys keys
* @param selector encryption key selector
* @return this
*/
fun addRecipients(keys: Iterable<PGPPublicKeyRing>, selector: EncryptionKeySelector) = apply {
keys.toList().let {
require(it.isNotEmpty()) {
"Set of recipient keys cannot be empty."
}
it.forEach { key -> addRecipient(key, selector) }
}
}
/**
* Add a recipient by providing a key.
*
* @param key key ring
* @return this
*/
fun addRecipient(key: PGPPublicKeyRing) = addRecipient(key, encryptionKeySelector)
/**
* Add a recipient by providing a key and recipient user-id.
* The user-id is used to determine the recipients preferences (algorithms etc.).
*
* @param key key ring
* @param userId user id
* @return this
*/
fun addRecipient(key: PGPPublicKeyRing, userId: CharSequence) =
addRecipient(key, userId, encryptionKeySelector)
fun addRecipient(key: PGPPublicKeyRing, userId: CharSequence, encryptionKeySelector: EncryptionKeySelector) = apply {
val info = KeyRingInfo(key, evaluationDate)
val subkeys = encryptionKeySelector.selectEncryptionSubkeys(info.getEncryptionSubkeys(userId, purpose))
if (subkeys.isEmpty()) {
throw KeyException.UnacceptableEncryptionKeyException(OpenPgpFingerprint.of(key))
}
for (subkey in subkeys) {
val keyId = SubkeyIdentifier(key, subkey.keyID)
(_keyRingInfo as MutableMap)[keyId] = info
(_keyViews as MutableMap)[keyId] = KeyAccessor.ViaUserId(info, keyId, userId.toString())
addRecipientKey(key, subkey, false)
}
}
fun addRecipient(key: PGPPublicKeyRing, encryptionKeySelector: EncryptionKeySelector) = apply {
addAsRecipient(key, encryptionKeySelector, false)
}
@JvmOverloads
fun addHiddenRecipient(key: PGPPublicKeyRing, selector: EncryptionKeySelector = encryptionKeySelector) = apply {
addAsRecipient(key, selector, true)
}
private fun addAsRecipient(key: PGPPublicKeyRing, selector: EncryptionKeySelector, wildcardKeyId: Boolean) = apply {
val info = KeyRingInfo(key, evaluationDate)
val primaryKeyExpiration = try {
info.primaryKeyExpirationDate
} catch (e: NoSuchElementException) {
throw UnacceptableSelfSignatureException(OpenPgpFingerprint.of(key))
}
if (primaryKeyExpiration != null && primaryKeyExpiration < evaluationDate) {
throw ExpiredKeyException(OpenPgpFingerprint.of(key), primaryKeyExpiration)
}
var encryptionSubkeys = selector.selectEncryptionSubkeys(info.getEncryptionSubkeys(purpose))
// There are some legacy keys around without key flags.
// If we allow encryption for those keys, we add valid keys without any key flags, if they are
// capable of encryption by means of their algorithm
if (encryptionSubkeys.isEmpty() && allowEncryptionWithMissingKeyFlags) {
encryptionSubkeys = info.validSubkeys
.filter { it.isEncryptionKey }
.filter { info.getKeyFlagsOf(it.keyID).isEmpty() }
}
if (encryptionSubkeys.isEmpty()) {
throw UnacceptableEncryptionKeyException(OpenPgpFingerprint.of(key))
}
for (subkey in encryptionSubkeys) {
val keyId = SubkeyIdentifier(key, subkey.keyID)
(_keyRingInfo as MutableMap)[keyId] = info
(_keyViews as MutableMap)[keyId] = KeyAccessor.ViaKeyId(info, keyId)
addRecipientKey(key, subkey, wildcardKeyId)
}
}
private fun addRecipientKey(certificate: PGPPublicKeyRing,
key: PGPPublicKey,
wildcardKeyId: Boolean) {
(_encryptionKeyIdentifiers as MutableSet).add(SubkeyIdentifier(certificate, key.keyID))
addEncryptionMethod(ImplementationFactory.getInstance()
.getPublicKeyKeyEncryptionMethodGenerator(key)
.also { it.setUseWildcardKeyID(wildcardKeyId) })
}
/**
* Add a symmetric passphrase which the message will be encrypted to.
*
* @param passphrase passphrase
* @return this
*/
fun addPassphrase(passphrase: Passphrase) = apply {
require(!passphrase.isEmpty) {
"Passphrase MUST NOT be empty."
}
addEncryptionMethod(ImplementationFactory.getInstance().getPBEKeyEncryptionMethodGenerator(passphrase))
}
/**
* Add an {@link PGPKeyEncryptionMethodGenerator} which will be used to encrypt the message.
* Method generators are either {@link PBEKeyEncryptionMethodGenerator} (passphrase)
* or {@link PGPKeyEncryptionMethodGenerator} (public key).
*
* This method is intended for advanced users to allow encryption for specific subkeys.
* This can come in handy for example if data needs to be encrypted to a subkey that's ignored by PGPainless.
*
* @param encryptionMethod encryption method
* @return this
*/
fun addEncryptionMethod(encryptionMethod: PGPKeyEncryptionMethodGenerator) = apply {
(_encryptionMethods as MutableSet).add(encryptionMethod)
}
/**
* Override the used symmetric encryption algorithm.
* The symmetric encryption algorithm is used to encrypt the message itself,
* while the used symmetric key will be encrypted to all recipients using public key
* cryptography.
*
* If the algorithm is not overridden, a suitable algorithm will be negotiated.
*
* @param encryptionAlgorithm encryption algorithm override
* @return this
*/
fun overrideEncryptionAlgorithm(encryptionAlgorithm: SymmetricKeyAlgorithm) = apply {
require(encryptionAlgorithm != SymmetricKeyAlgorithm.NULL) {
"Encryption algorithm override cannot be NULL."
}
_encryptionAlgorithmOverride = encryptionAlgorithm
}
/**
* If this method is called, subsequent calls to {@link #addRecipient(PGPPublicKeyRing)} will allow encryption
* for subkeys that do not carry any {@link org.pgpainless.algorithm.KeyFlag} subpacket.
* This is a workaround for dealing with legacy keys that have no key flags subpacket but rely on the key algorithm
* type to convey the subkeys use.
*
* @return this
*/
fun setAllowEncryptionWithMissingKeyFlags() = apply {
this.allowEncryptionWithMissingKeyFlags = true
}
fun hasEncryptionMethod() = _encryptionMethods.isNotEmpty()
fun interface EncryptionKeySelector {
fun selectEncryptionSubkeys(encryptionCapableKeys: List<PGPPublicKey>): List<PGPPublicKey>
}
companion object {
@JvmStatic
fun get() = EncryptionOptions()
@JvmStatic
fun encryptCommunications() = EncryptionOptions(EncryptionPurpose.COMMUNICATIONS)
@JvmStatic
fun encryptDataAtRest() = EncryptionOptions(EncryptionPurpose.STORAGE)
/**
* Only encrypt to the first valid encryption capable subkey we stumble upon.
*
* @return encryption key selector
*/
@JvmStatic
fun encryptToFirstSubkey() = EncryptionKeySelector { encryptionCapableKeys ->
encryptionCapableKeys.firstOrNull()?.let { listOf(it) } ?: listOf() }
/**
* Encrypt to any valid, encryption capable subkey on the key ring.
*
* @return encryption key selector
*/
@JvmStatic
fun encryptToAllCapableSubkeys() = EncryptionKeySelector { encryptionCapableKeys -> encryptionCapableKeys }
}
}

View file

@ -11,6 +11,7 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
import java.security.InvalidAlgorithmParameterException;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
@ -22,6 +23,7 @@ import org.bouncycastle.openpgp.PGPPublicKey;
import org.bouncycastle.openpgp.PGPPublicKeyRing;
import org.bouncycastle.openpgp.PGPPublicKeyRingCollection;
import org.bouncycastle.openpgp.PGPSecretKeyRing;
import org.jetbrains.annotations.NotNull;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.pgpainless.PGPainless;
@ -122,7 +124,7 @@ public class EncryptionOptionsTest {
EncryptionOptions options = new EncryptionOptions();
assertThrows(IllegalArgumentException.class, () -> options.addRecipients(Collections.emptyList()));
assertThrows(IllegalArgumentException.class, () -> options.addRecipients(Collections.emptyList(),
encryptionCapableKeys -> encryptionCapableKeys));
ArrayList::new));
}
@Test
@ -150,8 +152,9 @@ public class EncryptionOptionsTest {
assertThrows(KeyException.UnacceptableEncryptionKeyException.class,
() -> options.addRecipient(publicKeys, new EncryptionOptions.EncryptionKeySelector() {
@NotNull
@Override
public List<PGPPublicKey> selectEncryptionSubkeys(@Nonnull List<PGPPublicKey> encryptionCapableKeys) {
public List<PGPPublicKey> selectEncryptionSubkeys(@NotNull List<? extends PGPPublicKey> encryptionCapableKeys) {
return Collections.emptyList();
}
}));
@ -159,7 +162,7 @@ public class EncryptionOptionsTest {
assertThrows(KeyException.UnacceptableEncryptionKeyException.class,
() -> options.addRecipient(publicKeys, "test@pgpainless.org", new EncryptionOptions.EncryptionKeySelector() {
@Override
public List<PGPPublicKey> selectEncryptionSubkeys(@Nonnull List<PGPPublicKey> encryptionCapableKeys) {
public List<PGPPublicKey> selectEncryptionSubkeys(@Nonnull List<? extends PGPPublicKey> encryptionCapableKeys) {
return Collections.emptyList();
}
}));