pgpainless/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/DecryptionStreamFactory.java

651 lines
31 KiB
Java

// SPDX-FileCopyrightText: 2018 Paul Schaub <vanitasvitae@fsfe.org>
//
// SPDX-License-Identifier: Apache-2.0
package org.pgpainless.decryption_verification;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import org.bouncycastle.bcpg.ArmoredInputStream;
import org.bouncycastle.openpgp.PGPCompressedData;
import org.bouncycastle.openpgp.PGPEncryptedData;
import org.bouncycastle.openpgp.PGPEncryptedDataList;
import org.bouncycastle.openpgp.PGPException;
import org.bouncycastle.openpgp.PGPLiteralData;
import org.bouncycastle.openpgp.PGPObjectFactory;
import org.bouncycastle.openpgp.PGPOnePassSignature;
import org.bouncycastle.openpgp.PGPOnePassSignatureList;
import org.bouncycastle.openpgp.PGPPBEEncryptedData;
import org.bouncycastle.openpgp.PGPPrivateKey;
import org.bouncycastle.openpgp.PGPPublicKey;
import org.bouncycastle.openpgp.PGPPublicKeyEncryptedData;
import org.bouncycastle.openpgp.PGPPublicKeyRing;
import org.bouncycastle.openpgp.PGPSecretKey;
import org.bouncycastle.openpgp.PGPSecretKeyRing;
import org.bouncycastle.openpgp.PGPSessionKey;
import org.bouncycastle.openpgp.PGPSignature;
import org.bouncycastle.openpgp.PGPSignatureList;
import org.bouncycastle.openpgp.PGPUtil;
import org.bouncycastle.openpgp.operator.PBEDataDecryptorFactory;
import org.bouncycastle.openpgp.operator.PGPContentVerifierBuilderProvider;
import org.bouncycastle.openpgp.operator.PublicKeyDataDecryptorFactory;
import org.bouncycastle.openpgp.operator.SessionKeyDataDecryptorFactory;
import org.pgpainless.PGPainless;
import org.pgpainless.algorithm.CompressionAlgorithm;
import org.pgpainless.algorithm.EncryptionPurpose;
import org.pgpainless.algorithm.StreamEncoding;
import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
import org.pgpainless.decryption_verification.cleartext_signatures.ClearsignedMessageUtil;
import org.pgpainless.decryption_verification.cleartext_signatures.MultiPassStrategy;
import org.pgpainless.exception.FinalIOException;
import org.pgpainless.exception.MessageNotIntegrityProtectedException;
import org.pgpainless.exception.MissingDecryptionMethodException;
import org.pgpainless.exception.MissingLiteralDataException;
import org.pgpainless.exception.MissingPassphraseException;
import org.pgpainless.exception.SignatureValidationException;
import org.pgpainless.exception.UnacceptableAlgorithmException;
import org.pgpainless.implementation.ImplementationFactory;
import org.pgpainless.key.SubkeyIdentifier;
import org.pgpainless.key.info.KeyRingInfo;
import org.pgpainless.key.protection.SecretKeyRingProtector;
import org.pgpainless.key.protection.UnlockSecretKey;
import org.pgpainless.signature.SignatureUtils;
import org.pgpainless.signature.consumer.DetachedSignatureCheck;
import org.pgpainless.signature.consumer.OnePassSignatureCheck;
import org.pgpainless.util.ArmoredInputStreamFactory;
import org.pgpainless.util.Passphrase;
import org.pgpainless.util.SessionKey;
import org.pgpainless.util.Tuple;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public final class DecryptionStreamFactory {
private static final Logger LOGGER = LoggerFactory.getLogger(DecryptionStreamFactory.class);
// Maximum nesting depth of packets (e.g. compression, encryption...)
private static final int MAX_PACKET_NESTING_DEPTH = 16;
private final ConsumerOptions options;
private final OpenPgpMetadata.Builder resultBuilder = OpenPgpMetadata.getBuilder();
private final List<OnePassSignatureCheck> onePassSignatureChecks = new ArrayList<>();
private final List<DetachedSignatureCheck> detachedSignatureChecks = new ArrayList<>();
private final Map<Long, OnePassSignatureCheck> onePassSignaturesWithMissingCert = new HashMap<>();
private static final PGPContentVerifierBuilderProvider verifierBuilderProvider =
ImplementationFactory.getInstance().getPGPContentVerifierBuilderProvider();
private IntegrityProtectedInputStream integrityProtectedEncryptedInputStream;
public static DecryptionStream create(@Nonnull InputStream inputStream,
@Nonnull ConsumerOptions options)
throws PGPException, IOException {
DecryptionStreamFactory factory = new DecryptionStreamFactory(options);
OpenPgpInputStream openPgpIn = new OpenPgpInputStream(inputStream);
return factory.parseOpenPGPDataAndCreateDecryptionStream(openPgpIn);
}
public DecryptionStreamFactory(ConsumerOptions options) {
this.options = options;
initializeDetachedSignatures(options.getDetachedSignatures());
}
private void initializeDetachedSignatures(Set<PGPSignature> signatures) {
for (PGPSignature signature : signatures) {
long issuerKeyId = SignatureUtils.determineIssuerKeyId(signature);
PGPPublicKeyRing signingKeyRing = findSignatureVerificationKeyRing(issuerKeyId);
if (signingKeyRing == null) {
SignatureValidationException ex = new SignatureValidationException(
"Missing verification certificate " + Long.toHexString(issuerKeyId));
resultBuilder.addInvalidDetachedSignature(new SignatureVerification(signature, null), ex);
continue;
}
PGPPublicKey signingKey = signingKeyRing.getPublicKey(issuerKeyId);
SubkeyIdentifier signingKeyIdentifier = new SubkeyIdentifier(signingKeyRing, signingKey.getKeyID());
try {
signature.init(verifierBuilderProvider, signingKey);
DetachedSignatureCheck detachedSignature =
new DetachedSignatureCheck(signature, signingKeyRing, signingKeyIdentifier);
detachedSignatureChecks.add(detachedSignature);
} catch (PGPException e) {
SignatureValidationException ex = new SignatureValidationException(
"Cannot verify detached signature made by " + signingKeyIdentifier + ".", e);
resultBuilder.addInvalidDetachedSignature(new SignatureVerification(signature, signingKeyIdentifier), ex);
}
}
}
private DecryptionStream parseOpenPGPDataAndCreateDecryptionStream(OpenPgpInputStream openPgpIn)
throws IOException, PGPException {
InputStream pgpInStream;
InputStream outerDecodingStream;
PGPObjectFactory objectFactory;
// Non-OpenPGP data. We are probably verifying detached signatures
if (openPgpIn.isNonOpenPgp() || options.isForceNonOpenPgpData()) {
outerDecodingStream = openPgpIn;
pgpInStream = wrapInVerifySignatureStream(outerDecodingStream, null);
return new DecryptionStream(pgpInStream, resultBuilder, integrityProtectedEncryptedInputStream, null);
}
// Data appears to be OpenPGP message,
// or we handle it as such, since user provided a session-key for decryption
if (openPgpIn.isLikelyOpenPgpMessage() ||
(openPgpIn.isBinaryOpenPgp() && options.getSessionKey() != null)) {
outerDecodingStream = openPgpIn;
objectFactory = ImplementationFactory.getInstance().getPGPObjectFactory(outerDecodingStream);
// Parse OpenPGP message
pgpInStream = processPGPPackets(objectFactory, 1);
return new DecryptionStream(pgpInStream,
resultBuilder, integrityProtectedEncryptedInputStream, null);
}
if (openPgpIn.isAsciiArmored()) {
ArmoredInputStream armoredInputStream = ArmoredInputStreamFactory.get(openPgpIn);
if (armoredInputStream.isClearText()) {
resultBuilder.setCleartextSigned();
return parseCleartextSignedMessage(armoredInputStream);
} else {
outerDecodingStream = armoredInputStream;
objectFactory = ImplementationFactory.getInstance().getPGPObjectFactory(outerDecodingStream);
// Parse OpenPGP message
pgpInStream = processPGPPackets(objectFactory, 1);
return new DecryptionStream(pgpInStream,
resultBuilder, integrityProtectedEncryptedInputStream,
outerDecodingStream);
}
}
throw new PGPException("Not sure how to handle the input stream.");
}
private DecryptionStream parseCleartextSignedMessage(ArmoredInputStream armorIn)
throws IOException, PGPException {
resultBuilder.setCompressionAlgorithm(CompressionAlgorithm.UNCOMPRESSED)
.setFileEncoding(StreamEncoding.TEXT);
MultiPassStrategy multiPassStrategy = options.getMultiPassStrategy();
PGPSignatureList signatures = ClearsignedMessageUtil.detachSignaturesFromInbandClearsignedMessage(armorIn, multiPassStrategy.getMessageOutputStream());
for (PGPSignature signature : signatures) {
options.addVerificationOfDetachedSignature(signature);
}
initializeDetachedSignatures(options.getDetachedSignatures());
InputStream verifyIn = wrapInVerifySignatureStream(multiPassStrategy.getMessageInputStream(), null);
return new DecryptionStream(verifyIn, resultBuilder, integrityProtectedEncryptedInputStream,
null);
}
private InputStream wrapInVerifySignatureStream(InputStream bufferedIn, @Nullable PGPObjectFactory objectFactory) {
return new SignatureInputStream.VerifySignatures(
bufferedIn, objectFactory, onePassSignatureChecks,
onePassSignaturesWithMissingCert, detachedSignatureChecks, options,
resultBuilder);
}
private InputStream processPGPPackets(@Nonnull PGPObjectFactory objectFactory, int depth)
throws IOException, PGPException {
if (depth >= MAX_PACKET_NESTING_DEPTH) {
throw new PGPException("Maximum depth of nested packages exceeded.");
}
Object nextPgpObject;
try {
while ((nextPgpObject = objectFactory.nextObject()) != null) {
if (nextPgpObject instanceof PGPEncryptedDataList) {
return processPGPEncryptedDataList((PGPEncryptedDataList) nextPgpObject, depth);
}
if (nextPgpObject instanceof PGPCompressedData) {
return processPGPCompressedData((PGPCompressedData) nextPgpObject, depth);
}
if (nextPgpObject instanceof PGPOnePassSignatureList) {
return processOnePassSignatureList(objectFactory, (PGPOnePassSignatureList) nextPgpObject, depth);
}
if (nextPgpObject instanceof PGPLiteralData) {
return processPGPLiteralData(objectFactory, (PGPLiteralData) nextPgpObject, depth);
}
}
} catch (FinalIOException e) {
throw e;
} catch (IOException e) {
if (depth == 1 && e.getMessage().contains("invalid armor")) {
throw e;
}
if (depth == 1 && e.getMessage().contains("unknown object in stream:")) {
throw new MissingLiteralDataException("No Literal Data Packet found.");
} else {
throw new FinalIOException(e);
}
}
throw new MissingLiteralDataException("No Literal Data Packet found");
}
private InputStream processPGPEncryptedDataList(PGPEncryptedDataList pgpEncryptedDataList, int depth)
throws PGPException, IOException {
LOGGER.debug("Depth {}: Encountered PGPEncryptedDataList", depth);
SessionKey sessionKey = options.getSessionKey();
if (sessionKey != null) {
integrityProtectedEncryptedInputStream = decryptWithProvidedSessionKey(pgpEncryptedDataList, sessionKey);
InputStream decodedDataStream = PGPUtil.getDecoderStream(integrityProtectedEncryptedInputStream);
PGPObjectFactory factory = ImplementationFactory.getInstance().getPGPObjectFactory(decodedDataStream);
return processPGPPackets(factory, ++depth);
}
InputStream decryptedDataStream = decryptSessionKey(pgpEncryptedDataList);
InputStream decodedDataStream = PGPUtil.getDecoderStream(decryptedDataStream);
PGPObjectFactory factory = ImplementationFactory.getInstance().getPGPObjectFactory(decodedDataStream);
return processPGPPackets(factory, ++depth);
}
private IntegrityProtectedInputStream decryptWithProvidedSessionKey(
PGPEncryptedDataList pgpEncryptedDataList,
SessionKey sessionKey)
throws PGPException {
SessionKeyDataDecryptorFactory decryptorFactory = ImplementationFactory.getInstance()
.getSessionKeyDataDecryptorFactory(sessionKey);
InputStream decryptedDataStream = null;
PGPEncryptedData encryptedData = null;
for (PGPEncryptedData pgpEncryptedData : pgpEncryptedDataList) {
encryptedData = pgpEncryptedData;
if (!options.isIgnoreMDCErrors() && !encryptedData.isIntegrityProtected()) {
throw new MessageNotIntegrityProtectedException();
}
if (encryptedData instanceof PGPPBEEncryptedData) {
PGPPBEEncryptedData pbeEncrypted = (PGPPBEEncryptedData) encryptedData;
decryptedDataStream = pbeEncrypted.getDataStream(decryptorFactory);
break;
} else if (encryptedData instanceof PGPPublicKeyEncryptedData) {
PGPPublicKeyEncryptedData pkEncrypted = (PGPPublicKeyEncryptedData) encryptedData;
decryptedDataStream = pkEncrypted.getDataStream(decryptorFactory);
break;
}
}
if (decryptedDataStream == null) {
throw new PGPException("No valid PGP data encountered.");
}
resultBuilder.setSessionKey(sessionKey);
throwIfAlgorithmIsRejected(sessionKey.getAlgorithm());
integrityProtectedEncryptedInputStream =
new IntegrityProtectedInputStream(decryptedDataStream, encryptedData, options);
return integrityProtectedEncryptedInputStream;
}
private InputStream processPGPCompressedData(PGPCompressedData pgpCompressedData, int depth)
throws PGPException, IOException {
try {
CompressionAlgorithm compressionAlgorithm = CompressionAlgorithm.requireFromId(pgpCompressedData.getAlgorithm());
LOGGER.debug("Depth {}: Encountered PGPCompressedData: {}", depth, compressionAlgorithm);
resultBuilder.setCompressionAlgorithm(compressionAlgorithm);
} catch (NoSuchElementException e) {
throw new PGPException("Unknown compression algorithm encountered.", e);
}
InputStream inflatedDataStream = pgpCompressedData.getDataStream();
InputStream decodedDataStream = PGPUtil.getDecoderStream(inflatedDataStream);
PGPObjectFactory objectFactory = ImplementationFactory.getInstance().getPGPObjectFactory(decodedDataStream);
return processPGPPackets(objectFactory, ++depth);
}
private InputStream processOnePassSignatureList(
@Nonnull PGPObjectFactory objectFactory,
PGPOnePassSignatureList onePassSignatures,
int depth)
throws PGPException, IOException {
LOGGER.debug("Depth {}: Encountered PGPOnePassSignatureList of size {}", depth, onePassSignatures.size());
initOnePassSignatures(onePassSignatures);
return processPGPPackets(objectFactory, depth);
}
private InputStream processPGPLiteralData(
@Nonnull PGPObjectFactory objectFactory,
PGPLiteralData pgpLiteralData,
int depth) {
LOGGER.debug("Depth {}: Found PGPLiteralData", depth);
InputStream literalDataInputStream = pgpLiteralData.getInputStream();
resultBuilder.setFileName(pgpLiteralData.getFileName())
.setModificationDate(pgpLiteralData.getModificationTime())
.setFileEncoding(StreamEncoding.requireFromCode(pgpLiteralData.getFormat()));
if (onePassSignatureChecks.isEmpty() && onePassSignaturesWithMissingCert.isEmpty()) {
LOGGER.debug("No OnePassSignatures found -> We are done");
return literalDataInputStream;
}
return new SignatureInputStream.VerifySignatures(literalDataInputStream, objectFactory,
onePassSignatureChecks, onePassSignaturesWithMissingCert, detachedSignatureChecks, options, resultBuilder) {
};
}
private InputStream decryptSessionKey(@Nonnull PGPEncryptedDataList encryptedDataList)
throws PGPException {
Iterator<PGPEncryptedData> encryptedDataIterator = encryptedDataList.getEncryptedDataObjects();
if (!encryptedDataIterator.hasNext()) {
throw new PGPException("Decryption failed - EncryptedDataList has no items");
}
PGPPrivateKey decryptionKey = null;
PGPPublicKeyEncryptedData encryptedSessionKey = null;
List<PGPPBEEncryptedData> passphraseProtected = new ArrayList<>();
List<PGPPublicKeyEncryptedData> publicKeyProtected = new ArrayList<>();
List<Tuple<SubkeyIdentifier, PGPPublicKeyEncryptedData>> postponedDueToMissingPassphrase = new ArrayList<>();
// Sort PKESK and SKESK packets
while (encryptedDataIterator.hasNext()) {
PGPEncryptedData encryptedData = encryptedDataIterator.next();
if (!encryptedData.isIntegrityProtected() && !options.isIgnoreMDCErrors()) {
throw new MessageNotIntegrityProtectedException();
}
// SKESK
if (encryptedData instanceof PGPPBEEncryptedData) {
passphraseProtected.add((PGPPBEEncryptedData) encryptedData);
}
// PKESK
else if (encryptedData instanceof PGPPublicKeyEncryptedData) {
publicKeyProtected.add((PGPPublicKeyEncryptedData) encryptedData);
}
}
// Try decryption with passphrases first
for (PGPPBEEncryptedData pbeEncryptedData : passphraseProtected) {
for (Passphrase passphrase : options.getDecryptionPassphrases()) {
PBEDataDecryptorFactory passphraseDecryptor = ImplementationFactory.getInstance()
.getPBEDataDecryptorFactory(passphrase);
try {
InputStream decryptedDataStream = pbeEncryptedData.getDataStream(passphraseDecryptor);
PGPSessionKey pgpSessionKey = pbeEncryptedData.getSessionKey(passphraseDecryptor);
SessionKey sessionKey = new SessionKey(pgpSessionKey);
resultBuilder.setSessionKey(sessionKey);
throwIfAlgorithmIsRejected(sessionKey.getAlgorithm());
integrityProtectedEncryptedInputStream =
new IntegrityProtectedInputStream(decryptedDataStream, pbeEncryptedData, options);
return integrityProtectedEncryptedInputStream;
} catch (PGPException e) {
LOGGER.debug("Probable passphrase mismatch, skip PBE encrypted data block", e);
}
}
}
// Then try decryption with public key encryption
for (PGPPublicKeyEncryptedData publicKeyEncryptedData : publicKeyProtected) {
PGPPrivateKey privateKey = null;
if (options.getDecryptionKeys().isEmpty()) {
break;
}
long keyId = publicKeyEncryptedData.getKeyID();
// Wildcard KeyID
if (keyId == 0L) {
LOGGER.debug("Hidden recipient detected. Try to decrypt with all available secret keys.");
for (PGPSecretKeyRing secretKeys : options.getDecryptionKeys()) {
if (privateKey != null) {
break;
}
KeyRingInfo info = new KeyRingInfo(secretKeys);
List<PGPPublicKey> encryptionSubkeys = info.getEncryptionSubkeys(EncryptionPurpose.ANY);
for (PGPPublicKey pubkey : encryptionSubkeys) {
PGPSecretKey secretKey = secretKeys.getSecretKey(pubkey.getKeyID());
// Skip missing secret key
if (secretKey == null) {
continue;
}
privateKey = tryPublicKeyDecryption(secretKeys, secretKey, publicKeyEncryptedData,
postponedDueToMissingPassphrase, true);
}
}
}
// Non-wildcard key-id
else {
LOGGER.debug("PGPEncryptedData is encrypted for key {}", Long.toHexString(keyId));
resultBuilder.addRecipientKeyId(keyId);
PGPSecretKeyRing secretKeys = findDecryptionKeyRing(keyId);
if (secretKeys == null) {
LOGGER.debug("Missing certificate of {}. Skip.", Long.toHexString(keyId));
continue;
}
// Make sure that the recipient key is encryption capable and non-expired
KeyRingInfo info = new KeyRingInfo(secretKeys);
List<PGPPublicKey> encryptionSubkeys = info.getEncryptionSubkeys(EncryptionPurpose.ANY);
PGPSecretKey secretKey = null;
for (PGPPublicKey pubkey : encryptionSubkeys) {
if (pubkey.getKeyID() == keyId) {
secretKey = secretKeys.getSecretKey(keyId);
break;
}
}
if (secretKey == null) {
LOGGER.debug("Key " + Long.toHexString(keyId) + " is not valid or not capable for decryption.");
} else {
privateKey = tryPublicKeyDecryption(secretKeys, secretKey, publicKeyEncryptedData,
postponedDueToMissingPassphrase, true);
}
}
if (privateKey == null) {
continue;
}
decryptionKey = privateKey;
encryptedSessionKey = publicKeyEncryptedData;
break;
}
// Try postponed keys with missing passphrases (will cause missing passphrase callbacks to fire)
if (encryptedSessionKey == null) {
if (options.getMissingKeyPassphraseStrategy() == MissingKeyPassphraseStrategy.THROW_EXCEPTION) {
// Non-interactive mode: Throw an exception with all locked decryption keys
Set<SubkeyIdentifier> keyIds = new HashSet<>();
for (Tuple<SubkeyIdentifier, ?> k : postponedDueToMissingPassphrase) {
keyIds.add(k.getA());
}
if (!keyIds.isEmpty()) {
throw new MissingPassphraseException(keyIds);
}
}
else if (options.getMissingKeyPassphraseStrategy() == MissingKeyPassphraseStrategy.INTERACTIVE) {
// Interactive mode: Fire protector callbacks to get passphrases interactively
for (Tuple<SubkeyIdentifier, PGPPublicKeyEncryptedData> missingPassphrases : postponedDueToMissingPassphrase) {
SubkeyIdentifier keyId = missingPassphrases.getA();
PGPPublicKeyEncryptedData publicKeyEncryptedData = missingPassphrases.getB();
PGPSecretKeyRing secretKeys = findDecryptionKeyRing(keyId.getKeyId());
PGPSecretKey secretKey = secretKeys.getSecretKey(keyId.getSubkeyId());
PGPPrivateKey privateKey = tryPublicKeyDecryption(secretKeys, secretKey, publicKeyEncryptedData,
postponedDueToMissingPassphrase, false);
if (privateKey == null) {
continue;
}
decryptionKey = privateKey;
encryptedSessionKey = publicKeyEncryptedData;
break;
}
} else {
throw new IllegalStateException("Invalid PostponedKeysStrategy set in consumer options.");
}
}
return decryptWith(encryptedSessionKey, decryptionKey);
}
/**
* Try decryption of the provided public-key-encrypted-data using the given secret key.
* If the secret key is encrypted and the secret key protector does not have a passphrase available and the boolean
* postponeIfMissingPassphrase is true, data decryption is postponed by pushing a tuple of the encrypted data decryption key
* identifier to the postponed list.
*
* This method only returns a non-null private key, if the private key is able to decrypt the message successfully.
*
* @param secretKeys secret key ring
* @param secretKey secret key
* @param publicKeyEncryptedData encrypted data which is tried to decrypt using the secret key
* @param postponed list of postponed decryptions due to missing secret key passphrases
* @param postponeIfMissingPassphrase flag to specify whether missing secret key passphrases should result in postponed decryption
* @return private key if decryption is successful, null if decryption is unsuccessful or postponed
*
* @throws PGPException in case of an OpenPGP error
*/
private PGPPrivateKey tryPublicKeyDecryption(
PGPSecretKeyRing secretKeys,
PGPSecretKey secretKey,
PGPPublicKeyEncryptedData publicKeyEncryptedData,
List<Tuple<SubkeyIdentifier, PGPPublicKeyEncryptedData>> postponed,
boolean postponeIfMissingPassphrase) throws PGPException {
SecretKeyRingProtector protector = options.getSecretKeyProtector(secretKeys);
if (postponeIfMissingPassphrase && !protector.hasPassphraseFor(secretKey.getKeyID())) {
// Postpone decryption with key with missing passphrase
SubkeyIdentifier identifier = new SubkeyIdentifier(secretKeys, secretKey.getKeyID());
postponed.add(new Tuple<>(identifier, publicKeyEncryptedData));
return null;
}
PGPPrivateKey privateKey = UnlockSecretKey.unlockSecretKey(
secretKey, protector.getDecryptor(secretKey.getKeyID()));
// test if we have the right private key
PublicKeyDataDecryptorFactory decryptorFactory = ImplementationFactory.getInstance()
.getPublicKeyDataDecryptorFactory(privateKey);
try {
publicKeyEncryptedData.getSymmetricAlgorithm(decryptorFactory); // will only succeed if we have the right secret key
LOGGER.debug("Found correct decryption key {}.", Long.toHexString(secretKey.getKeyID()));
resultBuilder.setDecryptionKey(new SubkeyIdentifier(secretKeys, privateKey.getKeyID()));
return privateKey;
} catch (PGPException | ClassCastException e) {
return null;
}
}
private InputStream decryptWith(PGPPublicKeyEncryptedData encryptedSessionKey, PGPPrivateKey decryptionKey)
throws PGPException {
if (decryptionKey == null || encryptedSessionKey == null) {
throw new MissingDecryptionMethodException("Decryption failed - No suitable decryption key or passphrase found");
}
PublicKeyDataDecryptorFactory dataDecryptor = ImplementationFactory.getInstance()
.getPublicKeyDataDecryptorFactory(decryptionKey);
PGPSessionKey pgpSessionKey = encryptedSessionKey.getSessionKey(dataDecryptor);
SessionKey sessionKey = new SessionKey(pgpSessionKey);
resultBuilder.setSessionKey(sessionKey);
SymmetricKeyAlgorithm symmetricKeyAlgorithm = sessionKey.getAlgorithm();
if (symmetricKeyAlgorithm == SymmetricKeyAlgorithm.NULL) {
LOGGER.debug("Message is unencrypted");
} else {
LOGGER.debug("Message is encrypted using {}", symmetricKeyAlgorithm);
}
throwIfAlgorithmIsRejected(symmetricKeyAlgorithm);
integrityProtectedEncryptedInputStream = new IntegrityProtectedInputStream(
encryptedSessionKey.getDataStream(dataDecryptor), encryptedSessionKey, options);
return integrityProtectedEncryptedInputStream;
}
private void throwIfAlgorithmIsRejected(SymmetricKeyAlgorithm algorithm)
throws UnacceptableAlgorithmException {
if (!PGPainless.getPolicy().getSymmetricKeyDecryptionAlgorithmPolicy().isAcceptable(algorithm)) {
throw new UnacceptableAlgorithmException("Data is "
+ (algorithm == SymmetricKeyAlgorithm.NULL ?
"unencrypted" :
"encrypted with symmetric algorithm " + algorithm) + " which is not acceptable as per PGPainless' policy.\n" +
"To mark this algorithm as acceptable, use PGPainless.getPolicy().setSymmetricKeyDecryptionAlgorithmPolicy().");
}
}
private void initOnePassSignatures(@Nonnull PGPOnePassSignatureList onePassSignatureList)
throws PGPException {
Iterator<PGPOnePassSignature> iterator = onePassSignatureList.iterator();
if (!iterator.hasNext()) {
throw new PGPException("Verification failed - No OnePassSignatures found");
}
processOnePassSignatures(iterator);
}
private void processOnePassSignatures(Iterator<PGPOnePassSignature> signatures)
throws PGPException {
while (signatures.hasNext()) {
PGPOnePassSignature signature = signatures.next();
processOnePassSignature(signature);
}
}
private void processOnePassSignature(PGPOnePassSignature signature)
throws PGPException {
final long keyId = signature.getKeyID();
LOGGER.debug("Encountered OnePassSignature from {}", Long.toHexString(keyId));
// Find public key
PGPPublicKeyRing verificationKeyRing = findSignatureVerificationKeyRing(keyId);
if (verificationKeyRing == null) {
onePassSignaturesWithMissingCert.put(keyId, new OnePassSignatureCheck(signature, null));
return;
}
PGPPublicKey verificationKey = verificationKeyRing.getPublicKey(keyId);
signature.init(verifierBuilderProvider, verificationKey);
OnePassSignatureCheck onePassSignature = new OnePassSignatureCheck(signature, verificationKeyRing);
onePassSignatureChecks.add(onePassSignature);
}
private PGPSecretKeyRing findDecryptionKeyRing(long keyId) {
for (PGPSecretKeyRing key : options.getDecryptionKeys()) {
if (key.getSecretKey(keyId) != null) {
return key;
}
}
return null;
}
private PGPPublicKeyRing findSignatureVerificationKeyRing(long keyId) {
PGPPublicKeyRing verificationKeyRing = null;
for (PGPPublicKeyRing publicKeyRing : options.getCertificates()) {
PGPPublicKey verificationKey = publicKeyRing.getPublicKey(keyId);
if (verificationKey != null) {
LOGGER.debug("Found public key {} for signature verification", Long.toHexString(keyId));
verificationKeyRing = publicKeyRing;
break;
}
}
if (verificationKeyRing == null && options.getMissingCertificateCallback() != null) {
verificationKeyRing = options.getMissingCertificateCallback().onMissingPublicKeyEncountered(keyId);
}
return verificationKeyRing;
}
}