Java tutorial
/* * Copyright (C) 2014 Dominik Schrmann <dominik@dominikschuermann.de> * Copyright (C) 2014 Vincent Breitmoser <v.breitmoser@mugenguild.com> * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package org.sufficientlysecure.keychain.pgp; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.ArrayList; import java.util.Arrays; import java.util.Calendar; import java.util.Comparator; import java.util.Date; import java.util.HashSet; import java.util.Iterator; import java.util.Set; import java.util.TimeZone; import java.util.TreeSet; import android.support.annotation.VisibleForTesting; import org.bouncycastle.bcpg.ArmoredOutputStream; import org.bouncycastle.bcpg.PublicKeyAlgorithmTags; import org.bouncycastle.bcpg.SignatureSubpacketTags; import org.bouncycastle.bcpg.UserAttributeSubpacketTags; import org.bouncycastle.bcpg.sig.KeyFlags; import org.bouncycastle.openpgp.PGPKeyRing; import org.bouncycastle.openpgp.PGPObjectFactory; import org.bouncycastle.openpgp.PGPPrivateKey; import org.bouncycastle.openpgp.PGPPublicKey; import org.bouncycastle.openpgp.PGPPublicKeyRing; import org.bouncycastle.openpgp.PGPSecretKey; import org.bouncycastle.openpgp.PGPSecretKeyRing; import org.bouncycastle.openpgp.PGPSignature; import org.bouncycastle.openpgp.PGPSignatureGenerator; import org.bouncycastle.openpgp.PGPSignatureList; import org.bouncycastle.openpgp.PGPSignatureSubpacketGenerator; import org.bouncycastle.openpgp.PGPUserAttributeSubpacketVector; import org.bouncycastle.openpgp.PGPUtil; import org.bouncycastle.openpgp.operator.PBESecretKeyDecryptor; import org.bouncycastle.openpgp.operator.PGPContentSignerBuilder; import org.bouncycastle.openpgp.operator.jcajce.JcaKeyFingerprintCalculator; import org.bouncycastle.openpgp.operator.jcajce.JcaPGPContentSignerBuilder; import org.bouncycastle.openpgp.operator.jcajce.JcePBESecretKeyDecryptorBuilder; import org.sufficientlysecure.keychain.Constants; import org.sufficientlysecure.keychain.operations.results.OperationResult.LogType; import org.sufficientlysecure.keychain.operations.results.OperationResult.OperationLog; import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralException; import org.sufficientlysecure.keychain.ui.util.KeyFormattingUtils; import org.sufficientlysecure.keychain.util.IterableIterator; import org.sufficientlysecure.keychain.util.Log; import org.sufficientlysecure.keychain.util.Utf8Util; /** Wrapper around PGPKeyRing class, to be constructed from bytes. * * This class and its relatives UncachedPublicKey and UncachedSecretKey are * used to move around pgp key rings in non crypto related (UI, mostly) code. * It should be used for simple inspection only until it saved in the database, * all actual crypto operations should work with CanonicalizedKeyRings * exclusively. * * This class is also special in that it can hold either the PGPPublicKeyRing * or PGPSecretKeyRing derivate of the PGPKeyRing class, since these are * treated equally for most purposes in UI code. It is up to the programmer to * take care of the differences. * * @see CanonicalizedKeyRing * @see org.sufficientlysecure.keychain.pgp.UncachedPublicKey * @see org.sufficientlysecure.keychain.pgp.UncachedSecretKey * */ public class UncachedKeyRing { final PGPKeyRing mRing; final boolean mIsSecret; private static final int CANONICALIZE_MAX_USER_IDS = 100; UncachedKeyRing(PGPKeyRing ring) { mRing = ring; mIsSecret = ring instanceof PGPSecretKeyRing; } public long getMasterKeyId() { return mRing.getPublicKey().getKeyID(); } public UncachedPublicKey getPublicKey() { return new UncachedPublicKey(mRing.getPublicKey()); } public UncachedPublicKey getPublicKey(long keyId) { return new UncachedPublicKey(mRing.getPublicKey(keyId)); } public Iterator<UncachedPublicKey> getPublicKeys() { final Iterator<PGPPublicKey> it = mRing.getPublicKeys(); return new Iterator<UncachedPublicKey>() { public void remove() { throw new UnsupportedOperationException(); } public UncachedPublicKey next() { return new UncachedPublicKey(it.next()); } public boolean hasNext() { return it.hasNext(); } }; } /** Returns the dynamic (though final) property if this is a secret keyring or not. */ public boolean isSecret() { return mIsSecret; } public byte[] getEncoded() throws IOException { return mRing.getEncoded(); } public void encode(OutputStream out) throws IOException { mRing.encode(out); } public byte[] getFingerprint() { return mRing.getPublicKey().getFingerprint(); } public int getVersion() { return mRing.getPublicKey().getVersion(); } public static UncachedKeyRing decodeFromData(byte[] data) throws PgpGeneralException, IOException { IteratorWithIOThrow<UncachedKeyRing> parsed = fromStream(new ByteArrayInputStream(data)); if (!parsed.hasNext()) { throw new PgpGeneralException("Object not recognized as PGPKeyRing!"); } UncachedKeyRing ring = parsed.next(); if (parsed.hasNext()) { throw new PgpGeneralException("Expected single keyring in stream, found at least two"); } return ring; } public static IteratorWithIOThrow<UncachedKeyRing> fromStream(final InputStream stream) { return new IteratorWithIOThrow<UncachedKeyRing>() { UncachedKeyRing mNext = null; PGPObjectFactory mObjectFactory = null; private void cacheNext() throws IOException { if (mNext != null) { return; } try { while (stream.available() > 0) { // if there are no objects left from the last factory, create a new one if (mObjectFactory == null) { InputStream in = PGPUtil.getDecoderStream(stream); mObjectFactory = new PGPObjectFactory(in, new JcaKeyFingerprintCalculator()); } // go through all objects in this block Object obj; while ((obj = mObjectFactory.nextObject()) != null) { Log.d(Constants.TAG, "Found class: " + obj.getClass()); if (!(obj instanceof PGPKeyRing)) { Log.i(Constants.TAG, "Skipping object of bad type " + obj.getClass().getName() + " in stream"); // skip object continue; } mNext = new UncachedKeyRing((PGPKeyRing) obj); return; } // if we are past the while loop, that means the objectFactory had no next mObjectFactory = null; } } catch (ArrayIndexOutOfBoundsException e) { throw new IOException(e); } } @Override public boolean hasNext() throws IOException { cacheNext(); return mNext != null; } @Override public UncachedKeyRing next() throws IOException { try { cacheNext(); return mNext; } finally { mNext = null; } } }; } public interface IteratorWithIOThrow<E> { public boolean hasNext() throws IOException; public E next() throws IOException; } public void encodeArmored(OutputStream out, String version) throws IOException { ArmoredOutputStream aos = new ArmoredOutputStream(out); if (version != null) { aos.setHeader("Version", version); } aos.write(mRing.getEncoded()); aos.close(); } // An array of known algorithms. Note this must be numerically sorted for binarySearch() to work! static final int[] KNOWN_ALGORITHMS = new int[] { PublicKeyAlgorithmTags.RSA_GENERAL, // 1 PublicKeyAlgorithmTags.RSA_ENCRYPT, // 2 PublicKeyAlgorithmTags.RSA_SIGN, // 3 PublicKeyAlgorithmTags.ELGAMAL_ENCRYPT, // 16 PublicKeyAlgorithmTags.DSA, // 17 PublicKeyAlgorithmTags.ECDH, // 18 PublicKeyAlgorithmTags.ECDSA, // 19 PublicKeyAlgorithmTags.ELGAMAL_GENERAL, // 20 // PublicKeyAlgorithmTags.DIFFIE_HELLMAN, // 21 }; /** "Canonicalizes" a public key, removing inconsistencies in the process. * * More specifically: * - Remove all non-verifying self-certificates * - Remove all "future" self-certificates * - Remove all certificates flagged as "local" * - For UID certificates, remove all certificates which are * superseded by a newer one on the same target, including * revocations with later re-certifications. * - For subkey certifications, remove all certificates which * are superseded by a newer one on the same target, unless * it encounters a revocation certificate. The revocation * certificate is considered to permanently revoke the key, * even if contains later re-certifications. * This is the "behavior in practice" used by (e.g.) GnuPG, and * the rationale for both can be found as comments in the GnuPG * source. * UID signatures: * https://github.com/mtigas/gnupg/blob/50c98c7ed6b542857ee2f902eca36cda37407737/g10/getkey.c#L1668-L1674 * Subkey signatures: * https://github.com/mtigas/gnupg/blob/50c98c7ed6b542857ee2f902eca36cda37407737/g10/getkey.c#L1990-L1997 * - Remove all certificates in other positions if not of known type: * - key revocation signatures on the master key * - subkey binding signatures for subkeys * - certifications and certification revocations for user ids * - If a subkey retains no valid subkey binding certificate, remove it * - If a user id retains no valid self certificate, remove it * - If the key is a secret key, remove all certificates by foreign keys * - If no valid user id remains, log an error and return null * * This operation writes an OperationLog which can be used as part of an OperationResultParcel. * * @return A canonicalized key, or null on fatal error (log will include a message in this case) * */ @SuppressWarnings("ConstantConditions") public CanonicalizedKeyRing canonicalize(OperationLog log, int indent) { return canonicalize(log, indent, false); } /** "Canonicalizes" a public key, removing inconsistencies in the process. * * More specifically: * - Remove all non-verifying self-certificates * - Remove all "future" self-certificates * - Remove all certificates flagged as "local" * - For UID certificates, remove all certificates which are * superseded by a newer one on the same target, including * revocations with later re-certifications. * - For subkey certifications, remove all certificates which * are superseded by a newer one on the same target, unless * it encounters a revocation certificate. The revocation * certificate is considered to permanently revoke the key, * even if contains later re-certifications. * This is the "behavior in practice" used by (e.g.) GnuPG, and * the rationale for both can be found as comments in the GnuPG * source. * UID signatures: * https://github.com/mtigas/gnupg/blob/50c98c7ed6b542857ee2f902eca36cda37407737/g10/getkey.c#L1668-L1674 * Subkey signatures: * https://github.com/mtigas/gnupg/blob/50c98c7ed6b542857ee2f902eca36cda37407737/g10/getkey.c#L1990-L1997 * - Remove all certificates in other positions if not of known type: * - key revocation signatures on the master key * - subkey binding signatures for subkeys * - certifications and certification revocations for user ids * - If a subkey retains no valid subkey binding certificate, remove it * - If a user id retains no valid self certificate, remove it * - If the key is a secret key, remove all certificates by foreign keys * - If no valid user id remains, log an error and return null * * This operation writes an OperationLog which can be used as part of an OperationResultParcel. * * @param forExport if this is true, non-exportable signatures will be removed * @return A canonicalized key, or null on fatal error (log will include a message in this case) * */ @SuppressWarnings("ConstantConditions") public CanonicalizedKeyRing canonicalize(OperationLog log, int indent, boolean forExport) { log.add(isSecret() ? LogType.MSG_KC_SECRET : LogType.MSG_KC_PUBLIC, indent, KeyFormattingUtils.convertKeyIdToHex(getMasterKeyId())); indent += 1; // do not accept v3 keys if (getVersion() <= 3) { log.add(LogType.MSG_KC_ERROR_V3, indent); return null; } Calendar nowCal = Calendar.getInstance(TimeZone.getTimeZone("UTC")); // allow for diverging clocks up to one day when checking creation time nowCal.add(Calendar.DAY_OF_YEAR, 1); final Date nowPlusOneDay = nowCal.getTime(); int redundantCerts = 0, badCerts = 0; PGPKeyRing ring = mRing; PGPPublicKey masterKey = mRing.getPublicKey(); final long masterKeyId = masterKey.getKeyID(); if (Arrays.binarySearch(KNOWN_ALGORITHMS, masterKey.getAlgorithm()) < 0) { log.add(LogType.MSG_KC_ERROR_MASTER_ALGO, indent, Integer.toString(masterKey.getAlgorithm())); return null; } { log.add(LogType.MSG_KC_MASTER, indent, KeyFormattingUtils.convertKeyIdToHex(masterKey.getKeyID())); indent += 1; PGPPublicKey modified = masterKey; PGPSignature revocation = null; PGPSignature notation = null; for (PGPSignature zert : new IterableIterator<PGPSignature>(masterKey.getKeySignatures())) { int type = zert.getSignatureType(); // These should most definitely not be here... if (type == PGPSignature.NO_CERTIFICATION || type == PGPSignature.DEFAULT_CERTIFICATION || type == PGPSignature.CASUAL_CERTIFICATION || type == PGPSignature.POSITIVE_CERTIFICATION || type == PGPSignature.CERTIFICATION_REVOCATION) { log.add(LogType.MSG_KC_MASTER_BAD_TYPE_UID, indent); modified = PGPPublicKey.removeCertification(modified, zert); badCerts += 1; continue; } WrappedSignature cert = new WrappedSignature(zert); if (type != PGPSignature.KEY_REVOCATION && type != PGPSignature.DIRECT_KEY) { // Unknown type, just remove log.add(LogType.MSG_KC_MASTER_BAD_TYPE, indent, "0x" + Integer.toString(type, 16)); modified = PGPPublicKey.removeCertification(modified, zert); badCerts += 1; continue; } if (cert.getCreationTime().after(nowPlusOneDay)) { // Creation date in the future? No way! log.add(LogType.MSG_KC_MASTER_BAD_TIME, indent); modified = PGPPublicKey.removeCertification(modified, zert); badCerts += 1; continue; } try { cert.init(masterKey); if (!cert.verifySignature(masterKey)) { log.add(LogType.MSG_KC_MASTER_BAD, indent); modified = PGPPublicKey.removeCertification(modified, zert); badCerts += 1; continue; } } catch (PgpGeneralException e) { log.add(LogType.MSG_KC_MASTER_BAD_ERR, indent); modified = PGPPublicKey.removeCertification(modified, zert); badCerts += 1; continue; } // if this is for export, we always remove any non-exportable certs if (forExport && cert.isLocal()) { // Remove revocation certs with "local" flag log.add(LogType.MSG_KC_MASTER_LOCAL, indent); modified = PGPPublicKey.removeCertification(modified, zert); continue; } // special case: non-exportable, direct key signatures for notations! if (cert.getSignatureType() == PGPSignature.DIRECT_KEY) { // must be local, otherwise strip! if (!cert.isLocal()) { log.add(LogType.MSG_KC_MASTER_BAD_TYPE, indent); modified = PGPPublicKey.removeCertification(modified, zert); badCerts += 1; continue; } // first notation? fine then. if (notation == null) { notation = zert; // more notations? at least one is superfluous, then. } else if (notation.getCreationTime().before(zert.getCreationTime())) { log.add(LogType.MSG_KC_NOTATION_DUP, indent); modified = PGPPublicKey.removeCertification(modified, notation); redundantCerts += 1; notation = zert; } else { log.add(LogType.MSG_KC_NOTATION_DUP, indent); modified = PGPPublicKey.removeCertification(modified, zert); redundantCerts += 1; } continue; } else if (cert.isLocal()) { // Remove revocation certs with "local" flag log.add(LogType.MSG_KC_MASTER_BAD_LOCAL, indent); modified = PGPPublicKey.removeCertification(modified, zert); badCerts += 1; continue; } // first revocation? fine then. if (revocation == null) { revocation = zert; // more revocations? at least one is superfluous, then. } else if (revocation.getCreationTime().before(zert.getCreationTime())) { log.add(LogType.MSG_KC_REVOKE_DUP, indent); modified = PGPPublicKey.removeCertification(modified, revocation); redundantCerts += 1; revocation = zert; } else { log.add(LogType.MSG_KC_REVOKE_DUP, indent); modified = PGPPublicKey.removeCertification(modified, zert); redundantCerts += 1; } } // If we have a notation packet, check if there is even any data in it? if (notation != null) { // If there isn't, might as well strip it if (new WrappedSignature(notation).getNotation().isEmpty()) { log.add(LogType.MSG_KC_NOTATION_EMPTY, indent); modified = PGPPublicKey.removeCertification(modified, notation); redundantCerts += 1; } } ArrayList<String> processedUserIds = new ArrayList<>(); for (byte[] rawUserId : new IterableIterator<byte[]>(masterKey.getRawUserIDs())) { String userId = Utf8Util.fromUTF8ByteArrayReplaceBadEncoding(rawUserId); // warn if user id was made with bad encoding if (!Utf8Util.isValidUTF8(rawUserId)) { log.add(LogType.MSG_KC_UID_WARN_ENCODING, indent); } // check for duplicate user ids if (processedUserIds.contains(userId)) { log.add(LogType.MSG_KC_UID_DUP, indent, userId); // strip out the first found user id with this name modified = PGPPublicKey.removeCertification(modified, rawUserId); } if (processedUserIds.size() > CANONICALIZE_MAX_USER_IDS) { log.add(LogType.MSG_KC_UID_TOO_MANY, indent, userId); // strip out the user id modified = PGPPublicKey.removeCertification(modified, rawUserId); } processedUserIds.add(userId); PGPSignature selfCert = null; revocation = null; // look through signatures for this specific user id @SuppressWarnings("unchecked") Iterator<PGPSignature> signaturesIt = masterKey.getSignaturesForID(rawUserId); if (signaturesIt != null) { for (PGPSignature zert : new IterableIterator<>(signaturesIt)) { WrappedSignature cert = new WrappedSignature(zert); long certId = cert.getKeyId(); int type = zert.getSignatureType(); if (type != PGPSignature.DEFAULT_CERTIFICATION && type != PGPSignature.NO_CERTIFICATION && type != PGPSignature.CASUAL_CERTIFICATION && type != PGPSignature.POSITIVE_CERTIFICATION && type != PGPSignature.CERTIFICATION_REVOCATION) { log.add(LogType.MSG_KC_UID_BAD_TYPE, indent, "0x" + Integer.toString(zert.getSignatureType(), 16)); modified = PGPPublicKey.removeCertification(modified, rawUserId, zert); badCerts += 1; continue; } if (cert.getCreationTime().after(nowPlusOneDay)) { // Creation date in the future? No way! log.add(LogType.MSG_KC_UID_BAD_TIME, indent); modified = PGPPublicKey.removeCertification(modified, rawUserId, zert); badCerts += 1; continue; } if (cert.isLocal()) { // Creation date in the future? No way! log.add(LogType.MSG_KC_UID_BAD_LOCAL, indent); modified = PGPPublicKey.removeCertification(modified, rawUserId, zert); badCerts += 1; continue; } // If this is a foreign signature, ... if (certId != masterKeyId) { // never mind any further for public keys, but remove them from secret ones if (isSecret()) { log.add(LogType.MSG_KC_UID_FOREIGN, indent, KeyFormattingUtils.convertKeyIdToHex(certId)); modified = PGPPublicKey.removeCertification(modified, rawUserId, zert); badCerts += 1; } continue; } // Otherwise, first make sure it checks out try { cert.init(masterKey); if (!cert.verifySignature(masterKey, rawUserId)) { log.add(LogType.MSG_KC_UID_BAD, indent, userId); modified = PGPPublicKey.removeCertification(modified, rawUserId, zert); badCerts += 1; continue; } } catch (PgpGeneralException e) { log.add(LogType.MSG_KC_UID_BAD_ERR, indent, userId); modified = PGPPublicKey.removeCertification(modified, rawUserId, zert); badCerts += 1; continue; } switch (type) { case PGPSignature.DEFAULT_CERTIFICATION: case PGPSignature.NO_CERTIFICATION: case PGPSignature.CASUAL_CERTIFICATION: case PGPSignature.POSITIVE_CERTIFICATION: if (selfCert == null) { selfCert = zert; } else if (selfCert.getCreationTime().before(cert.getCreationTime())) { log.add(LogType.MSG_KC_UID_CERT_DUP, indent, userId); modified = PGPPublicKey.removeCertification(modified, rawUserId, selfCert); redundantCerts += 1; selfCert = zert; } else { log.add(LogType.MSG_KC_UID_CERT_DUP, indent, userId); modified = PGPPublicKey.removeCertification(modified, rawUserId, zert); redundantCerts += 1; } // If there is a revocation certificate, and it's older than this, drop it if (revocation != null && revocation.getCreationTime().before(selfCert.getCreationTime())) { log.add(LogType.MSG_KC_UID_REVOKE_OLD, indent, userId); modified = PGPPublicKey.removeCertification(modified, rawUserId, revocation); revocation = null; redundantCerts += 1; } break; case PGPSignature.CERTIFICATION_REVOCATION: // If this is older than the (latest) self cert, drop it if (selfCert != null && selfCert.getCreationTime().after(zert.getCreationTime())) { log.add(LogType.MSG_KC_UID_REVOKE_OLD, indent, userId); modified = PGPPublicKey.removeCertification(modified, rawUserId, zert); redundantCerts += 1; continue; } // first revocation? remember it. if (revocation == null) { revocation = zert; // more revocations? at least one is superfluous, then. } else if (revocation.getCreationTime().before(cert.getCreationTime())) { log.add(LogType.MSG_KC_UID_REVOKE_DUP, indent, userId); modified = PGPPublicKey.removeCertification(modified, rawUserId, revocation); redundantCerts += 1; revocation = zert; } else { log.add(LogType.MSG_KC_UID_REVOKE_DUP, indent, userId); modified = PGPPublicKey.removeCertification(modified, rawUserId, zert); redundantCerts += 1; } break; } } } // If no valid certificate (if only a revocation) remains, drop it if (selfCert == null && revocation == null) { log.add(LogType.MSG_KC_UID_REMOVE, indent, userId); modified = PGPPublicKey.removeCertification(modified, rawUserId); } } // If NO user ids remain, error out! if (modified == null || !modified.getUserIDs().hasNext()) { log.add(LogType.MSG_KC_ERROR_NO_UID, indent); return null; } ArrayList<PGPUserAttributeSubpacketVector> processedUserAttributes = new ArrayList<>(); for (PGPUserAttributeSubpacketVector userAttribute : new IterableIterator<PGPUserAttributeSubpacketVector>( masterKey.getUserAttributes())) { if (userAttribute.getSubpacket(UserAttributeSubpacketTags.IMAGE_ATTRIBUTE) != null) { log.add(LogType.MSG_KC_UAT_JPEG, indent); } else { log.add(LogType.MSG_KC_UAT_UNKNOWN, indent); } try { indent += 1; // check for duplicate user attributes if (processedUserAttributes.contains(userAttribute)) { log.add(LogType.MSG_KC_UAT_DUP, indent); // strip out the first found user id with this name modified = PGPPublicKey.removeCertification(modified, userAttribute); } processedUserAttributes.add(userAttribute); PGPSignature selfCert = null; revocation = null; // look through signatures for this specific user id @SuppressWarnings("unchecked") Iterator<PGPSignature> signaturesIt = masterKey.getSignaturesForUserAttribute(userAttribute); if (signaturesIt != null) { for (PGPSignature zert : new IterableIterator<>(signaturesIt)) { WrappedSignature cert = new WrappedSignature(zert); long certId = cert.getKeyId(); int type = zert.getSignatureType(); if (type != PGPSignature.DEFAULT_CERTIFICATION && type != PGPSignature.NO_CERTIFICATION && type != PGPSignature.CASUAL_CERTIFICATION && type != PGPSignature.POSITIVE_CERTIFICATION && type != PGPSignature.CERTIFICATION_REVOCATION) { log.add(LogType.MSG_KC_UAT_BAD_TYPE, indent, "0x" + Integer.toString(zert.getSignatureType(), 16)); modified = PGPPublicKey.removeCertification(modified, userAttribute, zert); badCerts += 1; continue; } if (cert.getCreationTime().after(nowPlusOneDay)) { // Creation date in the future? No way! log.add(LogType.MSG_KC_UAT_BAD_TIME, indent); modified = PGPPublicKey.removeCertification(modified, userAttribute, zert); badCerts += 1; continue; } if (cert.isLocal()) { // Creation date in the future? No way! log.add(LogType.MSG_KC_UAT_BAD_LOCAL, indent); modified = PGPPublicKey.removeCertification(modified, userAttribute, zert); badCerts += 1; continue; } // If this is a foreign signature, ... if (certId != masterKeyId) { // never mind any further for public keys, but remove them from secret ones if (isSecret()) { log.add(LogType.MSG_KC_UAT_FOREIGN, indent, KeyFormattingUtils.convertKeyIdToHex(certId)); modified = PGPPublicKey.removeCertification(modified, userAttribute, zert); badCerts += 1; } continue; } // Otherwise, first make sure it checks out try { cert.init(masterKey); if (!cert.verifySignature(masterKey, userAttribute)) { log.add(LogType.MSG_KC_UAT_BAD, indent); modified = PGPPublicKey.removeCertification(modified, userAttribute, zert); badCerts += 1; continue; } } catch (PgpGeneralException e) { log.add(LogType.MSG_KC_UAT_BAD_ERR, indent); modified = PGPPublicKey.removeCertification(modified, userAttribute, zert); badCerts += 1; continue; } switch (type) { case PGPSignature.DEFAULT_CERTIFICATION: case PGPSignature.NO_CERTIFICATION: case PGPSignature.CASUAL_CERTIFICATION: case PGPSignature.POSITIVE_CERTIFICATION: if (selfCert == null) { selfCert = zert; } else if (selfCert.getCreationTime().before(cert.getCreationTime())) { log.add(LogType.MSG_KC_UAT_CERT_DUP, indent); modified = PGPPublicKey.removeCertification(modified, userAttribute, selfCert); redundantCerts += 1; selfCert = zert; } else { log.add(LogType.MSG_KC_UAT_CERT_DUP, indent); modified = PGPPublicKey.removeCertification(modified, userAttribute, zert); redundantCerts += 1; } // If there is a revocation certificate, and it's older than this, drop it if (revocation != null && revocation.getCreationTime().before(selfCert.getCreationTime())) { log.add(LogType.MSG_KC_UAT_REVOKE_OLD, indent); modified = PGPPublicKey.removeCertification(modified, userAttribute, revocation); revocation = null; redundantCerts += 1; } break; case PGPSignature.CERTIFICATION_REVOCATION: // If this is older than the (latest) self cert, drop it if (selfCert != null && selfCert.getCreationTime().after(zert.getCreationTime())) { log.add(LogType.MSG_KC_UAT_REVOKE_OLD, indent); modified = PGPPublicKey.removeCertification(modified, userAttribute, zert); redundantCerts += 1; continue; } // first revocation? remember it. if (revocation == null) { revocation = zert; // more revocations? at least one is superfluous, then. } else if (revocation.getCreationTime().before(cert.getCreationTime())) { log.add(LogType.MSG_KC_UAT_REVOKE_DUP, indent); modified = PGPPublicKey.removeCertification(modified, userAttribute, revocation); redundantCerts += 1; revocation = zert; } else { log.add(LogType.MSG_KC_UAT_REVOKE_DUP, indent); modified = PGPPublicKey.removeCertification(modified, userAttribute, zert); redundantCerts += 1; } break; } } } // If no valid certificate (if only a revocation) remains, drop it if (selfCert == null && revocation == null) { log.add(LogType.MSG_KC_UAT_REMOVE, indent); modified = PGPPublicKey.removeCertification(modified, userAttribute); } } finally { indent -= 1; } } // Replace modified key in the keyring ring = replacePublicKey(ring, modified); indent -= 1; } // Keep track of ids we encountered so far Set<Long> knownIds = new HashSet<>(); // Process all keys for (PGPPublicKey key : new IterableIterator<PGPPublicKey>(ring.getPublicKeys())) { // Make sure this is not a duplicate, avoid undefined behavior! if (knownIds.contains(key.getKeyID())) { log.add(LogType.MSG_KC_ERROR_DUP_KEY, indent, KeyFormattingUtils.convertKeyIdToHex(key.getKeyID())); return null; } // Add the key id to known knownIds.add(key.getKeyID()); // Don't care about the master key any further, that one gets special treatment above if (key.isMasterKey()) { continue; } log.add(LogType.MSG_KC_SUB, indent, KeyFormattingUtils.convertKeyIdToHex(key.getKeyID())); indent += 1; if (Arrays.binarySearch(KNOWN_ALGORITHMS, key.getAlgorithm()) < 0) { ring = removeSubKey(ring, key); log.add(LogType.MSG_KC_SUB_UNKNOWN_ALGO, indent, Integer.toString(key.getAlgorithm())); indent -= 1; continue; } Date keyCreationTime = key.getCreationTime(), keyCreationTimeLenient; { Calendar keyCreationCal = Calendar.getInstance(); keyCreationCal.setTime(keyCreationTime); // allow for diverging clocks up to one day when checking creation time keyCreationCal.add(Calendar.MINUTE, -5); keyCreationTimeLenient = keyCreationCal.getTime(); } // A subkey needs exactly one subkey binding certificate, and optionally one revocation // certificate. PGPPublicKey modified = key; PGPSignature selfCert = null, revocation = null; uids: for (PGPSignature zert : new IterableIterator<PGPSignature>(key.getSignatures())) { // remove from keyring (for now) modified = PGPPublicKey.removeCertification(modified, zert); WrappedSignature cert = new WrappedSignature(zert); int type = cert.getSignatureType(); // filter out bad key types... if (cert.getKeyId() != masterKey.getKeyID()) { log.add(LogType.MSG_KC_SUB_BAD_KEYID, indent); badCerts += 1; continue; } if (type != PGPSignature.SUBKEY_BINDING && type != PGPSignature.SUBKEY_REVOCATION) { log.add(LogType.MSG_KC_SUB_BAD_TYPE, indent, "0x" + Integer.toString(type, 16)); badCerts += 1; continue; } if (cert.getCreationTime().after(nowPlusOneDay)) { // Creation date in the future? No way! log.add(LogType.MSG_KC_SUB_BAD_TIME, indent); badCerts += 1; continue; } if (cert.getCreationTime().before(keyCreationTime)) { // Signature is earlier than key creation time log.add(LogType.MSG_KC_SUB_BAD_TIME_EARLY, indent); // due to an earlier accident, we generated keys which had creation timestamps // a few seconds after their signature timestamp. for compatibility, we only // error out with some margin of error if (cert.getCreationTime().before(keyCreationTimeLenient)) { badCerts += 1; continue; } } if (cert.isLocal()) { // Creation date in the future? No way! log.add(LogType.MSG_KC_SUB_BAD_LOCAL, indent); badCerts += 1; continue; } if (type == PGPSignature.SUBKEY_BINDING) { // make sure the certificate checks out try { cert.init(masterKey); if (!cert.verifySignature(masterKey, key)) { log.add(LogType.MSG_KC_SUB_BAD, indent); badCerts += 1; continue; } } catch (PgpGeneralException e) { log.add(LogType.MSG_KC_SUB_BAD_ERR, indent); badCerts += 1; continue; } boolean needsPrimaryBinding = false; // If the algorithm is even suitable for signing if (isSigningAlgo(key.getAlgorithm())) { // If this certificate says it allows signing for the key if (zert.getHashedSubPackets() != null && zert.getHashedSubPackets().hasSubpacket(SignatureSubpacketTags.KEY_FLAGS)) { int flags = ((KeyFlags) zert.getHashedSubPackets() .getSubpacket(SignatureSubpacketTags.KEY_FLAGS)).getFlags(); if ((flags & KeyFlags.SIGN_DATA) == KeyFlags.SIGN_DATA) { needsPrimaryBinding = true; } } else { // If there are no key flags, we STILL require this because the key can sign! needsPrimaryBinding = true; } } // If this key can sign, it MUST have a primary key binding certificate if (needsPrimaryBinding) { boolean ok = false; if (zert.getUnhashedSubPackets() != null) try { // Check all embedded signatures, if any of them fits PGPSignatureList list = zert.getUnhashedSubPackets().getEmbeddedSignatures(); for (int i = 0; i < list.size(); i++) { WrappedSignature subsig = new WrappedSignature(list.get(i)); if (subsig.getSignatureType() == PGPSignature.PRIMARYKEY_BINDING) { subsig.init(key); if (subsig.verifySignature(masterKey, key)) { ok = true; } else { log.add(LogType.MSG_KC_SUB_PRIMARY_BAD, indent); badCerts += 1; continue uids; } } } } catch (Exception e) { log.add(LogType.MSG_KC_SUB_PRIMARY_BAD_ERR, indent); badCerts += 1; continue; } // if it doesn't, get rid of this! if (!ok) { log.add(LogType.MSG_KC_SUB_PRIMARY_NONE, indent); badCerts += 1; continue; } } // if we already have a cert, and this one is older: skip it if (selfCert != null && cert.getCreationTime().before(selfCert.getCreationTime())) { log.add(LogType.MSG_KC_SUB_DUP, indent); redundantCerts += 1; continue; } selfCert = zert; // it must be a revocation, then (we made sure above) } else { // make sure the certificate checks out try { cert.init(masterKey); if (!cert.verifySignature(masterKey, key)) { log.add(LogType.MSG_KC_SUB_REVOKE_BAD, indent); badCerts += 1; continue; } } catch (PgpGeneralException e) { log.add(LogType.MSG_KC_SUB_REVOKE_BAD_ERR, indent); badCerts += 1; continue; } // If we already have a newer revocation cert, skip this one. if (revocation != null && revocation.getCreationTime().after(cert.getCreationTime())) { log.add(LogType.MSG_KC_SUB_REVOKE_DUP, indent); redundantCerts += 1; continue; } revocation = zert; } } // it is not properly bound? error! if (selfCert == null) { ring = removeSubKey(ring, key); log.add(LogType.MSG_KC_SUB_NO_CERT, indent, KeyFormattingUtils.convertKeyIdToHex(key.getKeyID())); indent -= 1; continue; } // If we have flags, check if the algorithm supports all of them if (selfCert.getHashedSubPackets() != null && selfCert.getHashedSubPackets().hasSubpacket(SignatureSubpacketTags.KEY_FLAGS)) { int flags = ((KeyFlags) selfCert.getHashedSubPackets() .getSubpacket(SignatureSubpacketTags.KEY_FLAGS)).getFlags(); int algo = key.getAlgorithm(); // If this is a signing key, but not a signing algorithm, warn the user if (!isSigningAlgo(algo) && (flags & KeyFlags.SIGN_DATA) == KeyFlags.SIGN_DATA) { log.add(LogType.MSG_KC_SUB_ALGO_BAD_SIGN, indent); } // If this is an encryption key, but not an encryption algorithm, warn the user if (!isEncryptionAlgo(algo) && ((flags & KeyFlags.ENCRYPT_STORAGE) == KeyFlags.ENCRYPT_STORAGE || (flags & KeyFlags.ENCRYPT_COMMS) == KeyFlags.ENCRYPT_COMMS)) { log.add(LogType.MSG_KC_SUB_ALGO_BAD_ENCRYPT, indent); } } // re-add certification modified = PGPPublicKey.addCertification(modified, selfCert); // add revocation, if any if (revocation != null) { modified = PGPPublicKey.addCertification(modified, revocation); } // replace pubkey in keyring ring = replacePublicKey(ring, modified); indent -= 1; } if (badCerts > 0 && redundantCerts > 0) { // multi plural would make this complex, just leaving this as is... log.add(LogType.MSG_KC_SUCCESS_BAD_AND_RED, indent, Integer.toString(badCerts), Integer.toString(redundantCerts)); } else if (badCerts > 0) { log.add(LogType.MSG_KC_SUCCESS_BAD, indent, badCerts); } else if (redundantCerts > 0) { log.add(LogType.MSG_KC_SUCCESS_REDUNDANT, indent, redundantCerts); } else { log.add(LogType.MSG_KC_SUCCESS, indent); } return isSecret() ? new CanonicalizedSecretKeyRing((PGPSecretKeyRing) ring, 1) : new CanonicalizedPublicKeyRing((PGPPublicKeyRing) ring, 0); } /** This operation merges information from a different keyring, returning a combined * UncachedKeyRing. * * The combined keyring contains the subkeys, user ids and user attributes of both input * keyrings, but it does not necessarily have the canonicalized property. * * @param other The UncachedKeyRing to merge. Must not be empty, and of the same masterKeyId * @return A consolidated UncachedKeyRing with the data of both input keyrings. Same type as * this object, or null on error. * */ public UncachedKeyRing merge(UncachedKeyRing other, OperationLog log, int indent) { // This is logged in the calling method to provide more meta info // log.add(isSecret() ? LogType.MSG_MG_SECRET : LogType.MSG_MG_PUBLIC, // indent, KeyFormattingUtils.convertKeyIdToHex(getMasterKeyId())); indent += 1; long masterKeyId = other.getMasterKeyId(); if (getMasterKeyId() != masterKeyId || !Arrays.equals(getFingerprint(), other.getFingerprint())) { log.add(LogType.MSG_MG_ERROR_HETEROGENEOUS, indent); return null; } // remember which certs we already added. this is cheaper than semantic deduplication Set<byte[]> certs = new TreeSet<>(new Comparator<byte[]>() { public int compare(byte[] left, byte[] right) { // check for length equality if (left.length != right.length) { return left.length - right.length; } // compare byte-by-byte for (int i = 0; i < left.length; i++) { if (left[i] != right[i]) { return (left[i] & 0xff) - (right[i] & 0xff); } } // ok they're the same return 0; } }); try { PGPKeyRing result = mRing; PGPKeyRing candidate = other.mRing; // Pre-load all existing certificates for (PGPPublicKey key : new IterableIterator<PGPPublicKey>(result.getPublicKeys())) { for (PGPSignature cert : new IterableIterator<PGPSignature>(key.getSignatures())) { certs.add(cert.getEncoded()); } } // keep track of the number of new certs we add int newCerts = 0; for (PGPPublicKey key : new IterableIterator<PGPPublicKey>(candidate.getPublicKeys())) { final PGPPublicKey resultKey = result.getPublicKey(key.getKeyID()); if (resultKey == null) { log.add(LogType.MSG_MG_NEW_SUBKEY, indent); // special case: if both rings are secret, copy over the secret key if (isSecret() && other.isSecret()) { PGPSecretKey sKey = ((PGPSecretKeyRing) candidate).getSecretKey(key.getKeyID()); result = PGPSecretKeyRing.insertSecretKey((PGPSecretKeyRing) result, sKey); } else { // otherwise, just insert the public key result = replacePublicKey(result, key); } continue; } // Modifiable version of the old key, which we merge stuff into (keep old for comparison) PGPPublicKey modified = resultKey; // Iterate certifications for (PGPSignature cert : new IterableIterator<PGPSignature>(key.getKeySignatures())) { // Don't merge foreign stuff into secret keys if (cert.getKeyID() != masterKeyId && isSecret()) { continue; } byte[] encoded = cert.getEncoded(); // Known cert, skip it if (certs.contains(encoded)) { continue; } certs.add(encoded); modified = PGPPublicKey.addCertification(modified, cert); newCerts += 1; } // If this is a subkey, merge it in and stop here if (!key.isMasterKey()) { if (modified != resultKey) { result = replacePublicKey(result, modified); } continue; } // Copy over all user id certificates for (byte[] rawUserId : new IterableIterator<byte[]>(key.getRawUserIDs())) { @SuppressWarnings("unchecked") Iterator<PGPSignature> signaturesIt = key.getSignaturesForID(rawUserId); // no signatures for this User ID, skip it if (signaturesIt == null) { continue; } for (PGPSignature cert : new IterableIterator<>(signaturesIt)) { // Don't merge foreign stuff into secret keys if (cert.getKeyID() != masterKeyId && isSecret()) { continue; } byte[] encoded = cert.getEncoded(); // Known cert, skip it if (certs.contains(encoded)) { continue; } newCerts += 1; certs.add(encoded); modified = PGPPublicKey.addCertification(modified, rawUserId, cert); } } // Copy over all user attribute certificates for (PGPUserAttributeSubpacketVector vector : new IterableIterator<PGPUserAttributeSubpacketVector>( key.getUserAttributes())) { @SuppressWarnings("unchecked") Iterator<PGPSignature> signaturesIt = key.getSignaturesForUserAttribute(vector); // no signatures for this user attribute attribute, skip it if (signaturesIt == null) { continue; } for (PGPSignature cert : new IterableIterator<>(signaturesIt)) { // Don't merge foreign stuff into secret keys if (cert.getKeyID() != masterKeyId && isSecret()) { continue; } byte[] encoded = cert.getEncoded(); // Known cert, skip it if (certs.contains(encoded)) { continue; } newCerts += 1; certs.add(encoded); modified = PGPPublicKey.addCertification(modified, vector, cert); } } // If anything change, save the updated (sub)key if (modified != resultKey) { result = replacePublicKey(result, modified); } } if (newCerts > 0) { log.add(LogType.MSG_MG_FOUND_NEW, indent, Integer.toString(newCerts)); } else { log.add(LogType.MSG_MG_UNCHANGED, indent); } return new UncachedKeyRing(result); } catch (IOException e) { log.add(LogType.MSG_MG_ERROR_ENCODE, indent); return null; } } public UncachedKeyRing extractPublicKeyRing() throws IOException { if (!isSecret()) { throw new RuntimeException("Tried to extract public keyring from non-secret keyring. " + "This is a programming error and should never happen!"); } Iterator<PGPPublicKey> it = mRing.getPublicKeys(); ByteArrayOutputStream stream = new ByteArrayOutputStream(2048); while (it.hasNext()) { stream.write(it.next().getEncoded()); } return new UncachedKeyRing(new PGPPublicKeyRing(stream.toByteArray(), new JcaKeyFingerprintCalculator())); } /** This method replaces a public key in a keyring. * * This method essentially wraps PGP*KeyRing.insertPublicKey, where the keyring may be of either * the secret or public subclass. * * @return the resulting PGPKeyRing of the same type as the input */ private static PGPKeyRing replacePublicKey(PGPKeyRing ring, PGPPublicKey key) { if (ring instanceof PGPPublicKeyRing) { PGPPublicKeyRing pubRing = (PGPPublicKeyRing) ring; return PGPPublicKeyRing.insertPublicKey(pubRing, key); } else { PGPSecretKeyRing secRing = (PGPSecretKeyRing) ring; PGPSecretKey sKey = secRing.getSecretKey(key.getKeyID()); // if this is a secret key which does not yet occur in the secret ring if (sKey == null) { // generate a stripped secret (sub)key sKey = PGPSecretKey.constructGnuDummyKey(key); } sKey = PGPSecretKey.replacePublicKey(sKey, key); return PGPSecretKeyRing.insertSecretKey(secRing, sKey); } } /** This method removes a subkey in a keyring. * * This method essentially wraps PGP*KeyRing.remove*Key, where the keyring may be of either * the secret or public subclass. * * @return the resulting PGPKeyRing of the same type as the input */ private static PGPKeyRing removeSubKey(PGPKeyRing ring, PGPPublicKey key) { if (ring instanceof PGPPublicKeyRing) { return PGPPublicKeyRing.removePublicKey((PGPPublicKeyRing) ring, key); } else { PGPSecretKey sKey = ((PGPSecretKeyRing) ring).getSecretKey(key.getKeyID()); return PGPSecretKeyRing.removeSecretKey((PGPSecretKeyRing) ring, sKey); } } /** Returns true if the algorithm is of a type which is suitable for signing. */ static boolean isSigningAlgo(int algorithm) { return algorithm == PGPPublicKey.RSA_GENERAL || algorithm == PGPPublicKey.RSA_SIGN || algorithm == PGPPublicKey.DSA || algorithm == PGPPublicKey.ELGAMAL_GENERAL || algorithm == PGPPublicKey.ECDSA; } /** Returns true if the algorithm is of a type which is suitable for encryption. */ static boolean isEncryptionAlgo(int algorithm) { return algorithm == PGPPublicKey.RSA_GENERAL || algorithm == PGPPublicKey.RSA_ENCRYPT || algorithm == PGPPublicKey.ELGAMAL_ENCRYPT || algorithm == PGPPublicKey.ELGAMAL_GENERAL || algorithm == PGPPublicKey.ECDH; } // ONLY TO BE USED FOR TESTING!! @VisibleForTesting public static UncachedKeyRing forTestingOnlyAddDummyLocalSignature(UncachedKeyRing uncachedKeyRing, String passphrase) throws Exception { PGPSecretKeyRing sKR = (PGPSecretKeyRing) uncachedKeyRing.mRing; PBESecretKeyDecryptor keyDecryptor = new JcePBESecretKeyDecryptorBuilder() .setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME).build(passphrase.toCharArray()); PGPPrivateKey masterPrivateKey = sKR.getSecretKey().extractPrivateKey(keyDecryptor); PGPPublicKey masterPublicKey = uncachedKeyRing.mRing.getPublicKey(); // add packet with "pin" notation data PGPContentSignerBuilder signerBuilder = new JcaPGPContentSignerBuilder( masterPrivateKey.getPublicKeyPacket().getAlgorithm(), PgpSecurityConstants.SECRET_KEY_BINDING_SIGNATURE_HASH_ALGO) .setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME); PGPSignatureGenerator sGen = new PGPSignatureGenerator(signerBuilder); { // set subpackets PGPSignatureSubpacketGenerator hashedPacketsGen = new PGPSignatureSubpacketGenerator(); hashedPacketsGen.setExportable(false, false); hashedPacketsGen.setNotationData(false, true, "dummynotationdata", "some data"); sGen.setHashedSubpackets(hashedPacketsGen.generate()); } sGen.init(PGPSignature.DIRECT_KEY, masterPrivateKey); PGPSignature emptySig = sGen.generateCertification(masterPublicKey); masterPublicKey = PGPPublicKey.addCertification(masterPublicKey, emptySig); sKR = PGPSecretKeyRing.insertSecretKey(sKR, PGPSecretKey.replacePublicKey(sKR.getSecretKey(), masterPublicKey)); return new UncachedKeyRing(sKR); } }