/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.sshd.client.config.keys;
import java.io.IOException;
import java.nio.file.Path;
import java.security.GeneralSecurityException;
import java.security.KeyPair;
import java.security.PublicKey;
import java.util.Objects;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.Supplier;
import org.apache.sshd.common.config.keys.FilePasswordProvider;
import org.apache.sshd.common.config.keys.KeyUtils;
import org.apache.sshd.common.util.GenericUtils;
import org.apache.sshd.common.util.Pair;
import org.apache.sshd.common.util.io.IoUtils;
import org.apache.sshd.common.util.io.ModifiableFileWatcher;
/**
* A {@link ClientIdentityProvider} that watches a given key file re-loading
* its contents if it is ever modified, deleted or (re-)created
*
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public class ClientIdentityFileWatcher extends ModifiableFileWatcher implements ClientIdentityProvider {
private final AtomicReference<KeyPair> identityHolder = new AtomicReference<>(null);
private final Supplier<ClientIdentityLoader> loaderHolder;
private final Supplier<FilePasswordProvider> providerHolder;
private final boolean strict;
public ClientIdentityFileWatcher(Path path, ClientIdentityLoader loader, FilePasswordProvider provider) {
this(path, loader, provider, true);
}
public ClientIdentityFileWatcher(Path path, ClientIdentityLoader loader, FilePasswordProvider provider, boolean strict) {
this(path,
GenericUtils.supplierOf(Objects.requireNonNull(loader, "No client identity loader")),
GenericUtils.supplierOf(Objects.requireNonNull(provider, "No password provider")),
strict);
}
public ClientIdentityFileWatcher(Path path, Supplier<ClientIdentityLoader> loader, Supplier<FilePasswordProvider> provider) {
this(path, loader, provider, true);
}
public ClientIdentityFileWatcher(Path path, Supplier<ClientIdentityLoader> loader, Supplier<FilePasswordProvider> provider, boolean strict) {
super(path);
this.loaderHolder = Objects.requireNonNull(loader, "No client identity loader");
this.providerHolder = Objects.requireNonNull(provider, "No password provider");
this.strict = strict;
}
public final boolean isStrict() {
return strict;
}
public final ClientIdentityLoader getClientIdentityLoader() {
return loaderHolder.get();
}
public final FilePasswordProvider getFilePasswordProvider() {
return providerHolder.get();
}
@Override
public KeyPair getClientIdentity() throws IOException, GeneralSecurityException {
if (checkReloadRequired()) {
KeyPair kp = identityHolder.getAndSet(null); // start fresh
Path path = getPath();
if (exists()) {
KeyPair id = reloadClientIdentity(path);
if (!KeyUtils.compareKeyPairs(kp, id)) {
if (log.isDebugEnabled()) {
log.debug("getClientIdentity({}) identity {}", path, (kp == null) ? "loaded" : "re-loaded");
}
}
updateReloadAttributes();
identityHolder.set(id);
}
}
return identityHolder.get();
}
protected KeyPair reloadClientIdentity(Path path) throws IOException, GeneralSecurityException {
if (isStrict()) {
Pair<String, Object> violation = KeyUtils.validateStrictKeyFilePermissions(path, IoUtils.EMPTY_LINK_OPTIONS);
if (violation != null) {
if (log.isDebugEnabled()) {
log.debug("reloadClientIdentity({}) ignore due to {}", path, violation.getFirst());
}
return null;
}
}
String location = path.toString();
ClientIdentityLoader idLoader = Objects.requireNonNull(getClientIdentityLoader(), "No client identity loader");
if (idLoader.isValidLocation(location)) {
KeyPair kp = idLoader.loadClientIdentity(location, Objects.requireNonNull(getFilePasswordProvider(), "No file password provider"));
if (log.isTraceEnabled()) {
PublicKey key = (kp == null) ? null : kp.getPublic();
if (key != null) {
log.trace("reloadClientIdentity({}) loaded {}-{}",
location, KeyUtils.getKeyType(key), KeyUtils.getFingerPrint(key));
} else {
log.trace("reloadClientIdentity({}) no key loaded", location);
}
}
return kp;
}
if (log.isDebugEnabled()) {
log.debug("reloadClientIdentity({}) invalid location", location);
}
return null;
}
}