/*
* 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.common.keyprovider;
import java.io.IOException;
import java.io.InputStream;
import java.security.GeneralSecurityException;
import java.security.KeyPair;
import java.security.PublicKey;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Objects;
import java.util.TreeMap;
import java.util.TreeSet;
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.ValidateUtils;
import org.apache.sshd.common.util.security.SecurityUtils;
/**
* @param <R> Type of resource from which the {@link KeyPair} is generated
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public abstract class AbstractResourceKeyPairProvider<R> extends AbstractKeyPairProvider {
private FilePasswordProvider passwordFinder;
/*
* NOTE: the map is case insensitive even for Linux, as it is (very) bad
* practice to have 2 key files that differ from one another only in their
* case...
*/
private final Map<String, KeyPair> cacheMap = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
protected AbstractResourceKeyPairProvider() {
super();
}
public FilePasswordProvider getPasswordFinder() {
return passwordFinder;
}
public void setPasswordFinder(FilePasswordProvider passwordFinder) {
this.passwordFinder = passwordFinder;
}
/**
* Checks which of the new resources we already loaded and can keep the
* associated key pair
*
* @param resources The collection of new resources - can be {@code null}/empty
* in which case the cache is cleared
*/
protected void resetCacheMap(Collection<?> resources) {
// if have any cached pairs then see what we can keep from previous load
Collection<String> toDelete = Collections.emptySet();
synchronized (cacheMap) {
if (cacheMap.size() <= 0) {
return; // already empty - nothing to keep
}
if (GenericUtils.isEmpty(resources)) {
cacheMap.clear();
return;
}
for (Object r : resources) {
String resourceKey = ValidateUtils.checkNotNullAndNotEmpty(Objects.toString(r, null), "No resource key value");
if (cacheMap.containsKey(resourceKey)) {
continue;
}
if (toDelete.isEmpty()) {
toDelete = new TreeSet<>(String.CASE_INSENSITIVE_ORDER);
}
if (!toDelete.add(resourceKey)) {
continue; // debug breakpoint
}
}
if (GenericUtils.size(toDelete) > 0) {
toDelete.forEach(cacheMap::remove);
}
}
if (log.isDebugEnabled()) {
log.debug("resetCacheMap(" + resources + ") removed previous cached keys for " + toDelete);
}
}
protected Iterable<KeyPair> loadKeys(final Collection<? extends R> resources) {
if (GenericUtils.isEmpty(resources)) {
return Collections.emptyList();
} else {
return () -> new KeyPairIterator(resources);
}
}
protected KeyPair doLoadKey(R resource) throws IOException, GeneralSecurityException {
String resourceKey = ValidateUtils.checkNotNullAndNotEmpty(Objects.toString(resource, null), "No resource string value");
KeyPair kp;
synchronized (cacheMap) {
// check if lucky enough to have already loaded this file
kp = cacheMap.get(resourceKey);
}
if (kp != null) {
if (log.isTraceEnabled()) {
PublicKey key = kp.getPublic();
log.trace("doLoadKey({}) use cached key {}-{}",
resourceKey, KeyUtils.getKeyType(key), KeyUtils.getFingerPrint(key));
}
return kp;
}
kp = doLoadKey(resourceKey, resource, getPasswordFinder());
if (kp != null) {
boolean reusedKey;
synchronized (cacheMap) {
// if somebody else beat us to it, use the cached key - just in case file contents changed
reusedKey = cacheMap.containsKey(resourceKey);
if (reusedKey) {
kp = cacheMap.get(resourceKey);
} else {
cacheMap.put(resourceKey, kp);
}
}
if (log.isDebugEnabled()) {
PublicKey key = kp.getPublic();
log.debug("doLoadKey({}) {} {}-{}",
resourceKey, reusedKey ? "re-loaded" : "loaded",
KeyUtils.getKeyType(key), KeyUtils.getFingerPrint(key));
}
} else {
if (log.isDebugEnabled()) {
log.debug("doLoadKey({}) no key loaded", resourceKey);
}
}
return kp;
}
protected KeyPair doLoadKey(String resourceKey, R resource, FilePasswordProvider provider) throws IOException, GeneralSecurityException {
try (InputStream inputStream = openKeyPairResource(resourceKey, resource)) {
return doLoadKey(resourceKey, inputStream, provider);
}
}
protected abstract InputStream openKeyPairResource(String resourceKey, R resource) throws IOException;
protected KeyPair doLoadKey(String resourceKey, InputStream inputStream, FilePasswordProvider provider)
throws IOException, GeneralSecurityException {
return SecurityUtils.loadKeyPairIdentity(resourceKey, inputStream, provider);
}
protected class KeyPairIterator implements Iterator<KeyPair> {
private final Iterator<? extends R> iterator;
private KeyPair nextKeyPair;
private boolean nextKeyPairSet;
protected KeyPairIterator(Collection<? extends R> resources) {
iterator = resources.iterator();
}
@Override
public boolean hasNext() {
return nextKeyPairSet || setNextObject();
}
@Override
public KeyPair next() {
if (!nextKeyPairSet) {
if (!setNextObject()) {
throw new NoSuchElementException("Out of files to try");
}
}
nextKeyPairSet = false;
return nextKeyPair;
}
@Override
public void remove() {
throw new UnsupportedOperationException("loadKeys(files) Iterator#remove() N/A");
}
@SuppressWarnings("synthetic-access")
private boolean setNextObject() {
while (iterator.hasNext()) {
R r = iterator.next();
try {
nextKeyPair = doLoadKey(r);
} catch (Throwable e) {
log.warn("Failed (" + e.getClass().getSimpleName() + ")"
+ " to load key resource=" + r + ": " + e.getMessage());
if (log.isDebugEnabled()) {
log.debug("Key resource=" + r + " load failure details", e);
}
nextKeyPair = null;
continue;
}
if (nextKeyPair != null) {
nextKeyPairSet = true;
return true;
}
}
return false;
}
}
}