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* 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.io.StreamCorruptedException;
import java.security.GeneralSecurityException;
import java.security.KeyPair;
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.NamedResource;
import org.apache.sshd.common.config.keys.FilePasswordProvider;
import org.apache.sshd.common.session.SessionContext;
import org.apache.sshd.common.util.GenericUtils;
import org.apache.sshd.common.util.ValidateUtils;
import org.apache.sshd.common.util.io.resource.IoResource;
import org.apache.sshd.common.util.io.resource.ResourceStreamProvider;
import org.apache.sshd.common.util.security.SecurityUtils;
/**
* @param Type of resource from which the {@link KeyPair} is generated
* @author Apache MINA SSHD Project
*/
public abstract class AbstractResourceKeyPairProvider 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> 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 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({}) removed previous cached keys for {}", resources, toDelete);
}
}
protected Iterable loadKeys(SessionContext session, Collection resources) {
if (GenericUtils.isEmpty(resources)) {
return Collections.emptyList();
} else {
return () -> new KeyPairIterator(session, resources);
}
}
protected IoResource getIoResource(SessionContext session, R resource) {
return IoResource.forResource(resource);
}
protected Iterable doLoadKeys(SessionContext session, R resource)
throws IOException, GeneralSecurityException {
IoResource ioResource
= ValidateUtils.checkNotNull(getIoResource(session, resource), "No I/O resource available for %s", resource);
String resourceKey
= ValidateUtils.checkNotNullAndNotEmpty(ioResource.getName(), "No resource string value for %s", resource);
Iterable ids;
synchronized (cacheMap) {
// check if lucky enough to have already loaded this file
ids = cacheMap.get(resourceKey);
}
if (ids != null) {
if (log.isTraceEnabled()) {
log.trace("doLoadKeys({}) using cached identifiers", resourceKey);
}
return ids;
}
ids = doLoadKeys(session, ioResource, resource, getPasswordFinder());
if (ids != 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) {
ids = cacheMap.get(resourceKey);
} else {
cacheMap.put(resourceKey, ids);
}
}
if (log.isDebugEnabled()) {
log.debug("doLoadKeys({}) {}", resourceKey, reusedKey ? "re-loaded" : "loaded");
}
} else {
if (log.isDebugEnabled()) {
log.debug("doLoadKeys({}) no key loaded", resourceKey);
}
}
return ids;
}
protected Iterable doLoadKeys(
SessionContext session, NamedResource resourceKey, R resource, FilePasswordProvider provider)
throws IOException, GeneralSecurityException {
try (InputStream inputStream = openKeyPairResource(session, resourceKey, resource)) {
return doLoadKeys(session, resourceKey, inputStream, provider);
}
}
protected InputStream openKeyPairResource(
SessionContext session, NamedResource resourceKey, R resource)
throws IOException {
if (resourceKey instanceof ResourceStreamProvider) {
return ((ResourceStreamProvider) resourceKey).openInputStream();
}
throw new StreamCorruptedException("Cannot open resource data for " + resource);
}
protected Iterable doLoadKeys(
SessionContext session, NamedResource resourceKey, InputStream inputStream, FilePasswordProvider provider)
throws IOException, GeneralSecurityException {
return SecurityUtils.loadKeyPairIdentities(session, resourceKey, inputStream, provider);
}
protected class KeyPairIterator implements Iterator {
protected final SessionContext session;
private final Iterator iterator;
private Iterator currentIdentities;
private KeyPair nextKeyPair;
private boolean nextKeyPairSet;
protected KeyPairIterator(SessionContext session, Collection resources) {
this.session = session;
this.iterator = resources.iterator();
}
@Override
public boolean hasNext() {
return nextKeyPairSet || setNextObject();
}
@Override
public KeyPair next() {
if (!nextKeyPairSet && !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() {
nextKeyPair = KeyIdentityProvider.exhaustCurrentIdentities(currentIdentities);
if (nextKeyPair != null) {
nextKeyPairSet = true;
return true;
}
while (iterator.hasNext()) {
R r = iterator.next();
try {
Iterable ids = doLoadKeys(session, r);
currentIdentities = (ids == null) ? null : ids.iterator();
nextKeyPair = KeyIdentityProvider.exhaustCurrentIdentities(currentIdentities);
} catch (Throwable e) {
warn("Failed ({}) to load key resource={}: {}", e.getClass().getSimpleName(), r, e.getMessage(), e);
nextKeyPair = null;
continue;
}
if (nextKeyPair != null) {
nextKeyPairSet = true;
return true;
}
}
return false;
}
}
}