/*
* 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.server.auth.pubkey;
import java.security.PublicKey;
import java.security.SignatureException;
import java.util.Collection;
import java.util.List;
import org.apache.sshd.common.NamedFactory;
import org.apache.sshd.common.NamedResource;
import org.apache.sshd.common.RuntimeSshException;
import org.apache.sshd.common.SshConstants;
import org.apache.sshd.common.config.keys.KeyUtils;
import org.apache.sshd.common.signature.Signature;
import org.apache.sshd.common.signature.SignatureFactoriesManager;
import org.apache.sshd.common.util.GenericUtils;
import org.apache.sshd.common.util.ValidateUtils;
import org.apache.sshd.common.util.buffer.Buffer;
import org.apache.sshd.common.util.buffer.BufferUtils;
import org.apache.sshd.common.util.buffer.ByteArrayBuffer;
import org.apache.sshd.server.auth.AbstractUserAuth;
import org.apache.sshd.server.session.ServerSession;
/**
* TODO Add javadoc
*
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public class UserAuthPublicKey extends AbstractUserAuth implements SignatureFactoriesManager {
public static final String NAME = UserAuthPublicKeyFactory.NAME;
private List<NamedFactory<Signature>> factories;
public UserAuthPublicKey() {
this(null);
}
public UserAuthPublicKey(List<NamedFactory<Signature>> factories) {
super(NAME);
this.factories = factories; // OK if null/empty
}
@Override
public List<NamedFactory<Signature>> getSignatureFactories() {
return factories;
}
@Override
public void setSignatureFactories(List<NamedFactory<Signature>> factories) {
this.factories = factories;
}
@Override
public Boolean doAuth(Buffer buffer, boolean init) throws Exception {
ValidateUtils.checkTrue(init, "Instance not initialized");
boolean hasSig = buffer.getBoolean();
String alg = buffer.getString();
int oldLim = buffer.wpos();
int oldPos = buffer.rpos();
int len = buffer.getInt();
buffer.wpos(buffer.rpos() + len);
ServerSession session = getServerSession();
String username = getUsername();
PublicKey key = buffer.getRawPublicKey();
Collection<NamedFactory<Signature>> factories =
ValidateUtils.checkNotNullAndNotEmpty(
SignatureFactoriesManager.resolveSignatureFactories(this, session),
"No signature factories for session=%s",
session);
if (log.isDebugEnabled()) {
log.debug("doAuth({}@{}) verify key type={}, factories={}, fingerprint={}",
username, session, alg, NamedResource.getNames(factories), KeyUtils.getFingerPrint(key));
}
Signature verifier = ValidateUtils.checkNotNull(
NamedFactory.create(factories, alg),
"No verifier located for algorithm=%s",
alg);
verifier.initVerifier(key);
buffer.wpos(oldLim);
byte[] sig = hasSig ? buffer.getBytes() : null;
PublickeyAuthenticator authenticator = session.getPublickeyAuthenticator();
if (authenticator == null) {
if (log.isDebugEnabled()) {
log.debug("doAuth({}@{}) key type={}, fingerprint={} - no authenticator",
username, session, alg, KeyUtils.getFingerPrint(key));
}
return Boolean.FALSE;
}
boolean authed;
try {
authed = authenticator.authenticate(username, key, session);
} catch (Error e) {
log.warn("doAuth({}@{}) failed ({}) to consult delegate for {} key={}: {}",
username, session, e.getClass().getSimpleName(), alg, KeyUtils.getFingerPrint(key), e.getMessage());
if (log.isDebugEnabled()) {
log.debug("doAuth(" + username + "@" + session + ") delegate failure details", e);
}
throw new RuntimeSshException(e);
}
if (log.isDebugEnabled()) {
log.debug("doAuth({}@{}) key type={}, fingerprint={} - authentication result: {}",
username, session, alg, KeyUtils.getFingerPrint(key), authed);
}
if (!authed) {
return Boolean.FALSE;
}
if (!hasSig) {
sendPublicKeyResponse(session, username, alg, key, buffer.array(), oldPos, 4 + len, buffer);
return null;
}
buffer.rpos(oldPos);
buffer.wpos(oldPos + 4 + len);
if (!verifySignature(session, getService(), getName(), username, alg, key, buffer, verifier, sig)) {
throw new SignatureException("Key verification failed");
}
if (log.isDebugEnabled()) {
log.debug("doAuth({}@{}) key type={}, fingerprint={} - verified",
username, session, alg, KeyUtils.getFingerPrint(key));
}
return Boolean.TRUE;
}
protected boolean verifySignature(ServerSession session, String service, String name, String username,
String alg, PublicKey key, Buffer buffer, Signature verifier, byte[] sig) throws Exception {
byte[] id = session.getSessionId();
Buffer buf = new ByteArrayBuffer(id.length + username.length() + service.length() + name.length()
+ alg.length() + ByteArrayBuffer.DEFAULT_SIZE + Long.SIZE, false);
buf.putBytes(id);
buf.putByte(SshConstants.SSH_MSG_USERAUTH_REQUEST);
buf.putString(username);
buf.putString(service);
buf.putString(name);
buf.putBoolean(true);
buf.putString(alg);
buf.putBuffer(buffer);
if (log.isTraceEnabled()) {
log.trace("verifySignature({}@{})[{}][{}] key type={}, fingerprint={} - verification data={}",
username, session, service, name, alg, KeyUtils.getFingerPrint(key), buf.toHex());
log.trace("verifySignature({}@{})[{}][{}] key type={}, fingerprint={} - expected signature={}",
username, session, service, name, alg, KeyUtils.getFingerPrint(key), BufferUtils.toHex(sig));
}
verifier.update(buf.array(), buf.rpos(), buf.available());
return verifier.verify(sig);
}
protected void sendPublicKeyResponse(ServerSession session, String username, String alg, PublicKey key,
byte[] keyBlob, int offset, int blobLen, Buffer buffer) throws Exception {
if (log.isDebugEnabled()) {
log.debug("doAuth({}@{}) send SSH_MSG_USERAUTH_PK_OK for key type={}, fingerprint={}",
username, session, alg, KeyUtils.getFingerPrint(key));
}
Buffer buf = session.createBuffer(SshConstants.SSH_MSG_USERAUTH_PK_OK,
GenericUtils.length(alg) + blobLen + Integer.SIZE);
buf.putString(alg);
buf.putRawBytes(keyBlob, offset, blobLen);
session.writePacket(buf);
}
}