/*
* 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.auth;
import org.apache.sshd.agent.SshAgent;
import org.apache.sshd.agent.AgentClient;
import org.apache.sshd.client.UserAuth;
import org.apache.sshd.client.session.ClientSessionImpl;
import org.apache.sshd.common.KeyPairProvider;
import org.apache.sshd.common.SshConstants;
import org.apache.sshd.common.util.Buffer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.security.PublicKey;
import java.security.interfaces.RSAPublicKey;
import java.util.Iterator;
/**
* Authentication delegating to an SSH agent
*/
public class UserAuthAgent implements UserAuth {
protected final Logger log = LoggerFactory.getLogger(getClass());
private final ClientSessionImpl session;
private final String username;
private final SshAgent agent;
private Iterator<SshAgent.Pair<PublicKey, String>> keys;
public UserAuthAgent(ClientSessionImpl session, String username) throws IOException {
this.session = session;
this.username = username;
String authSocket = session.getFactoryManager().getProperties().get(SshAgent.SSH_AUTHSOCKET_ENV_NAME);
SshAgent agent = new AgentClient(authSocket);
this.agent = agent;
keys = agent.getIdentities().iterator();
sendNextKey();
}
protected void sendNextKey() throws IOException {
sendNextKey(keys.next().getFirst());
}
protected void sendNextKey(PublicKey key) throws IOException {
try {
log.info("Send SSH_MSG_USERAUTH_REQUEST for publickey");
Buffer buffer = session.createBuffer(SshConstants.Message.SSH_MSG_USERAUTH_REQUEST, 0);
int pos1 = buffer.wpos() - 1;
buffer.putString(username);
buffer.putString("ssh-connection");
buffer.putString("publickey");
buffer.putByte((byte) 1);
buffer.putString((key instanceof RSAPublicKey) ? KeyPairProvider.SSH_RSA : KeyPairProvider.SSH_DSS);
int pos2 = buffer.wpos();
buffer.putPublicKey(key);
Buffer bs = new Buffer();
bs.putString(session.getKex().getH());
bs.putCommand(SshConstants.Message.SSH_MSG_USERAUTH_REQUEST);
bs.putString(username);
bs.putString("ssh-connection");
bs.putString("publickey");
bs.putByte((byte) 1);
bs.putString((key instanceof RSAPublicKey) ? KeyPairProvider.SSH_RSA : KeyPairProvider.SSH_DSS);
bs.putPublicKey(key);
Buffer bs2 = new Buffer();
bs2.putString((key instanceof RSAPublicKey) ? KeyPairProvider.SSH_RSA : KeyPairProvider.SSH_DSS);
bs2.putBytes(agent.sign(key, bs.getCompactData()));
buffer.putBytes(bs2.array(), bs2.rpos(), bs2.available());
session.writePacket(buffer);
} catch (IOException e) {
throw e;
} catch (Exception e) {
throw (IOException) new IOException("Error performing public key authentication").initCause(e);
}
}
public Result next(Buffer buffer) throws IOException {
SshConstants.Message cmd = buffer.getCommand();
log.info("Received {}", cmd);
if (cmd == SshConstants.Message.SSH_MSG_USERAUTH_SUCCESS) {
return Result.Success;
} if (cmd == SshConstants.Message.SSH_MSG_USERAUTH_FAILURE) {
if (keys.hasNext()) {
sendNextKey(keys.next().getFirst());
return Result.Continued;
}
return Result.Failure;
} else {
// TODO: check packets
return Result.Continued;
}
}
}