/*
* Copyright 2010, 2011 sshj contributors
*
* Licensed 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 net.schmizz.sshj.transport.verification;
import net.schmizz.sshj.common.KeyType;
import net.schmizz.sshj.common.SecurityUtils;
import java.io.Console;
import java.io.File;
import java.io.IOException;
import java.security.PublicKey;
public class ConsoleKnownHostsVerifier
extends OpenSSHKnownHosts {
private static final String YES = "yes";
private static final String NO = "no";
private final Console console;
public ConsoleKnownHostsVerifier(File khFile, Console console)
throws IOException {
super(khFile);
this.console = console;
}
@Override
protected boolean hostKeyUnverifiableAction(String hostname, PublicKey key) {
final KeyType type = KeyType.fromKey(key);
console.printf("The authenticity of host '%s' can't be established.\n" +
"%s key fingerprint is %s.\n", hostname, type, SecurityUtils.getFingerprint(key));
String response = console.readLine("Are you sure you want to continue connecting (yes/no)? ");
while (!(response.equalsIgnoreCase(YES) || response.equalsIgnoreCase(NO))) {
response = console.readLine("Please explicitly enter yes/no: ");
}
if (response.equalsIgnoreCase(YES)) {
try {
entries().add(new SimpleEntry(hostname, key));
write();
console.printf("Warning: Permanently added '%s' (%s) to the list of known hosts.\n", hostname, type);
} catch (IOException e) {
throw new RuntimeException(e);
}
return true;
}
return false;
}
@Override
protected boolean hostKeyChangedAction(Entry entry, String hostname, PublicKey key) {
final KeyType type = KeyType.fromKey(key);
final String fp = SecurityUtils.getFingerprint(key);
final String path = getFile().getAbsolutePath();
console.printf(
"@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\n" +
"@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @\n" +
"@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\n" +
"IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!\n" +
"Someone could be eavesdropping on you right now (man-in-the-middle attack)!\n" +
"It is also possible that the host key has just been changed.\n" +
"The fingerprint for the %s key sent by the remote host is\n" +
"%s.\n" +
"Please contact your system administrator or" +
"add correct host key in %s to get rid of this message.\n",
type, fp, path);
return false;
}
}