1 /* 2 * Copyright (c) 2006-2011 Christian Plattner. All rights reserved. 3 * Please refer to the LICENSE.txt for licensing details. 4 */ 5 import ch.ethz.ssh2.KnownHosts; 6 import ch.ethz.ssh2.ServerHostKeyVerifier; 7 8 class SimpleVerifier implements ServerHostKeyVerifier 9 { 10 KnownHosts database; 11 12 /* 13 * This class is being used by the UsingKnownHosts.java example. 14 */ 15 16 public SimpleVerifier(KnownHosts database) 17 { 18 if (database == null) 19 throw new IllegalArgumentException(); 20 21 this.database = database; 22 } 23 24 public boolean verifyServerHostKey(String hostname, int port, String serverHostKeyAlgorithm, byte[] serverHostKey) 25 throws Exception 26 { 27 int result = database.verifyHostkey(hostname, serverHostKeyAlgorithm, serverHostKey); 28 29 switch (result) 30 { 31 case KnownHosts.HOSTKEY_IS_OK: 32 33 return true; // We are happy 34 35 case KnownHosts.HOSTKEY_IS_NEW: 36 37 // Unknown host? Blindly accept the key and put it into the cache. 38 // Well, you definitely can do better (e.g., ask the user). 39 40 // The following call will ONLY put the key into the memory cache! 41 // To save it in a known hosts file, also call "KnownHosts.addHostkeyToFile(...)" 42 database.addHostkey(new String[] { hostname }, serverHostKeyAlgorithm, serverHostKey); 43 44 return true; 45 46 case KnownHosts.HOSTKEY_HAS_CHANGED: 47 48 // Close the connection if the hostkey has changed. 49 // Better: ask user and add new key to database. 50 return false; 51 52 default: 53 throw new IllegalStateException(); 54 } 55 } 56 }