EncryptionKey sessionKey = null;
try {
Ticket t = new Ticket(encodedTicket);
EncryptedData encPart = t.encPart;
PrincipalName ticketSname = t.sname;
Realm ticketRealm = t.realm;
String serverPrincipal = serverKeys[0].getPrincipal().getName();
/*
* permission to access and use the secret key of the Kerberized
* "host" service is done in ServerHandshaker.getKerberosKeys()
* to ensure server has the permission to use the secret key
* before promising the client
*/
// Check that ticket Sname matches serverPrincipal
String ticketPrinc = ticketSname.toString().concat("@" +
ticketRealm.toString());
if (!ticketPrinc.equals(serverPrincipal)) {
if (debug != null && Debug.isOn("handshake"))
System.out.println("Service principal in Ticket does not"
+ " match associated principal in KerberosKey");
throw new IOException("Server principal is " +
serverPrincipal + " but ticket is for " +
ticketPrinc);
}
// See if we have the right key to decrypt the ticket to get
// the session key.
int encPartKeyType = encPart.getEType();
Integer encPartKeyVersion = encPart.getKeyVersionNumber();
KerberosKey dkey = null;
try {
dkey = findKey(encPartKeyType, encPartKeyVersion, serverKeys);
} catch (KrbException ke) { // a kvno mismatch
throw new IOException(
"Cannot find key matching version number", ke);
}
if (dkey == null) {
// %%% Should print string repr of etype
throw new IOException(
"Cannot find key of appropriate type to decrypt ticket - need etype " +
encPartKeyType);
}
EncryptionKey secretKey = new EncryptionKey(
encPartKeyType,
dkey.getEncoded());
// Decrypt encPart using server's secret key
byte[] bytes = encPart.decrypt(secretKey, KeyUsage.KU_TICKET);
// Reset data stream after decryption, remove redundant bytes
byte[] temp = encPart.reset(bytes);
EncTicketPart encTicketPart = new EncTicketPart(temp);
// Record the Kerberos Principals
peerPrincipal =
new KerberosPrincipal(encTicketPart.cname.getName());