KDC.java revision 678
/*
* Copyright 2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.net.*;
import java.io.*;
import java.lang.reflect.Method;
import java.security.SecureRandom;
import java.util.*;
import java.util.concurrent.*;
import sun.security.krb5.*;
import sun.security.krb5.internal.*;
import sun.security.krb5.internal.crypto.KeyUsage;
import sun.security.krb5.internal.ktab.KeyTab;
import sun.security.util.DerInputStream;
import sun.security.util.DerOutputStream;
import sun.security.util.DerValue;
/**
* A KDC server.
* <p>
* Features:
* <ol>
* <li> Supports TCP and UDP
* <li> Supports AS-REQ and TGS-REQ
* <li> Principal db and other settings hard coded in application
* <li> Options, say, request preauth or not
* </ol>
* Side effects:
* <ol>
* <li> The Sun-internal class <code>sun.security.krb5.Config</code> is a
* singleton and initialized according to Kerberos settings (krb5.conf and
* java.security.krb5.* system properties). This means once it's initialized
* it will not automatically notice any changes to these settings (or file
* changes of krb5.conf). The KDC class normally does not touch these
* settings (except for the <code>writeKtab()</code> method). However, to make
* sure nothing ever goes wrong, if you want to make any changes to these
* settings after calling a KDC method, call <code>Config.refresh()</code> to
* make sure your changes are reflected in the <code>Config</code> object.
* </ol>
* Issues and TODOs:
* <ol>
* <li> Generates krb5.conf to be used on another machine, currently the kdc is
* always localhost
* <li> More options to KDC, say, error output, say, response nonce !=
* request nonce
* </ol>
* Note: This program uses internal krb5 classes (including reflection to
* access private fields and methods).
* <p>
* Usages:
* <p>
* 1. Init and start the KDC:
* <pre>
* KDC kdc = KDC.create("REALM.NAME", port, isDaemon);
* KDC kdc = KDC.create("REALM.NAME");
* </pre>
* Here, <code>port</code> is the UDP and TCP port number the KDC server
* listens on. If zero, a random port is chosen, which you can use getPort()
* later to retrieve the value.
* <p>
* If <code>isDaemon</code> is true, the KDC worker threads will be daemons.
* <p>
* The shortcut <code>KDC.create("REALM.NAME")</code> has port=0 and
* isDaemon=false, and is commonly used in an embedded KDC.
* <p>
* 2. Adding users:
* <pre>
* kdc.addPrincipal(String principal_name, char[] password);
* kdc.addPrincipalRandKey(String principal_name);
* </pre>
* A service principal's name should look like "host/f.q.d.n". The second form
* generates a random key. To expose this key, call <code>writeKtab()</code> to
* save the keys into a keytab file.
* <p>
* Note that you need to add the principal name krbtgt/REALM.NAME yourself.
* <p>
* Note that you can safely add a principal at any time after the KDC is
* started and before a user requests info on this principal.
* <p>
* 3. Other public methods:
* <ul>
* <li> <code>getPort</code>: Returns the port number the KDC uses
* <li> <code>getRealm</code>: Returns the realm name
* <li> <code>writeKtab</code>: Writes all principals' keys into a keytab file
* <li> <code>saveConfig</code>: Saves a krb5.conf file to access this KDC
* <li> <code>setOption</code>: Sets various options
* </ul>
* Read the javadoc for details. Lazy developer can use <code>OneKDC</code>
* directly.
*/
public class KDC {
// Under the hood.
// The random generator to generate random keys (including session keys)
private static SecureRandom secureRandom = new SecureRandom();
// Principal db
private Map<String,char[]> passwords = new HashMap<String,char[]>();
// Realm name
private String realm;
// The request/response job queue
private BlockingQueue<Job> q = new ArrayBlockingQueue<Job>(100);
// Service port number
private int port;
// Options
private Map<Option,Object> options = new HashMap<Option,Object>();
/**
* Option names, to be expanded forever.
*/
public static enum Option {
/**
* Whether pre-authentication is required. Default Boolean.TRUE
*/
PREAUTH_REQUIRED,
};
/**
* A standalone KDC server.
* @param args
* @throws java.lang.Exception
*/
public static void main(String[] args) throws Exception {
if (args.length > 0) {
if (args[0].equals("-help") || args[0].equals("--help")) {
System.out.println("Usage:");
System.out.println(" java " + KDC.class + " " +
"Start KDC on port 8888");
return;
}
}
KDC kdc = create("RABBIT.HOLE", 8888, false);
kdc.addPrincipal("dummy", "bogus".toCharArray());
kdc.addPrincipal("foo", "bar".toCharArray());
kdc.addPrincipalRandKey("krbtgt/" + kdc.realm);
kdc.addPrincipalRandKey("server/localhost");
kdc.addPrincipalRandKey("backend/localhost");
}
/**
* Creates and starts a KDC running as a daemon on a random port.
* @param realm the realm name
* @return the running KDC instance
* @throws java.io.IOException for any socket creation error
*/
public static KDC create(String realm) throws IOException {
return create(realm, 0, true);
}
/**
* Creates and starts a KDC server.
* @param realm the realm name
* @param port the TCP and UDP port to listen to. A random port will to
* chosen if zero.
* @param asDaemon if true, KDC threads will be daemons. Otherwise, not.
* @return the running KDC instance
* @throws java.io.IOException for any socket creation error
*/
public static KDC create(String realm, int port, boolean asDaemon) throws IOException {
return new KDC(realm, port, asDaemon);
}
/**
* Sets an option
* @param key the option name
* @param obj the value
*/
public void setOption(Option key, Object value) {
options.put(key, value);
}
/**
* Write all principals' keys into a keytab file. Note that the keys for
* the krbtgt principal for this realm will not be written.
* <p>
* Attention: This method references krb5.conf settings. If you need to
* setup krb5.conf later, please call <code>Config.refresh()</code> after
* the new setting. For example:
* <pre>
* kdc.writeKtab("/etc/kdc/ktab"); // Config is initialized,
* System.setProperty("java.security.krb5.conf", "/home/mykrb5.conf");
* Config.refresh();
* </pre>
*
* Inside this method there are 2 places krb5.conf is used:
* <ol>
* <li> (Fatal) Generating keys: EncryptionKey.acquireSecretKeys
* <li> (Has workaround) Creating PrincipalName
* </ol>
* @param tab The keytab filename to write to.
* @throws java.io.IOException for any file output error
* @throws sun.security.krb5.KrbException for any realm and/or principal
* name error.
*/
public void writeKtab(String tab) throws IOException, KrbException {
KeyTab ktab = KeyTab.create(tab);
for (String name : passwords.keySet()) {
if (name.equals("krbtgt/" + realm)) {
continue;
}
ktab.addEntry(new PrincipalName(name + "@" + realm,
name.indexOf('/') < 0 ?
PrincipalName.KRB_NT_UNKNOWN :
PrincipalName.KRB_NT_SRV_HST), passwords.get(name));
}
ktab.save();
}
/**
* Adds a new principal to this realm with a given password.
* @param user the principal's name. For a service principal, use the
* form of host/f.q.d.n
* @param pass the password for the principal
*/
public void addPrincipal(String user, char[] pass) {
passwords.put(user, pass);
}
/**
* Adds a new principal to this realm with a random password
* @param user the principal's name. For a service principal, use the
* form of host/f.q.d.n
*/
public void addPrincipalRandKey(String user) {
passwords.put(user, randomPassword());
}
/**
* Returns the name of this realm
* @return the name of this realm
*/
public String getRealm() {
return realm;
}
/**
* Writes a krb5.conf for one or more KDC that includes KDC locations for
* each realm and the default realm name. You can also add extra strings
* into the file. The method should be called like:
* <pre>
* KDC.saveConfig("krb5.conf", kdc1, kdc2, ..., line1, line2, ...);
* </pre>
* Here you can provide one or more kdc# and zero or more line# arguments.
* The line# will be put after [libdefaults] and before [realms]. Therefore
* you can append new lines into [libdefaults] and/or create your new
* stanzas as well. Note that a newline character will be appended to
* each line# argument.
* <p>
* For example:
* <pre>
* KDC.saveConfig("krb5.conf", this);
* </pre>
* generates:
* <pre>
* [libdefaults]
* default_realm = REALM.NAME
*
* [realms]
* REALM.NAME = {
* kdc = localhost:port_number
* }
* </pre>
*
* Another example:
* <pre>
* KDC.saveConfig("krb5.conf", kdc1, kdc2, "forwardable = true", "",
* "[domain_realm]",
* ".kdc1.com = KDC1.NAME");
* </pre>
* generates:
* <pre>
* [libdefaults]
* default_realm = KDC1.NAME
* forwardable = true
*
* [domain_realm]
* .kdc1.com = KDC1.NAME
*
* [realms]
* KDC1.NAME = {
* kdc = localhost:port1
* }
* KDC2.NAME = {
* kdc = localhost:port2
* }
* </pre>
* @param file the name of the file to write into
* @param kdc the first (and default) KDC
* @param more more KDCs or extra lines (in their appearing order) to
* insert into the krb5.conf file. This method reads each argument's type
* to determine what it's for. This argument can be empty.
* @throws java.io.IOException for any file output error
*/
public static void saveConfig(String file, KDC kdc, Object... more)
throws IOException {
File f = new File(file);
StringBuffer sb = new StringBuffer();
sb.append("[libdefaults]\ndefault_realm = ");
sb.append(kdc.realm);
sb.append("\n");
for (Object o: more) {
if (o instanceof String) {
sb.append(o);
sb.append("\n");
}
}
sb.append("\n[realms]\n");
sb.append(realmLineForKDC(kdc));
for (Object o: more) {
if (o instanceof KDC) {
sb.append(realmLineForKDC((KDC)o));
}
}
FileOutputStream fos = new FileOutputStream(f);
fos.write(sb.toString().getBytes());
fos.close();
}
/**
* Returns the service port of the KDC server.
* @return the KDC service port
*/
public int getPort() {
return port;
}
// Private helper methods
/**
* Private constructor, cannot be called outside.
* @param realm
*/
private KDC(String realm) {
this.realm = realm;
}
/**
* A constructor that starts the KDC service also.
*/
protected KDC(String realm, int port, boolean asDaemon)
throws IOException {
this(realm);
startServer(port, asDaemon);
}
/**
* Generates a 32-char random password
* @return the password
*/
private static char[] randomPassword() {
char[] pass = new char[32];
for (int i=0; i<32; i++)
pass[i] = (char)secureRandom.nextInt();
return pass;
}
/**
* Generates a random key for the given encryption type.
* @param eType the encryption type
* @return the generated key
* @throws sun.security.krb5.KrbException for unknown/unsupported etype
*/
private static EncryptionKey generateRandomKey(int eType)
throws KrbException {
// Is 32 enough for AES256? I should have generated the keys directly
// but different cryptos have different rules on what keys are valid.
char[] pass = randomPassword();
String algo;
switch (eType) {
case EncryptedData.ETYPE_DES_CBC_MD5: algo = "DES"; break;
case EncryptedData.ETYPE_DES3_CBC_HMAC_SHA1_KD: algo = "DESede"; break;
case EncryptedData.ETYPE_AES128_CTS_HMAC_SHA1_96: algo = "AES128"; break;
case EncryptedData.ETYPE_ARCFOUR_HMAC: algo = "ArcFourHMAC"; break;
case EncryptedData.ETYPE_AES256_CTS_HMAC_SHA1_96: algo = "AES256"; break;
default: algo = "DES"; break;
}
return new EncryptionKey(pass, "NOTHING", algo); // Silly
}
/**
* Returns the password for a given principal
* @param p principal
* @return the password
* @throws sun.security.krb5.KrbException when the principal is not inside
* the database.
*/
private char[] getPassword(PrincipalName p) throws KrbException {
char[] pass = passwords.get(p.getNameString());
if (pass == null) {
throw new KrbException(Krb5.KDC_ERR_C_PRINCIPAL_UNKNOWN);
}
return pass;
}
/**
* Returns the salt string for the principal. For normal users, the
* concatenation for the realm name and the sections of the principal;
* for krgtgt/A@B and krbtgt/B@A, always return AB (so that inter-realm
* principals have the same key).
* @param p principal
* @return the salt
*/
private String getSalt(PrincipalName p) {
String[] ns = p.getNameStrings();
if (ns[0].equals("krbtgt") && ns.length > 1) {
// Shared cross-realm keys must be the same
if (ns[1].compareTo(realm) < 0) {
return ns[1] + realm;
} else {
return realm + ns[1];
}
} else {
String s = getRealm();
for (String n: p.getNameStrings()) {
s += n;
}
return s;
}
}
/**
* Returns the key for a given principal of the given encryption type
* @param p the principal
* @param etype the encryption type
* @return the key
* @throws sun.security.krb5.KrbException for unknown/unsupported etype
*/
private EncryptionKey keyForUser(PrincipalName p, int etype) throws KrbException {
try {
// Do not call EncryptionKey.acquireSecretKeys(), otherwise
// the krb5.conf config file would be loaded.
Method stringToKey = EncryptionKey.class.getDeclaredMethod("stringToKey", char[].class, String.class, byte[].class, Integer.TYPE);
stringToKey.setAccessible(true);
return new EncryptionKey((byte[]) stringToKey.invoke(null, getPassword(p), getSalt(p), null, etype), etype, null);
} catch (InvocationTargetException ex) {
KrbException ke = (KrbException)ex.getCause();
throw ke;
} catch (Exception e) {
throw new RuntimeException(e); // should not happen
}
}
/**
* Processes an incoming request and generates a response.
* @param in the request
* @return the response
* @throws java.lang.Exception for various errors
*/
private byte[] processMessage(byte[] in) throws Exception {
if ((in[0] & 0x1f) == Krb5.KRB_AS_REQ)
return processAsReq(in);
else
return processTgsReq(in);
}
/**
* Processes a TGS_REQ and generates a TGS_REP (or KRB_ERROR)
* @param in the request
* @return the response
* @throws java.lang.Exception for various errors
*/
private byte[] processTgsReq(byte[] in) throws Exception {
TGSReq tgsReq = new TGSReq(in);
try {
System.out.println(realm + "> " + tgsReq.reqBody.cname +
" sends TGS-REQ for " +
tgsReq.reqBody.sname);
KDCReqBody body = tgsReq.reqBody;
int etype = 0;
// Reflection: PAData[] pas = tgsReq.pAData;
Field f = KDCReq.class.getDeclaredField("pAData");
f.setAccessible(true);
PAData[] pas = (PAData[])f.get(tgsReq);
Ticket tkt = null;
EncTicketPart etp = null;
if (pas == null || pas.length == 0) {
throw new KrbException(Krb5.KDC_ERR_PADATA_TYPE_NOSUPP);
} else {
for (PAData pa: pas) {
if (pa.getType() == Krb5.PA_TGS_REQ) {
APReq apReq = new APReq(pa.getValue());
EncryptedData ed = apReq.authenticator;
tkt = apReq.ticket;
etype = tkt.encPart.getEType();
EncryptionKey kkey = null;
if (!tkt.realm.toString().equals(realm)) {
if (tkt.sname.getNameString().equals("krbtgt/" + realm)) {
kkey = keyForUser(new PrincipalName("krbtgt/" + tkt.realm.toString(), realm), etype);
}
} else {
kkey = keyForUser(tkt.sname, etype);
}
byte[] bb = tkt.encPart.decrypt(kkey, KeyUsage.KU_TICKET);
DerInputStream derIn = new DerInputStream(bb);
DerValue der = derIn.getDerValue();
etp = new EncTicketPart(der.toByteArray());
}
}
if (tkt == null) {
throw new KrbException(Krb5.KDC_ERR_PADATA_TYPE_NOSUPP);
}
}
EncryptionKey skey = keyForUser(body.sname, etype);
if (skey == null) {
throw new KrbException(Krb5.KDC_ERR_SUMTYPE_NOSUPP); // TODO
}
// Session key for original ticket, TGT
EncryptionKey ckey = etp.key;
// Session key for session with the service
EncryptionKey key = generateRandomKey(etype);
// Check time, TODO
KerberosTime till = body.till;
if (till == null) {
throw new KrbException(Krb5.KDC_ERR_NEVER_VALID); // TODO
} else if (till.isZero()) {
till = new KerberosTime(new Date().getTime() + 1000 * 3600 * 11);
}
boolean[] bFlags = new boolean[Krb5.TKT_OPTS_MAX+1];
if (body.kdcOptions.get(KDCOptions.FORWARDABLE)) {
bFlags[Krb5.TKT_OPTS_FORWARDABLE] = true;
}
if (body.kdcOptions.get(KDCOptions.FORWARDED) ||
etp.flags.get(Krb5.TKT_OPTS_FORWARDED)) {
bFlags[Krb5.TKT_OPTS_FORWARDED] = true;
}
if (body.kdcOptions.get(KDCOptions.RENEWABLE)) {
bFlags[Krb5.TKT_OPTS_RENEWABLE] = true;
//renew = new KerberosTime(new Date().getTime() + 1000 * 3600 * 24 * 7);
}
if (body.kdcOptions.get(KDCOptions.PROXIABLE)) {
bFlags[Krb5.TKT_OPTS_PROXIABLE] = true;
}
if (body.kdcOptions.get(KDCOptions.POSTDATED)) {
bFlags[Krb5.TKT_OPTS_POSTDATED] = true;
}
if (body.kdcOptions.get(KDCOptions.ALLOW_POSTDATE)) {
bFlags[Krb5.TKT_OPTS_MAY_POSTDATE] = true;
}
bFlags[Krb5.TKT_OPTS_INITIAL] = true;
TicketFlags tFlags = new TicketFlags(bFlags);
EncTicketPart enc = new EncTicketPart(
tFlags,
key,
etp.crealm,
etp.cname,
new TransitedEncoding(1, new byte[0]), // TODO
new KerberosTime(new Date()),
body.from,
till, body.rtime,
body.addresses,
null);
Ticket t = new Ticket(
body.crealm,
body.sname,
new EncryptedData(skey, enc.asn1Encode(), KeyUsage.KU_TICKET)
);
EncTGSRepPart enc_part = new EncTGSRepPart(
key,
new LastReq(new LastReqEntry[]{
new LastReqEntry(0, new KerberosTime(new Date().getTime() - 10000))
}),
body.getNonce(), // TODO: detect replay
new KerberosTime(new Date().getTime() + 1000 * 3600 * 24),
// Next 5 and last MUST be same with ticket
tFlags,
new KerberosTime(new Date()),
body.from,
till, body.rtime,
body.crealm,
body.sname,
body.addresses
);
EncryptedData edata = new EncryptedData(ckey, enc_part.asn1Encode(), KeyUsage.KU_ENC_TGS_REP_PART_SESSKEY);
TGSRep tgsRep = new TGSRep(null,
etp.crealm,
etp.cname,
t,
edata);
System.out.println(" Return " + tgsRep.cname
+ " ticket for " + tgsRep.ticket.sname);
DerOutputStream out = new DerOutputStream();
out.write(DerValue.createTag(DerValue.TAG_APPLICATION,
true, (byte)Krb5.KRB_TGS_REP), tgsRep.asn1Encode());
return out.toByteArray();
} catch (KrbException ke) {
ke.printStackTrace(System.out);
KRBError kerr = ke.getError();
KDCReqBody body = tgsReq.reqBody;
System.out.println(" Error " + ke.returnCode()
+ " " +ke.returnCodeMessage());
if (kerr == null) {
kerr = new KRBError(null, null, null,
new KerberosTime(new Date()),
0,
ke.returnCode(),
body.crealm, body.cname,
new Realm(getRealm()), body.sname,
KrbException.errorMessage(ke.returnCode()),
null);
}
return kerr.asn1Encode();
}
}
/**
* Processes a AS_REQ and generates a AS_REP (or KRB_ERROR)
* @param in the request
* @return the response
* @throws java.lang.Exception for various errors
*/
private byte[] processAsReq(byte[] in) throws Exception {
ASReq asReq = new ASReq(in);
int[] eTypes = null;
try {
System.out.println(realm + "> " + asReq.reqBody.cname +
" sends AS-REQ for " +
asReq.reqBody.sname);
KDCReqBody body = asReq.reqBody;
// Reflection: int[] eType = body.eType;
Field f = KDCReqBody.class.getDeclaredField("eType");
f.setAccessible(true);
eTypes = (int[])f.get(body);
int eType = eTypes[0];
EncryptionKey ckey = keyForUser(body.cname, eType);
EncryptionKey skey = keyForUser(body.sname, eType);
if (ckey == null) {
throw new KrbException(Krb5.KDC_ERR_ETYPE_NOSUPP);
}
if (skey == null) {
throw new KrbException(Krb5.KDC_ERR_SUMTYPE_NOSUPP); // TODO
}
// Session key
EncryptionKey key = generateRandomKey(eType);
// Check time, TODO
KerberosTime till = body.till;
if (till == null) {
throw new KrbException(Krb5.KDC_ERR_NEVER_VALID); // TODO
} else if (till.isZero()) {
till = new KerberosTime(new Date().getTime() + 1000 * 3600 * 11);
}
//body.from
boolean[] bFlags = new boolean[Krb5.TKT_OPTS_MAX+1];
if (body.kdcOptions.get(KDCOptions.FORWARDABLE)) {
bFlags[Krb5.TKT_OPTS_FORWARDABLE] = true;
}
if (body.kdcOptions.get(KDCOptions.RENEWABLE)) {
bFlags[Krb5.TKT_OPTS_RENEWABLE] = true;
//renew = new KerberosTime(new Date().getTime() + 1000 * 3600 * 24 * 7);
}
if (body.kdcOptions.get(KDCOptions.PROXIABLE)) {
bFlags[Krb5.TKT_OPTS_PROXIABLE] = true;
}
if (body.kdcOptions.get(KDCOptions.POSTDATED)) {
bFlags[Krb5.TKT_OPTS_POSTDATED] = true;
}
if (body.kdcOptions.get(KDCOptions.ALLOW_POSTDATE)) {
bFlags[Krb5.TKT_OPTS_MAY_POSTDATE] = true;
}
bFlags[Krb5.TKT_OPTS_INITIAL] = true;
f = KDCReq.class.getDeclaredField("pAData");
f.setAccessible(true);
PAData[] pas = (PAData[])f.get(asReq);
if (pas == null || pas.length == 0) {
Object preauth = options.get(Option.PREAUTH_REQUIRED);
if (preauth == null || preauth.equals(Boolean.TRUE)) {
throw new KrbException(Krb5.KDC_ERR_PREAUTH_REQUIRED);
}
} else {
try {
Constructor<EncryptedData> ctor = EncryptedData.class.getDeclaredConstructor(DerValue.class);
ctor.setAccessible(true);
EncryptedData data = ctor.newInstance(new DerValue(pas[0].getValue()));
data.decrypt(ckey, KeyUsage.KU_PA_ENC_TS);
} catch (Exception e) {
throw new KrbException(Krb5.KDC_ERR_PREAUTH_FAILED);
}
bFlags[Krb5.TKT_OPTS_PRE_AUTHENT] = true;
}
TicketFlags tFlags = new TicketFlags(bFlags);
EncTicketPart enc = new EncTicketPart(
tFlags,
key,
body.crealm,
body.cname,
new TransitedEncoding(1, new byte[0]),
new KerberosTime(new Date()),
body.from,
till, body.rtime,
body.addresses,
null);
Ticket t = new Ticket(
body.crealm,
body.sname,
new EncryptedData(skey, enc.asn1Encode(), KeyUsage.KU_TICKET)
);
EncASRepPart enc_part = new EncASRepPart(
key,
new LastReq(new LastReqEntry[]{
new LastReqEntry(0, new KerberosTime(new Date().getTime() - 10000))
}),
body.getNonce(), // TODO: detect replay?
new KerberosTime(new Date().getTime() + 1000 * 3600 * 24),
// Next 5 and last MUST be same with ticket
tFlags,
new KerberosTime(new Date()),
body.from,
till, body.rtime,
body.crealm,
body.sname,
body.addresses
);
EncryptedData edata = new EncryptedData(ckey, enc_part.asn1Encode(), KeyUsage.KU_ENC_AS_REP_PART);
ASRep asRep = new ASRep(null,
body.crealm,
body.cname,
t,
edata);
System.out.println(" Return " + asRep.cname
+ " ticket for " + asRep.ticket.sname);
DerOutputStream out = new DerOutputStream();
out.write(DerValue.createTag(DerValue.TAG_APPLICATION,
true, (byte)Krb5.KRB_AS_REP), asRep.asn1Encode());
return out.toByteArray();
} catch (KrbException ke) {
ke.printStackTrace(System.out);
KRBError kerr = ke.getError();
KDCReqBody body = asReq.reqBody;
System.out.println(" Error " + ke.returnCode()
+ " " +ke.returnCodeMessage());
byte[] eData = null;
if (kerr == null) {
if (ke.returnCode() == Krb5.KDC_ERR_PREAUTH_REQUIRED ||
ke.returnCode() == Krb5.KDC_ERR_PREAUTH_FAILED) {
PAData pa;
ETypeInfo2 ei2 = new ETypeInfo2(eTypes[0], null, null);
DerOutputStream eid = new DerOutputStream();
eid.write(DerValue.tag_Sequence, ei2.asn1Encode());
pa = new PAData(Krb5.PA_ETYPE_INFO2, eid.toByteArray());
DerOutputStream bytes = new DerOutputStream();
bytes.write(new PAData(Krb5.PA_ENC_TIMESTAMP, new byte[0]).asn1Encode());
bytes.write(pa.asn1Encode());
boolean allOld = true;
for (int i: eTypes) {
if (i == EncryptedData.ETYPE_AES128_CTS_HMAC_SHA1_96 ||
i == EncryptedData.ETYPE_AES256_CTS_HMAC_SHA1_96) {
allOld = false;
break;
}
}
if (allOld) {
ETypeInfo ei = new ETypeInfo(eTypes[0], null);
eid = new DerOutputStream();
eid.write(DerValue.tag_Sequence, ei.asn1Encode());
pa = new PAData(Krb5.PA_ETYPE_INFO, eid.toByteArray());
bytes.write(pa.asn1Encode());
}
DerOutputStream temp = new DerOutputStream();
temp.write(DerValue.tag_Sequence, bytes);
eData = temp.toByteArray();
}
kerr = new KRBError(null, null, null,
new KerberosTime(new Date()),
0,
ke.returnCode(),
body.crealm, body.cname,
new Realm(getRealm()), body.sname,
KrbException.errorMessage(ke.returnCode()),
eData);
}
return kerr.asn1Encode();
}
}
/**
* Generates a line for a KDC to put inside [realms] of krb5.conf
* @param kdc the KDC
* @return REALM.NAME = { kdc = localhost:port }
*/
private static String realmLineForKDC(KDC kdc) {
return String.format(" %s = {\n kdc = localhost:%d\n }\n", kdc.realm, kdc.port);
}
/**
* Start the KDC service. This server listens on both UDP and TCP using
* the same port number. It uses three threads to deal with requests.
* They can be set to daemon threads if requested.
* @param port the port number to listen to. If zero, a random available
* port no less than 8000 will be chosen and used.
* @param asDaemon true if the KDC threads should be daemons
* @throws java.io.IOException for any communication error
*/
protected void startServer(int port, boolean asDaemon) throws IOException {
DatagramSocket u1 = null;
ServerSocket t1 = null;
if (port > 0) {
u1 = new DatagramSocket(port, InetAddress.getByName("127.0.0.1"));
t1 = new ServerSocket(port);
} else {
while (true) {
// Try to find a port number that's both TCP and UDP free
try {
port = 8000 + new java.util.Random().nextInt(10000);
u1 = null;
u1 = new DatagramSocket(port, InetAddress.getByName("127.0.0.1"));
t1 = new ServerSocket(port);
break;
} catch (Exception e) {
if (u1 != null) u1.close();
}
}
}
final DatagramSocket udp = u1;
final ServerSocket tcp = t1;
System.out.println("Start KDC on " + port);
this.port = port;
// The UDP consumer
Thread thread = new Thread() {
public void run() {
while (true) {
try {
byte[] inbuf = new byte[8192];
DatagramPacket p = new DatagramPacket(inbuf, inbuf.length);
udp.receive(p);
System.out.println("-----------------------------------------------");
System.out.println(">>>>> UDP packet received");
q.put(new Job(processMessage(Arrays.copyOf(inbuf, p.getLength())), udp, p));
} catch (Exception e) {
e.printStackTrace();
}
}
}
};
thread.setDaemon(asDaemon);
thread.start();
// The TCP consumer
thread = new Thread() {
public void run() {
while (true) {
try {
Socket socket = tcp.accept();
System.out.println("-----------------------------------------------");
System.out.println(">>>>> TCP connection established");
DataInputStream in = new DataInputStream(socket.getInputStream());
DataOutputStream out = new DataOutputStream(socket.getOutputStream());
byte[] token = new byte[in.readInt()];
in.readFully(token);
q.put(new Job(processMessage(token), socket, out));
} catch (Exception e) {
e.printStackTrace();
}
}
}
};
thread.setDaemon(asDaemon);
thread.start();
// The dispatcher
thread = new Thread() {
public void run() {
while (true) {
try {
q.take().send();
} catch (Exception e) {
}
}
}
};
thread.setDaemon(true);
thread.start();
}
/**
* Helper class to encapsulate a job in a KDC.
*/
private static class Job {
byte[] token; // The received request at creation time and
// the response at send time
Socket s; // The TCP socket from where the request comes
DataOutputStream out; // The OutputStream of the TCP socket
DatagramSocket s2; // The UDP socket from where the request comes
DatagramPacket dp; // The incoming UDP datagram packet
boolean useTCP; // Whether TCP or UDP is used
// Creates a job object for TCP
Job(byte[] token, Socket s, DataOutputStream out) {
useTCP = true;
this.token = token;
this.s = s;
this.out = out;
}
// Creates a job object for UDP
Job(byte[] token, DatagramSocket s2, DatagramPacket dp) {
useTCP = false;
this.token = token;
this.s2 = s2;
this.dp = dp;
}
// Sends the output back to the client
void send() {
try {
if (useTCP) {
System.out.println(">>>>> TCP request honored");
out.writeInt(token.length);
out.write(token);
s.close();
} else {
System.out.println(">>>>> UDP request honored");
s2.send(new DatagramPacket(token, token.length, dp.getAddress(), dp.getPort()));
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
}