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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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).
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package sun.security.jgss.krb5;

import org.ietf.jgss.*;
import java.io.InputStream;
import java.io.IOException;
import sun.security.krb5.*;
import java.net.InetAddress;
import sun.security.krb5.internal.AuthorizationData;
import sun.security.krb5.internal.KerberosTime;

class InitSecContextToken extends InitialToken {

    private KrbApReq apReq = null;

    
For the context initiator to call. It constructs a new
InitSecContextToken to send over to the peer containing the desired
flags and the AP-REQ. It also updates the context with the local
sequence number and shared context key.
(When mutual auth is enabled the peer has an opportunity to
renegotiate the session key in the followup AcceptSecContextToken
that it sends.)
/**
     * For the context initiator to call. It constructs a new
     * InitSecContextToken to send over to the peer containing the desired
     * flags and the AP-REQ. It also updates the context with the local
     * sequence number and shared context key.
     * (When mutual auth is enabled the peer has an opportunity to
     * renegotiate the session key in the followup AcceptSecContextToken
     * that it sends.)
     */
    InitSecContextToken(Krb5Context context,
                               Credentials tgt,
                               Credentials serviceTicket)
        throws KrbException, IOException, GSSException {

        boolean mutualRequired = context.getMutualAuthState();
        boolean useSubkey = true; // MIT Impl will crash if this is not set!
        boolean useSequenceNumber = true;

        OverloadedChecksum gssChecksum =
            new OverloadedChecksum(context, tgt, serviceTicket);

        Checksum checksum = gssChecksum.getChecksum();

        context.setTktFlags(serviceTicket.getFlags());
        context.setAuthTime(
                new KerberosTime(serviceTicket.getAuthTime()).toString());
        apReq = new KrbApReq(serviceTicket,
                             mutualRequired,
                             useSubkey,
                             useSequenceNumber,
                             checksum);

        context.resetMySequenceNumber(apReq.getSeqNumber().intValue());

        EncryptionKey subKey = apReq.getSubKey();
        if (subKey != null)
            context.setKey(Krb5Context.INITIATOR_SUBKEY, subKey);
        else
            context.setKey(Krb5Context.SESSION_KEY, serviceTicket.getSessionKey());

        if (!mutualRequired)
            context.resetPeerSequenceNumber(0);
    }

    
For the context acceptor to call. It reads the bytes out of an
InputStream and constructs an InitSecContextToken with them.
/**
     * For the context acceptor to call. It reads the bytes out of an
     * InputStream and constructs an InitSecContextToken with them.
     */
    InitSecContextToken(Krb5Context context, Krb5AcceptCredential cred,
                               InputStream is)
        throws IOException, GSSException, KrbException  {

        int tokenId = ((is.read()<<8) | is.read());

        if (tokenId != Krb5Token.AP_REQ_ID)
            throw new GSSException(GSSException.DEFECTIVE_TOKEN, -1,
                                   "AP_REQ token id does not match!");

        // XXX Modify KrbApReq cons to take an InputStream
        byte[] apReqBytes =
            new sun.security.util.DerValue(is).toByteArray();
        //debug("=====ApReqBytes: [" + getHexBytes(apReqBytes) + "]\n");

        InetAddress addr = null;
        if (context.getChannelBinding() != null) {
            addr = context.getChannelBinding().getInitiatorAddress();
        }
        apReq = new KrbApReq(apReqBytes, cred, addr);
        //debug("\nReceived AP-REQ and authenticated it.\n");

        EncryptionKey sessionKey = apReq.getCreds().getSessionKey();

        /*
          System.out.println("\n\nSession key from service ticket is: " +
          getHexBytes(sessionKey.getBytes()));
        */

        EncryptionKey subKey = apReq.getSubKey();
        if (subKey != null) {
            context.setKey(Krb5Context.INITIATOR_SUBKEY, subKey);
            /*
              System.out.println("Sub-Session key from authenticator is: " +
              getHexBytes(subKey.getBytes()) + "\n");
            */
        } else {
            context.setKey(Krb5Context.SESSION_KEY, sessionKey);
            //System.out.println("Sub-Session Key Missing in Authenticator.\n");
        }

        OverloadedChecksum gssChecksum = new OverloadedChecksum(
                context, apReq.getChecksum(), sessionKey, subKey);
        gssChecksum.setContextFlags(context);
        Credentials delegCred = gssChecksum.getDelegatedCreds();
        if (delegCred != null) {
            Krb5CredElement credElement =
                Krb5InitCredential.getInstance(
                                   (Krb5NameElement)context.getSrcName(),
                                   delegCred);
            context.setDelegCred(credElement);
        }

        Integer apReqSeqNumber = apReq.getSeqNumber();
        int peerSeqNumber = (apReqSeqNumber != null ?
                             apReqSeqNumber.intValue() :
                             0);
        context.resetPeerSequenceNumber(peerSeqNumber);
        if (!context.getMutualAuthState())
            // Use the same sequence number as the peer
            // (Behaviour exhibited by the Windows SSPI server)
            context.resetMySequenceNumber(peerSeqNumber);
        context.setAuthTime(
                new KerberosTime(apReq.getCreds().getAuthTime()).toString());
        context.setTktFlags(apReq.getCreds().getFlags());
        AuthorizationData ad = apReq.getCreds().getAuthzData();
        context.setAuthzData(ad);
    }

    public final KrbApReq getKrbApReq() {
        return apReq;
    }

    public final byte[] encode() throws IOException {
        byte[] apReqBytes = apReq.getMessage();
        byte[] retVal = new byte[2 + apReqBytes.length];
        writeInt(Krb5Token.AP_REQ_ID, retVal, 0);
        System.arraycopy(apReqBytes, 0, retVal, 2, apReqBytes.length);
        //      System.out.println("GSS-Token with AP_REQ is:");
        //      System.out.println(getHexBytes(retVal));
        return retVal;
    }
}