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package sun.security.jgss.krb5;

import org.ietf.jgss.*;
import java.io.InputStream;
import java.io.IOException;

import sun.security.action.GetPropertyAction;
import sun.security.krb5.*;
import java.net.InetAddress;
import sun.security.krb5.internal.AuthorizationData;
import sun.security.krb5.internal.KerberosTime;

class InitSecContextToken extends InitialToken {

    // If non-mutual authentication is requested, there is no AP-REP message.
    // The acceptor thus has no chance to send the seq-number field to the
    // initiator. In this case, the initiator and acceptor should has an
    // agreement to derive acceptor's initial seq-number if the acceptor wishes
    // to send messages to the initiator.

    // If this flag is true, it will the same as the initiator's initial
    // seq-number (as MIT krb5 and Windows SSPI do). Otherwise, it will be zero
    // (as Heimdal does). The default value is true.
    private static final boolean ACCEPTOR_USE_INITIATOR_SEQNUM;

    static {
        // The ACCEPTOR_USE_INITIATOR_SEQNUM value is determined by the system
        // property "sun.security.krb5.acceptor.sequence.number.nonmutual",
        // which can be set to "initiator", "zero" or "0".
        String propName = "sun.security.krb5.acceptor.sequence.number.nonmutual";
        String s = GetPropertyAction.privilegedGetProperty(propName, "initiator");
        if (s.equals("initiator")) {
            ACCEPTOR_USE_INITIATOR_SEQNUM = true;
        } else if (s.equals("zero") || s.equals("0")) {
            ACCEPTOR_USE_INITIATOR_SEQNUM = false;
        } else {
            throw new AssertionError("Unrecognized value for " + propName
                    + ": " + s);
        }
    }

    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( ACCEPTOR_USE_INITIATOR_SEQNUM ? apReq.getSeqNumber().intValue() : 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()) { context.resetMySequenceNumber( ACCEPTOR_USE_INITIATOR_SEQNUM ? peerSeqNumber : 0); } 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; } }