com.hierynomus.spnego.NegTokenInit Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of smbj Show documentation
SMB2 protocol library for communication with Windows servers
The newest version!
/*
 * Copyright (C)2016 - SMBJ Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.hierynomus.spnego;

import com.hierynomus.asn1.ASN1InputStream;
import com.hierynomus.asn1.encodingrules.der.DERDecoder;
import com.hierynomus.asn1.types.ASN1Object;
import com.hierynomus.asn1.types.ASN1Tag;
import com.hierynomus.asn1.types.ASN1TagClass;
import com.hierynomus.asn1.types.constructed.ASN1Sequence;
import com.hierynomus.asn1.types.constructed.ASN1TaggedObject;
import com.hierynomus.asn1.types.primitive.ASN1ObjectIdentifier;
import com.hierynomus.asn1.types.string.ASN1OctetString;
import com.hierynomus.protocol.commons.buffer.Buffer;
import com.hierynomus.protocol.commons.buffer.Endian;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import static com.hierynomus.spnego.ObjectIdentifiers.SPNEGO;

/**
 * This class can encode and decode the SPNEGO negTokenInit Token.
 * 
 * The entire token is an ASN.1 DER encoded sequence of bytes in little endian byte encoding.
 * 

 * The following is the full ASN.1 specification of the token:
 * 

 * 
 * GSSAPI          ::=  [APPLICATION 0] IMPLICIT SEQUENCE {
 *   mech                MechType,
 *   negTokenInit        NegotiationToken
 * }
 *
 * NegotiationToken ::=  CHOICE {
 *   negTokenInit   [0]  NegTokenInit,
 *   negTokenTarg   [1]  NegTokenTarg
 * }
 *
 * NegTokenInit     ::=  SEQUENCE {
 *   mechTypes      [0]  MechTypeList  OPTIONAL,
 *   reqFlags       [1]  ContextFlags  OPTIONAL,
 *   mechToken      [2]  OCTET STRING  OPTIONAL,
 *   mechListMIC    [3]  OCTET STRING  OPTIONAL
 * }
 *
 * MechTypeList     ::=  SEQUENCE of MechType
 *
 * ContextFlags     ::=  BIT_STRING {
 *   delegFlag      (0),
 *   mutualFlag     (1),
 *   replayFlag     (2),
 *   sequenceFlag   (3),
 *   anonFlag       (4),
 *   confFlag       (5),
 *   integFlag      (6)
 * }
 *
 * MechType         ::=  OBJECT IDENTIFIER
 * 
 * 
 * In the context of this class only the NegTokenInit is covered.
 * 

 * 

 * When an InitToken is sent, it is prepended by the generic GSSAPI header.
 * The "mech" field of the GSSAPI header is always set to the SPNEGO OID (1.3.6.1.5.5.2)
 * The negTokenInit will have a lead byte of 0xa0 (the CHOICE tagged object).
 * 
 */
public class NegTokenInit extends SpnegoToken {
    static final String ADS_IGNORE_PRINCIPAL = "not_defined_in_RFC4178@please_ignore";

    private List mechTypes = new ArrayList<>();
    protected byte[] mechToken;

    public NegTokenInit() {
        super(0x0, "NegTokenInit");
    }

    @SuppressWarnings("rawtypes")
    public void write(Buffer buffer) throws SpnegoException {
        try {
            List negTokenInit = new ArrayList<>();
//            ASN1EncodableVector negTokenInit = new ASN1EncodableVector();
            addMechTypeList(negTokenInit);
            addMechToken(negTokenInit);

            writeGss(buffer, new ASN1Sequence(negTokenInit));
        } catch (IOException e) {
            throw new SpnegoException("Unable to write NegTokenInit", e);
        }
    }

    public NegTokenInit read(byte[] bytes) throws SpnegoException {
        return read(new Buffer.PlainBuffer(bytes, Endian.LE));
    }

    private NegTokenInit read(Buffer buffer) throws SpnegoException {
        try (ASN1InputStream is = new ASN1InputStream(new DERDecoder(), buffer.asInputStream())) {
            ASN1TaggedObject applicationSpecific = is.readObject();
            if (applicationSpecific.getTag().getAsn1TagClass() != ASN1TagClass.APPLICATION) {
                throw new SpnegoException("Incorrect GSS-API ASN.1 token received, expected to find an [APPLICATION 0], not: " + applicationSpecific);
            }
            ASN1Sequence implicitSequence = applicationSpecific.getObject(ASN1Tag.SEQUENCE);
            ASN1Object spnegoOid = implicitSequence.get(0);
            if (!(spnegoOid instanceof ASN1ObjectIdentifier)) {
                throw new SpnegoException("Expected to find the SPNEGO OID (" + SPNEGO + "), not: " + spnegoOid);
            }

            parseSpnegoToken(implicitSequence.get(1));
        } catch (IOException ioe) {
            throw new SpnegoException("Could not read NegTokenInit from buffer", ioe);
        }
        return this;
    }

    @Override
    protected void parseTagged(ASN1TaggedObject asn1TaggedObject) throws SpnegoException {
        if (asn1TaggedObject.getObject().toString().contains(ADS_IGNORE_PRINCIPAL)) {
            // Ignore
            return;
        }
        switch (asn1TaggedObject.getTagNo()) {
            case 0:
                readMechTypeList(asn1TaggedObject.getObject());
                break;
            case 1:
                // Ignore reqFlags for now...
                break;
            case 2:
                readMechToken(asn1TaggedObject.getObject());
                break;
            case 3:
                // Ignore mechListMIC for now...
                break;
            default:
                throw new SpnegoException("Unknown Object Tag " + asn1TaggedObject.getTagNo() + " encountered.");
        }
    }

    void readMechToken(ASN1Object mechToken) throws SpnegoException {
        if (!(mechToken instanceof ASN1OctetString)) {
            throw new SpnegoException("Expected the MechToken (OCTET_STRING) contents, not: " + mechToken);
        }
        this.mechToken = ((ASN1OctetString) mechToken).getValue();
    }

    void readMechTypeList(ASN1Object sequence) throws SpnegoException {
        if (!(sequence instanceof ASN1Sequence)) {
            throw new SpnegoException("Expected the MechTypeList (SEQUENCE) contents, not: " + sequence);
        }
        for (ASN1Object mechType : (ASN1Sequence) sequence) {
            if (!(mechType instanceof ASN1ObjectIdentifier)) {
                throw new SpnegoException("Expected a MechType (OBJECT IDENTIFIER) as contents of the MechTypeList, not: " + mechType);
            }
            mechTypes.add((ASN1ObjectIdentifier) mechType);
        }
    }

    @SuppressWarnings("rawtypes")
    private void addMechToken(List negTokenInit) {
        if (mechToken != null && mechToken.length > 0) {
            ASN1TaggedObject token = new ASN1TaggedObject(ASN1Tag.contextSpecific(2).constructed(), new ASN1OctetString(mechToken), true);
            negTokenInit.add(token);
        }
    }

    @SuppressWarnings("rawtypes")
    private void addMechTypeList(List negTokenInit) {
        if (mechTypes.size() > 0) {
            List supportedMechVector = new ArrayList(mechTypes);
            negTokenInit.add(new ASN1TaggedObject(ASN1Tag.contextSpecific(0).constructed(), new ASN1Sequence(supportedMechVector), true));
        }
    }

    public void addSupportedMech(ASN1ObjectIdentifier oid) {
        this.mechTypes.add(oid);
    }

    public void setMechToken(byte[] mechToken) {
        this.mechToken = mechToken;
    }

    public List getSupportedMechTypes() {
        return mechTypes;
    }
}