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
There is a newer version: 0.13.0
/*
 * 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.protocol.commons.buffer.Buffer;
import com.hierynomus.protocol.commons.buffer.Endian;
import com.hierynomus.smbj.common.SMBRuntimeException;
import org.bouncycastle.asn1.*;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Enumeration;
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 {
    private static final String ADS_IGNORE_PRINCIPAL = "not_defined_in_RFC4178@please_ignore";

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

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

    public void write(Buffer buffer) {
        try {
            ASN1EncodableVector negTokenInit = new ASN1EncodableVector();
            addMechTypeList(negTokenInit);
            addMechToken(negTokenInit);

            writeGss(buffer, negTokenInit);
        } catch (IOException e) {
            throw new SMBRuntimeException(e);
        }
    }

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

    private NegTokenInit read(Buffer buffer) throws IOException {
        try(ASN1InputStream is = new ASN1InputStream(buffer.asInputStream())) {
            ASN1Primitive applicationSpecific = is.readObject();
            if (!(applicationSpecific instanceof BERApplicationSpecific || applicationSpecific instanceof DERApplicationSpecific)) {
                throw new SpnegoException("Incorrect GSS-API ASN.1 token received, expected to find an [APPLICATION 0], not: " + applicationSpecific);
            }
            ASN1Sequence implicitSequence = (ASN1Sequence) ((ASN1ApplicationSpecific) applicationSpecific).getObject(BERTags.SEQUENCE);
            ASN1Encodable spnegoOid = implicitSequence.getObjectAt(0);
            if (!(spnegoOid instanceof ASN1ObjectIdentifier)) {
                throw new SpnegoException("Expected to find the SPNEGO OID (" + SPNEGO + "), not: " + spnegoOid);
            }

            parseSpnegoToken(implicitSequence.getObjectAt(1));
        } catch (SpnegoException e) {
            throw new SMBRuntimeException(e);
        }
        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 2:
                readMechToken(asn1TaggedObject.getObject());
                break;
            default:
                throw new SpnegoException("Unknown Object Tag " + asn1TaggedObject.getTagNo() + " encountered.");
        }
    }

    private void readMechToken(ASN1Primitive mechToken) throws SpnegoException {
        if (!(mechToken instanceof ASN1OctetString)) {
            throw new SpnegoException("Expected the MechToken (OCTET_STRING) contents, not: " + mechToken);
        }
        this.mechToken = ((ASN1OctetString) mechToken).getOctets();
    }

    private void readMechTypeList(ASN1Primitive sequence) throws SpnegoException {
        if (!(sequence instanceof ASN1Sequence)) {
            throw new SpnegoException("Expected the MechTypeList (SEQUENCE) contents, not: " + sequence);
        }
        Enumeration mechTypeElems = ((ASN1Sequence) sequence).getObjects();
        while (mechTypeElems.hasMoreElements()) {
            ASN1Encodable mechType = (ASN1Encodable) mechTypeElems.nextElement();
            if (!(mechType instanceof ASN1ObjectIdentifier)) {
                throw new SpnegoException("Expected a MechType (OBJECT IDENTIFIER) as contents of the MechTypeList, not: " + mechType);
            }
            mechTypes.add((ASN1ObjectIdentifier) mechType);
        }
    }

    private void addMechToken(ASN1EncodableVector negTokenInit) {
        if (mechToken != null && mechToken.length > 0) {
            ASN1Primitive token = new DERTaggedObject(true, 0x02, new DEROctetString(mechToken));
            negTokenInit.add(token);
        }
    }

    private void addMechTypeList(ASN1EncodableVector negTokenInit) {
        if (mechTypes.size() > 0) {
            ASN1EncodableVector supportedMechVector = new ASN1EncodableVector();
            for (ASN1ObjectIdentifier mechType : mechTypes) {
                supportedMechVector.add(mechType);
            }

            ASN1Primitive asn1Encodables1 = new DERTaggedObject(true, 0x0, new DERSequence(supportedMechVector));
            negTokenInit.add(asn1Encodables1);
        }
    }

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

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

    public List getSupportedMechTypes() {
        return mechTypes;
    }
}