/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.contrib.auth;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.impl.auth.SpnegoTokenGenerator;
import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1InputStream;
import org.bouncycastle.asn1.ASN1Object;
import org.bouncycastle.asn1.ASN1OutputStream;
import org.bouncycastle.asn1.DERObjectIdentifier;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.DERSequence;
import org.bouncycastle.asn1.DERTaggedObject;
import org.bouncycastle.asn1.util.ASN1Dump;
/**
* Takes Kerberos ticket and wraps into a SPNEGO token. Leaving some optional fields out.
*/
public class BouncySpnegoTokenGenerator implements SpnegoTokenGenerator {
private final Log log = LogFactory.getLog(getClass());
private final DERObjectIdentifier spnegoOid;
private final DERObjectIdentifier kerbOid;
public BouncySpnegoTokenGenerator() {
super();
this.spnegoOid = new DERObjectIdentifier("1.3.6.1.5.5.2");
this.kerbOid = new DERObjectIdentifier("1.2.840.113554.1.2.2");
}
public byte [] generateSpnegoDERObject(byte [] kerbTicket) throws IOException {
DEROctetString ourKerberosTicket = new DEROctetString(kerbTicket);
DERSequence kerbOidSeq = new DERSequence(kerbOid);
DERTaggedObject tagged0 = new DERTaggedObject(0, kerbOidSeq);
DERTaggedObject tagged2 = new DERTaggedObject(2, ourKerberosTicket);
ASN1EncodableVector v = new ASN1EncodableVector();
v.add(tagged0);
v.add(tagged2);
DERSequence seq = new DERSequence(v);
DERTaggedObject taggedSpnego = new DERTaggedObject(0, seq);
ByteArrayOutputStream out = new ByteArrayOutputStream();
ASN1OutputStream asn1Out = new ASN1OutputStream(out);
ASN1Object spnegoOIDASN1 = (ASN1Object) spnegoOid.toASN1Object();
ASN1Object taggedSpnegoASN1 = (ASN1Object) taggedSpnego.toASN1Object();
int length = spnegoOIDASN1.getDEREncoded().length + taggedSpnegoASN1.getDEREncoded().length;
byte [] lenBytes = writeLength(length);
byte[] appWrap = new byte[lenBytes.length + 1];
appWrap[0] = 0x60;
for(int i=1; i < appWrap.length; i++){
appWrap[i] = lenBytes[i-1];
}
asn1Out.write(appWrap);
asn1Out.writeObject(spnegoOid.toASN1Object());
asn1Out.writeObject(taggedSpnego.toASN1Object());
byte[] app = out.toByteArray();
ASN1InputStream in = new ASN1InputStream(app);
if (log.isDebugEnabled() ){
int skip = 12;
byte [] manipBytes = new byte[app.length - skip];
for(int i=skip; i < app.length; i++){
manipBytes[i-skip] = app[i];
}
ASN1InputStream ourSpnego = new ASN1InputStream( manipBytes );
log.debug(ASN1Dump.dumpAsString(ourSpnego.readObject()));
}
return in.readObject().getDEREncoded();
}
private byte [] writeLength(int length) throws IOException {
ByteArrayOutputStream out = new ByteArrayOutputStream();
if (length > 127) {
int size = 1;
int val = length;
while ((val >>>= 8) != 0) {
size++;
}
out.write((byte) (size | 0x80));
for (int i = (size - 1) * 8; i >= 0; i -= 8) {
out.write((byte) (length >> i));
}
} else {
out.write((byte) length);
}
return out.toByteArray();
}
}