Java tutorial
/* * ==================================================================== * 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(); } }