/**
* Encode an SPNEGO NegTokenInit blob
*
* @return byte[]
* @exception IOException
*/
public byte[] encode() throws IOException {
// Create the list of objects to be encoded
List objList = new ArrayList();
objList.add(new DEROid(OID.ID_SPNEGO));
// Build the sequence of tagged objects
DERSequence derSeq = new DERSequence();
derSeq.setTagNo(0);
// mechTypes sequence
DERSequence mechTypesSeq = new DERSequence();
mechTypesSeq.setTagNo(0);
for (int i = 0; i < m_mechTypes.length; i++) {
Oid mechType = m_mechTypes[i];
mechTypesSeq.addObject(new DEROid(mechType.toString()));
}
derSeq.addObject(mechTypesSeq);
// mechListMIC
//
// Note: This field is not as specified
if (m_mecListMICPrincipal != null) {
DERSequence derMecSeq = new DERSequence();
derMecSeq.setTagNo(3);
DERGeneralString mecStr = new DERGeneralString(m_mecListMICPrincipal);
mecStr.setTagNo(0);
derMecSeq.addObject(mecStr);
derSeq.addObject(derMecSeq);
}
// Add the sequence to the object list
objList.add(derSeq);
// Pack the objects
DERBuffer derBuf = new DERBuffer();
derBuf.packApplicationSpecific(objList);
// Return the packed negTokenInit blob
return derBuf.getBytes();
}
/**
* Decode an SPNEGO NegTokenInit blob
*
* @param buf byte[]
* @param off int
* @param len int
* @exception IOException
*/
public void decode(byte[] buf, int off, int len) throws IOException {
// Create a DER buffer to decode the blob
DERBuffer derBuf = new DERBuffer(buf, off, len);
// Get the first object from the blob
DERObject derObj = derBuf.unpackApplicationSpecific();
if (derObj instanceof DEROid) {
// Check that the OID indicates SPNEGO
DEROid derOid = (DEROid) derObj;
if (derOid.getOid().equals(OID.ID_SPNEGO) == false)
throw new IOException("Not an SPNEGO blob");
// Get the remaining objects from the DER buffer
derObj = derBuf.unpackObject();
if (derObj instanceof DERSequence) {
// Access the sequence, should be a sequence of tagged values
DERSequence derSeq = (DERSequence) derObj;
// Get the mechTypes list
derObj = derSeq.getTaggedObject(0);
if (derObj == null) throw new IOException("No mechTypes list in blob");
if (derObj instanceof DERSequence == false)
throw new IOException("Invalid mechTypes object");
// Unpack the OID list (required)
DERSequence derOidSeq = (DERSequence) derObj;
m_mechTypes = new Oid[derOidSeq.numberOfObjects()];
int idx = 0;
for (int i = 0; i < derOidSeq.numberOfObjects(); i++) {
derObj = derOidSeq.getObjectAt(i);
if (derObj instanceof DEROid) {
derOid = (DEROid) derObj;
try {
m_mechTypes[idx++] = new Oid(derOid.getOid());
} catch (GSSException ex) {
throw new IOException("Bad mechType OID");
}
}
}
// Unpack the context flags (optional)
derObj = derSeq.getTaggedObject(1);
if (derObj != null) {
// Check the type
if (derObj instanceof DERBitString) {
// Get the bit flags
DERBitString derBitStr = (DERBitString) derObj;
m_contextFlags = derBitStr.intValue();
}
}
// Unpack the mechToken (required)
derObj = derSeq.getTaggedObject(2);
if (derObj == null) throw new IOException("No mechToken in blob");
if (derObj instanceof DEROctetString == false)
throw new IOException("Invalid mechToken object");
DEROctetString derStr = (DEROctetString) derObj;
m_mechToken = derStr.getValue();
// Unpack the mechListMIC (optional)
/**
* derObj = derSeq.getTaggedObject( 3);
*
* <p>if ( derObj != null) {
*
* <p>// Check for the Microsoft format mechListMIC
*
* <p>if ( derObj instanceof DERSequence) { } }
*/
} else throw new IOException("Bad object type in blob");
} else throw new IOException("Invalid security blob");
}