/**
* build an object given its tag and the number of bytes to construct it from.
*/
private Asn1Object BuildObject(
int tag,
int tagNo,
int length)
{
bool isConstructed = (tag & Asn1Tags.Constructed) != 0;
DefiniteLengthInputStream defIn = new DefiniteLengthInputStream(this.s, length);
if ((tag & Asn1Tags.Application) != 0)
{
return new DerApplicationSpecific(isConstructed, tagNo, defIn.ToArray());
}
if ((tag & Asn1Tags.Tagged) != 0)
{
return new Asn1StreamParser(defIn).ReadTaggedObject(isConstructed, tagNo);
}
if (isConstructed)
{
// TODO There are other tags that may be constructed (e.g. BitString)
switch (tagNo)
{
case Asn1Tags.OctetString:
//
// yes, people actually do this...
//
return new BerOctetString(BuildDerEncodableVector(defIn));
case Asn1Tags.Sequence:
return CreateDerSequence(defIn);
case Asn1Tags.Set:
return CreateDerSet(defIn);
case Asn1Tags.External:
return new DerExternal(BuildDerEncodableVector(defIn));
default:
throw new IOException("unknown tag " + tagNo + " encountered");
}
}
return CreatePrimitiveDerObject(tagNo, defIn, tmpBuffers);
}
internal override DerSet CreateDerSet(
DefiniteLengthInputStream dIn)
{
return new LazyDerSet(dIn.ToArray());
}
internal virtual DerSequence CreateDerSequence(
DefiniteLengthInputStream dIn)
{
return DerSequence.FromVector(BuildDerEncodableVector(dIn));
}
internal virtual DerSet CreateDerSet(
DefiniteLengthInputStream dIn)
{
return DerSet.FromVector(BuildDerEncodableVector(dIn), false);
}
internal virtual Asn1EncodableVector BuildDerEncodableVector(
DefiniteLengthInputStream dIn)
{
return new Asn1InputStream(dIn).BuildEncodableVector();
}
internal static byte[] GetBuffer(DefiniteLengthInputStream defIn, byte[][] tmpBuffers)
{
int len = defIn.GetRemaining();
if (len >= tmpBuffers.Length)
{
return defIn.ToArray();
}
byte[] buf = tmpBuffers[len];
if (buf == null)
{
buf = tmpBuffers[len] = new byte[len];
}
defIn.ReadAllIntoByteArray(buf);
return buf;
}
internal static Asn1Object CreatePrimitiveDerObject(
int tagNo,
DefiniteLengthInputStream defIn,
byte[][] tmpBuffers)
{
switch (tagNo)
{
case Asn1Tags.Boolean:
return DerBoolean.FromOctetString(GetBuffer(defIn, tmpBuffers));
case Asn1Tags.Enumerated:
return DerEnumerated.FromOctetString(GetBuffer(defIn, tmpBuffers));
case Asn1Tags.ObjectIdentifier:
return DerObjectIdentifier.FromOctetString(GetBuffer(defIn, tmpBuffers));
}
byte[] bytes = defIn.ToArray();
switch (tagNo)
{
case Asn1Tags.BitString:
return DerBitString.FromAsn1Octets(bytes);
case Asn1Tags.BmpString:
return new DerBmpString(bytes);
case Asn1Tags.GeneralizedTime:
return new DerGeneralizedTime(bytes);
case Asn1Tags.GeneralString:
return new DerGeneralString(bytes);
case Asn1Tags.IA5String:
return new DerIA5String(bytes);
case Asn1Tags.Integer:
return new DerInteger(bytes);
case Asn1Tags.Null:
return DerNull.Instance; // actual content is ignored (enforce 0 length?)
case Asn1Tags.NumericString:
return new DerNumericString(bytes);
case Asn1Tags.OctetString:
return new DerOctetString(bytes);
case Asn1Tags.PrintableString:
return new DerPrintableString(bytes);
case Asn1Tags.T61String:
return new DerT61String(bytes);
case Asn1Tags.UniversalString:
return new DerUniversalString(bytes);
case Asn1Tags.UtcTime:
return new DerUtcTime(bytes);
case Asn1Tags.Utf8String:
return new DerUtf8String(bytes);
case Asn1Tags.VisibleString:
return new DerVisibleString(bytes);
default:
throw new IOException("unknown tag " + tagNo + " encountered");
}
}
internal DerOctetStringParser(
DefiniteLengthInputStream stream)
{
this.stream = stream;
}
public virtual IAsn1Convertible ReadObject()
{
int tag = _in.ReadByte();
if (tag == -1)
return null;
// turn of looking for "00" while we resolve the tag
Set00Check(false);
//
// calculate tag number
//
int tagNo = Asn1InputStream.ReadTagNumber(_in, tag);
bool isConstructed = (tag & Asn1Tags.Constructed) != 0;
//
// calculate length
//
int length = Asn1InputStream.ReadLength(_in, _limit);
if (length < 0) // indefinite length method
{
if (!isConstructed)
throw new IOException("indefinite length primitive encoding encountered");
IndefiniteLengthInputStream indIn = new IndefiniteLengthInputStream(_in, _limit);
Asn1StreamParser sp = new Asn1StreamParser(indIn, _limit);
if ((tag & Asn1Tags.Application) != 0)
{
return new BerApplicationSpecificParser(tagNo, sp);
}
if ((tag & Asn1Tags.Tagged) != 0)
{
return new BerTaggedObjectParser(true, tagNo, sp);
}
return sp.ReadIndef(tagNo);
}
else
{
DefiniteLengthInputStream defIn = new DefiniteLengthInputStream(_in, length);
if ((tag & Asn1Tags.Application) != 0)
{
return new DerApplicationSpecific(isConstructed, tagNo, defIn.ToArray());
}
if ((tag & Asn1Tags.Tagged) != 0)
{
return new BerTaggedObjectParser(isConstructed, tagNo, new Asn1StreamParser(defIn));
}
if (isConstructed)
{
// TODO There are other tags that may be constructed (e.g. BitString)
switch (tagNo)
{
case Asn1Tags.OctetString:
//
// yes, people actually do this...
//
return new BerOctetStringParser(new Asn1StreamParser(defIn));
case Asn1Tags.Sequence:
return new DerSequenceParser(new Asn1StreamParser(defIn));
case Asn1Tags.Set:
return new DerSetParser(new Asn1StreamParser(defIn));
case Asn1Tags.External:
return new DerExternalParser(new Asn1StreamParser(defIn));
default:
throw new IOException("unknown tag " + tagNo + " encountered");
}
}
// Some primitive encodings can be handled by parsers too...
switch (tagNo)
{
case Asn1Tags.OctetString:
return new DerOctetStringParser(defIn);
}
try
{
return Asn1InputStream.CreatePrimitiveDerObject(tagNo, defIn, tmpBuffers);
}
catch (ArgumentException e)
{
throw new Asn1Exception("corrupted stream detected", e);
}
}
}