private static Asn1Node ReadUniversalNode(Asn1UniversalNodeType type, Asn1TagForm tagForm, Stream stream)
{
switch (type)
{
case Asn1UniversalNodeType.Boolean: return(Asn1Boolean.ReadFrom(stream));
case Asn1UniversalNodeType.Integer: return(Asn1Integer.ReadFrom(stream));
case Asn1UniversalNodeType.BitString: return(Asn1BitString.ReadFrom(stream));
case Asn1UniversalNodeType.OctetString: return(Asn1OctetString.ReadFrom(stream));
case Asn1UniversalNodeType.Null: return(Asn1Null.ReadFrom(stream));
case Asn1UniversalNodeType.ObjectId: return(Asn1ObjectIdentifier.ReadFrom(stream));
case Asn1UniversalNodeType.Utf8String: return(Asn1Utf8String.ReadFrom(stream));
case Asn1UniversalNodeType.PrintableString: return(Asn1PrintableString.ReadFrom(stream));
case Asn1UniversalNodeType.Ia5String: return(Asn1Ia5String.ReadFrom(stream));
case Asn1UniversalNodeType.UtcTime: return(Asn1UtcTime.ReadFrom(stream));
case Asn1UniversalNodeType.Sequence: return(Asn1Sequence.ReadFrom(stream));
case Asn1UniversalNodeType.Set: return(Asn1Set.ReadFrom(stream));
default:
throw new NotSupportedException($"unsupported universal type {type}");
}
}
public static Asn1DynamicArray ReadFrom(Asn1UniversalNodeType type, Stream stream)
{
Asn1DynamicArray array = new Asn1DynamicArray(type);
Asn1Node node;
while ((node = Asn1Node.ReadNode(stream)) != null)
{
array.Nodes.Add(node);
}
return(array);
}
public static Asn1CustomNode ReadFrom(Asn1UniversalNodeType type, Asn1TagForm tagForm, Stream stream)
{
if (tagForm == Asn1TagForm.Primitive)
{
var data = new byte[stream.Length];
stream.Read(data, 0, data.Length);
return(new Asn1CustomNode((int)type, tagForm)
{
Data = data
});
}
else
{
var res = new Asn1CustomNode((int)type, tagForm);
res.ReadChildren(stream);
return(res);
}
}
public static Asn1Node ReadNode(Stream stream)
{
var identifier = stream.ReadByte();
Asn1UniversalNodeType type = (Asn1UniversalNodeType)(identifier & 0x1f);
Asn1TagClass tagClass = (Asn1TagClass)(identifier >> 6);
Asn1TagForm tagForm = (Asn1TagForm)((identifier >> 5) & 1);
int?length = ReadTagLength(stream);
if (identifier == 0 && length == 0)
{
return(null); // EOC detected
}
if (length > stream.Length)
{
throw new Asn1ParsingException($"Try to read more bytes from stream than exists {length} > {stream.Length}");
}
if (length != null)
{
var data = new byte[(int)length];
stream.Read(data, 0, (int)length);
stream = new MemoryStream(data);
if (tagClass == Asn1TagClass.Universal)
{
var tag = ReadUniversalNode(type, tagForm, stream);
tag.TagClass = tagClass;
return(tag);
}
else
{
var tag = Asn1CustomNode.ReadFrom(type, tagForm, stream);
tag.TagClass = tagClass;
return(tag);
}
}
else
{
// We must just keep on reading the stream rather than keeping a separate memory buffer
Asn1DynamicArray tag = Asn1DynamicArray.ReadFrom(type, stream);
tag.TagClass = tagClass;
return(tag);
}
}
public bool Is(Asn1UniversalNodeType nodeType)
{
return(TagClass == Asn1TagClass.Universal && NodeType == nodeType);
}
public Asn1DynamicArray(Asn1UniversalNodeType type)
{
_type = type;
}
