/// <summary>
/// Decode an LBER encoded value into an Asn1Object from an InputStream.
/// This method also returns the total length of this encoded
/// Asn1Object (length of type + length of length + length of content)
/// in the parameter len. This information is helpful when decoding
/// structured types.
/// </summary>
/// <param name="stream">The stream.</param>
/// <param name="len">The length.</param>
/// <returns>
/// Decoded Asn1Obect.
/// </returns>
/// <exception cref="EndOfStreamException">Unknown tag.</exception>
public static Asn1Object Decode(Stream stream, int[] len)
{
var asn1Id = new Asn1Identifier(stream);
var asn1Len = new Asn1Length(stream);
var length = asn1Len.Length;
len[0] = asn1Id.EncodedLength + asn1Len.EncodedLength + length;
if (asn1Id.Universal == false)
{
return(new Asn1Tagged(stream, length, (Asn1Identifier)asn1Id.Clone()));
}
switch (asn1Id.Tag)
{
case Asn1Sequence.Tag:
return(new Asn1Sequence(stream, length));
case Asn1Set.Tag:
return(new Asn1Set(stream, length));
case Asn1Boolean.Tag:
return(new Asn1Boolean(stream, length));
case Asn1Integer.Tag:
return(new Asn1Integer(stream, length));
case Asn1OctetString.Tag:
return(new Asn1OctetString(stream, length));
case Asn1Enumerated.Tag:
return(new Asn1Enumerated(stream, length));
case Asn1Null.Tag:
return(new Asn1Null()); // has no content to decode.
default:
throw new EndOfStreamException("Unknown tag");
}
}
/// <summary>
/// Decode an LBER encoded value into an Asn1Object from an InputStream.
/// This method also returns the total length of this encoded
/// Asn1Object (length of type + length of length + length of content)
/// in the parameter len. This information is helpful when decoding
/// structured types.
/// </summary>
/// <param name="stream">The stream.</param>
/// <param name="len">The length.</param>
/// <returns>
/// Decoded Asn1Obect
/// </returns>
/// <exception cref="EndOfStreamException">Unknown tag</exception>
public virtual Asn1Object Decode(Stream stream, int[] len)
{
asn1ID.Reset(stream);
asn1Len.Reset(stream);
var length = asn1Len.Length;
len[0] = asn1ID.EncodedLength + asn1Len.EncodedLength + length;
if (asn1ID.Universal == false)
{
return(new Asn1Tagged(this, stream, length, (Asn1Identifier)asn1ID.Clone()));
}
switch (asn1ID.Tag)
{
case Asn1Sequence.Tag:
return(new Asn1Sequence(this, stream, length));
case Asn1Set.Tag:
return(new Asn1Set(this, stream, length));
case Asn1Boolean.Tag:
return(new Asn1Boolean(this, stream, length));
case Asn1Integer.Tag:
return(new Asn1Integer(this, stream, length));
case Asn1OctetString.Tag:
return(new Asn1OctetString(this, stream, length));
case Asn1Enumerated.Tag:
return(new Asn1Enumerated(this, stream, length));
case Asn1Null.Tag:
return(new Asn1Null()); // has no content to decode.
default:
throw new EndOfStreamException("Unknown tag"); // !!! need a better exception
}
}