Extending System.Formats.Asn1 to use other rules

[shaggygi]

I believe I asked (or searched around) before but couldn't find the answer on how it would be possible to extend System.Formats.Asn1 to use other rules. Meaning, use the API to read/wirte/encode/deocde bytes to and from objects other than the provided 3 types. The BACnet protocol (basic example below) defines the various objects/services and would be great to use this API (or at least utilize most of the provided). It does appear like there are a few items missing like Date, as well.

CCing @bartonjs or @stephentoub to see if they had some options. Thx

BACnetTimeStamp ::= CHOICE {
time [0] Time,
sequence-number [1] Unsigned (0..65535),
datetime [2] BACnetDateTime
}

An example of a context-tagged Boolean is below where it would produce a byte array of 0x2901.

Example: Context-tagged Boolean value
ASN.1 = [2] BOOLEAN
Value = TRUE
Context Tag = 2
Encoded Tag = X'29'
Encoded Data = X'01'

[shaggygi]

My bad, I meant to create this in the runtime repo. Closing this and added where it should have been created. Oops.

dotnet/runtime#88010