urbit/sur/asn1.hoon
2018-12-11 11:38:44 -08:00

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:: |asn1: small selection of types and constants for ASN.1
::
:: A minimal representation of some basic ASN.1 types,
:: created to support PKCS keys, digests, and cert requests.
::
^?
|%
:: +bespoke:asn1: context-specific, generic ASN.1 tag type
::
:: Note that *explicit* implies *constructed* (ie, bit 5 is set in DER).
::
+= bespoke
:: imp: & is implicit, | is explicit
:: tag: 5 bits for the custom tag number
::
[imp=? tag=@ud]
:: +spec:asn1: minimal representations of basic ASN.1 types
::
+= spec
$% :: %int: arbitrary-sized, unsigned integers
::
:: Unsigned integers, represented as having a positive sign.
:: Negative integers would be two's complement in DER,
:: but we don't need them.
::
[%int int=@u]
:: %bit: very minimal support for bit strings
::
:: Specifically, values must already be padded and byte-aligned.
:: len: bitwidth
:: bit: data
::
[%bit len=@ud bit=@ux]
:: %oct: octets in little-endian byte order
::
:: len: bytewidth
:: bit: data
::
[%oct len=@ud oct=@ux]
:: %nul: fully supported!
::
[%nul ~]
:: %obj: object identifiers, pre-packed
::
:: Object identifiers are technically a sequence of integers,
:: represented here in their already-encoded form.
::
[%obj obj=@ux]
:: %seq: a list of specs
::
[%seq seq=(list spec)]
:: %set: a logical set of specs
::
:: Implemented here as a list for the sake of simplicity.
:: must be already deduplicated and sorted!
::
[%set set=(list spec)]
:: %con: context-specific
::
:: General support for context-specific tags.
:: bes: custom tag number, implicit or explicit
:: con: already-encoded bytes
::
[%con bes=bespoke con=(list @D)]
==
:: |obj:asn1: constant object ids, pre-encoded
::
++ obj
^?
|% :: rfc4055
++ sha-256 0x1.0204.0365.0148.8660 :: 2.16.840.1.101.3.4.2.1
++ rsa 0x1.0101.0df7.8648.862a :: 1.2.840.113549.1.1.1
++ rsa-sha-256 0xb.0101.0df7.8648.862a :: 1.2.840.113549.1.1.11
:: rfc2985
++ csr-ext 0xe.0901.0df7.8648.862a :: 1.2.840.113549.1.9.14
:: rfc3280
++ sub-alt 0x11.1d55 :: 2.5.29.17
--
--