783 lines
27 KiB
Nim
783 lines
27 KiB
Nim
## Nim-Libp2p
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## Copyright (c) 2018 Status Research & Development GmbH
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## Licensed under either of
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## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
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## * MIT license ([LICENSE-MIT](LICENSE-MIT))
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## at your option.
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## This file may not be copied, modified, or distributed except according to
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## those terms.
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## This module implements minimal ASN.1 encoding/decoding primitives.
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import endians
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import nimcrypto/utils
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type
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Asn1Status* {.pure.} = enum
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Error,
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Success,
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Overflow,
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Incomplete,
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Indefinite,
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Incorrect,
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NoSupport,
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Overrun
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Asn1Class* {.pure.} = enum
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Universal = 0x00,
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Application = 0x01
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ContextSpecific = 0x02
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Private = 0x03
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Asn1Tag* {.pure.} = enum
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## Protobuf's field types enum
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NoSupport,
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Boolean,
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Integer,
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BitString,
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OctetString,
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Null,
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Oid,
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Sequence,
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Context
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Asn1Buffer* = object of RootObj
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## ASN.1's message representation object
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buffer*: seq[byte]
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offset*: int
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length*: int
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Asn1Field* = object
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klass*: Asn1Class
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index*: int
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offset*: int
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length*: int
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buffer*: seq[byte]
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case kind*: Asn1Tag
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of Asn1Tag.Boolean:
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vbool*: bool
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of Asn1Tag.Integer:
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vint*: uint64
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of Asn1Tag.BitString:
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ubits*: int
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else:
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discard
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Asn1Composite* = object of Asn1Buffer
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tag*: Asn1Tag
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idx*: int
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const
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Asn1OidSecp256r1* = [
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0x2A'u8, 0x86'u8, 0x48'u8, 0xCE'u8, 0x3D'u8, 0x03'u8, 0x01'u8, 0x07'u8
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]
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## Encoded OID for `secp256r1` curve (1.2.840.10045.3.1.7)
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Asn1OidSecp384r1* = [
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0x2B'u8, 0x81'u8, 0x04'u8, 0x00'u8, 0x22'u8
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]
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## Encoded OID for `secp384r1` curve (1.3.132.0.34)
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Asn1OidSecp521r1* = [
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0x2B'u8, 0x81'u8, 0x04'u8, 0x00'u8, 0x23'u8
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]
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## Encoded OID for `secp521r1` curve (1.3.132.0.35)
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Asn1OidSecp256k1* = [
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0x2B'u8, 0x81'u8, 0x04'u8, 0x00'u8, 0x0A'u8
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]
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## Encoded OID for `secp256k1` curve (1.3.132.0.10)
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Asn1OidEcPublicKey* = [
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0x2A'u8, 0x86'u8, 0x48'u8, 0xCE'u8, 0x3D'u8, 0x02'u8, 0x01'u8
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]
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## Encoded OID for Elliptic Curve Public Key (1.2.840.10045.2.1)
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Asn1OidRsaEncryption* = [
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0x2A'u8, 0x86'u8, 0x48'u8, 0x86'u8, 0xF7'u8, 0x0D'u8, 0x01'u8,
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0x01'u8, 0x01'u8
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]
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## Encoded OID for RSA Encryption (1.2.840.113549.1.1.1)
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Asn1True* = [0x01'u8, 0x01'u8, 0xFF'u8]
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## Encoded boolean ``TRUE``.
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Asn1False* = [0x01'u8, 0x01'u8, 0x00'u8]
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## Encoded boolean ``FALSE``.
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Asn1Null* = [0x05'u8, 0x00'u8]
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## Encoded ``NULL`` value.
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template toOpenArray*(ab: Asn1Buffer): untyped =
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toOpenArray(ab.buffer, ab.offset, len(ab.buffer) - 1)
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template toOpenArray*(ac: Asn1Composite): untyped =
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toOpenArray(ac.buffer, ac.offset, len(ac.buffer) - 1)
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template toOpenArray*(af: Asn1Field): untyped =
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toOpenArray(af.buffer, af.offset, af.offset + af.length - 1)
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template isEmpty*(ab: Asn1Buffer): bool =
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ab.offset >= len(ab.buffer)
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template isEnough*(ab: Asn1Buffer, length: int): bool =
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len(ab.buffer) >= ab.offset + length
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proc len*[T: Asn1Buffer|Asn1Composite](abc: T): int {.inline.} =
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len(abc.buffer) - abc.offset
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proc len*(field: Asn1Field): int {.inline.} =
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result = field.length
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template getPtr*(field: untyped): pointer =
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cast[pointer](unsafeAddr field.buffer[field.offset])
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proc extend*[T: Asn1Buffer|Asn1Composite](abc: var T, length: int) {.inline.} =
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## Extend buffer or composite's internal buffer by ``length`` octets.
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abc.buffer.setLen(len(abc.buffer) + length)
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proc code*(tag: Asn1Tag): byte {.inline.} =
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## Converts Nim ``tag`` enum to ASN.1 tag code.
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case tag:
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of Asn1Tag.NoSupport:
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0x00'u8
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of Asn1Tag.Boolean:
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0x01'u8
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of Asn1Tag.Integer:
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0x02'u8
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of Asn1Tag.BitString:
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0x03'u8
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of Asn1Tag.OctetString:
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0x04'u8
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of Asn1Tag.Null:
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0x05'u8
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of Asn1Tag.Oid:
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0x06'u8
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of Asn1Tag.Sequence:
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0x30'u8
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of Asn1Tag.Context:
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0xA0'u8
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proc asn1EncodeLength*(dest: var openarray[byte], length: int64): int =
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## Encode ASN.1 DER length part of TLV triple and return number of bytes
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## (octets) used.
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##
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## If length of ``dest`` is less then number of required bytes to encode
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## ``length`` value, then result of encoding will not be stored in ``dest``
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## but number of bytes (octets) required will be returned.
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if length < 0x80:
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if len(dest) >= 1:
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dest[0] = cast[byte](length)
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result = 1
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else:
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result = 0
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var z = length
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while z != 0:
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inc(result)
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z = z shr 8
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if len(dest) >= result + 1:
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dest[0] = cast[byte](0x80 + result)
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var o = 1
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for j in countdown(result - 1, 0):
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dest[o] = cast[byte](length shr (j shl 3))
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inc(o)
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inc(result)
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proc asn1EncodeInteger*(dest: var openarray[byte],
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value: openarray[byte]): int =
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## Encode big-endian binary representation of integer as ASN.1 DER `INTEGER`
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## and return number of bytes (octets) used.
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##
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## If length of ``dest`` is less then number of required bytes to encode
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## ``value``, then result of encoding will not be stored in ``dest``
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## but number of bytes (octets) required will be returned.
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var buffer: array[16, byte]
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var o = 0
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var lenlen = 0
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for i in 0..<len(value):
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if value[o] != 0x00:
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break
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inc(o)
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if len(value) > 0:
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if o == len(value):
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dec(o)
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if value[o] >= 0x80'u8:
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lenlen = asn1EncodeLength(buffer, len(value) - o + 1)
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result = 1 + lenlen + 1 + (len(value) - o)
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else:
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lenlen = asn1EncodeLength(buffer, len(value) - o)
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result = 1 + lenlen + (len(value) - o)
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else:
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result = 2
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if len(dest) >= result:
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var s = 1
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dest[0] = Asn1Tag.Integer.code()
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copyMem(addr dest[1], addr buffer[0], lenlen)
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if value[o] >= 0x80'u8:
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dest[1 + lenlen] = 0x00'u8
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s = 2
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if len(value) > 0:
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copyMem(addr dest[s + lenlen], unsafeAddr value[o], len(value) - o)
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proc asn1EncodeInteger*[T: SomeUnsignedInt](dest: var openarray[byte],
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value: T): int =
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## Encode Nim's unsigned integer as ASN.1 DER `INTEGER` and return number of
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## bytes (octets) used.
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##
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## If length of ``dest`` is less then number of required bytes to encode
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## ``value``, then result of encoding will not be stored in ``dest``
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## but number of bytes (octets) required will be returned.
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when T is uint64:
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var buffer: array[8, byte]
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bigEndian64(addr buffer[0], cast[pointer](unsafeAddr value))
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result = asn1EncodeInteger(dest, buffer)
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elif T is uint32:
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var buffer: array[4, byte]
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bigEndian32(addr buffer[0], cast[pointer](unsafeAddr value))
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result = asn1EncodeInteger(dest, buffer)
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elif T is uint16:
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var buffer: array[2, byte]
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bigEndian16(addr buffer[0], cast[pointer](unsafeAddr value))
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result = asn1EncodeInteger(dest, buffer)
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elif T is uint8:
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var buffer: array[1, byte]
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buffer[0] = value
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result = asn1EncodeInteger(dest, buffer)
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proc asn1EncodeBoolean*(dest: var openarray[byte], value: bool): int =
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## Encode Nim's boolean as ASN.1 DER `BOOLEAN` and return number of bytes
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## (octets) used.
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##
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## If length of ``dest`` is less then number of required bytes to encode
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## ``value``, then result of encoding will not be stored in ``dest``
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## but number of bytes (octets) required will be returned.
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result = 3
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if len(dest) >= result:
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dest[0] = Asn1Tag.Boolean.code()
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dest[1] = 0x01'u8
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dest[2] = if value: 0xFF'u8 else: 0x00'u8
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proc asn1EncodeNull*(dest: var openarray[byte]): int =
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## Encode ASN.1 DER `NULL` and return number of bytes (octets) used.
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##
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## If length of ``dest`` is less then number of required bytes to encode
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## ``value``, then result of encoding will not be stored in ``dest``
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## but number of bytes (octets) required will be returned.
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result = 2
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if len(dest) >= result:
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dest[0] = Asn1Tag.Null.code()
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dest[1] = 0x00'u8
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proc asn1EncodeOctetString*(dest: var openarray[byte],
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value: openarray[byte]): int =
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## Encode array of bytes as ASN.1 DER `OCTET STRING` and return number of
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## bytes (octets) used.
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##
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## If length of ``dest`` is less then number of required bytes to encode
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## ``value``, then result of encoding will not be stored in ``dest``
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## but number of bytes (octets) required will be returned.
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var buffer: array[16, byte]
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var lenlen = asn1EncodeLength(buffer, len(value))
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result = 1 + lenlen + len(value)
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if len(dest) >= result:
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dest[0] = Asn1Tag.OctetString.code()
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copyMem(addr dest[1], addr buffer[0], lenlen)
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if len(value) > 0:
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copyMem(addr dest[1 + lenlen], unsafeAddr value[0], len(value))
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proc asn1EncodeBitString*(dest: var openarray[byte],
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value: openarray[byte], bits = 0): int =
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## Encode array of bytes as ASN.1 DER `BIT STRING` and return number of bytes
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## (octets) used.
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##
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## ``bits`` number of used bits in ``value``. If ``bits == 0``, all the bits
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## from ``value`` are used, if ``bits != 0`` only number of ``bits`` will be
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## used.
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##
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## If length of ``dest`` is less then number of required bytes to encode
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## ``value``, then result of encoding will not be stored in ``dest``
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## but number of bytes (octets) required will be returned.
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var buffer: array[16, byte]
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var lenlen = asn1EncodeLength(buffer, len(value) + 1)
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var lbits = 0
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if bits != 0:
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lbits = len(value) shl 3 - bits
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result = 1 + lenlen + 1 + len(value)
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if len(dest) >= result:
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dest[0] = Asn1Tag.BitString.code()
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copyMem(addr dest[1], addr buffer[0], lenlen)
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dest[1 + lenlen] = cast[byte](lbits)
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if len(value) > 0:
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copyMem(addr dest[2 + lenlen], unsafeAddr value[0], len(value))
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proc asn1EncodeTag[T: SomeUnsignedInt](dest: var openarray[byte],
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value: T): int =
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var v = value
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if value <= cast[T](0x7F):
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if len(dest) >= 1:
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dest[0] = cast[byte](value)
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result = 1
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else:
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var s = 0
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while v != 0:
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v = v shr 7
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s += 7
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inc(result)
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if len(dest) >= result:
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var k = 0
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while s != 0:
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s -= 7
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dest[k] = cast[byte](((value shr s) and cast[T](0x7F)) or cast[T](0x80))
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inc(k)
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dest[k - 1] = dest[k - 1] and 0x7F'u8
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proc asn1EncodeOid*(dest: var openarray[byte], value: openarray[int]): int =
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## Encode array of integers ``value`` as ASN.1 DER `OBJECT IDENTIFIER` and
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## return number of bytes (octets) used.
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##
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## OBJECT IDENTIFIER requirements for ``value`` elements:
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## * len(value) >= 2
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## * value[0] >= 1 and value[0] < 2
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## * value[1] >= 1 and value[1] < 39
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##
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## If length of ``dest`` is less then number of required bytes to encode
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## ``value``, then result of encoding will not be stored in ``dest``
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## but number of bytes (octets) required will be returned.
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var buffer: array[16, byte]
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result = 1
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assert(len(value) >= 2)
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assert(value[0] >= 1 and value[0] < 2)
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assert(value[1] >= 1 and value[1] <= 39)
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var oidlen = 1
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for i in 2..<len(value):
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oidlen += asn1EncodeTag(buffer, cast[uint64](value[i]))
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result += asn1EncodeLength(buffer, oidlen)
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result += oidlen
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if len(dest) >= result:
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let last = len(dest) - 1
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var offset = 1
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dest[0] = Asn1Tag.Oid.code()
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offset += asn1EncodeLength(dest.toOpenArray(offset, last), oidlen)
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dest[offset] = cast[byte](value[0] * 40 + value[1])
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offset += 1
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for i in 2..<len(value):
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offset += asn1EncodeTag(dest.toOpenArray(offset, last),
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cast[uint64](value[i]))
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proc asn1EncodeOid*(dest: var openarray[byte], value: openarray[byte]): int =
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## Encode array of bytes ``value`` as ASN.1 DER `OBJECT IDENTIFIER` and return
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## number of bytes (octets) used.
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##
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## This procedure is useful to encode constant predefined identifiers such
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## as ``asn1OidSecp256r1``, ``asn1OidRsaEncryption``.
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##
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## If length of ``dest`` is less then number of required bytes to encode
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## ``value``, then result of encoding will not be stored in ``dest``
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## but number of bytes (octets) required will be returned.
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var buffer: array[16, byte]
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var lenlen = asn1EncodeLength(buffer, len(value))
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result = 1 + lenlen + len(value)
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if len(dest) >= result:
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dest[0] = Asn1Tag.Oid.code()
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copyMem(addr dest[1], addr buffer[0], lenlen)
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copyMem(addr dest[1 + lenlen], unsafeAddr value[0], len(value))
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proc asn1EncodeSequence*(dest: var openarray[byte],
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value: openarray[byte]): int =
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## Encode ``value`` as ASN.1 DER `SEQUENCE` and return number of bytes
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## (octets) used.
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##
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## If length of ``dest`` is less then number of required bytes to encode
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## ``value``, then result of encoding will not be stored in ``dest``
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## but number of bytes (octets) required will be returned.
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var buffer: array[16, byte]
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var lenlen = asn1EncodeLength(buffer, len(value))
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result = 1 + lenlen + len(value)
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if len(dest) >= result:
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dest[0] = Asn1Tag.Sequence.code()
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copyMem(addr dest[1], addr buffer[0], lenlen)
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copyMem(addr dest[1 + lenlen], unsafeAddr value[0], len(value))
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proc asn1EncodeComposite*(dest: var openarray[byte],
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value: Asn1Composite): int =
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## Encode composite value and return number of bytes (octets) used.
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##
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## If length of ``dest`` is less then number of required bytes to encode
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## ``value``, then result of encoding will not be stored in ``dest``
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## but number of bytes (octets) required will be returned.
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var buffer: array[16, byte]
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var lenlen = asn1EncodeLength(buffer, len(value.buffer))
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result = 1 + lenlen + len(value.buffer)
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if len(dest) >= result:
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dest[0] = value.tag.code()
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copyMem(addr dest[1], addr buffer[0], lenlen)
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copyMem(addr dest[1 + lenlen], unsafeAddr value.buffer[0],
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len(value.buffer))
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proc asn1EncodeContextTag*(dest: var openarray[byte], value: openarray[byte],
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tag: int): int =
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## Encode ASN.1 DER `CONTEXT SPECIFIC TAG` ``tag`` for value ``value`` and
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## return number of bytes (octets) used.
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##
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## If length of ``dest`` is less then number of required bytes to encode
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## ``value``, then result of encoding will not be stored in ``dest``
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## but number of bytes (octets) required will be returned.
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var buffer: array[16, byte]
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var lenlen = asn1EncodeLength(buffer, len(value))
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result = 1 + lenlen + len(value)
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if len(dest) >= result:
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dest[0] = 0xA0'u8 or (cast[byte](tag) and 0x0F)
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copyMem(addr dest[1], addr buffer[0], lenlen)
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copyMem(addr dest[1 + lenlen], unsafeAddr value[0], len(value))
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proc getLength(ab: var Asn1Buffer, length: var uint64): Asn1Status =
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## Decode length part of ASN.1 TLV triplet.
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result = Asn1Status.Incomplete
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if not ab.isEmpty():
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let b = ab.buffer[ab.offset]
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if (b and 0x80'u8) == 0x00'u8:
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length = cast[uint64](b)
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ab.offset += 1
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result = Asn1Status.Success
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return
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if b == 0x80'u8:
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length = 0'u64
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result = Asn1Status.Indefinite
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return
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if b == 0xFF'u8:
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length = 0'u64
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result = Asn1Status.Incorrect
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return
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let octets = cast[uint64](b and 0x7F'u8)
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if octets > 8'u64:
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length = 0'u64
|
|
result = Asn1Status.Overflow
|
|
return
|
|
length = 0'u64
|
|
if ab.isEnough(int(octets)):
|
|
for i in 0..<int(octets):
|
|
length = (length shl 8) or cast[uint64](ab.buffer[ab.offset + i + 1])
|
|
ab.offset = ab.offset + int(octets) + 1
|
|
result = Asn1Status.Success
|
|
|
|
proc getTag(ab: var Asn1Buffer, tag: var int,
|
|
klass: var Asn1Class): Asn1Status =
|
|
## Decode tag part of ASN.1 TLV triplet.
|
|
result = Asn1Status.Incomplete
|
|
if not ab.isEmpty():
|
|
let b = ab.buffer[ab.offset]
|
|
var c = int((b and 0xC0'u8) shr 6)
|
|
if c >= 0 and c < 4:
|
|
klass = cast[Asn1Class](c)
|
|
else:
|
|
return Asn1Status.Incorrect
|
|
tag = int(b and 0x3F)
|
|
ab.offset += 1
|
|
result = Asn1Status.Success
|
|
|
|
proc read*(ab: var Asn1Buffer, field: var Asn1Field): Asn1Status =
|
|
## Decode value part of ASN.1 TLV triplet.
|
|
var
|
|
tag, ttag, offset: int
|
|
length, tlength: uint64
|
|
klass: Asn1Class
|
|
res: Asn1Status
|
|
inclass: bool
|
|
|
|
inclass = false
|
|
while true:
|
|
offset = ab.offset
|
|
result = ab.getTag(tag, klass)
|
|
if result != Asn1Status.Success:
|
|
break
|
|
|
|
if klass == Asn1Class.ContextSpecific:
|
|
if inclass:
|
|
result = Asn1Status.Incorrect
|
|
break
|
|
inclass = true
|
|
ttag = tag
|
|
result = ab.getLength(tlength)
|
|
if result != Asn1Status.Success:
|
|
break
|
|
|
|
elif klass == Asn1Class.Universal:
|
|
result = ab.getLength(length)
|
|
if result != Asn1Status.Success:
|
|
break
|
|
|
|
if inclass:
|
|
if length >= tlength:
|
|
result = Asn1Status.Incorrect
|
|
break
|
|
|
|
if cast[byte](tag) == Asn1Tag.Boolean.code():
|
|
# BOOLEAN
|
|
if length != 1:
|
|
result = Asn1Status.Incorrect
|
|
break
|
|
if not ab.isEnough(cast[int](length)):
|
|
result = Asn1Status.Incomplete
|
|
break
|
|
let b = ab.buffer[ab.offset]
|
|
if b != 0xFF'u8 and b != 0x00'u8:
|
|
result = Asn1Status.Incorrect
|
|
break
|
|
field = Asn1Field(kind: Asn1Tag.Boolean, klass: klass,
|
|
index: ttag, offset: cast[int](ab.offset),
|
|
length: 1)
|
|
shallowCopy(field.buffer, ab.buffer)
|
|
field.vbool = (b == 0xFF'u8)
|
|
ab.offset += 1
|
|
result = Asn1Status.Success
|
|
break
|
|
elif cast[byte](tag) == Asn1Tag.Integer.code():
|
|
# INTEGER
|
|
if not ab.isEnough(cast[int](length)):
|
|
result = Asn1Status.Incomplete
|
|
break
|
|
if ab.buffer[ab.offset] == 0x00'u8:
|
|
length -= 1
|
|
ab.offset += 1
|
|
field = Asn1Field(kind: Asn1Tag.Integer, klass: klass,
|
|
index: ttag, offset: cast[int](ab.offset),
|
|
length: cast[int](length))
|
|
shallowCopy(field.buffer, ab.buffer)
|
|
if length <= 8:
|
|
for i in 0..<int(length):
|
|
field.vint = (field.vint shl 8) or
|
|
cast[uint64](ab.buffer[ab.offset + i])
|
|
ab.offset += cast[int](length)
|
|
result = Asn1Status.Success
|
|
break
|
|
elif cast[byte](tag) == Asn1Tag.BitString.code():
|
|
# BIT STRING
|
|
if not ab.isEnough(cast[int](length)):
|
|
result = Asn1Status.Incomplete
|
|
break
|
|
field = Asn1Field(kind: Asn1Tag.BitString, klass: klass,
|
|
index: ttag, offset: cast[int](ab.offset + 1),
|
|
length: cast[int](length - 1))
|
|
shallowCopy(field.buffer, ab.buffer)
|
|
field.ubits = cast[int](((length - 1) shl 3) - ab.buffer[ab.offset])
|
|
ab.offset += cast[int](length)
|
|
result = Asn1Status.Success
|
|
break
|
|
elif cast[byte](tag) == Asn1Tag.OctetString.code():
|
|
# OCT STRING
|
|
if not ab.isEnough(cast[int](length)):
|
|
result = Asn1Status.Incomplete
|
|
break
|
|
field = Asn1Field(kind: Asn1Tag.OctetString, klass: klass,
|
|
index: ttag, offset: cast[int](ab.offset),
|
|
length: cast[int](length))
|
|
shallowCopy(field.buffer, ab.buffer)
|
|
ab.offset += cast[int](length)
|
|
result = Asn1Status.Success
|
|
break
|
|
elif cast[byte](tag) == Asn1Tag.Null.code():
|
|
# NULL
|
|
if length != 0:
|
|
result = Asn1Status.Incorrect
|
|
break
|
|
field = Asn1Field(kind: Asn1Tag.Null, klass: klass,
|
|
index: ttag, offset: cast[int](ab.offset),
|
|
length: 0)
|
|
shallowCopy(field.buffer, ab.buffer)
|
|
ab.offset += cast[int](length)
|
|
result = Asn1Status.Success
|
|
break
|
|
elif cast[byte](tag) == Asn1Tag.Oid.code():
|
|
# OID
|
|
if not ab.isEnough(cast[int](length)):
|
|
result = Asn1Status.Incomplete
|
|
break
|
|
field = Asn1Field(kind: Asn1Tag.Oid, klass: klass,
|
|
index: ttag, offset: cast[int](ab.offset),
|
|
length: cast[int](length))
|
|
shallowCopy(field.buffer, ab.buffer)
|
|
ab.offset += cast[int](length)
|
|
result = Asn1Status.Success
|
|
break
|
|
elif cast[byte](tag) == Asn1Tag.Sequence.code():
|
|
# SEQUENCE
|
|
if not ab.isEnough(cast[int](length)):
|
|
result = Asn1Status.Incomplete
|
|
break
|
|
field = Asn1Field(kind: Asn1Tag.Sequence, klass: klass,
|
|
index: ttag, offset: cast[int](ab.offset),
|
|
length: cast[int](length))
|
|
shallowCopy(field.buffer, ab.buffer)
|
|
ab.offset += cast[int](length)
|
|
result = Asn1Status.Success
|
|
break
|
|
else:
|
|
result = Asn1Status.NoSupport
|
|
break
|
|
inclass = false
|
|
ttag = 0
|
|
else:
|
|
result = Asn1Status.NoSupport
|
|
break
|
|
|
|
proc getBuffer*(field: Asn1Field): Asn1Buffer =
|
|
## Return ``field`` as Asn1Buffer to enter composite types.
|
|
shallowCopy(result.buffer, field.buffer)
|
|
result.offset = field.offset
|
|
result.length = field.length
|
|
|
|
proc `==`*(field: Asn1Field, data: openarray[byte]): bool =
|
|
## Compares field ``field`` data with ``data`` and returns ``true`` if both
|
|
## buffers are equal.
|
|
let length = len(field.buffer)
|
|
if length > 0:
|
|
if field.length == len(data):
|
|
result = equalMem(unsafeAddr field.buffer[field.offset],
|
|
unsafeAddr data[0], field.length)
|
|
|
|
proc init*(t: typedesc[Asn1Buffer], data: openarray[byte]): Asn1Buffer =
|
|
## Initialize ``Asn1Buffer`` from array of bytes ``data``.
|
|
result.buffer = @data
|
|
|
|
proc init*(t: typedesc[Asn1Buffer], data: string): Asn1Buffer =
|
|
## Initialize ``Asn1Buffer`` from hexadecimal string ``data``.
|
|
result.buffer = fromHex(data)
|
|
|
|
proc init*(t: typedesc[Asn1Buffer]): Asn1Buffer =
|
|
## Initialize empty ``Asn1Buffer``.
|
|
result.buffer = newSeq[byte]()
|
|
|
|
proc init*(t: typedesc[Asn1Composite], tag: Asn1Tag): Asn1Composite =
|
|
## Initialize ``Asn1Composite`` with tag ``tag``.
|
|
result.tag = tag
|
|
result.buffer = newSeq[byte]()
|
|
|
|
proc init*(t: typedesc[Asn1Composite], idx: int): Asn1Composite =
|
|
## Initialize ``Asn1Composite`` with tag context-specific id ``id``.
|
|
result.tag = Asn1Tag.Context
|
|
result.idx = idx
|
|
result.buffer = newSeq[byte]()
|
|
|
|
proc `$`*(buffer: Asn1Buffer): string =
|
|
## Return string representation of ``buffer``.
|
|
result = toHex(buffer.toOpenArray())
|
|
|
|
proc `$`*(field: Asn1Field): string =
|
|
## Return string representation of ``field``.
|
|
result = "["
|
|
result.add($field.kind)
|
|
result.add("]")
|
|
if field.kind == Asn1Tag.NoSupport:
|
|
result.add(" ")
|
|
result.add(toHex(field.toOpenArray()))
|
|
elif field.kind == Asn1Tag.Boolean:
|
|
result.add(" ")
|
|
result.add($field.vbool)
|
|
elif field.kind == Asn1Tag.Integer:
|
|
result.add(" ")
|
|
if field.length <= 8:
|
|
result.add($field.vint)
|
|
else:
|
|
result.add(toHex(field.toOpenArray()))
|
|
elif field.kind == Asn1Tag.BitString:
|
|
result.add(" ")
|
|
result.add("(")
|
|
result.add($field.ubits)
|
|
result.add(" bits) ")
|
|
result.add(toHex(field.toOpenArray()))
|
|
elif field.kind == Asn1Tag.OctetString:
|
|
result.add(" ")
|
|
result.add(toHex(field.toOpenArray()))
|
|
elif field.kind == Asn1Tag.Null:
|
|
result.add(" NULL")
|
|
elif field.kind == Asn1Tag.Oid:
|
|
result.add(" ")
|
|
result.add(toHex(field.toOpenArray()))
|
|
elif field.kind == Asn1Tag.Sequence:
|
|
result.add(" ")
|
|
result.add(toHex(field.toOpenArray()))
|
|
|
|
proc write*[T: Asn1Buffer|Asn1Composite](abc: var T, tag: Asn1Tag) =
|
|
## Write empty value to buffer or composite with ``tag``.
|
|
##
|
|
## This procedure must be used to write `NULL`, `0` or empty `BIT STRING`,
|
|
## `OCTET STRING` types.
|
|
assert(tag in {Asn1Tag.Null, Asn1Tag.Integer, Asn1Tag.BitString,
|
|
Asn1Tag.OctetString})
|
|
var length: int
|
|
if tag == Asn1Tag.Null:
|
|
length = asn1EncodeNull(abc.toOpenArray())
|
|
abc.extend(length)
|
|
discard asn1EncodeNull(abc.toOpenArray())
|
|
elif tag == Asn1Tag.Integer:
|
|
length = asn1EncodeInteger(abc.toOpenArray(), 0'u64)
|
|
abc.extend(length)
|
|
discard asn1EncodeInteger(abc.toOpenArray(), 0'u64)
|
|
elif tag == Asn1Tag.BitString:
|
|
var tmp: array[1, byte]
|
|
length = asn1EncodeBitString(abc.toOpenArray(), tmp.toOpenArray(0, -1))
|
|
abc.extend(length)
|
|
discard asn1EncodeBitString(abc.toOpenArray(), tmp.toOpenArray(0, -1))
|
|
elif tag == Asn1Tag.OctetString:
|
|
var tmp: array[1, byte]
|
|
length = asn1EncodeOctetString(abc.toOpenArray(), tmp.toOpenArray(0, -1))
|
|
abc.extend(length)
|
|
discard asn1EncodeOctetString(abc.toOpenArray(), tmp.toOpenArray(0, -1))
|
|
abc.offset += length
|
|
|
|
proc write*[T: Asn1Buffer|Asn1Composite](abc: var T, value: uint64) =
|
|
## Write uint64 ``value`` to buffer or composite as ASN.1 `INTEGER`.
|
|
let length = asn1EncodeInteger(abc.toOpenArray(), value)
|
|
abc.extend(length)
|
|
discard asn1EncodeInteger(abc.toOpenArray(), value)
|
|
abc.offset += length
|
|
|
|
proc write*[T: Asn1Buffer|Asn1Composite](abc: var T, value: bool) =
|
|
## Write bool ``value`` to buffer or composite as ASN.1 `BOOLEAN`.
|
|
let length = asn1EncodeBoolean(abc.toOpenArray(), value)
|
|
abc.extend(length)
|
|
discard asn1EncodeBoolean(abc.toOpenArray(), value)
|
|
abc.offset += length
|
|
|
|
proc write*[T: Asn1Buffer|Asn1Composite](abc: var T, tag: Asn1Tag,
|
|
value: openarray[byte], bits = 0) =
|
|
## Write array ``value`` using ``tag``.
|
|
##
|
|
## This procedure is used to write ASN.1 `INTEGER`, `OCTET STRING`,
|
|
## `BIT STRING` or `OBJECT IDENTIFIER`.
|
|
##
|
|
## For `BIT STRING` you can use ``bits`` argument to specify number of used
|
|
## bits.
|
|
assert(tag in {Asn1Tag.Integer, Asn1Tag.OctetString, Asn1Tag.BitString,
|
|
Asn1Tag.Oid})
|
|
var length: int
|
|
if tag == Asn1Tag.Integer:
|
|
length = asn1EncodeInteger(abc.toOpenArray(), value)
|
|
abc.extend(length)
|
|
discard asn1EncodeInteger(abc.toOpenArray(), value)
|
|
elif tag == Asn1Tag.OctetString:
|
|
length = asn1EncodeOctetString(abc.toOpenArray(), value)
|
|
abc.extend(length)
|
|
discard asn1EncodeOctetString(abc.toOpenArray(), value)
|
|
elif tag == Asn1Tag.BitString:
|
|
length = asn1EncodeBitString(abc.toOpenArray(), value, bits)
|
|
abc.extend(length)
|
|
discard asn1EncodeBitString(abc.toOpenArray(), value, bits)
|
|
elif tag == Asn1Tag.Oid:
|
|
length = asn1EncodeOid(abc.toOpenArray(), value)
|
|
abc.extend(length)
|
|
discard asn1EncodeOid(abc.toOpenArray(), value)
|
|
abc.offset += length
|
|
|
|
proc write*[T: Asn1Buffer|Asn1Composite](abc: var T, value: Asn1Composite) =
|
|
assert(len(value) > 0, "Composite value not finished")
|
|
var length: int
|
|
if value.tag == Asn1Tag.Sequence:
|
|
length = asn1EncodeSequence(abc.toOpenArray(), value.buffer)
|
|
abc.extend(length)
|
|
discard asn1EncodeSequence(abc.toOpenArray(), value.buffer)
|
|
elif value.tag == Asn1Tag.BitString:
|
|
length = asn1EncodeBitString(abc.toOpenArray(), value.buffer)
|
|
abc.extend(length)
|
|
discard asn1EncodeBitString(abc.toOpenArray(), value.buffer)
|
|
elif value.tag == Asn1Tag.Context:
|
|
length = asn1EncodeContextTag(abc.toOpenArray(), value.buffer, value.idx)
|
|
abc.extend(length)
|
|
discard asn1EncodeContextTag(abc.toOpenArray(), value.buffer, value.idx)
|
|
abc.offset += length
|
|
|
|
proc finish*[T: Asn1Buffer|Asn1Composite](abc: var T) {.inline.} =
|
|
## Finishes buffer or composite and prepares it for writing.
|
|
abc.offset = 0
|