Add minimal ASN.1 encoding/decoding primitives.
Add ASN.1 DER serialization for EC NIST curves.
This commit is contained in:
cheatfate
parent
467d8e1db6
commit
f67a7a2a3e
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@ -8,6 +8,7 @@
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## those terms.
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import common
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import nimcrypto/utils
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import minasn1
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const
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PubKey256Length* = 65
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@ -120,24 +121,6 @@ proc getOffset(seckey: EcPrivateKey): int {.inline.} =
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else:
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result = cast[int](o)
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proc copyKey(dest: var openarray[byte], seckey: EcPrivateKey): bool {.inline.} =
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let length = seckey.key.xlen
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if length > 0:
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if len(dest) >= length:
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let offset = getOffset(seckey)
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if offset >= 0:
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copyMem(addr dest[0], unsafeAddr seckey.buffer[offset], length - offset)
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result = true
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proc copyKey(dest: var openarray[byte], pubkey: EcPublicKey): bool {.inline.} =
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let length = pubkey.key.qlen
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if length > 0:
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if len(dest) >= length:
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let offset = getOffset(pubkey)
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if offset >= 0:
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copyMem(addr dest[0], unsafeAddr pubkey.buffer[offset], length - offset)
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result = true
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template getSignatureLength*(curve: EcCurveKind): int =
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case curve
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of Secp256r1:
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@ -313,57 +296,92 @@ proc `$`*(sig: EcSignature): string =
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else:
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result = toHex(sig.buffer)
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proc toBytes*(seckey: EcPrivateKey, data: var openarray[byte]): bool =
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## Serialize EC private key ``seckey`` to raw binary form and store it to
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## ``data``.
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proc toBytes*(seckey: EcPrivateKey, data: var openarray[byte]): int =
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## Serialize EC private key ``seckey`` to ASN.1 DER binary form and store it
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## to ``data``.
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##
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## If ``seckey`` curve is ``Secp256r1`` length of ``data`` array must be at
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## least ``SecKey256Length``.
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##
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## If ``seckey`` curve is ``Secp384r1`` length of ``data`` array must be at
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## least ``SecKey384Length``.
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##
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## If ``seckey`` curve is ``Secp521r1`` length of ``data`` array must be at
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## least ``SecKey521Length``.
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##
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## Procedure returns ``true`` if serialization successfull, ``false``
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## otherwise.
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## Procedure returns number of bytes (octets) needed to store EC private key,
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## or `0` if private key is not in supported curve.
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if seckey.key.curve in EcSupportedCurvesCint:
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if copyKey(data, seckey):
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result = true
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var offset, length: int
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var pubkey = seckey.getKey()
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var b = Asn1Buffer.init()
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var p = Asn1Composite.init(Asn1Tag.Sequence)
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var c0 = Asn1Composite.init(0)
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var c1 = Asn1Composite.init(1)
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if seckey.key.curve == BR_EC_SECP256R1:
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c0.write(Asn1Tag.Oid, Asn1OidSecp256r1)
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elif seckey.key.curve == BR_EC_SECP384R1:
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c0.write(Asn1Tag.Oid, Asn1OidSecp384r1)
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elif seckey.key.curve == BR_EC_SECP521R1:
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c0.write(Asn1Tag.Oid, Asn1OidSecp521r1)
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c0.finish()
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offset = pubkey.getOffset()
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length = pubkey.key.qlen
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c1.write(Asn1Tag.BitString,
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pubkey.buffer.toOpenArray(offset, offset + length - 1))
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c1.finish()
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offset = seckey.getOffset()
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length = seckey.key.xlen
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p.write(1'u64)
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p.write(Asn1Tag.OctetString,
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seckey.buffer.toOpenArray(offset, offset + length - 1))
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p.write(c0)
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p.write(c1)
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p.finish()
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b.write(p)
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b.finish()
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result = len(b)
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if len(data) >= len(b):
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copyMem(addr data[0], addr b.buffer[0], len(b))
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proc toBytes*(pubkey: EcPublicKey, data: var openarray[byte]): bool =
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## Serialize EC public key ``pubkey`` to raw binary form and store it to
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## ``data``.
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proc toBytes*(pubkey: EcPublicKey, data: var openarray[byte]): int =
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## Serialize EC public key ``pubkey`` to ASN.1 DER binary form and store it
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## to ``data``.
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##
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## If ``pubkey`` curve is ``Secp256r1`` length of ``data`` array must be at
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## least ``PubKey256Length``.
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##
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## If ``pubkey`` curve is ``Secp384r1`` length of ``data`` array must be at
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## least ``PubKey384Length``.
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##
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## If ``pubkey`` curve is ``Secp521r1`` length of ``data`` array must be at
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## least ``PubKey521Length``.
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##
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## Procedure returns ``true`` if serialization successfull, ``false``
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## otherwise.
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## Procedure returns number of bytes (octets) needed to store EC public key,
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## or `0` if public key is not in supported curve.
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if pubkey.key.curve in EcSupportedCurvesCint:
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if copyKey(data, pubkey):
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result = true
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var b = Asn1Buffer.init()
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var p = Asn1Composite.init(Asn1Tag.Sequence)
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var c = Asn1Composite.init(Asn1Tag.Sequence)
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c.write(Asn1Tag.Oid, Asn1OidEcPublicKey)
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if pubkey.key.curve == BR_EC_SECP256R1:
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c.write(Asn1Tag.Oid, Asn1OidSecp256r1)
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elif pubkey.key.curve == BR_EC_SECP384R1:
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c.write(Asn1Tag.Oid, Asn1OidSecp384r1)
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elif pubkey.key.curve == BR_EC_SECP521R1:
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c.write(Asn1Tag.Oid, Asn1OidSecp521r1)
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c.finish()
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p.write(c)
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let offset = getOffset(pubkey)
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let length = pubkey.key.qlen
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p.write(Asn1Tag.BitString,
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pubkey.buffer.toOpenArray(offset, offset + length - 1))
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p.finish()
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b.write(p)
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b.finish()
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result = len(b)
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if len(data) >= len(b):
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copyMem(addr data[0], addr b.buffer[0], len(b))
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proc getBytes*(seckey: EcPrivateKey): seq[byte] =
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## Serialize EC private key ``seckey`` to raw binary form and return it.
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## Serialize EC private key ``seckey`` to ASN.1 DER binary form and return it.
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if seckey.key.curve in EcSupportedCurvesCint:
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result = newSeq[byte](seckey.key.xlen)
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discard toBytes(seckey, result)
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result = newSeq[byte]()
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let length = seckey.toBytes(result)
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result.setLen(length)
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discard seckey.toBytes(result)
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else:
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raise newException(EcKeyIncorrectError, "Incorrect private key")
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proc getBytes*(pubkey: EcPublicKey): seq[byte] =
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## Serialize EC public key ``pubkey`` to raw binary form and return it.
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## Serialize EC public key ``pubkey`` to ASN.1 DER binary form and return it.
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if pubkey.key.curve in EcSupportedCurvesCint:
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result = newSeq[byte](pubkey.key.qlen)
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discard toBytes(pubkey, result)
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result = newSeq[byte]()
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let length = pubkey.toBytes(result)
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result.setLen(length)
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discard pubkey.toBytes(result)
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else:
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raise newException(EcKeyIncorrectError, "Incorrect public key")
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@ -399,67 +417,127 @@ proc `==`*(sig1, sig2: EcSignature): bool =
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return false
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result = (sig1.buffer == sig2.buffer)
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proc init*(key: var EcPrivateKey, data: openarray[byte]): bool =
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## Initialize EC `private key` or `scalar` ``key`` from raw binary
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proc init*(key: var EcPrivateKey, data: openarray[byte]): Asn1Status =
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## Initialize EC `private key` or `scalar` ``key`` from ASN.1 DER binary
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## representation ``data``.
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##
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## Length of ``data`` array must be ``SecKey256Length``, ``SecKey384Length``
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## or ``SecKey521Length``.
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##
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## Procedure returns ``true`` on success, ``false`` otherwise.
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## Procedure returns ``Asn1Status``.
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var raw, oid, field: Asn1Field
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var curve: cint
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if len(data) == SecKey256Length:
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curve = cast[cint](Secp256r1)
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result = true
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elif len(data) == SecKey384Length:
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curve = cast[cint](Secp384r1)
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result = true
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elif len(data) == SecKey521Length:
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curve = cast[cint](Secp521r1)
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result = true
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if result:
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result = false
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if checkScalar(data, curve) == 1'u32:
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let length = len(data)
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key = new EcPrivateKey
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key.buffer = newSeq[byte](length)
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copyMem(addr key.buffer[0], unsafeAddr data[0], length)
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key.key.x = cast[ptr cuchar](addr key.buffer[0])
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key.key.xlen = length
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key.key.curve = curve
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result = true
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proc init*(pubkey: var EcPublicKey, data: openarray[byte]): bool =
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## Initialize EC public key ``pubkey`` from raw binary representation
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var ab = Asn1Buffer.init(data)
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result = ab.read(field)
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if result != Asn1Status.Success:
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return
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if field.kind != Asn1Tag.Sequence:
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return Asn1Status.Incorrect
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var ib = field.getBuffer()
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result = ib.read(field)
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if result != Asn1Status.Success:
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return
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if field.kind != Asn1Tag.Integer:
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return Asn1Status.Incorrect
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if field.vint != 1'u64:
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return Asn1Status.Incorrect
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result = ib.read(raw)
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if result != Asn1Status.Success:
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return
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if raw.kind != Asn1Tag.OctetString:
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return Asn1Status.Incorrect
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result = ib.read(oid)
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if result != Asn1Status.Success:
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return
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if oid.kind != Asn1Tag.Oid:
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return Asn1Status.Incorrect
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if oid == Asn1OidSecp256r1:
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curve = cast[cint](Secp256r1)
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elif oid == Asn1OidSecp384r1:
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curve = cast[cint](Secp384r1)
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elif oid == Asn1OidSecp521r1:
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curve = cast[cint](Secp521r1)
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else:
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return Asn1Status.Incorrect
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if checkScalar(raw.toOpenArray(), curve) == 1'u32:
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key = new EcPrivateKey
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key.buffer = newSeq[byte](raw.length)
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copyMem(addr key.buffer[0], addr raw.buffer[raw.offset], raw.length)
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key.key.x = cast[ptr cuchar](addr key.buffer[0])
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key.key.xlen = raw.length
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key.key.curve = curve
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result = Asn1Status.Success
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else:
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result = Asn1Status.Incorrect
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proc init*(pubkey: var EcPublicKey, data: openarray[byte]): Asn1Status =
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## Initialize EC public key ``pubkey`` from ASN.1 DER binary representation
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## ``data``.
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##
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## Length of ``data`` array must be ``PubKey256Length``, ``PubKey384Length``
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## or ``PubKey521Length``.
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##
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## Procedure returns ``true`` on success, ``false`` otherwise.
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## Procedure returns ``Asn1Status``.
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var raw, oid, field: Asn1Field
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var curve: cint
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if len(data) > 0:
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if data[0] == 0x04'u8:
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if len(data) == PubKey256Length:
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var ab = Asn1Buffer.init(data)
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result = ab.read(field)
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if result != Asn1Status.Success:
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return
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if field.kind != Asn1Tag.Sequence:
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return Asn1Status.Incorrect
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var ib = field.getBuffer()
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result = ib.read(field)
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if result != Asn1Status.Success:
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return
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if field.kind != Asn1Tag.Sequence:
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return Asn1Status.Incorrect
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var ob = field.getBuffer()
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result = ob.read(oid)
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if result != Asn1Status.Success:
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return
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if oid.kind != Asn1Tag.Oid:
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return Asn1Status.Incorrect
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if oid != Asn1OidEcPublicKey:
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return Asn1Status.Incorrect
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result = ob.read(oid)
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if result != Asn1Status.Success:
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return
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if oid.kind != Asn1Tag.Oid:
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return Asn1Status.Incorrect
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if oid == Asn1OidSecp256r1:
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curve = cast[cint](Secp256r1)
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result = true
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elif len(data) == PubKey384Length:
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elif oid == Asn1OidSecp384r1:
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curve = cast[cint](Secp384r1)
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result = true
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elif len(data) == PubKey521Length:
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elif oid == Asn1OidSecp521r1:
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curve = cast[cint](Secp521r1)
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result = true
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if result:
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result = false
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if checkPublic(data, curve) != 0:
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let length = len(data)
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else:
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return Asn1Status.Incorrect
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result = ib.read(raw)
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if result != Asn1Status.Success:
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return
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if raw.kind != Asn1Tag.BitString:
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return Asn1Status.Incorrect
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if checkPublic(raw.toOpenArray(), curve) != 0:
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pubkey = new EcPublicKey
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pubkey.buffer = newSeq[byte](length)
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copyMem(addr pubkey.buffer[0], unsafeAddr data[0], length)
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pubkey.buffer = newSeq[byte](raw.length)
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copyMem(addr pubkey.buffer[0], addr raw.buffer[raw.offset], raw.length)
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pubkey.key.q = cast[ptr cuchar](addr pubkey.buffer[0])
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pubkey.key.qlen = length
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pubkey.key.qlen = raw.length
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pubkey.key.curve = curve
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result = true
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result = Asn1Status.Success
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else:
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result = Asn1Status.Incorrect
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proc init*(sig: var EcSignature, data: openarray[byte]): bool =
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## Initialize EC signature ``sig`` from raw binary representation ``data``.
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@ -493,16 +571,20 @@ proc init*[T: EcPKI](sospk: var T, data: string): bool {.inline.} =
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result = sospk.init(fromHex(data))
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proc init*(t: typedesc[EcPrivateKey], data: openarray[byte]): EcPrivateKey =
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## Initialize EC private key from raw binary representation ``data`` and
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## Initialize EC private key from ASN.1 DER binary representation ``data`` and
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## return constructed object.
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if not result.init(data):
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raise newException(EcKeyIncorrectError, "Incorrect private key")
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let res = result.init(data)
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if res != Asn1Status.Success:
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raise newException(EcKeyIncorrectError,
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"Incorrect private key (" & $res & ")")
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proc init*(t: typedesc[EcPublicKey], data: openarray[byte]): EcPublicKey =
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## Initialize EC public key from raw binary representation ``data`` and
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## Initialize EC public key from ASN.1 DER binary representation ``data`` and
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## return constructed object.
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if not result.init(data):
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raise newException(EcKeyIncorrectError, "Incorrect public key")
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let res = result.init(data)
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if res != Asn1Status.Success:
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raise newException(EcKeyIncorrectError,
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"Incorrect public key (" & $res & ")")
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proc init*(t: typedesc[EcSignature], data: openarray[byte]): EcSignature =
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## Initialize EC signature from raw binary representation ``data`` and
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@ -585,3 +667,20 @@ proc verify*[T: byte|char](sig: EcSignature, message: openarray[T],
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# Clear context with initial value
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kv.init(addr hc.vtable)
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result = (res == 1)
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when isMainModule:
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var buffer = newSeq[byte]()
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var kp = EcKeyPair.random(Secp256r1)
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var length: int
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var serializedSK = kp.seckey.getBytes()
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var serializedPK = kp.pubkey.getBytes()
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echo toHex(serializedPK)
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echo toHex(serializedSK)
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var kp2 = EcPrivateKey.init(serializedSK)
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echo toHex(kp2.getBytes())
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var pk2 = EcPublicKey.init(serializedPK)
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echo repr pk2
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echo toHex(pk2.getBytes())
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@ -0,0 +1,773 @@
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## 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
|
||||
length*: int
|
||||
buffer*: seq[byte]
|
||||
case kind*: Asn1Tag
|
||||
of Asn1Tag.Boolean:
|
||||
vbool*: bool
|
||||
of Asn1Tag.Integer:
|
||||
vint*: uint64
|
||||
of Asn1Tag.BitString:
|
||||
ubits*: int
|
||||
else:
|
||||
discard
|
||||
|
||||
Asn1Composite* = object of Asn1Buffer
|
||||
tag*: Asn1Tag
|
||||
idx*: int
|
||||
|
||||
const
|
||||
Asn1OidSecp256r1* = [
|
||||
0x2A'u8, 0x86'u8, 0x48'u8, 0xCE'u8, 0x3D'u8, 0x03'u8, 0x01'u8, 0x07'u8
|
||||
]
|
||||
## Encoded OID for `secp256r1` curve (1.2.840.10045.3.1.7)
|
||||
Asn1OidSecp384r1* = [
|
||||
0x2B'u8, 0x81'u8, 0x04'u8, 0x00'u8, 0x22'u8
|
||||
]
|
||||
## Encoded OID for `secp384r1` curve (1.3.132.0.34)
|
||||
Asn1OidSecp521r1* = [
|
||||
0x2B'u8, 0x81'u8, 0x04'u8, 0x00'u8, 0x23'u8
|
||||
]
|
||||
## Encoded OID for `secp521r1` curve (1.3.132.0.35)
|
||||
Asn1OidSecp256k1* = [
|
||||
0x2B'u8, 0x81'u8, 0x04'u8, 0x00'u8, 0x0A'u8
|
||||
]
|
||||
## Encoded OID for `secp256k1` curve (1.3.132.0.10)
|
||||
Asn1OidEcPublicKey* = [
|
||||
0x2A'u8, 0x86'u8, 0x48'u8, 0xCE'u8, 0x3D'u8, 0x02'u8, 0x01'u8
|
||||
]
|
||||
## Encoded OID for Elliptic Curve Public Key (1.2.840.10045.2.1)
|
||||
Asn1OidRsaEncryption* = [
|
||||
0x2A'u8, 0x86'u8, 0x48'u8, 0x86'u8, 0xF7'u8, 0x0D'u8, 0x01'u8,
|
||||
0x01'u8, 0x01'u8
|
||||
]
|
||||
## Encoded OID for RSA Encryption (1.2.840.113549.1.1.1)
|
||||
Asn1True* = [0x01'u8, 0x01'u8, 0xFF'u8]
|
||||
## Encoded boolean ``TRUE``.
|
||||
Asn1False* = [0x01'u8, 0x01'u8, 0x00'u8]
|
||||
## Encoded boolean ``FALSE``.
|
||||
Asn1Null* = [0x05'u8, 0x00'u8]
|
||||
## Encoded ``NULL`` value.
|
||||
|
||||
template toOpenArray*(ab: Asn1Buffer): untyped =
|
||||
toOpenArray(ab.buffer, ab.offset, len(ab.buffer) - 1)
|
||||
|
||||
template toOpenArray*(ac: Asn1Composite): untyped =
|
||||
toOpenArray(ac.buffer, ac.offset, len(ac.buffer) - 1)
|
||||
|
||||
template toOpenArray*(af: Asn1Field): untyped =
|
||||
toOpenArray(af.buffer, af.offset, af.offset + af.length - 1)
|
||||
|
||||
template isEmpty*(ab: Asn1Buffer): bool =
|
||||
ab.offset >= len(ab.buffer)
|
||||
|
||||
template isEnough*(ab: Asn1Buffer, length: int): bool =
|
||||
len(ab.buffer) >= ab.offset + length
|
||||
|
||||
proc len*[T: Asn1Buffer|Asn1Composite](abc: T): int {.inline.} =
|
||||
len(abc.buffer) - abc.offset
|
||||
|
||||
proc extend*[T: Asn1Buffer|Asn1Composite](abc: var T, length: int) {.inline.} =
|
||||
## Extend buffer or composite's internal buffer by ``length`` octets.
|
||||
abc.buffer.setLen(len(abc.buffer) + length)
|
||||
|
||||
proc code*(tag: Asn1Tag): byte {.inline.} =
|
||||
## Converts Nim ``tag`` enum to ASN.1 tag code.
|
||||
case tag:
|
||||
of Asn1Tag.NoSupport:
|
||||
0x00'u8
|
||||
of Asn1Tag.Boolean:
|
||||
0x01'u8
|
||||
of Asn1Tag.Integer:
|
||||
0x02'u8
|
||||
of Asn1Tag.BitString:
|
||||
0x03'u8
|
||||
of Asn1Tag.OctetString:
|
||||
0x04'u8
|
||||
of Asn1Tag.Null:
|
||||
0x05'u8
|
||||
of Asn1Tag.Oid:
|
||||
0x06'u8
|
||||
of Asn1Tag.Sequence:
|
||||
0x30'u8
|
||||
of Asn1Tag.Context:
|
||||
0xA0'u8
|
||||
|
||||
proc asn1EncodeLength*(dest: var openarray[byte], length: int64): int =
|
||||
## Encode ASN.1 DER length part of TLV triple and return number of bytes
|
||||
## (octets) used.
|
||||
##
|
||||
## If length of ``dest`` is less then number of required bytes to encode
|
||||
## ``length`` value, then result of encoding will not be stored in ``dest``
|
||||
## but number of bytes (octets) required will be returned.
|
||||
if length < 0x80:
|
||||
if len(dest) >= 1:
|
||||
dest[0] = cast[byte](length)
|
||||
result = 1
|
||||
else:
|
||||
result = 0
|
||||
var z = length
|
||||
while z != 0:
|
||||
inc(result)
|
||||
z = z shr 8
|
||||
if len(dest) >= result + 1:
|
||||
dest[0] = cast[byte](0x80 + result)
|
||||
var o = 1
|
||||
for j in countdown(result - 1, 0):
|
||||
dest[o] = cast[byte](length shr (j shl 3))
|
||||
inc(o)
|
||||
inc(result)
|
||||
|
||||
proc asn1EncodeInteger*(dest: var openarray[byte],
|
||||
value: openarray[byte]): int =
|
||||
## Encode big-endian binary representation of integer as ASN.1 DER `INTEGER`
|
||||
## and return number of bytes (octets) used.
|
||||
##
|
||||
## If length of ``dest`` is less then number of required bytes to encode
|
||||
## ``value``, then result of encoding will not be stored in ``dest``
|
||||
## but number of bytes (octets) required will be returned.
|
||||
var buffer: array[16, byte]
|
||||
var o = 0
|
||||
var lenlen = 0
|
||||
for i in 0..<len(value):
|
||||
if value[o] != 0x00:
|
||||
break
|
||||
inc(o)
|
||||
if len(value) > 0:
|
||||
if o == len(value):
|
||||
dec(o)
|
||||
if value[o] >= 0x80'u8:
|
||||
lenlen = asn1EncodeLength(buffer, len(value) - o + 1)
|
||||
result = 1 + lenlen + 1 + (len(value) - o)
|
||||
else:
|
||||
lenlen = asn1EncodeLength(buffer, len(value) - o)
|
||||
result = 1 + lenlen + (len(value) - o)
|
||||
else:
|
||||
result = 2
|
||||
if len(dest) >= result:
|
||||
var s = 1
|
||||
dest[0] = Asn1Tag.Integer.code()
|
||||
copyMem(addr dest[1], addr buffer[0], lenlen)
|
||||
if value[o] >= 0x80'u8:
|
||||
dest[1 + lenlen] = 0x00'u8
|
||||
s = 2
|
||||
if len(value) > 0:
|
||||
copyMem(addr dest[s + lenlen], unsafeAddr value[o], len(value) - o)
|
||||
|
||||
proc asn1EncodeInteger*[T: SomeUnsignedInt](dest: var openarray[byte],
|
||||
value: T): int =
|
||||
## Encode Nim's unsigned integer as ASN.1 DER `INTEGER` and return number of
|
||||
## bytes (octets) used.
|
||||
##
|
||||
## If length of ``dest`` is less then number of required bytes to encode
|
||||
## ``value``, then result of encoding will not be stored in ``dest``
|
||||
## but number of bytes (octets) required will be returned.
|
||||
when T is uint64:
|
||||
var buffer: array[8, byte]
|
||||
bigEndian64(addr buffer[0], cast[pointer](unsafeAddr value))
|
||||
result = asn1EncodeInteger(dest, buffer)
|
||||
elif T is uint32:
|
||||
var buffer: array[4, byte]
|
||||
bigEndian32(addr buffer[0], cast[pointer](unsafeAddr value))
|
||||
result = asn1EncodeInteger(dest, buffer)
|
||||
elif T is uint16:
|
||||
var buffer: array[2, byte]
|
||||
bigEndian16(addr buffer[0], cast[pointer](unsafeAddr value))
|
||||
result = asn1EncodeInteger(dest, buffer)
|
||||
elif T is uint8:
|
||||
var buffer: array[1, byte]
|
||||
buffer[0] = value
|
||||
result = asn1EncodeInteger(dest, buffer)
|
||||
|
||||
proc asn1EncodeBoolean*(dest: var openarray[byte], value: bool): int =
|
||||
## Encode Nim's boolean as ASN.1 DER `BOOLEAN` and return number of bytes
|
||||
## (octets) used.
|
||||
##
|
||||
## If length of ``dest`` is less then number of required bytes to encode
|
||||
## ``value``, then result of encoding will not be stored in ``dest``
|
||||
## but number of bytes (octets) required will be returned.
|
||||
result = 3
|
||||
if len(dest) >= result:
|
||||
dest[0] = Asn1Tag.Boolean.code()
|
||||
dest[1] = 0x01'u8
|
||||
dest[2] = if value: 0xFF'u8 else: 0x00'u8
|
||||
|
||||
proc asn1EncodeNull*(dest: var openarray[byte]): int =
|
||||
## Encode ASN.1 DER `NULL` and return number of bytes (octets) used.
|
||||
##
|
||||
## If length of ``dest`` is less then number of required bytes to encode
|
||||
## ``value``, then result of encoding will not be stored in ``dest``
|
||||
## but number of bytes (octets) required will be returned.
|
||||
result = 2
|
||||
if len(dest) >= result:
|
||||
dest[0] = Asn1Tag.Null.code()
|
||||
dest[1] = 0x00'u8
|
||||
|
||||
proc asn1EncodeOctetString*(dest: var openarray[byte],
|
||||
value: openarray[byte]): int =
|
||||
## Encode array of bytes as ASN.1 DER `OCTET STRING` and return number of
|
||||
## bytes (octets) used.
|
||||
##
|
||||
## If length of ``dest`` is less then number of required bytes to encode
|
||||
## ``value``, then result of encoding will not be stored in ``dest``
|
||||
## but number of bytes (octets) required will be returned.
|
||||
var buffer: array[16, byte]
|
||||
var lenlen = asn1EncodeLength(buffer, len(value))
|
||||
result = 1 + lenlen + len(value)
|
||||
if len(dest) >= result:
|
||||
dest[0] = Asn1Tag.OctetString.code()
|
||||
copyMem(addr dest[1], addr buffer[0], lenlen)
|
||||
if len(value) > 0:
|
||||
copyMem(addr dest[1 + lenlen], unsafeAddr value[0], len(value))
|
||||
|
||||
proc asn1EncodeBitString*(dest: var openarray[byte],
|
||||
value: openarray[byte], bits = 0): int =
|
||||
## Encode array of bytes as ASN.1 DER `BIT STRING` and return number of bytes
|
||||
## (octets) used.
|
||||
##
|
||||
## ``bits`` number of used bits in ``value``. If ``bits == 0``, all the bits
|
||||
## from ``value`` are used, if ``bits != 0`` only number of ``bits`` will be
|
||||
## used.
|
||||
##
|
||||
## If length of ``dest`` is less then number of required bytes to encode
|
||||
## ``value``, then result of encoding will not be stored in ``dest``
|
||||
## but number of bytes (octets) required will be returned.
|
||||
var buffer: array[16, byte]
|
||||
var lenlen = asn1EncodeLength(buffer, len(value) + 1)
|
||||
var lbits = 0
|
||||
if bits != 0:
|
||||
lbits = len(value) shl 3 - bits
|
||||
result = 1 + lenlen + 1 + len(value)
|
||||
if len(dest) >= result:
|
||||
dest[0] = Asn1Tag.BitString.code()
|
||||
copyMem(addr dest[1], addr buffer[0], lenlen)
|
||||
dest[1 + lenlen] = cast[byte](lbits)
|
||||
if len(value) > 0:
|
||||
copyMem(addr dest[2 + lenlen], unsafeAddr value[0], len(value))
|
||||
|
||||
proc asn1EncodeTag[T: SomeUnsignedInt](dest: var openarray[byte],
|
||||
value: T): int =
|
||||
var v = value
|
||||
if value <= cast[T](0x7F):
|
||||
if len(dest) >= 1:
|
||||
dest[0] = cast[byte](value)
|
||||
result = 1
|
||||
else:
|
||||
var s = 0
|
||||
while v != 0:
|
||||
v = v shr 7
|
||||
s += 7
|
||||
inc(result)
|
||||
if len(dest) >= result:
|
||||
var k = 0
|
||||
while s != 0:
|
||||
s -= 7
|
||||
dest[k] = cast[byte](((value shr s) and cast[T](0x7F)) or cast[T](0x80))
|
||||
inc(k)
|
||||
dest[k - 1] = dest[k - 1] and 0x7F'u8
|
||||
|
||||
proc asn1EncodeOid*(dest: var openarray[byte], value: openarray[int]): int =
|
||||
## Encode array of integers ``value`` as ASN.1 DER `OBJECT IDENTIFIER` and
|
||||
## return number of bytes (octets) used.
|
||||
##
|
||||
## OBJECT IDENTIFIER requirements for ``value`` elements:
|
||||
## * len(value) >= 2
|
||||
## * value[0] >= 1 and value[0] < 2
|
||||
## * value[1] >= 1 and value[1] < 39
|
||||
##
|
||||
## If length of ``dest`` is less then number of required bytes to encode
|
||||
## ``value``, then result of encoding will not be stored in ``dest``
|
||||
## but number of bytes (octets) required will be returned.
|
||||
var buffer: array[16, byte]
|
||||
result = 1
|
||||
assert(len(value) >= 2)
|
||||
assert(value[0] >= 1 and value[0] < 2)
|
||||
assert(value[1] >= 1 and value[1] <= 39)
|
||||
var oidlen = 1
|
||||
for i in 2..<len(value):
|
||||
oidlen += asn1EncodeTag(buffer, cast[uint64](value[i]))
|
||||
result += asn1EncodeLength(buffer, oidlen)
|
||||
result += oidlen
|
||||
if len(dest) >= result:
|
||||
let last = len(dest) - 1
|
||||
var offset = 1
|
||||
dest[0] = Asn1Tag.Oid.code()
|
||||
offset += asn1EncodeLength(dest.toOpenArray(offset, last), oidlen)
|
||||
dest[offset] = cast[byte](value[0] * 40 + value[1])
|
||||
offset += 1
|
||||
for i in 2..<len(value):
|
||||
offset += asn1EncodeTag(dest.toOpenArray(offset, last),
|
||||
cast[uint64](value[i]))
|
||||
|
||||
proc asn1EncodeOid*(dest: var openarray[byte], value: openarray[byte]): int =
|
||||
## Encode array of bytes ``value`` as ASN.1 DER `OBJECT IDENTIFIER` and return
|
||||
## number of bytes (octets) used.
|
||||
##
|
||||
## This procedure is useful to encode constant predefined identifiers such
|
||||
## as ``asn1OidSecp256r1``, ``asn1OidRsaEncryption``.
|
||||
##
|
||||
## If length of ``dest`` is less then number of required bytes to encode
|
||||
## ``value``, then result of encoding will not be stored in ``dest``
|
||||
## but number of bytes (octets) required will be returned.
|
||||
var buffer: array[16, byte]
|
||||
var lenlen = asn1EncodeLength(buffer, len(value))
|
||||
result = 1 + lenlen + len(value)
|
||||
if len(dest) >= result:
|
||||
dest[0] = Asn1Tag.Oid.code()
|
||||
copyMem(addr dest[1], addr buffer[0], lenlen)
|
||||
copyMem(addr dest[1 + lenlen], unsafeAddr value[0], len(value))
|
||||
|
||||
proc asn1EncodeSequence*(dest: var openarray[byte],
|
||||
value: openarray[byte]): int =
|
||||
## Encode ``value`` as ASN.1 DER `SEQUENCE` and return number of bytes
|
||||
## (octets) used.
|
||||
##
|
||||
## If length of ``dest`` is less then number of required bytes to encode
|
||||
## ``value``, then result of encoding will not be stored in ``dest``
|
||||
## but number of bytes (octets) required will be returned.
|
||||
var buffer: array[16, byte]
|
||||
var lenlen = asn1EncodeLength(buffer, len(value))
|
||||
result = 1 + lenlen + len(value)
|
||||
if len(dest) >= result:
|
||||
dest[0] = Asn1Tag.Sequence.code()
|
||||
copyMem(addr dest[1], addr buffer[0], lenlen)
|
||||
copyMem(addr dest[1 + lenlen], unsafeAddr value[0], len(value))
|
||||
|
||||
proc asn1EncodeComposite*(dest: var openarray[byte],
|
||||
value: Asn1Composite): int =
|
||||
## Encode composite value and return number of bytes (octets) used.
|
||||
##
|
||||
## If length of ``dest`` is less then number of required bytes to encode
|
||||
## ``value``, then result of encoding will not be stored in ``dest``
|
||||
## but number of bytes (octets) required will be returned.
|
||||
var buffer: array[16, byte]
|
||||
var lenlen = asn1EncodeLength(buffer, len(value.buffer))
|
||||
result = 1 + lenlen + len(value.buffer)
|
||||
if len(dest) >= result:
|
||||
dest[0] = value.tag.code()
|
||||
copyMem(addr dest[1], addr buffer[0], lenlen)
|
||||
copyMem(addr dest[1 + lenlen], unsafeAddr value.buffer[0],
|
||||
len(value.buffer))
|
||||
|
||||
proc asn1EncodeContextTag*(dest: var openarray[byte], value: openarray[byte],
|
||||
tag: int): int =
|
||||
## Encode ASN.1 DER `CONTEXT SPECIFIC TAG` ``tag`` for value ``value`` and
|
||||
## return number of bytes (octets) used.
|
||||
##
|
||||
## If length of ``dest`` is less then number of required bytes to encode
|
||||
## ``value``, then result of encoding will not be stored in ``dest``
|
||||
## but number of bytes (octets) required will be returned.
|
||||
var buffer: array[16, byte]
|
||||
var lenlen = asn1EncodeLength(buffer, len(value))
|
||||
result = 1 + lenlen + len(value)
|
||||
if len(dest) >= result:
|
||||
dest[0] = 0xA0'u8 or (cast[byte](tag) and 0x0F)
|
||||
copyMem(addr dest[1], addr buffer[0], lenlen)
|
||||
copyMem(addr dest[1 + lenlen], unsafeAddr value[0], len(value))
|
||||
|
||||
proc getLength(ab: var Asn1Buffer, length: var uint64): Asn1Status =
|
||||
## Decode length part of ASN.1 TLV triplet.
|
||||
result = Asn1Status.Incomplete
|
||||
if not ab.isEmpty():
|
||||
let b = ab.buffer[ab.offset]
|
||||
if (b and 0x80'u8) == 0x00'u8:
|
||||
length = cast[uint64](b)
|
||||
ab.offset += 1
|
||||
result = Asn1Status.Success
|
||||
return
|
||||
if b == 0x80'u8:
|
||||
length = 0'u64
|
||||
result = Asn1Status.Indefinite
|
||||
return
|
||||
if b == 0xFF'u8:
|
||||
length = 0'u64
|
||||
result = Asn1Status.Incorrect
|
||||
return
|
||||
let octets = cast[uint64](b and 0x7F'u8)
|
||||
if octets > 8'u64:
|
||||
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
|
||||
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
|
||||
Loading…
Reference in New Issue