rfc5751.py
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# This file is being contributed to pyasn1-modules software.
#
# Created by Russ Housley with assistance from asn1ate v.0.6.0.
#
# Copyright (c) 2019, Vigil Security, LLC
# License: http://snmplabs.com/pyasn1/license.html
#
# S/MIME Version 3.2 Message Specification
#
# ASN.1 source from:
# https://www.rfc-editor.org/rfc/rfc5751.txt
from pyasn1.type import namedtype
from pyasn1.type import opentype
from pyasn1.type import tag
from pyasn1.type import univ
from pyasn1_modules import rfc5652
from pyasn1_modules import rfc8018
def _OID(*components):
output = []
for x in tuple(components):
if isinstance(x, univ.ObjectIdentifier):
output.extend(list(x))
else:
output.append(int(x))
return univ.ObjectIdentifier(output)
# Imports from RFC 5652 and RFC 8018
IssuerAndSerialNumber = rfc5652.IssuerAndSerialNumber
RecipientKeyIdentifier = rfc5652.RecipientKeyIdentifier
SubjectKeyIdentifier = rfc5652.SubjectKeyIdentifier
rc2CBC = rfc8018.rc2CBC
# S/MIME Capabilities Attribute
smimeCapabilities = univ.ObjectIdentifier('1.2.840.113549.1.9.15')
smimeCapabilityMap = { }
class SMIMECapability(univ.Sequence):
pass
SMIMECapability.componentType = namedtype.NamedTypes(
namedtype.NamedType('capabilityID', univ.ObjectIdentifier()),
namedtype.OptionalNamedType('parameters', univ.Any(),
openType=opentype.OpenType('capabilityID', smimeCapabilityMap))
)
class SMIMECapabilities(univ.SequenceOf):
pass
SMIMECapabilities.componentType = SMIMECapability()
class SMIMECapabilitiesParametersForRC2CBC(univ.Integer):
# which carries the RC2 Key Length (number of bits)
pass
# S/MIME Encryption Key Preference Attribute
id_smime = univ.ObjectIdentifier('1.2.840.113549.1.9.16')
id_aa = _OID(id_smime, 2)
id_aa_encrypKeyPref = _OID(id_aa, 11)
class SMIMEEncryptionKeyPreference(univ.Choice):
pass
SMIMEEncryptionKeyPreference.componentType = namedtype.NamedTypes(
namedtype.NamedType('issuerAndSerialNumber',
IssuerAndSerialNumber().subtype(implicitTag=tag.Tag(
tag.tagClassContext, tag.tagFormatSimple, 0))),
namedtype.NamedType('receipentKeyId',
# Yes, 'receipentKeyId' is spelled incorrectly, but kept
# this way for alignment with the ASN.1 module in the RFC.
RecipientKeyIdentifier().subtype(implicitTag=tag.Tag(
tag.tagClassContext, tag.tagFormatSimple, 1))),
namedtype.NamedType('subjectAltKeyIdentifier',
SubjectKeyIdentifier().subtype(implicitTag=tag.Tag(
tag.tagClassContext, tag.tagFormatSimple, 2)))
)
# The Prefer Binary Inside SMIMECapabilities attribute
id_cap = _OID(id_smime, 11)
id_cap_preferBinaryInside = _OID(id_cap, 1)
# CMS Attribute Map
_cmsAttributesMapUpdate = {
smimeCapabilities: SMIMECapabilities(),
id_aa_encrypKeyPref: SMIMEEncryptionKeyPreference(),
}
rfc5652.cmsAttributesMap.update(_cmsAttributesMapUpdate)
# SMIMECapabilities Attribute Map
#
# Do not include OIDs in the dictionary when the parameters are absent.
_smimeCapabilityMapUpdate = {
rc2CBC: SMIMECapabilitiesParametersForRC2CBC(),
}
smimeCapabilityMap.update(_smimeCapabilityMapUpdate)