Add support for RFC 6211 and RFC 8649 (#59)

1 files changed, 74 insertions, 0 deletions

diff --git a/pyasn1_modules/rfc6211.py b/pyasn1_modules/rfc6211.py
new file mode 100644
index 0000000..3853817
--- /dev/null
+++ b/pyasn1_modules/rfc6211.py
@@ -0,0 +1,74 @@
+#
+# This file is part of 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
+#
+# CMS Algorithm Identifier Protection Attribute
+#
+# ASN.1 source from:
+# https://www.rfc-editor.org/rfc/rfc6211.txt
+#
+
+from pyasn1.type import constraint
+from pyasn1.type import namedtype
+from pyasn1.type import tag
+from pyasn1.type import univ
+
+from pyasn1_modules import rfc5652
+
+
+# Imports from RFC 5652
+
+DigestAlgorithmIdentifier = rfc5652.DigestAlgorithmIdentifier
+
+MessageAuthenticationCodeAlgorithm = rfc5652.MessageAuthenticationCodeAlgorithm
+
+SignatureAlgorithmIdentifier = rfc5652.SignatureAlgorithmIdentifier
+
+
+# CMS Algorithm Protection attribute
+
+id_aa_cmsAlgorithmProtect = univ.ObjectIdentifier('1.2.840.113549.1.9.52')
+
+
+class CMSAlgorithmProtection(univ.Sequence):
+    pass
+
+CMSAlgorithmProtection.componentType = namedtype.NamedTypes(
+    namedtype.NamedType('digestAlgorithm', DigestAlgorithmIdentifier()),
+    namedtype.OptionalNamedType('signatureAlgorithm',
+        SignatureAlgorithmIdentifier().subtype(
+            implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 1))),
+    namedtype.OptionalNamedType('macAlgorithm',
+        MessageAuthenticationCodeAlgorithm().subtype(
+            implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 2)))
+)
+
+# TODO: Add constraints to implement the WITH COMPONENTS part of the ASN.1:
+#
+# CMSAlgorithmProtection.subtypeSpec = constraint.ConstraintsIntersection(
+#     constraint.WithComponentsConstraint(
+#         ('signatureAlgorithm', constraint.ComponentPresentConstraint()),
+#         ('macAlgorithm', constraint.ComponentAbsentConstraint())),
+#     constraint.WithComponentsConstraint(
+#         ('signatureAlgorithm', constraint.ComponentAbsentConstraint()),
+#         ('macAlgorithm', constraint.ComponentPresentConstraint()))
+# )
+
+
+aa_cmsAlgorithmProtection = rfc5652.Attribute()
+aa_cmsAlgorithmProtection['attrType'] = id_aa_cmsAlgorithmProtect
+aa_cmsAlgorithmProtection['attrValues'][0] = CMSAlgorithmProtection()
+
+
+# Map of Attribute Type OIDs to Attributes are
+# added to the ones that are in rfc5652.py
+
+_cmsAttributesMapUpdate = {
+    id_aa_cmsAlgorithmProtect: CMSAlgorithmProtection(),
+}
+
+rfc5652.cmsAttributesMap.update(_cmsAttributesMapUpdate)
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