Add support for RFC 2631 (#101)

CHANGES.txt

@@ -26,6 +26,7 @@ Revision 0.2.8, released XX-XX-2019
 - Added RFC5916 providing Device Owner Attribute
 - Update RFC8226 to use ComponentPresentConstraint() instead of the
   previous work around
+- Add RFC2631 providing OtherInfo for Diffie-Hellman Key Agreement
 
 Revision 0.2.7, released 09-10-2019
 -----------------------------------

pyasn1_modules/rfc2631.py

@@ -0,0 +1,37 @@
+#
+# 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
+#
+# Diffie-Hellman Key Agreement
+#
+# ASN.1 source from:
+# https://www.rfc-editor.org/rfc/rfc2631.txt
+# https://www.rfc-editor.org/errata/eid5897
+#
+
+from pyasn1.type import constraint
+from pyasn1.type import namedtype
+from pyasn1.type import tag
+from pyasn1.type import univ
+
+
+class KeySpecificInfo(univ.Sequence):
+    componentType = namedtype.NamedTypes(
+        namedtype.NamedType('algorithm', univ.ObjectIdentifier()),
+        namedtype.NamedType('counter', univ.OctetString().subtype(
+            subtypeSpec=constraint.ValueSizeConstraint(4, 4)))
+    )
+
+
+class OtherInfo(univ.Sequence):
+    componentType = namedtype.NamedTypes(
+        namedtype.NamedType('keyInfo', KeySpecificInfo()),
+        namedtype.OptionalNamedType('partyAInfo', univ.OctetString().subtype(
+            explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0))),
+        namedtype.NamedType('suppPubInfo', univ.OctetString().subtype(
+            explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 2)))
+    )

tests/__main__.py

@@ -18,6 +18,7 @@
      'tests.test_rfc2459.suite',
      'tests.test_rfc2511.suite',
      'tests.test_rfc2560.suite',
+     'tests.test_rfc2631.suite',
      'tests.test_rfc2634.suite',
      'tests.test_rfc2985.suite',
      'tests.test_rfc2986.suite',

tests/test_rfc2631.py

@@ -0,0 +1,48 @@
+#
+# This file is part of pyasn1-modules software.
+#
+# Created by Russ Housley
+# Copyright (c) 2019, Vigil Security, LLC
+# License: http://snmplabs.com/pyasn1/license.html
+#
+
+import sys
+
+from pyasn1.codec.der.decoder import decode as der_decode
+from pyasn1.codec.der.encoder import encode as der_encode
+
+from pyasn1.type import univ
+
+from pyasn1_modules import pem
+from pyasn1_modules import rfc2631
+
+try:
+    import unittest2 as unittest
+except ImportError:
+    import unittest
+
+
+class OtherInfoTestCase(unittest.TestCase):
+    pem_text = "MB0wEwYLKoZIhvcNAQkQAwYEBAAAAAGiBgQEAAAAwA=="
+
+    def setUp(self):
+        self.asn1Spec = rfc2631.OtherInfo()
+
+    def testDerCodec(self):
+        substrate = pem.readBase64fromText(self.pem_text)
+        asn1Object, rest = der_decode(substrate, asn1Spec=self.asn1Spec)
+        assert not rest
+        assert asn1Object.prettyPrint()
+        assert der_encode(asn1Object) == substrate
+
+        hex1 = univ.OctetString(hexValue='00000001')
+        assert asn1Object['keyInfo']['counter'] == hex1
+
+
+suite = unittest.TestLoader().loadTestsFromModule(sys.modules[__name__])
+
+if __name__ == '__main__':
+    import sys
+
+    result = unittest.TextTestRunner(verbosity=2).run(suite)
+    sys.exit(not result.wasSuccessful())