Add support for RFC 4985 (#96)

4 files changed, 161 insertions, 0 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index ab45ec6..487c0b8 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -19,6 +19,8 @@ Revision 0.2.8, released XX-XX-2019
 - Added RFC6664 providing S/MIME Capabilities for Public Keys
 - Added RFC6120 providing Extensible Messaging and Presence Protocol
   names in certificates
+- Added RFC4985 providing Subject Alternative Name for expression of
+  service names in certificates
 
 Revision 0.2.7, released 09-10-2019
 -----------------------------------
diff --git a/pyasn1_modules/rfc4985.py b/pyasn1_modules/rfc4985.py
new file mode 100644
index 0000000..318e412
--- /dev/null
+++ b/pyasn1_modules/rfc4985.py
@@ -0,0 +1,49 @@
+#
+# 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
+#
+# Expression of Service Names in X.509 Certificates
+#
+# ASN.1 source from:
+# https://www.rfc-editor.org/rfc/rfc4985.txt
+#
+
+from pyasn1.type import char
+from pyasn1.type import constraint
+from pyasn1.type import univ
+
+from pyasn1_modules import rfc5280
+
+MAX = float('inf')
+
+
+# As specified in Appendix A.2 of RFC 4985
+
+id_pkix = rfc5280.id_pkix
+
+id_on = id_pkix + (8, )
+
+id_on_dnsSRV = id_on + (7, )
+
+
+class SRVName(char.IA5String):
+    subtypeSpec = constraint.ValueSizeConstraint(1, MAX)
+
+
+srvName = rfc5280.AnotherName()
+srvName['type-id'] = id_on_dnsSRV
+srvName['value'] = SRVName()
+
+
+# Map of Other Name OIDs to Other Name is added to the
+# ones that are in rfc5280.py
+
+_anotherNameMapUpdate = {
+    id_on_dnsSRV: SRVName(),
+}
+
+rfc5280.anotherNameMap.update(_anotherNameMapUpdate)
diff --git a/tests/__main__.py b/tests/__main__.py
index 9bc9f0a..27e279d 100644
--- a/tests/__main__.py
+++ b/tests/__main__.py
@@ -38,6 +38,7 @@ suite = unittest.TestLoader().loadTestsFromNames(
      'tests.test_rfc4108.suite',
      'tests.test_rfc4210.suite',
      'tests.test_rfc4211.suite',
+     'tests.test_rfc4985.suite',
      'tests.test_rfc5035.suite',
      'tests.test_rfc5083.suite',
      'tests.test_rfc5084.suite',
diff --git a/tests/test_rfc4985.py b/tests/test_rfc4985.py
new file mode 100644
index 0000000..132b12b
--- /dev/null
+++ b/tests/test_rfc4985.py
@@ -0,0 +1,109 @@
+#
+# 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_modules import pem
+from pyasn1_modules import rfc5280
+from pyasn1_modules import rfc4985
+
+try:
+    import unittest2 as unittest
+except ImportError:
+    import unittest
+
+
+class XMPPCertificateTestCase(unittest.TestCase):
+    xmpp_server_cert_pem_text = """\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+"""
+
+    def setUp(self):
+        self.asn1Spec = rfc5280.Certificate()
+
+    def testDerCodec(self):
+        substrate = pem.readBase64fromText(self.xmpp_server_cert_pem_text)
+        asn1Object, rest = der_decode(substrate, asn1Spec=self.asn1Spec)
+        assert not rest
+        assert asn1Object.prettyPrint()
+        assert der_encode(asn1Object) == substrate
+
+        count = 0
+        for extn in asn1Object['tbsCertificate']['extensions']:
+            if extn['extnID'] == rfc5280.id_ce_subjectAltName:
+                extnValue, rest = der_decode(extn['extnValue'],
+                    asn1Spec=rfc5280.SubjectAltName())
+                assert not rest
+                assert extnValue.prettyPrint()
+                assert der_encode(extnValue) == extn['extnValue']
+                for gn in extnValue:
+                    if gn['otherName'].hasValue():
+                        gn_on = gn['otherName']
+                        if gn_on['type-id'] == rfc4985.id_on_dnsSRV:
+                            assert gn_on['type-id'] in rfc5280.anotherNameMap.keys()
+                            spec = rfc5280.anotherNameMap[gn['otherName']['type-id']]
+                            on, rest = der_decode(gn_on['value'], asn1Spec=spec)
+                            assert not rest
+                            assert on.prettyPrint()
+                            assert der_encode(on) == gn_on['value']
+                            assert 'im.example.com' in on
+                            count += 1
+
+        assert count == 2
+
+    def testOpenTypes(self):
+        substrate = pem.readBase64fromText(self.xmpp_server_cert_pem_text)
+        asn1Object, rest = der_decode(substrate,
+            asn1Spec=self.asn1Spec,
+            decodeOpenTypes=True)
+        assert not rest
+        assert asn1Object.prettyPrint()
+        assert der_encode(asn1Object) == substrate
+
+        count = 0
+        for extn in asn1Object['tbsCertificate']['extensions']:
+            if extn['extnID'] == rfc5280.id_ce_subjectAltName:
+                extnValue, rest = der_decode(extn['extnValue'],
+                    asn1Spec=rfc5280.SubjectAltName(), decodeOpenTypes=True)
+                assert not rest
+                assert extnValue.prettyPrint()
+                assert der_encode(extnValue) == extn['extnValue']
+                for gn in extnValue:
+                    if gn['otherName'].hasValue():
+                        if gn['otherName']['type-id'] == rfc4985.id_on_dnsSRV:
+                            assert 'im.example.com' in gn['otherName']['value']
+                            count += 1
+
+        assert count == 2
+
+
+suite = unittest.TestLoader().loadTestsFromModule(sys.modules[__name__])
+
+if __name__ == '__main__':
+    import sys
+
+    result = unittest.TextTestRunner(verbosity=2).run(suite)
+    sys.exit(not result.wasSuccessful())