Correct tagging in cms.AttCertIssuer

V2Form needs to be tagged implicitly, not explicitly.
wbond · Dec 22, 2021 · f8214f9 · f8214f9
1 parent 9ae350f
commit f8214f9
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Showing 3 changed files with 13 additions and 1 deletion.
diff --git a/asn1crypto/cms.py b/asn1crypto/cms.py
@@ -273,7 +273,7 @@ class V2Form(Sequence):
 class AttCertIssuer(Choice):
     _alternatives = [
         ('v1_form', GeneralNames),
-        ('v2_form', V2Form, {'explicit': 0}),
+        ('v2_form', V2Form, {'implicit': 0}),
     ]
 
 

diff --git a/tests/fixtures/example-attr-cert.der b/tests/fixtures/example-attr-cert.der
diff --git a/tests/test_cms.py b/tests/test_cms.py
@@ -901,3 +901,15 @@ def test_bad_teletex_inside_pkcs7(self):
             ]),
             content['certificates'][0].chosen['tbs_certificate']['subject'].native
         )
+
+    def test_parse_attribute_cert(self):
+        # regression test for tagging issue in AttCertIssuer
+
+        with open(os.path.join(fixtures_dir, 'example-attr-cert.der'), 'rb') as f:
+            ac_bytes = f.read()
+        ac_parsed = cms.AttributeCertificateV2.load(ac_bytes)
+        self.assertEqual(ac_bytes, ac_parsed.dump(force=True))
+
+        ac_info = ac_parsed['ac_info']
+        self.assertIsInstance(ac_info['issuer'].chosen, cms.V2Form)
+        self.assertEqual(1, len(ac_info['issuer'].chosen['issuer_name']))