handle case where certificate issuer is not in existing cache

atst/domain/authnid/crl/__init__.py

@@ -71,15 +71,24 @@ class CRLCache():
     def _build_store(self, issuer):
         store = self.store_class()
         store.set_flags(crypto.X509StoreFlags.CRL_CHECK)
-        crl_location = self.crl_cache[issuer]
+        crl_location = self._get_crl_location(issuer)
         with open(crl_location, "rb") as crl_file:
             crl = crypto.load_crl(crypto.FILETYPE_ASN1, crl_file.read())
             store.add_crl(crl)
             store = self._add_certificate_chain_to_store(store, crl.get_issuer())
             return store
 
+    def _get_crl_location(self, issuer):
+        crl_location = self.crl_cache.get(issuer)
+
+        if not crl_location:
+            raise CRLRevocationException("Could not find matching CRL for issuer")
+
+        return crl_location
+
     # this _should_ happen just twice for the DoD PKI (intermediary, root) but
     # theoretically it can build a longer certificate chain
+
     def _add_certificate_chain_to_store(self, store, issuer):
         ca = self.certificate_authorities.get(issuer.der())
         store.add_cert(ca)
@@ -87,6 +96,6 @@ class CRLCache():
         if issuer == ca.get_subject():
             # i.e., it is the root CA and we are at the end of the chain
             return store
+
         else:
             return self._add_certificate_chain_to_store(store, ca.get_issuer())
-

tests/domain/authnid/test_crl.py

@@ -4,11 +4,15 @@ import re
 import os
 import shutil
 from OpenSSL import crypto, SSL
+
 from atst.domain.authnid.crl import crl_check, CRLCache, CRLRevocationException
 import atst.domain.authnid.crl.util as util
 
+from tests.mocks import FIXTURE_EMAIL_ADDRESS
+
 
 class MockX509Store():
+
     def __init__(self):
         self.crls = []
         self.certs = []
@@ -24,46 +28,69 @@ class MockX509Store():
 
 
 def test_can_build_crl_list(monkeypatch):
-    location = 'ssl/client-certs/client-ca.der.crl'
+    location = "ssl/client-certs/client-ca.der.crl"
-    cache = CRLCache('ssl/client-certs/client-ca.crt', crl_locations=[location], store_class=MockX509Store)
+    cache = CRLCache(
+        "ssl/client-certs/client-ca.crt",
+        crl_locations=[location],
+        store_class=MockX509Store,
+    )
     assert len(cache.crl_cache.keys()) == 1
 
 
 def test_can_build_trusted_root_list():
-    location = 'ssl/server-certs/ca-chain.pem'
+    location = "ssl/server-certs/ca-chain.pem"
-    cache = CRLCache(root_location=location, crl_locations=[], store_class=MockX509Store)
+    cache = CRLCache(
+        root_location=location, crl_locations=[], store_class=MockX509Store
+    )
     with open(location) as f:
         content = f.read()
-        assert len(cache.certificate_authorities.keys()) == content.count('BEGIN CERT')
+        assert len(cache.certificate_authorities.keys()) == content.count("BEGIN CERT")
+
 
 def test_can_validate_certificate():
-    cache = CRLCache('ssl/server-certs/ca-chain.pem', crl_locations=['ssl/client-certs/client-ca.der.crl'])
+    cache = CRLCache(
-    good_cert = open('ssl/client-certs/atat.mil.crt', 'rb').read()
+        "ssl/server-certs/ca-chain.pem",
-    bad_cert = open('ssl/client-certs/bad-atat.mil.crt', 'rb').read()
+        crl_locations=["ssl/client-certs/client-ca.der.crl"],
+    )
+    good_cert = open("ssl/client-certs/atat.mil.crt", "rb").read()
+    bad_cert = open("ssl/client-certs/bad-atat.mil.crt", "rb").read()
     assert crl_check(cache, good_cert)
     with pytest.raises(CRLRevocationException):
         crl_check(cache, bad_cert)
 
+
 def test_can_dynamically_update_crls(tmpdir):
-    crl_file = tmpdir.join('test.crl')
+    crl_file = tmpdir.join("test.crl")
-    shutil.copyfile('ssl/client-certs/client-ca.der.crl', crl_file)
+    shutil.copyfile("ssl/client-certs/client-ca.der.crl", crl_file)
-    cache = CRLCache('ssl/server-certs/ca-chain.pem', crl_locations=[crl_file])
+    cache = CRLCache("ssl/server-certs/ca-chain.pem", crl_locations=[crl_file])
-    cert = open('ssl/client-certs/atat.mil.crt', 'rb').read()
+    cert = open("ssl/client-certs/atat.mil.crt", "rb").read()
     assert crl_check(cache, cert)
     # override the original CRL with one that revokes atat.mil.crt
-    shutil.copyfile('tests/fixtures/test.der.crl', crl_file)
+    shutil.copyfile("tests/fixtures/test.der.crl", crl_file)
     with pytest.raises(CRLRevocationException):
         assert crl_check(cache, cert)
 
+
+def test_throws_error_for_missing_issuer():
+    cache = CRLCache("ssl/server-certs/ca-chain.pem", crl_locations=[])
+    cert = open("tests/fixtures/{}.crt".format(FIXTURE_EMAIL_ADDRESS), "rb").read()
+    with pytest.raises(CRLRevocationException) as exc:
+        assert crl_check(cache, cert)
+    (message,) = exc.value.args
+    assert "issuer" in message
+
+
 def test_parse_disa_pki_list():
-    with open('tests/fixtures/disa-pki.html') as disa:
+    with open("tests/fixtures/disa-pki.html") as disa:
         disa_html = disa.read()
         crl_list = util.crl_list_from_disa_html(disa_html)
-        href_matches = re.findall('DOD(ROOT|EMAIL|ID)?CA', disa_html)
+        href_matches = re.findall("DOD(ROOT|EMAIL|ID)?CA", disa_html)
         assert len(crl_list) > 0
         assert len(crl_list) == len(href_matches)
 
+
 class MockStreamingResponse():
+
     def __init__(self, content_chunks, code=200):
         self.content_chunks = content_chunks
         self.status_code = code
@@ -77,13 +104,19 @@ class MockStreamingResponse():
     def __exit__(self, *args):
         pass
 
+
 def test_write_crl(tmpdir, monkeypatch):
-    monkeypatch.setattr('requests.get', lambda u, **kwargs: MockStreamingResponse([b'it worked']))
+    monkeypatch.setattr(
-    crl = 'crl_1'
+        "requests.get", lambda u, **kwargs: MockStreamingResponse([b"it worked"])
+    )
+    crl = "crl_1"
     assert util.write_crl(tmpdir, "random_target_dir", crl)
     assert [p.basename for p in tmpdir.listdir()] == [crl]
-    assert [p.read() for p in tmpdir.listdir()] == ['it worked']
+    assert [p.read() for p in tmpdir.listdir()] == ["it worked"]
+
 
 def test_skips_crl_if_it_has_not_been_modified(tmpdir, monkeypatch):
-    monkeypatch.setattr('requests.get', lambda u, **kwargs: MockStreamingResponse([b'it worked'], 304))
+    monkeypatch.setattr(
-    assert not util.write_crl(tmpdir, "random_target_dir", 'crl_file_name')
+        "requests.get", lambda u, **kwargs: MockStreamingResponse([b"it worked"], 304)
+    )
+    assert not util.write_crl(tmpdir, "random_target_dir", "crl_file_name")