Test coverage dns ecdsa (#9174)

* Added test coverage for ES256 signing keys in DNS challenges.

* pass tests

* Feedback

4 files changed, 35 insertions, 8 deletions

diff --git a/acme/tests/challenges_test.py b/acme/tests/challenges_test.py
index ed8470fa6..d7815a6c3 100644
--- a/acme/tests/challenges_test.py
+++ b/acme/tests/challenges_test.py
@@ -6,6 +6,7 @@ from unittest import mock
 import josepy as jose
 import OpenSSL
 import requests
+from josepy.jwk import JWKEC
 
 from acme import errors
 
@@ -401,8 +402,11 @@ class DNSTest(unittest.TestCase):
         hash(DNS.from_json(self.jmsg))
 
     def test_gen_check_validation(self):
-        self.assertTrue(self.msg.check_validation(
-            self.msg.gen_validation(KEY), KEY.public_key()))
+        ec_key_secp384r1 = JWKEC(key=test_util.load_ecdsa_private_key('ec_secp384r1_key.pem'))
+        for key, alg in [(KEY, jose.RS256), (ec_key_secp384r1, jose.ES384)]:
+            with self.subTest(key=key, alg=alg):
+                self.assertTrue(self.msg.check_validation(
+                    self.msg.gen_validation(key, alg=alg), key.public_key()))
 
     def test_gen_check_validation_wrong_key(self):
         key2 = jose.JWKRSA.load(test_util.load_vector('rsa1024_key.pem'))
@@ -423,8 +427,7 @@ class DNSTest(unittest.TestCase):
             payload=self.msg.update(
                 token=b'x' * 20).json_dumps().encode('utf-8'),
             alg=jose.RS256, key=KEY)
-        self.assertFalse(self.msg.check_validation(
-            bad_validation, KEY.public_key()))
+        self.assertFalse(self.msg.check_validation(bad_validation, KEY.public_key()))
 
     def test_gen_response(self):
         with mock.patch('acme.challenges.DNS.gen_validation') as mock_gen:
@@ -435,8 +438,14 @@ class DNSTest(unittest.TestCase):
         self.assertEqual(response.validation, mock.sentinel.validation)
 
     def test_validation_domain_name(self):
-        self.assertEqual(
-            '_acme-challenge.le.wtf', self.msg.validation_domain_name('le.wtf'))
+        self.assertEqual('_acme-challenge.le.wtf', self.msg.validation_domain_name('le.wtf'))
+
+    def test_validation_domain_name_ecdsa(self):
+        ec_key_secp384r1 = JWKEC(key=test_util.load_ecdsa_private_key('ec_secp384r1_key.pem'))
+        self.assertIs(self.msg.check_validation(
+            self.msg.gen_validation(ec_key_secp384r1, alg=jose.ES384),
+            ec_key_secp384r1.public_key()), True
+        )
 
 
 class DNSResponseTest(unittest.TestCase):
@@ -474,8 +483,7 @@ class DNSResponseTest(unittest.TestCase):
         hash(DNSResponse.from_json(self.jmsg_from))
 
     def test_check_validation(self):
-        self.assertTrue(
-            self.msg.check_validation(self.chall, KEY.public_key()))
+        self.assertTrue(self.msg.check_validation(self.chall, KEY.public_key()))
 
 
 class JWSPayloadRFC8555Compliant(unittest.TestCase):
diff --git a/acme/tests/test_util.py b/acme/tests/test_util.py
index d4a45272d..efa5a219c 100644
--- a/acme/tests/test_util.py
+++ b/acme/tests/test_util.py
@@ -10,6 +10,7 @@ from cryptography.hazmat.primitives import serialization
 import josepy as jose
 from OpenSSL import crypto
 import pkg_resources
+from josepy.util import ComparableECKey
 
 
 def load_vector(*names):
@@ -60,6 +61,14 @@ def load_rsa_private_key(*names):
         load_vector(*names), password=None, backend=default_backend()))
 
 
+def load_ecdsa_private_key(*names):
+    """Load ECDSA private key."""
+    loader = _guess_loader(names[-1], serialization.load_pem_private_key,
+                           serialization.load_der_private_key)
+    return ComparableECKey(loader(
+        load_vector(*names), password=None, backend=default_backend()))
+
+
 def load_pyopenssl_private_key(*names):
     """Load pyOpenSSL private key."""
     loader = _guess_loader(
diff --git a/acme/tests/testdata/README b/acme/tests/testdata/README
index 9c1a12d80..5a3ca4663 100644
--- a/acme/tests/testdata/README
+++ b/acme/tests/testdata/README
@@ -15,3 +15,7 @@ and for the certificates:
   openssl req -key rsa2048_key.pem -new -subj '/CN=example.com' -x509 -outform DER > cert.der
   openssl req -key rsa2048_key.pem -new -subj '/CN=example.com' -x509 > rsa2048_cert.pem
   openssl req -key rsa1024_key.pem -new -subj '/CN=example.com' -x509 > rsa1024_cert.pem
+
+and for the elliptic key curves:
+
+  openssl genpkey -algorithm EC -out ec_secp384r1.pem -pkeyopt ec_paramgen_curve:P-384 -pkeyopt ec_param_enc:named_curve
diff --git a/acme/tests/testdata/ec_secp384r1_key.pem b/acme/tests/testdata/ec_secp384r1_key.pem
new file mode 100644
index 000000000..4bc4e68e5
--- /dev/null
+++ b/acme/tests/testdata/ec_secp384r1_key.pem
@@ -0,0 +1,6 @@
+-----BEGIN PRIVATE KEY-----
+MIG2AgEAMBAGByqGSM49AgEGBSuBBAAiBIGeMIGbAgEBBDArTn0pbFk3xHfKeXte
+xJgS4JVdJQ8mqvezhaNpULZPnwb+mcKLlrj6f5SRM52yREGhZANiAAQcrMoPMVqV
+rHnDGGz5HUKLNmXfChlNgsrwsruawXF+M283CA6eckAjTXNyiC/ounWmvtoKsZG0
+2UQOfQUNSCANId/r986yRGc03W6RJSkcRp86qBYjNsLgbZpber/3+M4=
+-----END PRIVATE KEY-----