Revert "switch signature verification to use pure cryptography (#6000)" (#6074)

This reverts commit 366c50e28e.

certbot/crypto_util.py

@@ -12,16 +12,11 @@ import os
 import pyrfc3339
 import six
 import zope.component
-from cryptography.exceptions import InvalidSignature
-from cryptography.hazmat.backends import default_backend
-from cryptography.hazmat.primitives.asymmetric.ec import ECDSA
-from cryptography.hazmat.primitives.asymmetric.ec import EllipticCurvePublicKey
-from cryptography.hazmat.primitives.asymmetric.padding import PKCS1v15
-from cryptography.hazmat.primitives.asymmetric.rsa import RSAPublicKey
-# https://github.com/python/typeshed/tree/master/third_party/2/cryptography
-from cryptography import x509 # type: ignore
 from OpenSSL import crypto
 from OpenSSL import SSL  # type: ignore
+from cryptography.hazmat.backends import default_backend
+# https://github.com/python/typeshed/tree/master/third_party/2/cryptography
+from cryptography import x509  # type: ignore
 
 from acme import crypto_util as acme_crypto_util
 from acme.magic_typing import IO  # pylint: disable=unused-import, no-name-in-module
@@ -233,26 +228,13 @@ def verify_renewable_cert_sig(renewable_cert):
     """
     try:
         with open(renewable_cert.chain, 'rb') as chain_file:  # type: IO[bytes]
-            chain = x509.load_pem_x509_certificate(chain_file.read(), default_backend())
+            chain, _ = pyopenssl_load_certificate(chain_file.read())
         with open(renewable_cert.cert, 'rb') as cert_file:  # type: IO[bytes]
-            cert = x509.load_pem_x509_certificate(cert_file.read(), default_backend())
-        pk = chain.public_key()
-        if isinstance(pk, RSAPublicKey):
-            # https://github.com/python/typeshed/blob/master/third_party/2/cryptography/hazmat/primitives/asymmetric/rsa.pyi
-            verifier = pk.verifier(  # type: ignore
-                cert.signature, PKCS1v15(), cert.signature_hash_algorithm
-            )
-            verifier.update(cert.tbs_certificate_bytes)
-            verifier.verify()
-        elif isinstance(pk, EllipticCurvePublicKey):
-            verifier = pk.verifier(
-                cert.signature, ECDSA(cert.signature_hash_algorithm)
-            )
-            verifier.update(cert.tbs_certificate_bytes)
-            verifier.verify()
-        else:
-            raise errors.Error("Unsupported public key type")
-    except (IOError, ValueError, InvalidSignature) as e:
+            cert = x509.load_pem_x509_certificate(
+                cert_file.read(), default_backend())
+        hash_name = cert.signature_hash_algorithm.name
+        crypto.verify(chain, cert.signature, cert.tbs_certificate_bytes, hash_name)
+    except (IOError, ValueError, crypto.Error) as e:
         error_str = "verifying the signature of the cert located at {0} has failed. \
                 Details: {1}".format(renewable_cert.cert, e)
         logger.exception(error_str)

certbot/tests/crypto_util_test.py

@@ -21,9 +21,6 @@ CERT_PATH = test_util.vector_path('cert_512.pem')
 CERT = test_util.load_vector('cert_512.pem')
 SS_CERT_PATH = test_util.vector_path('cert_2048.pem')
 SS_CERT = test_util.load_vector('cert_2048.pem')
-P256_KEY = test_util.load_vector('nistp256_key.pem')
-P256_CERT_PATH = test_util.vector_path('cert-nosans_nistp256.pem')
-P256_CERT = test_util.load_vector('cert-nosans_nistp256.pem')
 
 class InitSaveKeyTest(test_util.TempDirTestCase):
     """Tests for certbot.crypto_util.init_save_key."""
@@ -220,13 +217,6 @@ class VerifyRenewableCertSigTest(VerifyCertSetup):
     def test_cert_sig_match(self):
         self.assertEqual(None, self._call(self.renewable_cert))
 
-    def test_cert_sig_match_ec(self):
-        renewable_cert = mock.MagicMock()
-        renewable_cert.cert = P256_CERT_PATH
-        renewable_cert.chain = P256_CERT_PATH
-        renewable_cert.privkey = P256_KEY
-        self.assertEqual(None, self._call(renewable_cert))
-
     def test_cert_sig_mismatch(self):
         self.bad_renewable_cert.cert = test_util.vector_path('cert_512_bad.pem')
         self.assertRaises(errors.Error, self._call, self.bad_renewable_cert)

certbot/tests/testdata/cert-nosans_nistp256.pem

@@ -1,11 +0,0 @@
------BEGIN CERTIFICATE-----
-MIIBoDCCAUYCCQDCnzfUZ7TQdDAKBggqhkjOPQQDAjBYMQswCQYDVQQGEwJVUzER
-MA8GA1UECAwITWljaGlnYW4xEjAQBgNVBAcMCUFubiBBcmJvcjEMMAoGA1UECgwD
-RUZGMRQwEgYDVQQDDAtleGFtcGxlLmNvbTAeFw0xODA1MTUxNzIyMzlaFw0xODA2
-MTQxNzIyMzlaMFgxCzAJBgNVBAYTAlVTMREwDwYDVQQIDAhNaWNoaWdhbjESMBAG
-A1UEBwwJQW5uIEFyYm9yMQwwCgYDVQQKDANFRkYxFDASBgNVBAMMC2V4YW1wbGUu
-Y29tMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEPPl0JauSZukvAUWv4l5VNLAY
-QXhuPXYQBf4dVET3s0E5q9ZCbSe+pNUbko9F+TFkuc7XVjQPsfkDbh0I9nD0tzAK
-BggqhkjOPQQDAgNIADBFAiEAv8S2GXmWJqZ+j3DBfm72E1YK+HkOf+TOUHsbVR+O
-Z1oCIFWNt1SPdIgRp4QAyzVk2pcTF8jDNajEMLWETDtxgRvM
------END CERTIFICATE-----

certbot/tests/testdata/csr-nosans_nistp256.pem

@@ -1,8 +0,0 @@
------BEGIN CERTIFICATE REQUEST-----
-MIIBFDCBugIBADBYMQswCQYDVQQGEwJVUzERMA8GA1UECAwITWljaGlnYW4xEjAQ
-BgNVBAcMCUFubiBBcmJvcjEMMAoGA1UECgwDRUZGMRQwEgYDVQQDDAtleGFtcGxl
-LmNvbTBZMBMGByqGSM49AgEGCCqGSM49AwEHA0IABDz5dCWrkmbpLwFFr+JeVTSw
-GEF4bj12EAX+HVRE97NBOavWQm0nvqTVG5KPRfkxZLnO11Y0D7H5A24dCPZw9Leg
-ADAKBggqhkjOPQQDAgNJADBGAiEAuoZHrYA5sy2DRTdLAxJTBNHKFFKbtaGt+QaJ
-A62qa8sCIQCUkSgSAiNaEnJ7r5fKphdjeORHqhpl6flYkLE3lGmGdg==
------END CERTIFICATE REQUEST-----

certbot/tests/testdata/nistp256_key.pem

@@ -1,5 +0,0 @@
------BEGIN EC PRIVATE KEY-----
-MHcCAQEEIOvXH384CyNNv2lfxvjc7hg2f7ScYoLvlk/VpINLJlGBoAoGCCqGSM49
-AwEHoUQDQgAEPPl0JauSZukvAUWv4l5VNLAYQXhuPXYQBf4dVET3s0E5q9ZCbSe+
-pNUbko9F+TFkuc7XVjQPsfkDbh0I9nD0tw==
------END EC PRIVATE KEY-----