fix grammar in error message (#5322)

pyca · Jul 19, 2020 · 31359f3 · 31359f3
1 parent 084da16
commit 31359f3
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/cryptography/hazmat/backends/openssl/backend.py b/src/cryptography/hazmat/backends/openssl/backend.py
@@ -743,7 +743,7 @@ def _x509_check_signature_params(self, private_key, algorithm):
         elif not isinstance(private_key, (rsa.RSAPrivateKey, dsa.DSAPrivateKey,
                             ec.EllipticCurvePrivateKey)):
             raise TypeError(
-                "Key must be rsa, dsa, ec, ed25519 or ed448 private key."
+                "Key must be an rsa, dsa, ec, ed25519, or ed448 private key."
             )
         elif not isinstance(algorithm, hashes.HashAlgorithm):
             raise TypeError("Algorithm must be a registered hash algorithm.")