Import EC key from certificate.

Author: rohe

src/cryptojwt/jwk/ec.py

@@ -346,3 +346,8 @@ def import_ec_key(pem_data):
         return public_key
     else:
         return ValueError("Not a Elliptic Curve key")
+
+
+def import_ec_key_from_cert_file(pem_file):
+    with open(pem_file, "r") as cert_file:
+        return import_ec_key(cert_file.read())