Support Custom CA for certificate issuing (#438)

previously we have one giant class certificatemanager which has a
certificatauthority class which is basically ACM PCA.

Now we want to add support for custom ca, without impacting existing
contracts/apis on `/v1/certificates prefix`. So a new base class is
created so that both acm pca and custom ca can inherit from.

other changes are mostly tests and settings along side this.

confidant/routes/certificates.py

@@ -4,6 +4,10 @@
 
 from confidant import authnz, settings
 from confidant.services import certificatemanager
+from confidant.services.certificate_authority.certificateauthoritybase import (
+    CertificateAuthorityNotFoundError,
+    CertificateNotReadyError,
+)
 from confidant.schema.certificates import (
     certificate_authority_response_schema,
     certificate_authorities_response_schema,
@@ -69,7 +73,7 @@ def get_certificate(ca, cn):
     '''
     try:
         ca_object = certificatemanager.get_ca(ca)
-    except certificatemanager.CertificateAuthorityNotFoundError:
+    except CertificateAuthorityNotFoundError:
         return jsonify({'error': 'Provided CA not found.'}), 404
     san = request.args.getlist('san')
 
@@ -83,8 +87,9 @@ def get_certificate(ca, cn):
             'san': san,
         },
     ):
-        msg = ('{} does not have access to get certificate cn {} against'
-               ' ca {}').format(
+        msg = (
+            '{} does not have access to get certificate cn {} against' ' ca {}'
+        ).format(
             authnz.get_logged_in_user(),
             cn,
             ca,
@@ -93,11 +98,10 @@ def get_certificate(ca, cn):
         return jsonify(error_msg), 403
 
     logger.info(
-        'get_certificate called on id={} for ca={} by user={}'.format(
-            cn,
-            ca,
-            logged_in_user,
-        )
+        'get_certificate called on id=%s for ca=%s by user=%s',
+        cn,
+        ca,
+        logged_in_user,
     )
 
     validity = request.args.get(
@@ -111,7 +115,7 @@ def get_certificate(ca, cn):
             validity,
             san,
         )
-    except certificatemanager.CertificateNotReadyError:
+    except CertificateNotReadyError:
         # Ratelimit response for a locked certificate in the cache
         error_msg = 'Certificate being requested, please wait and try again.'
         response = jsonify(error_msg)
@@ -173,13 +177,17 @@ def get_certificate_from_csr(ca):
     '''
     try:
         ca_object = certificatemanager.get_ca(ca)
-    except certificatemanager.CertificateAuthorityNotFoundError:
+    except CertificateAuthorityNotFoundError:
         return jsonify({'error': 'Provided CA not found.'}), 404
     data = request.get_json()
+
     if not data or not data.get('csr'):
-        return jsonify(
-            {'error': 'csr must be provided in the POST body.'},
-        ), 400
+        return (
+            jsonify(
+                {'error': 'csr must be provided in the POST body.'},
+            ),
+            400,
+        )
     validity = data.get(
         'validity',
         ca_object.settings['max_validity_days'],
@@ -188,9 +196,12 @@ def get_certificate_from_csr(ca):
         csr = ca_object.decode_csr(data['csr'])
     except Exception:
         logger.exception('Failed to decode PEM csr')
-        return jsonify(
-            {'error': 'csr could not be decoded'},
-        ), 400
+        return (
+            jsonify(
+                {'error': 'csr could not be decoded'},
+            ),
+            400,
+        )
     # Get the cn and san values from the csr object, so that we can use them
     # for the ACL check.
     cn = ca_object.get_csr_common_name(csr)
@@ -206,28 +217,24 @@ def get_certificate_from_csr(ca):
             'san': san,
         },
     ):
-        msg = ('{} does not have access to get certificate cn {} against'
-               ' ca {}').format(
-            authnz.get_logged_in_user(),
-            cn,
-            ca,
+        msg = (
+            f'{authnz.get_logged_in_user()} does not have access to get'
+            'certificate cn {cn} against ca {ca}'
         )
         error_msg = {'error': msg, 'reference': cn}
         return jsonify(error_msg), 403
 
     logger.info(
-        'get_certificate called on id={} for ca={} by user={}'.format(
-            cn,
-            ca,
-            logged_in_user,
-        )
+        'get_certificate called on id=%s for ca=%s by user=%s',
+        cn,
+        ca,
+        logged_in_user,
     )
 
-    arn = ca_object.issue_certificate(data['csr'], validity)
-    certificate = ca_object.get_certificate_from_arn(arn)
+    certificate_json = ca_object.issue_certificate(data['csr'], validity)
     certificate_response = CertificateResponse(
-        certificate=certificate['certificate'],
-        certificate_chain=certificate['certificate_chain'],
+        certificate=certificate_json['certificate'],
+        certificate_chain=certificate_json['certificate_chain'],
     )
     return certificate_response_schema.dumps(certificate_response)
 
@@ -284,7 +291,7 @@ def list_cas():
 
     cas = certificatemanager.list_cas()
 
-    logger.info('list_cas called by user={}'.format(logged_in_user))
+    logger.info('list_cas called by user=%s', logged_in_user)
 
     cas_response = CertificateAuthoritiesResponse.from_cas(cas)
     return certificate_authorities_response_schema.dumps(cas_response)
@@ -331,29 +338,23 @@ def get_ca(ca):
     '''
     try:
         ca_object = certificatemanager.get_ca(ca)
-    except certificatemanager.CertificateAuthorityNotFoundError:
+    except CertificateAuthorityNotFoundError:
         return jsonify({'error': 'Provided CA not found.'}), 404
 
     logged_in_user = authnz.get_logged_in_user()
+
     if not acl_module_check(
         resource_type='ca',
         action='get',
         resource_id=ca,
     ):
-        msg = '{} does not have access to get ca {}'.format(
-            authnz.get_logged_in_user(),
-            ca,
-        )
+        msg = f'''
+        {authnz.get_logged_in_user()} does not have access to get ca {ca}
+        '''
         error_msg = {'error': msg, 'reference': ca}
         return jsonify(error_msg), 403
 
-    logger.info(
-        'get_ca called on id={} by user={}'.format(
-            ca,
-            logged_in_user,
-        )
-    )
-
+    logger.info('get_ca called on id=%s by user=%s', ca, logged_in_user)
     _ca = ca_object.get_certificate_authority_certificate()
     ca_response = CertificateAuthorityResponse(
         ca=_ca['ca'],