[authentication] named scanner broke auth factory (RedHatProductSecur…

…ity#127)

The authentication factory expected a fixed string for the scanners, to
get to the authentication type.

This was broken by the named scanner (e.g.: `zap_anonymous`).

This commit fixes that.

Also, while at it, I tidied a little:
- moved the factory into its own file
- improved the dev documentation for authentication

docs/DEVELOPER-GUIDE.md

@@ -63,23 +63,26 @@ likely either anonymous or error handling)
 
 Example for the ZAP scanner (`scanners.zap`):
 
-```
-from scanners import generic_authentication_factory
+```python
+from scanners.authentication_factory import generic_authentication_factory
 
-@generic_authentication_factory("zap")
+@generic_authentication_factory()
 def authentication_factory(self):
-  """Default action"""
+  """Default action, called when no corresponding authenticator were found"""
 ```
 
 Once done, simply register each authentication type, based on
-`scanners.zap.authentication.type` :
+`scanners.*.authentication.type` :
 
-```
+```python
 @authentication_factory.register("http_basic")
 def authentication_set_http_basic_auth(self):
   """Configure HTTP Basic authentication"""
 ```
 
+Then calling the `authentication_factory()` function will automatically redirect the call to the correct authentication function.
+
+
 ### Path helper
 
 Because scanners may need to handle path from the "host" view and the "container" view, and translate from one to another, we have created a `path_translator` module to facilitate this.

scanners/__init__.py

@@ -67,60 +67,3 @@ def str_to_scanner(name, method):
     mod = importlib.import_module(f"scanners.{name}.{name}_{method}")
     class_ = getattr(mod, mod.CLASSNAME)
     return class_
-
-
-###########################################################
-# AUTHENTICATION HELPERS                                  #
-# - authentication factory                                #
-###########################################################
-
-
-def generic_authentication_factory(scanner_name):
-    """Decorator factory for generic authentication.
-    First create the decorator:
-        @generic_authentication_factory("zap")
-        def authentication_factory(self):
-            [ default action. i.e.: probably raise error]
-
-    Then populate it by registering methods:
-        @authentication_factory.register(None)
-        def authentication_set_anonymous(self):
-            [return authentication of type `None`]
-    """
-
-    def config_authentication_dispatcher(func):
-        """This is intended to be a decorator to register authentication functions
-        The function passed during creation will be called in case no suitable functions are found.
-        i.e.: it should raise an error.
-
-        It is possible to retrieve an authenticator by calling <dispatcher>.dispatch(<version>)
-        This may be used for testing purpose
-        """
-        registry = {}  # "method" -> authenticator()
-
-        registry["error"] = func
-
-        def register(method):
-            def inner(func):
-                registry[method] = func
-                return func
-
-            return inner
-
-        def decorator(scanner):
-            authenticator = scanner.config.get(
-                f"scanners.{scanner_name}.authentication.type", default=None
-            )
-            func = registry.get(authenticator, registry["error"])
-            return func(scanner)
-
-        def dispatch(scanner):
-            return registry.get(scanner, registry["error"])
-
-        decorator.register = register
-        decorator.registry = registry
-        decorator.dispatch = dispatch
-
-        return decorator
-
-    return config_authentication_dispatcher

scanners/authentication_factory.py

@@ -0,0 +1,53 @@
+###########################################################
+# AUTHENTICATION HELPERS                                  #
+# - authentication factory                                #
+###########################################################
+
+
+def generic_authentication_factory():
+    """Decorator factory for generic authentication.
+    First create the decorator:
+        @generic_authentication_factory("zap")
+        def authentication_factory(self):
+            [ default action. i.e.: probably raise error]
+
+    Then populate it by registering methods:
+        @authentication_factory.register(None)
+        def authentication_set_anonymous(self):
+            [return authentication of type `None`]
+    """
+
+    def config_authentication_dispatcher(func):
+        """This is intended to be a decorator to register authentication functions
+        The function passed during creation will be called in case no suitable functions are found.
+        i.e.: it should raise an error.
+
+        It is possible to retrieve an authenticator by calling <dispatcher>.dispatch(<version>)
+        This may be used for testing purpose
+        """
+        registry = {}  # "method" -> authenticator()
+
+        registry["error"] = func
+
+        def register(method):
+            def inner(func):
+                registry[method] = func
+                return func
+
+            return inner
+
+        def decorator(scanner):
+            authenticator = scanner.my_conf("authentication.type")
+            func = registry.get(authenticator, registry["error"])
+            return func(scanner)
+
+        def dispatch(scanner):
+            return registry.get(scanner, registry["error"])
+
+        decorator.register = register
+        decorator.registry = registry
+        decorator.dispatch = dispatch
+
+        return decorator
+
+    return config_authentication_dispatcher

scanners/zap/zap.py

@@ -10,8 +10,8 @@
 
 import yaml
 
-from scanners import generic_authentication_factory
 from scanners import RapidastScanner
+from scanners.authentication_factory import generic_authentication_factory
 from scanners.downloaders import authenticated_download_with_rtoken
 
 
@@ -549,7 +549,7 @@ def _save_automation_file(self):
     # - May modify `self.automation_config` (e.g.: adding jobs, users)
     # - May add environment vars
     # - MUST return True if it created a user, and False otherwise
-    @generic_authentication_factory("zap")
+    @generic_authentication_factory()
     def authentication_factory(self):
         """This is the default function, attached to error reporting"""
         raise RuntimeError(