Implement rights types directly

This is faster and easier to understand.

radicale/rights.py

@@ -41,51 +41,29 @@ import os.path
 import re
 from configparser import ConfigParser
 from importlib import import_module
-from io import StringIO
 
 from . import storage
 
 
 def load(configuration, logger):
     """Load the rights manager chosen in configuration."""
-    auth_type = configuration.get("auth", "type")
     rights_type = configuration.get("rights", "type")
-    if auth_type == "None" or rights_type == "None":
-        return lambda user, collection, permission: True
-    elif rights_type in DEFINED_RIGHTS or rights_type == "from_file":
-        return Rights(configuration, logger).authorized
+    if configuration.get("auth", "type") == "None":
+        rights_type = "None"
+    logger.info("Rights type is %r", rights_type)
+    if rights_type == "None":
+        rights_class = NoneRights
+    elif rights_type == "authenticated":
+        rights_class = AuthenticatedRights
+    elif rights_type == "owner_write":
+        rights_class = OwnerWriteRights
+    elif rights_type == "owner_only":
+        rights_class = OwnerOnlyRights
+    elif rights_type == "from_file":
+        rights_class = Rights
     else:
-        module = import_module(rights_type)
-        return module.Rights(configuration, logger).authorized
-
-
-DEFINED_RIGHTS = {
-    "authenticated": """
-[rw]
-user:.+
-collection:.*
-permission:rw
-    """,
-    "owner_write": """
-[w]
-user:.+
-collection:%(login)s(/.*)?
-permission:rw
-[r]
-user:.+
-collection:.*
-permission:r
-    """,
-    "owner_only": """
-[rw]
-user:.+
-collection:%(login)s(/.*)?
-permission:rw
-[r]
-user:.+
-collection:
-permission:r
-    """}
+        rights_class = import_module(rights_type).Rights
+    return rights_class(configuration, logger).authorized
 
 
 class BaseRights:
@@ -102,32 +80,48 @@ class BaseRights:
         raise NotImplementedError
 
 
+class NoneRights(BaseRights):
+    def authorized(self, user, path, permission):
+        return True
+
+
+class AuthenticatedRights(BaseRights):
+    def authorized(self, user, path, permission):
+        return bool(user)
+
+
+class OwnerWriteRights(BaseRights):
+    def authorized(self, user, path, permission):
+        sane_path = storage.sanitize_path(path).strip("/")
+        return bool(user) and (permission == "r" or
+                               user == sane_path.split("/", maxsplit=1)[0])
+
+
+class OwnerOnlyRights(BaseRights):
+    def authorized(self, user, path, permission):
+        sane_path = storage.sanitize_path(path).strip("/")
+        return bool(user) and (
+            permission == "r" and not sane_path.strip("/") or
+            user == sane_path.split("/", maxsplit=1)[0])
+
+
 class Rights(BaseRights):
     def __init__(self, configuration, logger):
         super().__init__(configuration, logger)
         self.filename = os.path.expanduser(configuration.get("rights", "file"))
-        self.rights_type = configuration.get("rights", "type").lower()
 
     def authorized(self, user, path, permission):
         user = user or ""
-        if user and not storage.is_safe_path_component(user):
-            # Prevent usernames like "user/calendar.ics"
-            raise ValueError("Refused unsafe username: %s", user)
         sane_path = storage.sanitize_path(path).strip("/")
         # Prevent "regex injection"
         user_escaped = re.escape(user)
         sane_path_escaped = re.escape(sane_path)
         regex = ConfigParser(
             {"login": user_escaped, "path": sane_path_escaped})
-        if self.rights_type in DEFINED_RIGHTS:
-            self.logger.debug("Rights type '%s'", self.rights_type)
-            regex.readfp(StringIO(DEFINED_RIGHTS[self.rights_type]))
-        else:
-            self.logger.debug("Reading rights from file '%s'", self.filename)
-            if not regex.read(self.filename):
-                self.logger.error(
-                    "File '%s' not found for rights", self.filename)
-                return False
+        if not regex.read(self.filename):
+            raise RuntimeError("Failed to read rights from file %r",
+                               self.filename)
+            return False
 
         for section in regex.sections():
             re_user = regex.get(section, "user")