Changes between Version 1 and Version 2 of TracFineGrainedPermissions

Timestamp:

2015-05-25T08:23:07-07:00 (9 years ago)

Author:

trac

Comment:

--

TracFineGrainedPermissions

@@ +1 @@
+[[PageOutline(2-5, Contents, floated)]]
 = Fine grained permissions =
 
@@ -16 +17 @@
 {{{
 [trac]
-permission_policies = AuthzSourcePolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
-}}}
-This lists the [#AuthzSourcePolicy] described below as the first policy, followed by the !DefaultPermissionPolicy which checks for the traditional coarse grained style permissions described in TracPermissions, and the !LegacyAttachmentPolicy which knows how to use the coarse grained permissions for checking the permissions available on attachments.
+permission_policies = ReadonlyWikiPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
+}}}
+This lists the [#ReadonlyWikiPolicy] which controls readonly access to wiki pages, followed by the !DefaultPermissionPolicy which checks for the traditional coarse grained style permissions described in TracPermissions, and the !LegacyAttachmentPolicy which knows how to use the coarse grained permissions for checking the permissions available on attachments.
 
 Among the possible optional choices, there is [#AuthzPolicy], a very generic permission policy, based on an Authz-style system. See
@@ -29 +30 @@
 
 === !AuthzPolicy === 
-
- - Install [http://www.voidspace.org.uk/python/configobj.html ConfigObj] (required).
- - Copy authz_policy.py into your plugins directory.
- - Put a [http://swapoff.org/files/authzpolicy.conf authzpolicy.conf] file somewhere, preferably on a secured location on the server, not readable for others than the webuser. If the  file contains non-ASCII characters, the UTF-8 encoding should be used.
- - Update your `trac.ini`:
-   1. modify the [TracIni#trac-section permission_policies] entry in the `[trac]` section
+==== Configuration ====
+* Install [http://www.voidspace.org.uk/python/configobj.html ConfigObj] (still needed for 0.12 and later).
+* Copy [browser:/trunk/tracopt/perm/authz_policy.py /tracopt/perm/authz_policy.py] to your environment's plugins directory (only for Trac 0.11).
+* Put a [http://swapoff.org/files/authzpolicy.conf authzpolicy.conf] file somewhere, preferably on a secured location on the server, not readable for others than the webuser. If the  file contains non-ASCII characters, the UTF-8 encoding should be used.
+* Update your `trac.ini`:
+  1. modify the [TracIni#trac-section permission_policies] entry in the `[trac]` section
 {{{
 [trac]
 ...
-permission_policies = AuthzPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
-}}}
-   2. add a new `[authz_policy]` section
+permission_policies = AuthzPolicy, ReadonlyWikiPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
+}}}
+  1. add a new `[authz_policy]` section
 {{{
 [authz_policy]
 authz_file = /some/trac/env/conf/authzpolicy.conf
 }}}
-   3. enable the single file plugin
+  1. enable the plugin through [/admin/general/plugin WebAdmin] or by editing the `[components]` section
 {{{
 [components]
@@ -55 +56 @@
 }}}
 
+
+==== Usage Notes ====
 Note that the order in which permission policies are specified is quite critical, 
 as policies will be examined in the sequence provided.
 
-A policy will return either `True`, `False` or `None` for a given permission check.
-Only if the return value is `None` will the ''next'' permission policy be consulted.
-If no policy explicitly grants the permission, the final result will be `False` 
-(i.e. no permission).
+A policy will return either `True`, `False` or `None` for a given permission check. `True` is returned if the policy explicitly grants the permission. `False` is returned if the policy explicitly denies the permission. `None` is returned if the policy is unable to either grant or deny the permission.
+
+NOTE: Only if the return value is `None` will the ''next'' permission policy be consulted.
+If none of the policies explicitly grants the permission, the final result will be `False` 
+(i.e. permission denied).
+
+The `authzpolicy.conf` file is a `.ini` style configuration file:
+{{{
+[wiki:PrivatePage@*]
+john = WIKI_VIEW, !WIKI_MODIFY
+jack = WIKI_VIEW
+* =
+}}}
+* Each section of the config is a glob pattern used to match against a Trac resource
+  descriptor. These descriptors are in the form:
+{{{
+<realm>:<id>@<version>[/<realm>:<id>@<version> ...]
+}}}
+  Resources are ordered left to right, from parent to child. If any
+  component is inapplicable, `*` is substituted. If the version pattern is
+  not specified explicitely, all versions (`@*`) is added implicitly
+
+  Example: Match the WikiStart page
+{{{
+[wiki:*]
+[wiki:WikiStart*]
+[wiki:WikiStart@*]
+[wiki:WikiStart]
+}}}
+
+  Example: Match the attachment `wiki:WikiStart@117/attachment:FOO.JPG@*`
+  on WikiStart
+{{{
+[wiki:*]
+[wiki:WikiStart*]
+[wiki:WikiStart@*]
+[wiki:WikiStart@*/attachment:*]
+[wiki:WikiStart@117/attachment:FOO.JPG]
+}}}
+
+* Sections are checked against the current Trac resource descriptor '''IN ORDER''' of
+  appearance in the configuration file. '''ORDER IS CRITICAL'''.
+
+* Once a section matches, the current username is matched against the keys 
+  (usernames) of the section, '''IN ORDER'''. 
+  * If a key (username) is prefixed with a `@`, it is treated as a group. 
+  * If a value (permission) is prefixed with a `!`, the permission is
+    denied rather than granted.
+
+  The username will match any of 'anonymous', 'authenticated', <username> or '*', using normal Trac permission rules. || '''Note:''' Other groups which are created by user (e.g. by 'adding subjects to groups' on web interface page //Admin / Permissions//) cannot be used. See [trac:ticket:5648 #5648] for details about this missing feature ||
 
 For example, if the `authz_file` contains:
@@ -70 +119 @@
 [wiki:PrivatePage@*]
 john = WIKI_VIEW
-* =
+* = !WIKI_VIEW
 }}}
 and the default permissions are set like this:
@@ -80 +129 @@
 
 Then: 
- - All versions of WikiStart will be viewable by everybody (including anonymous)
- - !PrivatePage will be viewable only by john
- - other pages will be viewable only by john and jack
-
+  * All versions of WikiStart will be viewable by everybody (including anonymous)
+  * !PrivatePage will be viewable only by john
+  * other pages will be viewable only by john and jack
+
+Groups:
+{{{
+[groups]
+admins = john, jack
+devs = alice, bob
+
+[wiki:Dev@*]
+@admins = TRAC_ADMIN
+@devs = WIKI_VIEW
+* =
+
+[*]
+@admins = TRAC_ADMIN
+* =
+}}}
+
+Then:
+- everything is blocked (whitelist approach), but
+- admins get all TRAC_ADMIN everywhere and
+- devs can view wiki pages.
+
+Some repository examples (Browse Source specific):
+{{{
+# A single repository:
+[repository:test_repo@*]
+john = BROWSER_VIEW, FILE_VIEW
+# John has BROWSER_VIEW and FILE_VIEW for the entire test_repo
+
+# The default repository (requires Trac 1.0.2 or later):
+[repository:@*]
+john = BROWSER_VIEW, FILE_VIEW
+# John has BROWSER_VIEW and FILE_VIEW for the entire default repository
+
+# All repositories:
+[repository:*@*]
+jack = BROWSER_VIEW, FILE_VIEW
+# Jack has BROWSER_VIEW and FILE_VIEW for all repositories
+}}}
+
+Very fine grain repository access:
+{{{
+# John has BROWSER_VIEW and FILE_VIEW access to trunk/src/some/location/ only
+[repository:test_repo@*/source:trunk/src/some/location/*@*]
+john = BROWSER_VIEW, FILE_VIEW
+
+
+# John has BROWSER_VIEW and FILE_VIEW access to only revision 1 of all files at trunk/src/some/location only
+[repository:test_repo@*/source:trunk/src/some/location/*@1]
+john = BROWSER_VIEW, FILE_VIEW
+
+
+# John has BROWSER_VIEW and FILE_VIEW access to all revisions of 'somefile' at trunk/src/some/location only 
+[repository:test_repo@*/source:trunk/src/some/location/somefile@*]
+john = BROWSER_VIEW, FILE_VIEW
+
+
+# John has BROWSER_VIEW and FILE_VIEW access to only revision 1 of 'somefile' at trunk/src/some/location only
+[repository:test_repo@*/source:trunk/src/some/location/somefile@1]
+john = BROWSER_VIEW, FILE_VIEW
+}}}
+
+Note: In order for Timeline to work/visible for John, we must add CHANGESET_VIEW to the above permission list.
+
+
+==== Missing Features ====
+Although possible with the !DefaultPermissionPolicy handling (see Admin panel), fine-grained permissions still miss those grouping features (see [trac:ticket:9573 #9573], [trac:ticket:5648 #5648]). Patches are partially available, see forgotten authz_policy.2.patch  part of [trac:ticket:6680 #6680]).
+
+You cannot do the following:
+{{{
+[groups]
+team1 = a, b, c
+team2 = d, e, f
+team3 = g, h, i
+departmentA = team1, team2
+}}}
+
+Permission groups are not supported either. You cannot do the following:
+{{{
+[groups]
+permission_level_1 = WIKI_VIEW, TICKET_VIEW
+permission_level_2  = permission_level_1, WIKI_MODIFY, TICKET_MODIFY
+[*]
+@team1 = permission_level_1
+@team2 = permission_level_2
+@team3 = permission_level_2, TICKET_CREATE
+}}}
 
 === !AuthzSourcePolicy  (mod_authz_svn-like permission policy) === #AuthzSourcePolicy
@@ -142 +277 @@
 {{{ 
 [trac]
-permission_policies = AuthzSourcePolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
+permission_policies = AuthzSourcePolicy, ReadonlyWikiPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
 }}}
 
@@ -159 +294 @@
 
 For information about how to restrict access to entire projects in a multiple project environment see [trac:wiki:TracMultipleProjectsSVNAccess]
+
+=== ReadonlyWikiPolicy
+
+Since 1.1.2, the read-only attribute of wiki pages is enabled and enforced when `ReadonlyWikiPolicy` is in the list of active permission policies. The default for new Trac installations in 1.1.2 and later is:
+{{{
+[trac]
+permission_policies = ReadonlyWikiPolicy,
+ DefaultPermissionPolicy,
+ LegacyAttachmentPolicy
+}}}
+
+When upgrading from earlier versions of Trac, `ReadonlyWikiPolicy` will be appended to the list of `permission_policies` when upgrading the environment, provided that `permission_policies` has the default value. If any non-default `permission_polices` are active, `ReadonlyWikiPolicy` **will need to be manually added** to the list. A message will be echoed to the console when upgrading the environment, indicating if any action needs to be taken.
+
+**!ReadonlyWikiPolicy must be listed //before// !DefaultPermissionPolicy**. The latter returns `True` to allow modify, delete or rename actions when the user has the respective `WIKI_*` permission, without consideration for the read-only attribute.
+
+The `ReadonlyWikiPolicy` returns `False` to deny modify, delete and rename actions on wiki pages when the page has the read-only attribute set and the user does not have `WIKI_ADMIN`, regardless of `WIKI_MODIFY`, `WIKI_DELETE` and `WIKI_RENAME` permissions. It returns `None` for all other cases.
+
+When active, the [#AuthzPolicy] should therefore come before `ReadonlyWikiPolicy`, allowing it to grant or deny the actions on individual resources, which is the usual ordering for `AuthzPolicy` in the `permission_policies` list.
+{{{
+[trac]
+permission_policies = AuthzPolicy,
+ ReadonlyWikiPolicy,
+ DefaultPermissionPolicy,
+ LegacyAttachmentPolicy
+}}}
+
+The placement of [#AuthzSourcePolicy] relative to `ReadonlyWikiPolicy` does not matter since they don't perform checks on the same realms.
+
+For all other permission policies, the user will need to decide the proper ordering. Generally, if the permission policy should be capable of overriding the check performed by `ReadonlyWikiPolicy`, it should come before `ReadonlyWikiPolicy` in the list. If the `ReadonlyWikiPolicy` should override the check performed by another permission policy, as is the case for `DefaultPermissionPolicy`, then `ReadonlyWikiPolicy` should come first.
 
 == Debugging permissions
@@ -176 +340 @@
 to understand what checks are being performed. See the sourced documentation of the plugin for more info.
 
-
 ----
 See also: TracPermissions,