Changes between Version 1 and Version 2 of TracFineGrainedPermissions


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Timestamp:
Jul 6, 2013 6:47:50 PM (10 months ago)
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trac
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  • TracFineGrainedPermissions

    v1 v2  
    33Before Trac 0.11, it was only possible to define fine-grained permissions checks on the repository browser sub-system. 
    44 
    5 Since 0.11, there's a general mechanism in place that allows custom permission policy plugins to grant or deny any action on any kind of Trac resources, even at the level of specific versions of such resources. 
     5Since 0.11, there's a general mechanism in place that allows custom **permission policy plugins** to grant or deny any action on any kind of Trac resources, even at the level of specific versions of such resources. 
     6 
     7Note that for Trac 0.12, `authz_policy` has been integrated as an optional module (in `tracopt.perm.authz_policy.*`), so it's installed by default and can simply be activated via the //Plugins// panel in the Trac administration module. 
     8 
    69 
    710== Permission Policies == 
    811 
    9 === !AuthzPolicy === 
    10  
    11 An example policy based on an Authz-style system has been added. See 
    12 [trac:source:branches/0.11-stable/sample-plugins/permissions/authz_policy.py authz_policy.py] for details (current version requires >= Python 2.4). (See also [trac:source:branches/0.11-stable/sample-plugins/permissions sample-plugins/permissions] for more samples.) 
    13  
    14  - Install [http://www.voidspace.org.uk/python/configobj.html ConfigObj] (required). 
    15  - Copy authz_policy.py into your plugins directory. 
    16  - 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. 
    17  - Update your `trac.ini`: 
    18    1. modify the [TracIni#trac-section permission_policies] entry in the `[trac]` section 
     12A great diversity of permission policies can be implemented, and Trac comes with a few examples.  
     13 
     14Which policies are currently active is determined by a configuration setting in TracIni: 
     15e.g. 
     16{{{ 
     17[trac] 
     18permission_policies = AuthzSourcePolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy 
     19}}} 
     20This 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. 
     21 
     22Among the possible optional choices, there is [#AuthzPolicy], a very generic permission policy, based on an Authz-style system. See 
     23[trac:source:branches/0.12-stable/tracopt/perm/authz_policy.py authz_policy.py] for details.  
     24 
     25Another popular permission policy [#AuthzSourcePolicy], re-implements the pre-0.12 support for checking fine-grained permissions limited to Subversion repositories in terms of the new system. 
     26 
     27See also [trac:source:branches/0.12-stable/sample-plugins/permissions sample-plugins/permissions] for more examples. 
     28 
     29 
     30=== !AuthzPolicy ===  
     31==== Configuration ==== 
     32* Install [http://www.voidspace.org.uk/python/configobj.html ConfigObj] (still needed for 0.12). 
     33* Copy authz_policy.py into your plugins directory. 
     34* 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. 
     35* Update your `trac.ini`: 
     36  1. modify the [TracIni#trac-section permission_policies] entry in the `[trac]` section 
    1937{{{ 
    2038[trac] 
     
    2240permission_policies = AuthzPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy 
    2341}}} 
    24    2. add a new `[authz_policy]` section 
     42  2. add a new `[authz_policy]` section 
    2543{{{ 
    2644[authz_policy] 
    2745authz_file = /some/trac/env/conf/authzpolicy.conf 
    2846}}} 
    29    3. enable the single file plugin 
     47  3. enable the single file plugin 
    3048{{{ 
    3149[components] 
    3250... 
    33 authz_policy.* = enabled 
    34 }}} 
    35  
     51# Trac 0.12 
     52tracopt.perm.authz_policy.* = enabled 
     53# for Trac 0.11 use this 
     54#authz_policy.* = enabled  
     55}}} 
     56==== Usage Notes ==== 
    3657Note that the order in which permission policies are specified is quite critical,  
    3758as policies will be examined in the sequence provided. 
    3859 
    39 A policy will return either `True`, `False` or `None` for a given permission check. 
    40 Only if the return value is `None` will the ''next'' permission policy be consulted. 
    41 If no policy explicitly grants the permission, the final result will be `False`  
    42 (i.e. no permission). 
     60A 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. 
     61 
     62NOTE: Only if the return value is `None` will the ''next'' permission policy be consulted. 
     63If none of the policies explicitly grants the permission, the final result will be `False`  
     64(i.e. permission denied). 
     65 
     66The `authzpolicy.conf` file is a `.ini` style configuration file: 
     67{{{ 
     68[wiki:PrivatePage@*] 
     69john = WIKI_VIEW, !WIKI_MODIFY 
     70jack = WIKI_VIEW 
     71* = 
     72}}} 
     73* Each section of the config is a glob pattern used to match against a Trac resource 
     74  descriptor. These descriptors are in the form: 
     75{{{ 
     76<realm>:<id>@<version>[/<realm>:<id>@<version> ...] 
     77}}} 
     78  Resources are ordered left to right, from parent to child. If any 
     79  component is inapplicable, `*` is substituted. If the version pattern is 
     80  not specified explicitely, all versions (`@*`) is added implicitly 
     81 
     82  Example: Match the WikiStart page 
     83{{{ 
     84[wiki:*] 
     85[wiki:WikiStart*] 
     86[wiki:WikiStart@*] 
     87[wiki:WikiStart] 
     88}}} 
     89 
     90  Example: Match the attachment `wiki:WikiStart@117/attachment/FOO.JPG@*` 
     91  on WikiStart 
     92{{{ 
     93[wiki:*] 
     94[wiki:WikiStart*] 
     95[wiki:WikiStart@*] 
     96[wiki:WikiStart@*/attachment/*] 
     97[wiki:WikiStart@117/attachment/FOO.JPG] 
     98}}} 
     99 
     100* Sections are checked against the current Trac resource descriptor '''IN ORDER''' of 
     101  appearance in the configuration file. '''ORDER IS CRITICAL'''. 
     102 
     103* Once a section matches, the current username is matched against the keys  
     104  (usernames) of the section, '''IN ORDER'''.  
     105  * If a key (username) is prefixed with a `@`, it is treated as a group.  
     106  * If a value (permission) is prefixed with a `!`, the permission is 
     107    denied rather than granted. 
     108 
     109  The username will match any of 'anonymous', 
     110  'authenticated', <username> or '*', using normal Trac permission rules. 
    43111 
    44112For example, if the `authz_file` contains: 
     
    49117[wiki:PrivatePage@*] 
    50118john = WIKI_VIEW 
    51 * = 
     119* = !WIKI_VIEW 
    52120}}} 
    53121and the default permissions are set like this: 
     
    59127 
    60128Then:  
    61  - All versions of WikiStart will be viewable by everybody (including anonymous) 
    62  - !PrivatePage will be viewable only by john 
    63  - other pages will be viewable only by john and jack 
    64  
    65  
    66 === mod_authz_svn-like permission policy === 
    67  
    68 At the time of this writing, the old fine grained permissions system from Trac 0.10 and before used for restricting access to the repository has not yet been converted to a permission policy component, but from the user point of view, this makes little if no difference. 
     129  * All versions of WikiStart will be viewable by everybody (including anonymous) 
     130  * !PrivatePage will be viewable only by john 
     131  * other pages will be viewable only by john and jack 
     132 
     133Groups: 
     134{{{ 
     135[groups] 
     136admins = john, jack 
     137devs = alice, bob 
     138 
     139[wiki:Dev@*] 
     140@admins = TRAC_ADMIN 
     141@devs = WIKI_VIEW 
     142* = 
     143 
     144[*] 
     145@admins = TRAC_ADMIN 
     146* = 
     147}}} 
     148 
     149Then: 
     150- everything is blocked (whitelist approach), but 
     151- admins get all TRAC_ADMIN everywhere and 
     152- devs can view wiki pages. 
     153 
     154Some repository examples (Browse Source specific): 
     155{{{ 
     156# A single repository: 
     157[repository:test_repo@*] 
     158john = BROWSER_VIEW, FILE_VIEW 
     159# John has BROWSER_VIEW and FILE_VIEW for the entire test_repo 
     160 
     161# All repositories: 
     162[repository:*@*] 
     163jack = BROWSER_VIEW, FILE_VIEW 
     164# John has BROWSER_VIEW and FILE_VIEW for all repositories 
     165}}} 
     166 
     167Very fine grain repository access: 
     168{{{ 
     169# John has BROWSER_VIEW and FILE_VIEW access to trunk/src/some/location/ only 
     170[repository:test_repo@*/source:trunk/src/some/location/*@*] 
     171john = BROWSER_VIEW, FILE_VIEW 
     172 
     173 
     174# John has BROWSER_VIEW and FILE_VIEW access to only revision 1 of all files at trunk/src/some/location only 
     175[repository:test_repo@*/source:trunk/src/some/location/*@1] 
     176john = BROWSER_VIEW, FILE_VIEW 
     177 
     178 
     179# John has BROWSER_VIEW and FILE_VIEW access to all revisions of 'somefile' at trunk/src/some/location only  
     180[repository:test_repo@*/source:trunk/src/some/location/somefile@*] 
     181john = BROWSER_VIEW, FILE_VIEW 
     182 
     183 
     184# John has BROWSER_VIEW and FILE_VIEW access to only revision 1 of 'somefile' at trunk/src/some/location only 
     185[repository:test_repo@*/source:trunk/src/some/location/somefile@1] 
     186john = BROWSER_VIEW, FILE_VIEW 
     187}}} 
     188 
     189Note: In order for Timeline to work/visible for John, we must add CHANGESET_VIEW to the above permission list. 
     190 
     191 
     192=== !AuthzSourcePolicy  (mod_authz_svn-like permission policy) === #AuthzSourcePolicy 
     193 
     194At the time of this writing, the old fine grained permissions system from Trac 0.11 and before used for restricting access to the repository has  been converted to a permission policy component, but from the user point of view, this makes little if no difference. 
    69195 
    70196That kind of fine-grained permission control needs a definition file, which is the one used by Subversion's mod_authz_svn.  
     
    97223}}} 
    98224 
    99 if you want to support the use of the `[`''modulename''`:/`''some''`/`''path''`]` syntax within the `authz_file`, add  
     225If you want to support the use of the `[`''modulename''`:/`''some''`/`''path''`]` syntax within the `authz_file`, add  
    100226 
    101227{{{ 
     
    103229}}} 
    104230 
    105 where ''modulename'' refers to the same repository indicated by the `repository_dir` entry in the `[trac]` section. 
     231where ''modulename'' refers to the same repository indicated by the `repository_dir` entry in the `[trac]` section. As an example, if the `repository_dir` entry in the `[trac]` section is {{{/srv/active/svn/blahblah}}}, that would yield the following: 
     232 
     233{{{  
     234[trac] 
     235authz_file = /path/to/svnaccessfile 
     236authz_module_name = blahblah 
     237... 
     238repository_dir = /srv/active/svn/blahblah  
     239}}} 
     240 
     241where the svn access file, {{{/path/to/svnaccessfile}}}, contains entries such as {{{[blahblah:/some/path]}}}. 
    106242 
    107243'''Note:''' Usernames inside the Authz file __must__ be the same as those used inside trac.  
     244 
     245As of version 0.12, make sure you have ''!AuthzSourcePolicy'' included in the permission_policies list in trac.ini, otherwise the authz permissions file will be ignored. 
     246 
     247{{{  
     248[trac] 
     249permission_policies = AuthzSourcePolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy 
     250}}} 
    108251 
    109252==== Subversion Configuration ==== 
     
    122265For information about how to restrict access to entire projects in a multiple project environment see [trac:wiki:TracMultipleProjectsSVNAccess] 
    123266 
    124 == Getting TracFineGrainedPermissions to work == 
    125  
    126 Don't forget to restart Trac engine to apply new configuration if you are running tracd standalone server. 
     267== Debugging permissions 
     268In trac.ini set: 
     269{{{ 
     270[logging] 
     271log_file = trac.log 
     272log_level = DEBUG 
     273log_type = file 
     274}}} 
     275 
     276And watch: 
     277{{{ 
     278tail -n 0 -f log/trac.log | egrep '\[perm\]|\[authz_policy\]' 
     279}}} 
     280 
     281to understand what checks are being performed. See the sourced documentation of the plugin for more info. 
     282 
    127283 
    128284---- 
    129 See also: TracPermissions 
    130 http://trac-hacks.org/wiki/FineGrainedPageAuthzEditorPlugin for a simple editor plugin. 
     285See also: TracPermissions, 
     286[http://trac-hacks.org/wiki/FineGrainedPageAuthzEditorPlugin TracHacks:FineGrainedPageAuthzEditorPlugin] for a simple editor plugin.