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Changes between Version 1 and Version 2 of TracFineGrainedPermissions


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Timestamp:
Jul 17, 2018, 2:09:57 PM (6 years ago)
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trac
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  • TracFineGrainedPermissions

    v1 v2  
    1 = Fine grained permissions =
     1= Fine grained permissions
    22[[PageOutline(2-5, Contents, floated)]]
    33[[TracGuideToc]]
    44
    5 There is a general mechanism in place that allows custom **permission policy plugins** to grant or deny any action on any kind of Trac resource, even at the level of specific versions of such resources.
     5There is a general mechanism in place that allows custom **permission policies** to grant or deny any action on any Trac resource, or even specific versions of a resource.
    66
    77That mechanism is `authz_policy`, which is an optional module in `tracopt.perm.authz_policy.*`, so it is installed by default. It can be activated via the //Plugins// panel in the Trac administration module.
    88
    9 == Permission Policies ==
     9== Permission Policies
    1010
    1111A great diversity of permission policies can be implemented and Trac comes with a few examples.
    1212
    13 Which policies are currently active is determined by a configuration setting in TracIni:
    14 
    15 {{{#!ini
    16 [trac]
    17 permission_policies = AuthzSourcePolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
    18 }}}
    19 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.
     13The active policies are determined by a [TracIni#trac-permission_policies-option configuration setting]:
     14
     15{{{#!ini
     16[trac]
     17permission_policies = ReadonlyWikiPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
     18}}}
     19
     20* [#ReadonlyWikiPolicy] controls readonly access to wiki pages.
     21* !DefaultPermissionPolicy checks for the traditional coarse-grained permissions described in TracPermissions.
     22* !LegacyAttachmentPolicy uses the coarse-grained permissions to check permissions on attachments.
    2023
    2124Among the optional choices, there is [#AuthzPolicy], a very generic permission policy, based on an Authz-style system. See
    22 [trac:source:branches/1.0-stable/tracopt/perm/authz_policy.py authz_policy.py] for details.
    23 
    24 Another 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.
    25 
    26 See also [trac:source:branches/1.0-stable/sample-plugins/permissions sample-plugins/permissions] for more examples.
    27 
    28 === !AuthzPolicy ===
    29 ==== Configuration ====
    30 * Install [http://www.voidspace.org.uk/python/configobj.html ConfigObj].
    31 * 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.
     25[trac:source:branches/1.2-stable/tracopt/perm/authz_policy.py authz_policy.py] for details.
     26
     27Another permission policy [#AuthzSourcePolicy], uses the [http://svnbook.red-bean.com/nightly/en/svn.serverconfig.pathbasedauthz.html path-based authorization] defined by Subversion to enforce permissions on the version control system.
     28
     29See also [trac:source:branches/1.2-stable/sample-plugins/permissions sample-plugins/permissions] for more examples.
     30
     31=== !AuthzPolicy
     32==== Configuration
     33* Put a [http://swapoff.org/files/authzpolicy.conf conf] file in a secure location on the server, not readable by users other than the webuser. If the  file contains non-ASCII characters, the UTF-8 encoding should be used.
    3234* Update your `trac.ini`:
    3335  1. modify the [TracIni#trac-section permission_policies] entry in the `[trac]` section:
    3436{{{#!ini
    3537[trac]
    36 ...
    37 permission_policies = AuthzPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
    38 }}}
    39   1. add a new `[authz_policy]` section:
     38permission_policies = AuthzPolicy, ReadonlyWikiPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
     39}}}
     40  1. add a new `[authz_policy]` section and point the `authz_file` option to the conf file:
    4041{{{#!ini
    4142[authz_policy]
    … …  
    4849}}}
    4950
    50 ==== Usage Notes ====
     51==== Usage Notes
    5152
    5253Note the order in which permission policies are specified: policies are implemented in the sequence provided and therefore may override earlier policy specifications.
    … …  
    174175Note: In order for Timeline to work/visible for John, we must add CHANGESET_VIEW to the above permission list.
    175176
    176 ==== Missing Features ====
     177==== Missing Features
    177178Although 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 authz_policy.2.patch, part of [trac:ticket:6680 #6680].
    178179
    … …  
    197198}}}
    198199
    199 === !AuthzSourcePolicy  (mod_authz_svn-like permission policy) === #AuthzSourcePolicy
    200 
    201 At the time of this writing, the old granular 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's point of view, this makes little if any difference.
    202 
    203 That kind of granular permission control needs a definition file, which is the one used by Subversion's mod_authz_svn.
    204 More information about this file format and about its usage in Subversion is available in the [http://svnbook.red-bean.com/en/1.5/svn.serverconfig.pathbasedauthz.html Path-Based Authorization] section in the Server Configuration chapter of the svn book.
     200=== !AuthzSourcePolicy  (mod_authz_svn-like permission policy) #AuthzSourcePolicy
     201
     202`AuthzSourcePolicy` can be used for restricting access to the repository. Granular permission control needs a definition file, which is the one used by Subversion's mod_authz_svn.
     203More information about this file format and about its usage in Subversion is available in the [http://svnbook.red-bean.com/en/1.7/svn.serverconfig.pathbasedauthz.html Path-Based Authorization] section in the Server Configuration chapter of the svn book.
    205204
    206205Example:
    … …  
    221220 * '''/branches/calc/bug-142/secret''' = ''harry has no access, sally has read access (inherited as a sub folder permission)''
    222221
    223 ==== Trac Configuration ====
    224 
    225 To activate granular permissions you __must__ specify the {{{authz_file}}} option in the {{{[trac]}}} section of trac.ini. If this option is set to null or not specified, the permissions will not be used.
    226 
    227 {{{#!ini
    228 [trac]
     222==== Trac Configuration
     223
     224To activate granular permissions you __must__ specify the {{{authz_file}}} option in the `[svn]` section of trac.ini. If this option is set to null or not specified, the permissions will not be used.
     225
     226{{{#!ini
     227[svn]
    229228authz_file = /path/to/svnaccessfile
    230229}}}
    … …  
    236235}}}
    237236
    238 where ''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/somemodule}}}, that would yield the following:
     237where ''modulename'' refers to the same repository indicated by the `<name>.dir` entry in the `[repositories]` section. As an example, if the `somemodule.dir` entry in the `[repositories]` section is `/srv/active/svn/somemodule`, that would yield the following:
    239238
    240239{{{ #!ini
    241 [trac]
     240[svn]
    242241authz_file = /path/to/svnaccessfile
    243242authz_module_name = somemodule
    244243...
    245 repository_dir = /srv/active/svn/somemodule
     244[repositories]
     245somemodule.dir = /srv/active/svn/somemodule
    246246}}}
    247247
    … …  
    254254{{{#!ini
    255255[trac]
    256 permission_policies = AuthzSourcePolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
    257 }}}
    258 
    259 ==== Subversion Configuration ====
     256permission_policies = AuthzSourcePolicy, ReadonlyWikiPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
     257}}}
     258
     259==== Subversion Configuration
    260260
    261261The same access file is typically applied to the corresponding Subversion repository using an Apache directive like this:
    … …  
    272272For information about how to restrict access to entire projects in a multiple project environment see [trac:wiki:TracMultipleProjectsSVNAccess].
    273273
     274=== ReadonlyWikiPolicy
     275
     276Since 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:
     277{{{
     278[trac]
     279permission_policies = ReadonlyWikiPolicy,
     280 DefaultPermissionPolicy,
     281 LegacyAttachmentPolicy
     282}}}
     283
     284When 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.
     285
     286**!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.
     287
     288The `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.
     289
     290When 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.
     291{{{
     292[trac]
     293permission_policies = AuthzPolicy,
     294 ReadonlyWikiPolicy,
     295 DefaultPermissionPolicy,
     296 LegacyAttachmentPolicy
     297}}}
     298
     299The placement of [#AuthzSourcePolicy] relative to `ReadonlyWikiPolicy` does not matter since they don't perform checks on the same realms.
     300
     301For 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.
     302
    274303== Debugging permissions
    275304In trac.ini set: