| 2 | | = Fine grained permissions = |
| 3 | | |
| 4 | | Before Trac 0.11, it was only possible to define fine-grained permissions checks on the repository browser sub-system. |
| 5 | | |
| 6 | | 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. |
| 7 | | |
| 8 | | Note 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. |
| 9 | | |
| 10 | | |
| 11 | | == Permission Policies == |
| 12 | | |
| 13 | | A great diversity of permission policies can be implemented, and Trac comes with a few examples. |
| 14 | | |
| 15 | | Which policies are currently active is determined by a configuration setting in TracIni: |
| 16 | | e.g. |
| 17 | | {{{ |
| 18 | | [trac] |
| 19 | | permission_policies = AuthzSourcePolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy |
| 20 | | }}} |
| 21 | | 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. |
| 22 | | |
| 23 | | Among the possible optional choices, there is [#AuthzPolicy], a very generic permission policy, based on an Authz-style system. See |
| 24 | | [trac:source:branches/0.12-stable/tracopt/perm/authz_policy.py authz_policy.py] for details. |
| 25 | | |
| 26 | | 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. |
| 27 | | |
| 28 | | See also [trac:source:branches/0.12-stable/sample-plugins/permissions sample-plugins/permissions] for more examples. |
| 29 | | |
| 30 | | |
| 31 | | === !AuthzPolicy === |
| 32 | | ==== Configuration ==== |
| 33 | | * Install [http://www.voidspace.org.uk/python/configobj.html ConfigObj] (still needed for 0.12). |
| 34 | | * Copy authz_policy.py into your plugins directory (only for Trac 0.11). |
| 35 | | * 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. |
| | 3 | [[TracGuideToc]] |
| | 4 | |
| | 5 | There 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. |
| | 6 | |
| | 7 | That mechanism is `AuthzPolicy`, an optional component in `tracopt.perm.authz_policy.*` which is not activated by default. It can be activated via the //Plugins// panel in the Trac administration module. |
| | 8 | |
| | 9 | See TracPermissions for a more general introduction to Trac permissions and permission policies. |
| | 10 | |
| | 11 | == Permission Policies |
| | 12 | |
| | 13 | A great diversity of permission policies can be implemented and Trac comes with a few examples. |
| | 14 | |
| | 15 | The active policies are determined by a [TracIni#trac-permission_policies-option configuration setting]: |
| | 16 | |
| | 17 | {{{#!ini |
| | 18 | [trac] |
| | 19 | permission_policies = DefaultWikiPolicy, |
| | 20 | DefaultTicketPolicy, |
| | 21 | DefaultPermissionPolicy, |
| | 22 | LegacyAttachmentPolicy |
| | 23 | }}} |
| | 24 | |
| | 25 | * [#DefaultWikiPolicyandDefaultTicketPolicy DefaultWikiPolicy] controls readonly access to wiki pages. |
| | 26 | * [#DefaultWikiPolicyandDefaultTicketPolicy DefaultTicketPolicy] provides elevated privileges in the ticket system for authenticated users. |
| | 27 | * !DefaultPermissionPolicy checks for the traditional coarse-grained permissions described in TracPermissions. |
| | 28 | * !LegacyAttachmentPolicy uses the coarse-grained permissions to check permissions on attachments. |
| | 29 | |
| | 30 | Among the optional choices, there is [#AuthzPolicy], a very generic permission policy, based on an Authz-style system. See |
| | 31 | [trac:source:branches/1.4-stable/tracopt/perm/authz_policy.py authz_policy.py] for details. |
| | 32 | |
| | 33 | Another 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. |
| | 34 | |
| | 35 | See also [trac:source:branches/1.4-stable/sample-plugins/permissions sample-plugins/permissions] for more examples. |
| | 36 | |
| | 37 | === !AuthzPolicy |
| | 38 | ==== Configuration |
| | 39 | * Put an empty conf file (`authzpolicy.conf`) 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. |
| 99 | | [wiki:WikiStart@*/attachment/*] |
| 100 | | [wiki:WikiStart@117/attachment/FOO.JPG] |
| 101 | | }}} |
| 102 | | |
| 103 | | * Sections are checked against the current Trac resource descriptor '''IN ORDER''' of |
| 104 | | appearance in the configuration file. '''ORDER IS CRITICAL'''. |
| 105 | | |
| 106 | | * Once a section matches, the current username is matched against the keys |
| 107 | | (usernames) of the section, '''IN ORDER'''. |
| 108 | | * If a key (username) is prefixed with a `@`, it is treated as a group. |
| 109 | | * If a value (permission) is prefixed with a `!`, the permission is |
| 110 | | denied rather than granted. |
| 111 | | |
| 112 | | 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 || |
| | 90 | [wiki:WikiStart@*/attachment:*] |
| | 91 | [wiki:WikiStart@117/attachment:FOO.JPG] |
| | 92 | }}} |
| | 93 | |
| | 94 | * Sections are checked against the current Trac resource descriptor '''IN ORDER''' of appearance in the configuration file. '''ORDER IS CRITICAL'''. |
| | 95 | |
| | 96 | * Once a section matches, the current username is matched against the keys (usernames) of the section, '''IN ORDER'''. |
| | 97 | * If a key (username) is prefixed with a `@`, it is treated as a group. |
| | 98 | * If a value (permission) is prefixed with a `!`, the permission is denied rather than granted. |
| | 99 | |
| | 100 | The username will match any of 'anonymous', 'authenticated', <username> or '*', using normal Trac permission rules. |
| | 101 | |
| | 102 | || '''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:#5648] for details about this missing feature. || |
| 217 | | === !AuthzSourcePolicy (mod_authz_svn-like permission policy) === #AuthzSourcePolicy |
| 218 | | |
| 219 | | At 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. |
| 220 | | |
| 221 | | That kind of fine-grained permission control needs a definition file, which is the one used by Subversion's mod_authz_svn. |
| 222 | | 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. |
| | 208 | === !AuthzSourcePolicy (`mod_authz_svn`-like permission policy) #AuthzSourcePolicy |
| | 209 | |
| | 210 | `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`. |
| | 211 | More 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. |
| 263 | | repository_dir = /srv/active/svn/blahblah |
| 264 | | }}} |
| 265 | | |
| 266 | | where the svn access file, {{{/path/to/svnaccessfile}}}, contains entries such as {{{[blahblah:/some/path]}}}. |
| 267 | | |
| 268 | | '''Note:''' Usernames inside the Authz file __must__ be the same as those used inside trac. |
| 269 | | |
| 270 | | As 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. |
| 271 | | |
| 272 | | {{{ |
| 273 | | [trac] |
| 274 | | permission_policies = AuthzSourcePolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy |
| 275 | | }}} |
| 276 | | |
| 277 | | ==== Subversion Configuration ==== |
| | 252 | [repositories] |
| | 253 | somemodule.dir = /srv/active/svn/somemodule |
| | 254 | }}} |
| | 255 | |
| | 256 | where the svn access file, {{{/path/to/svnaccessfile}}}, contains entries such as {{{[somemodule:/some/path]}}}. |
| | 257 | |
| | 258 | '''Note:''' Usernames inside the Authz file __must__ be the same as those used inside trac. |
| | 259 | |
| | 260 | Make sure you have ''!AuthzSourcePolicy'' included in the permission_policies list in trac.ini, otherwise the authz permissions file will be ignored. |
| | 261 | |
| | 262 | {{{#!ini |
| | 263 | [trac] |
| | 264 | permission_policies = AuthzSourcePolicy, DefaultWikiPolicy, DefaultTicketPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy |
| | 265 | }}} |
| | 266 | |
| | 267 | ==== Subversion Configuration |
| 290 | | For information about how to restrict access to entire projects in a multiple project environment see [trac:wiki:TracMultipleProjectsSVNAccess] |
| | 280 | For information about how to restrict access to entire projects in a multiple project environment see [trac:wiki:TracMultipleProjectsSVNAccess]. |
| | 281 | |
| | 282 | === !DefaultWikiPolicy and !DefaultTicketPolicy |
| | 283 | |
| | 284 | Since 1.1.2, the read-only attribute of wiki pages is enabled and enforced when `DefaultWikiPolicy` is in the list of active permission policies (`DefaultWikiPolicy` was named `ReadonlyWikiPolicy` from Trac 1.1.2 to 1.3.1). The default for new Trac installations in 1.3.2 and later is: |
| | 285 | {{{#!ini |
| | 286 | [trac] |
| | 287 | permission_policies = DefaultWikiPolicy, |
| | 288 | DefaultTicketPolicy, |
| | 289 | DefaultPermissionPolicy, |
| | 290 | LegacyAttachmentPolicy |
| | 291 | }}} |
| | 292 | |
| | 293 | `DefaultWikiPolicy` 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, which causes the next permission policy in the list to be consulted. |
| | 294 | |
| | 295 | Since 1.3.2 `DefaultTicketPolicy` implements the following behaviors: |
| | 296 | * Authenticated user can edit their own comments. |
| | 297 | * Authenticated user with `TICKET_APPEND` or `TICKET_CHGPROP` can modify the description of a ticket they reported. |
| | 298 | * User with `MILESTONE_VIEW` can change the ticket milestone. |
| | 299 | |
| | 300 | The wiki- and ticket-specific behaviors are implemented in permission policies so they can be easily replaced in case other behavior is desired. |
| | 301 | |
| | 302 | When upgrading from earlier versions of Trac, `DefaultWikiPolicy, DefaultTicketPolicy` will be appended to the list of `permission_policies` when upgrading the environment, provided that `permission_policies` has the default value (`ReadonlyWikiPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy` if upgrading from Trac 1.1.2 or later). If any non-default `permission_polices` are active, `DefaultWikiPolicy, DefaultTicketPolicy` **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. |
| | 303 | |
| | 304 | **!DefaultWikiPolicy and !DefaultTicketPolicy 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. Similarly, some of the behaviors implemented in `DefaultTicketPolicy` won't be considered if `DefaultPermissionPolicy` is executed first. |
| | 305 | |
| | 306 | When active, the [#AuthzPolicy] should therefore come before `DefaultWikiPolicy, DefaultTicketPolicy`, allowing it to grant or deny the actions on individual resources, which is the usual ordering for `AuthzPolicy` in the `permission_policies` list. |
| | 307 | {{{#!ini |
| | 308 | [trac] |
| | 309 | permission_policies = AuthzPolicy, |
| | 310 | DefaultWikiPolicy, |
| | 311 | DefaultTicketPolicy, |
| | 312 | DefaultPermissionPolicy, |
| | 313 | LegacyAttachmentPolicy |
| | 314 | }}} |
| | 315 | |
| | 316 | The placement of [#AuthzSourcePolicy] relative to `DefaultWikiPolicy, DefaultTicketPolicy` does not matter since they don't perform checks on the same realms. |
| | 317 | |
| | 318 | 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 checks performed by `DefaultWikiPolicy` or `DefaultTicketPolicy`, it should come before the policy it overrides. If `DefaultWikiPolicy` or `DefaultTicketPolicy` should override the check performed by another permission policy, as is the case for those policies relative to `DefaultPermissionPolicy`, then the overriding policy should come first. |
