Changes between Version 2 and Version 3 of TracFineGrainedPermissions


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Timestamp:
Jul 18, 2019, 10:38:41 AM (3 years ago)
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trac
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  • TracFineGrainedPermissions

    v2 v3  
     1= Fine grained permissions
    12[[PageOutline(2-5, Contents, floated)]]
    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 {{{
     3[[TracGuideToc]]
     4
     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.
     6
     7That 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.
     8
     9== Permission Policies
     10
     11A great diversity of permission policies can be implemented and Trac comes with a few examples.
     12
     13The active policies are determined by a [TracIni#trac-permission_policies-option configuration setting]:
     14
     15{{{#!ini
    1816[trac]
    1917permission_policies = ReadonlyWikiPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
    2018}}}
    21 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.
    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 and later).
    34 * Copy [browser:/trunk/tracopt/perm/authz_policy.py /tracopt/perm/authz_policy.py] to your environment's 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.
     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.
     23
     24Among the optional choices, there is [#AuthzPolicy], a very generic permission policy, based on an Authz-style system. See
     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.
    3634* Update your `trac.ini`:
    37   1. modify the [TracIni#trac-section permission_policies] entry in the `[trac]` section
    38 {{{
    39 [trac]
    40 ...
     35  1. modify the [TracIni#trac-section permission_policies] entry in the `[trac]` section:
     36{{{#!ini
     37[trac]
    4138permission_policies = AuthzPolicy, ReadonlyWikiPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
    4239}}}
    43   1. add a new `[authz_policy]` section
    44 {{{
     40  1. add a new `[authz_policy]` section and point the `authz_file` option to the conf file:
     41{{{#!ini
    4542[authz_policy]
    4643authz_file = /some/trac/env/conf/authzpolicy.conf
    4744}}}
    48   1. enable the plugin through [/admin/general/plugin WebAdmin] or by editing the `[components]` section
    49 {{{
     45  1. enable the plugin through [/admin/general/plugin WebAdmin] or by editing the `[components]` section:
     46{{{#!ini
    5047[components]
    51 ...
    52 # Trac 0.12
    5348tracopt.perm.authz_policy.* = enabled
    54 # for Trac 0.11 use this
    55 #authz_policy.* = enabled
    56 }}}
    57 
    58 
    59 ==== Usage Notes ====
    60 Note that the order in which permission policies are specified is quite critical,
    61 as policies will be examined in the sequence provided.
     49}}}
     50
     51==== Usage Notes
     52
     53Note the order in which permission policies are specified: policies are implemented in the sequence provided and therefore may override earlier policy specifications.
    6254
    6355A 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.
    6456
    65 NOTE: Only if the return value is `None` will the ''next'' permission policy be consulted.
    66 If none of the policies explicitly grants the permission, the final result will be `False`
    67 (i.e. permission denied).
     57NOTE: 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.
    6858
    6959The `authzpolicy.conf` file is a `.ini` style configuration file:
    70 {{{
     60{{{#!ini
    7161[wiki:PrivatePage@*]
    7262john = WIKI_VIEW, !WIKI_MODIFY
     
    7464* =
    7565}}}
    76 * Each section of the config is a glob pattern used to match against a Trac resource
    77   descriptor. These descriptors are in the form:
     66* Each section of the config is a glob pattern used to match against a Trac resource descriptor. These descriptors are in the form:
    7867{{{
    7968<realm>:<id>@<version>[/<realm>:<id>@<version> ...]
    8069}}}
    81   Resources are ordered left to right, from parent to child. If any
    82   component is inapplicable, `*` is substituted. If the version pattern is
    83   not specified explicitely, all versions (`@*`) is added implicitly
    84 
    85   Example: Match the WikiStart page
    86 {{{
     70
     71Resources are ordered left to right, from parent to child. If any component is inapplicable, `*` is substituted. If the version pattern is not specified explicitly, all versions (`@*`) is added implicitly. Example: Match the WikiStart page:
     72{{{#!ini
    8773[wiki:*]
    8874[wiki:WikiStart*]
     
    9177}}}
    9278
    93   Example: Match the attachment `wiki:WikiStart@117/attachment:FOO.JPG@*`
    94   on WikiStart
    95 {{{
     79Example: Match the attachment `wiki:WikiStart@117/attachment:FOO.JPG@*` on WikiStart:
     80{{{#!ini
    9681[wiki:*]
    9782[wiki:WikiStart*]
     
    10186}}}
    10287
    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'''.
     88* Sections are checked against the current Trac resource descriptor '''IN ORDER''' of appearance in the configuration file. '''ORDER IS CRITICAL'''.
     89
     90* Once a section matches, the current username is matched against the keys (usernames) of the section, '''IN ORDER'''.
    10891  * 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 ||
     92  * If a value (permission) is prefixed with a `!`, the permission is denied rather than granted.
     93
     94The 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. ||
    11395
    11496For example, if the `authz_file` contains:
    115 {{{
     97{{{#!ini
    11698[wiki:WikiStart@*]
    11799* = WIKI_VIEW
     
    129111
    130112Then:
    131   * All versions of WikiStart will be viewable by everybody (including anonymous)
     113  * All versions of WikiStart will be viewable by everybody, including anonymous
    132114  * !PrivatePage will be viewable only by john
    133115  * other pages will be viewable only by john and jack
    134116
    135117Groups:
    136 {{{
     118{{{#!ini
    137119[groups]
    138120admins = john, jack
     
    155137
    156138Some repository examples (Browse Source specific):
    157 {{{
     139{{{#!ini
    158140# A single repository:
    159141[repository:test_repo@*]
     
    172154}}}
    173155
    174 Very fine grain repository access:
    175 {{{
     156Very granular repository access:
     157{{{#!ini
    176158# John has BROWSER_VIEW and FILE_VIEW access to trunk/src/some/location/ only
    177159[repository:test_repo@*/source:trunk/src/some/location/*@*]
    178160john = BROWSER_VIEW, FILE_VIEW
    179161
    180 
    181162# John has BROWSER_VIEW and FILE_VIEW access to only revision 1 of all files at trunk/src/some/location only
    182163[repository:test_repo@*/source:trunk/src/some/location/*@1]
    183164john = BROWSER_VIEW, FILE_VIEW
    184165
    185 
    186166# John has BROWSER_VIEW and FILE_VIEW access to all revisions of 'somefile' at trunk/src/some/location only
    187167[repository:test_repo@*/source:trunk/src/some/location/somefile@*]
    188168john = BROWSER_VIEW, FILE_VIEW
    189169
    190 
    191170# John has BROWSER_VIEW and FILE_VIEW access to only revision 1 of 'somefile' at trunk/src/some/location only
    192171[repository:test_repo@*/source:trunk/src/some/location/somefile@1]
     
    196175Note: In order for Timeline to work/visible for John, we must add CHANGESET_VIEW to the above permission list.
    197176
    198 
    199 ==== Missing Features ====
    200 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]).
     177==== Missing Features
     178Although 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].
    201179
    202180You cannot do the following:
    203 {{{
     181{{{#!ini
    204182[groups]
    205183team1 = a, b, c
     
    209187}}}
    210188
    211 Permission groups are not supported either. You cannot do the following:
    212 {{{
     189Permission groups are not supported either, so you cannot do the following:
     190{{{#!ini
    213191[groups]
    214192permission_level_1 = WIKI_VIEW, TICKET_VIEW
     
    220198}}}
    221199
    222 === !AuthzSourcePolicy  (mod_authz_svn-like permission policy) === #AuthzSourcePolicy
    223 
    224 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.
    225 
    226 That kind of fine-grained permission control needs a definition file, which is the one used by Subversion's mod_authz_svn.
    227 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.
    228204
    229205Example:
    230 {{{
     206{{{#!ini
    231207[/]
    232208* = r
     
    244220 * '''/branches/calc/bug-142/secret''' = ''harry has no access, sally has read access (inherited as a sub folder permission)''
    245221
    246 ==== Trac Configuration ====
    247 
    248 To activate fine grained 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.
    249 
    250 {{{
    251 [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]
    252228authz_file = /path/to/svnaccessfile
    253229}}}
    254230
    255 If you want to support the use of the `[`''modulename''`:/`''some''`/`''path''`]` syntax within the `authz_file`, add 
    256 
    257 {{{
     231If you want to support the use of the `[`''modulename''`:/`''some''`/`''path''`]` syntax within the `authz_file`, add:
     232
     233{{{#!ini
    258234authz_module_name = modulename
    259235}}}
    260236
    261 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/blahblah}}}, that would yield the following:
    262 
    263 {{{
    264 [trac]
     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:
     238
     239{{{ #!ini
     240[svn]
    265241authz_file = /path/to/svnaccessfile
    266 authz_module_name = blahblah
     242authz_module_name = somemodule
    267243...
    268 repository_dir = /srv/active/svn/blahblah
    269 }}}
    270 
    271 where the svn access file, {{{/path/to/svnaccessfile}}}, contains entries such as {{{[blahblah:/some/path]}}}.
     244[repositories]
     245somemodule.dir = /srv/active/svn/somemodule
     246}}}
     247
     248where the svn access file, {{{/path/to/svnaccessfile}}}, contains entries such as {{{[somemodule:/some/path]}}}.
    272249
    273250'''Note:''' Usernames inside the Authz file __must__ be the same as those used inside trac.
     
    275252As 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.
    276253
    277 {{{ 
     254{{{#!ini
    278255[trac]
    279256permission_policies = AuthzSourcePolicy, ReadonlyWikiPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy
    280257}}}
    281258
    282 ==== Subversion Configuration ====
     259==== Subversion Configuration
    283260
    284261The same access file is typically applied to the corresponding Subversion repository using an Apache directive like this:
    285 {{{
     262{{{#!apache
    286263<Location /repos>
    287264  DAV svn
     
    293270}}}
    294271
    295 For information about how to restrict access to entire projects in a multiple project environment see [trac:wiki:TracMultipleProjectsSVNAccess]
     272For information about how to restrict access to entire projects in a multiple project environment see [trac:wiki:TracMultipleProjectsSVNAccess].
    296273
    297274=== ReadonlyWikiPolicy
     
    326303== Debugging permissions
    327304In trac.ini set:
    328 {{{
     305{{{#!ini
    329306[logging]
    330307log_file = trac.log
     
    333310}}}
    334311
    335 And watch:
    336 {{{
     312Display the trac.log to understand what checks are being performed:
     313{{{#!sh
    337314tail -n 0 -f log/trac.log | egrep '\[perm\]|\[authz_policy\]'
    338315}}}
    339316
    340 to understand what checks are being performed. See the sourced documentation of the plugin for more info.
     317See the sourced documentation of the plugin for more info.
    341318
    342319----