Access (module for Omeka S)
New versions of this module and support for Omeka S version 3.0 and above are available on GitLab, which seems to respect users and privacy better than the previous repository.
Access is a module for Omeka S that allows to protect files to be accessed from the anonymous visitors, but nevertheless available globally or on requests by guests users, reserved to a list of ips, or available by an email or a token. Start and end dates of an embargo can be used too, separately or not.
See below for more information on usage.
You may use module Guest Private to access public or private resources on private sites.
Installation
Associated modules
To allow access to reserved resources for user with role "Guest", the module will need to identify users, generally with the module Guest or Guest Role.
To define specific item sets, you can use standard item sets or use the module Dynamic Item Sets to include items automatically in specific items sets according to metadata.
For old themes, the public part can be managed easily via the module Blocks Disposition, but it is recommended to use resource page blocks for new themes.
The module is compatible with the module Analytics (and the older Statistics)
for download tracking. When Access is active with its own .htaccess rule, the
download rule is not needed because Access calls Analytics directly. On uninstall,
the Access rule is automatically converted to an Analytics (or Statistics)
download rule if the module is active (see below).
The module is compatible with the module Derivative Media that allows to use specific derivative files instead original (for example a standard mp4 instead of a proprietary and unreadable Microsoft wmf). Note the paths should be added to the Apache config (htaccess).
Incompatibility
Until version 3.4.16, the module was not compatible with module Group.
If the module Statistics is installed, it must be version 3.4.12 or later. The version that was tracking downloads was moved to the dedicated module Analytics.
Installation of the module
See general end user documentation for installing a module.
This module requires the module Common, that should be installed first.
- From the zip
Download the last release Access.zip from the list of releases, and uncompress
it in the modules directory.
- From the source and for development:
If the module was installed from the source, rename the name of the folder of
the module to Access.
- For test
The module includes a comprehensive test suite with unit and functional tests. Run them from the root of Omeka:
vendor/bin/phpunit -c modules/Access/phpunit.xml
Configuration of the web server
Without a rewrite rule, the web server (Apache or Nginx) serves files directly, bypassing Omeka entirely. You must configure the web server to redirect file requests to the module so it can check access rights before serving or denying the file.
Automatic management of .htaccess
The module can automatically manage the Apache rewrite rule in the root
.htaccess file. On installation, a rule protecting original and large
files is written automatically.
The configuration form (admin > modules > Access > Configure) provides:
- File type checkboxes: select which standard derivative types to protect among
original,large,mediumandsquare. - Custom types field: add extra path segments separated by spaces, for example
mp3 mp4 webm ogg pdfwhen using module Derivative Media.
When you save the configuration, the module inserts or updates a managed block
in the .htaccess:
# Module Access: protect files.
# This rule is automatically managed by the module.
RewriteRule "^files/(original|large)/(.*)$" "access/files/$1/$2" [NC,L]
The block is identified by its marker comment, so the module can update or remove it without affecting the rest of the file.
When the .htaccess is not writable, the module cannot modify it. In that
case the rule to add or remove is displayed in the configuration form so you can
apply it manually.
Important: by default, files are not protected. Installing the module
alone does not restrict access to files when the .htaccess is write-protected.
Legacy rules
If the module detects a rewrite rule that was written manually (without the marker comment), it is treated as a legacy rule. A warning is displayed with the detected file types. Saving the configuration converts the legacy rule into the managed format automatically.
Uninstall and module Analytics (ex-part of module Statistics)
When the module is uninstalled, the managed block is removed from the
.htaccess. If the module Analytics is active and has no download rule of its
own, the Access rule is automatically converted into an Analytics download rule
so that download tracking continues to work:
# Module Analytics: count downloads.
# This rule is automatically managed by the module.
RewriteRule "^files/(original|large)/(.*)$" "download/files/$1/$2" [NC,L]
Manual Apache configuration
If you prefer to configure Apache manually, or if the .htaccess is not
writable, follow the instructions below.
WARNING: Because the configuration of Apache is complex and infrastructures vary, always check access to free and restricted files from a private browser.
The Apache file .htaccess at the root of Omeka should be updated to avoid
direct access to files and to redirect urls to the module.
For that, you have to adapt the following code to your needs in the main .htaccess
at the root of Omeka, in a .htaccess file in the files directory, or
directly in the config of the virtual host of the server (quicker). The example
below is written for the Omeka .htaccess file. If you prefer to use other
files, adapt the paths.
In this example, all original and large files will be protected: a check will be done by the module before delivering files. If the user has no access to a file, a fake file is displayed.
The small derivatives files (medium and square thumbnails), can be protected too, but it is generally useless. Anyway, it depends on the original images.
Don't forget to add derivative paths if you use module Derivative Media.
You can adapt routes.ini as you wish too, but this is useless in most cases.
Process of the rewrite
The goal of the rewrite rule is to prevent Apache from serving files directly
(bypassing Omeka) and to route the request through the module's controller
(AccessFileController). The controller checks the user's rights before serving
the file or a locked placeholder.
The module's Laminas route ([/access]/files/:type/:filename) matches both
/files/... and /access/files/.... A simple internal rewrite [NC,L] is
enough: its only role is to prevent Apache from serving the static file directly
(the RewriteCond %{REQUEST_FILENAME} -f rule in Omeka's default .htaccess
would otherwise bypass PHP entirely). No mod_proxy and no external redirect
are needed.
For the flag [P], useless in most of the cases, you should enable the module Proxy and restart Apache:
# Depending on your config, either:
sudo a2enmod proxy
# Or something similar:
sudo a2enmod proxy_fcgi
# Then:
sudo systemctl restart apache2
When Omeka S is installed at the root of a domain or a sub-domain
Insert the following lines at line 4 of .htaccess, just after RewriteEngine On,
eventually adding |medium|square to the list of thumbnails:
# Set rule for original and selected derivative files (usually at least large thumbnails).
RewriteRule "^files/(original|large)/(.*)$" "/access/files/$1/$2" [NC,L]
Alternatively, with flag [P] (requires mod_proxy):
RewriteRule "^files/(original|large)/(.*)$" "/access/files/$1/$2" [P]
Using a full URL to force an external redirect (302) is not recommended, as it adds a round-trip and may expose internal ports behind a reverse proxy:
# Not recommended.
RewriteRule "^files/(original|large)/(.*)$" "%{REQUEST_SCHEME}://%{HTTP_HOST}/access/files/$1/$2" [NC,L]
When Omeka S is installed in a sub-path (https://example.org/digital-library/)
Insert the following lines at line 4 of .htaccess, just after RewriteEngine On,
adapting it to your real config (here, the sub-path is digital-library),
eventually adding |medium|square to the list of thumbnails:
# Set rule for original and selected derivative files (usually at least large thumbnails).
RewriteRule "^files/(original|large)/(.*)$" "/digital-library/access/files/$1/$2" [NC,L]
Common issues
- Remove the leading "/" before "files/" in
.htaccess
In .htaccess context, Apache strips the leading / before matching RewriteRule
patterns. Use ^files/... instead of ^/files/.... The leading / form is
only valid inside the virtual host configuration.
- Unable to proxy with https (flag [P] only)
If the flag [P] is used with a secured server (https), the certificate
should be running and up-to-date and the option SSLProxyEngine on should
be set in the Apache config of the web server.
If you have access to the Apache config, you can include all rules inside it
directly (ProxyPass). If you don't have access to it, just use the full
unsecure url with http:// (with real domain or %{HTTP_HOST}), for the
internal proxy. Because it is a fake proxy, it doesn't matter if the
internal redirect url is unsecure:
RewriteRule "^files/(original|large)/(.*)$" "http://%{HTTP_HOST}/digital-library/access/files/$1/$2" [P]
Compatibility with module Analytics (ex-part of module Statistics)
The module is compatible with the module Analytics for download tracking.
When Access is active with its own .htaccess rule, only the Access rule
(/access/files/) is needed: the module calls Analytics directly when serving
files, so a separate /download/ rule is not necessary.
Important: do not keep a /download/ rule alongside the /access/ rule.
The /download/ route does not check access rights, so a private file would
become public.
When the module Access is uninstalled, it automatically converts its .htaccess
rule into an Analytics download rule if the module is active, so download
tracking continues seamlessly (see above).
Nginx
The configuration of Apache above should be adapted for Nginx.
Usage
Omeka has two modes of visibility: public or private. This module adds a second check for anonymous or specific users: the right to access to a resource. This rights has four levels: free, reserved, protected or forbidden. These access levels applies on record or media files, but the current version supports only protection of media contents. The mode protected is not used in current version. Furthermore, a check is done on embargo dates, if any.
So with this module, there are three conditions to make a file accessible by a visitor or a user: - visibility of the item and the media should be public; - access level should be free for anonymous visitor or reserved if the user has some rights defined in config; - embargo dates should be undefined or ended.
So an anonymous visitor can see a public media, but can view the file only if the level is set to free. The user should have a permission when the level is reserved or protected, and cannot see it in any case when the level is forbidden, even if the media is public.
There is no difference between reserved or protected when the type of protection is limited to files, that is the only type in the current version of the module.
The permission to see a reserved content can be done via many ways: Users can be checked via the role guest, the authentication via an external identity provider (module CAS, LDAP and Single Sign-On), by ip (v4 or v6), by email or by a token.
One important thing to understand is to choose to define the access for each type of resource: item sets, items and media and to choose if the access is done recursively during storing or in request. If the request is set to apply recursively for an item set, all items and medias attached to it will be available. If the request is set to apply recursively for an item, all medias attached to it will be available. So when an item set or an item is saved and when a request is validated, set if the access or the request applies recursively.
Take care that for resource, the recursivity should be set each time it is saved, if needed, else access won't be updated to the attached resources. It allows to have specific access for specific items or medias. Furthermore, this mechanism does not apply when the access status is set via property. In that case, all resources are managed individually.
Anyway, the recursivity is useful only when there are multiple medias and the status of some of them is different.
Finally, the option applies only to existing resources: if an item is created after a change in an item set, it won't apply to it, so you will need to set the right mode or to update the item set with the recursive option set.
When an embargo is set, it can be bypassed, or not, for the users. Only files can be under embargo currently.
Access mode
The rights to see the files are controlled on the fly. The reserved visibility can be managed in multiple ways:
- Global modes
ip: all visitors with a specific ip, for example the ip of the physical library or the one of a researcher, can have access to all the reserved files. Ip can be configured to access specific item sets, for example123.45.67.89 = 51, 54guest: all guest users have access to all the reserved files.auth_external: all users authenticated via an external identity provider (currently via module CAS and SingleSignOn, later for Ldap) have access to media contents.auth_cas: all users authenticated via CAS (module CAS) have access to all reserved files.auth_ldap: all users authenticated via Ldap (module Ldap) have access to all reserved files (currently unsupported).auth_sso: all users authenticated via SAML/Shibboleth (module SingleSignOn) have access to all reserved files.auth_sso_idp: users authenticated by specified identity providers have access to a list of reserved media by item sets.email_regex: all authenticated users with an email matching a regex pattern have access to all reserved files.- Individual modes
user: each file should be made accessible by a specific user one by one. So the module has some forms to manage individual requests and accesses.email: anybody authenticated via an email have access to specific media contents. This protection is simple and light, but not the most secure.token: all users or visitor authenticated via a token have access to specific media contents.
Individual modes require that an admin allow each right for each resource.
Identification of the reserved resources
After the configuration, you should identify all resources that you want to make available via a reserved access. By default, private resources remain private, so you need to allow visitors to know that they exist. That is to say you can keep some private resources private, and some other ones available on request, or globally.
There are two ways to indicate which resources are reserved.
- By default, it is a specific setting available as a radio button in the advanced tab of the resource form.
- The second way is to set a value to a specified property, for example
dcterms:accessRightsorcuration:access. The default values are "free", "reserved", "protected" or "forbidden". The property and the names can be translated or modified in the config. It is recommended to create a custom vocab and to use it via the resource templates to avoid errors in the values.
A private media remains private. A public media will be accessible only if its status is not forbidden and not during an embargo, if any.
Note that a public item can have a private media and vice-versa. So, most of the time, the value should be set in the metadata of the media. The value can be specified for the item too to simplify management.
Inheritance behavior
When a media does not have an explicit access status set:
- At runtime: The media inherits the access level and embargo settings from its parent item. If neither the media nor the item has an access status, the media content is accessible (free by default).
- On save with property mode: When access is managed via properties, if a media does not have the access level property set, it will inherit the value from the parent item property. The same applies to embargo start and end properties.
- On save without property mode: When creating new medias via an item, the item access data is applied to the new medias by default. Use the "recursive" option to explicitly copy access settings to all medias.
This inheritance behavior ensures that restricted items have their medias restricted as well, even when access is not explicitly set on individual medias.
Advanced search
The advanced search form includes a multi-select filter for access levels. You can select multiple levels to search for resources matching any of the selected levels. When no levels are selected, all resources are returned regardless of their access level.
Item sets
As indicated above, it is possible to define specific rights by item sets when using some access mode, mainly ip and sso idp.
To define a specific rights, set the ip or the idp, then "=", then the item set ids to which the ip or the idp can access. If there is no item set defined, the check will be defined per item. Each item set may be prepended with a "-" to forbid access to a specific item set. This option is useful when a global item set is defined to identify all reserved resources. When a federation like Renater is used, set "federation =" then the item sets.
The order matters: the user is checked in the order of the list, so the federation is generally specified at last.
The use of the module Dynamic Item Sets may be useful, because it allows to define items included in a item sets according to a standard query.
Example for the access mode "ip"
12.34.56.78
124.8.16.32 = 17 89 -1940
65.43.21.0/24 = -2005
Here, the user identified via the first ip has access to all reserved resources; the user identified via the second ip has access to item sets #17 and #89, but not to item set #1940. The federation has access to all items, except those of item set 2005.
Example for the access mode "sso idp"
idp.example.org =
shibboleth.another-example.org = 17 89 -1940
federation = -2005
Here, the user identified via idp.example.org has access to all reserved resources; the user identifier via the second idp has access to item sets #17 and #89, but not to item set #1940. The federation has access to all items, except those of item set #2005.
Embargo
By construction, the embargo works only on the media files: metadata are always visible for public and reserved resources.
An option in the config can be used to use it with or without the reserved access.
To create an embargo on a file, simply set the dates in the advanced tab or use
properties curation:start and/or curation:end, or the ones specified in the
config.
If you use a property to define the date of the embargo, it is recommended to
use the datatype "numeric timestamp" from the module Numeric Datatypes, but a
literal is fine. The date must be an iso one (2022-03-14). A time can be set
too (2022-03-14T12:34:56).
Important: Generally, it is enough to set the embargo on the item. Set it on medias only when there are multiple medias with various status or date of embargo.
Two settings control what happens when an embargo ends:
- What to do with the access level:
free: Set access level to "free"under: Set access level to the level under ("free" for reserved, "reserved" for protected/forbidden)keep: Keep the current access level- What to do with the embargo dates:
clear: Remove the embargo dateskeep: Keep the embargo dates
A job is run automatically once a day to update access status and embargo.
Furthermore, a check is automatically done when an anonymous visitor or a restricted user is accessing a restricted file. In that case, the media may be set public automatically when the embargo is finished.
The job does not update the resource when the visibility is not logical, for example when the resource have been set public with a date of end of embargo. Of course, don't set a date of end of embargo if the record is not ready or when it should remain private.
Management of requests
If you choose modes ip, guest, or external, there is nothing to do more.
Once users are authenticated or authorized, they will be able to see the files.
In the case of the single modes user, email or token, there are two ways
to process.
-
The admin can made some item sets, items or medias available directly in the menu "Access requests" in the sidebar. Simply add a new access, select a resource and a user, a email or a token, and the person will be able to view it.
-
The user or visitor can request an access to a specific resource. It can be done directly via a button, for logged users, or via a contact form for the anonymous visitors. The contact form may be added by this module or the module Contact Us. After the request, the admin will receive an email to accept or reject the request.
Once accepted, the requester will receive an email with an url to click, that will add a session cookie that will allow to browse the selected resources.
In public front-end, a dashboard is added for visitors: /s/my-site/access-request.
Guest users have a specific board too: /s/my-site/guest/access-request.
Check of status levels
In some cases, when the status is stored in a property, you may want to check if all resources values statuses are well stored in the table access_status. Here are some sql queries for that, with French values and where curation:access is used (property 185 here):
# Items
SELECT `access_status`.`id`, `access_status`.`level`, `resource`.`is_public`
FROM `value`
INNER JOIN `access_status` ON `value`.`resource_id` = `access_status`.`id`
INNER JOIN `item` ON `item`.`id` = `access_status`.`id`
INNER JOIN `resource` ON `resource`.`id` = `item`.`id`
WHERE `value`.`property_id` = 185
AND `value`.`value` = "Accès libre"
AND `access_status`.`level` != 'free';
SELECT `access_status`.`id`, `access_status`.`level`, `resource`.`is_public`
FROM `value`
INNER JOIN `access_status` ON `value`.`resource_id` = `access_status`.`id`
INNER JOIN `item` ON `item`.`id` = `access_status`.`id`
INNER JOIN `resource` ON `resource`.`id` = `item`.`id`
WHERE `value`.`property_id` = 185
AND `value`.`value` = "Accès restreint"
AND `access_status`.`level` != 'reserved';
SELECT `access_status`.`id`, `access_status`.`level`, `resource`.`is_public`
FROM `value`
INNER JOIN `access_status` ON `value`.`resource_id` = `access_status`.`id`
INNER JOIN `item` ON `item`.`id` = `access_status`.`id`
INNER JOIN `resource` ON `resource`.`id` = `item`.`id`
WHERE `value`.`property_id` = 185
AND `value`.`value` = "Non consultable"
AND `access_status`.`level` != 'forbidden';
# Media
SELECT `access_status`.`id`, `access_status`.`level`, `resource`.`is_public`
FROM `value`
INNER JOIN `access_status` ON `value`.`resource_id` = `access_status`.`id`
INNER JOIN `media` ON `media`.`id` = `access_status`.`id`
INNER JOIN `resource` ON `resource`.`id` = `media`.`id`
WHERE `value`.`property_id` = 185
AND `value`.`value` = "Accès libre"
AND `access_status`.`level` != 'free';
SELECT `access_status`.`id`, `access_status`.`level`, `resource`.`is_public`
FROM `value`
INNER JOIN `access_status` ON `value`.`resource_id` = `access_status`.`id`
INNER JOIN `media` ON `media`.`id` = `access_status`.`id`
INNER JOIN `resource` ON `resource`.`id` = `media`.`id`
WHERE `value`.`property_id` = 185
AND `value`.`value` = "Accès restreint"
AND `access_status`.`level` != 'reserved';
SELECT `access_status`.`id`, `access_status`.`level`, `resource`.`is_public`
FROM `value`
INNER JOIN `access_status` ON `value`.`resource_id` = `access_status`.`id`
INNER JOIN `media` ON `media`.`id` = `access_status`.`id`
INNER JOIN `resource` ON `resource`.`id` = `media`.`id`
WHERE `value`.`property_id` = 185
AND `value`.`value` = "Non consultable"
AND `access_status`.`level` != 'forbidden';
TODO
- [x] Fix ip check for ipv6.
- [ ] Use Omeka Store instead of local file system.
- [ ] Update temporal to avoid to check embargo each time via php.
- [x] Reindexation (trigger event?) when embargo is updated automatically. Use the cron task of module EasyAdmin?
- [ ] Clarify process for embargo start and update embargo start date with a specific option (no one seems to use it anyway).
- [ ] Add a mode cas_itemsets to define access rules by cas attributes and item sets (like sso_idp).
Warning
Use it at your own risk.
It’s always recommended to backup your files and your databases and to check your archives regularly so you can roll back if needed.
Troubleshooting
See online issues on the module issues page on GitLab.
License
Module
This module is published under the CeCILL v2.1 license, compatible with GNU/GPL and approved by FSF and OSI.
This software is governed by the CeCILL license under French law and abiding by the rules of distribution of free software. You can use, modify and/ or redistribute the software under the terms of the CeCILL license as circulated by CEA, CNRS and INRIA at the following URL "http://www.cecill.info".
As a counterpart to the access to the source code and rights to copy, modify and redistribute granted by the license, users are provided only with a limited warranty and the software’s author, the holder of the economic rights, and the successive licensors have only limited liability.
In this respect, the user’s attention is drawn to the risks associated with loading, using, modifying and/or developing or reproducing the software by the user in light of its specific status of free software, that may mean that it is complicated to manipulate, and that also therefore means that it is reserved for developers and experienced professionals having in-depth computer knowledge. Users are therefore encouraged to load and test the software’s suitability as regards their requirements in conditions enabling the security of their systems and/or data to be ensured and, more generally, to use and operate it in the same conditions as regards security.
The fact that you are presently reading this means that you have had knowledge of the CeCILL license and that you accept its terms.
Image Locked file
The image Locked file is licensed under GNU/GPL.
Copyright
- Copyright Daniel Berthereau, 2019-2026 (see Daniel-KM on GitLab)
- Copyright Saki (image Locked file, see Saki)