Security

There are many strategies for securing a Swarm installation. This section provides guidance on security features Swarm controls, and recommendations for several areas for the system hosting Swarm.

Tip

If you make a configuration change, Swarm will not use it until the configuration cache has been reloaded, this forces Swarm to use the new configuration. You must be an admin or super user to reload the Swarm config cache. Navigate to the User id dropdown menu, select System Information, click the Cache Info tab, and click the Reload Configuration button.

Require login

Important

Prior to Swarm's 2016.1 release, require_login defaulted to false. For 2016.1 and later releases, the default is true.

By default, Swarm prevents anonymous users from viewing any Helix server resources; users must login to see commits, reviews, etc.

Swarm can be configured to allow anonymous users to access any readable resources (creating or editing resources by anonymous users is not permitted). Add the following configuration block to the SWARM_ROOT/data/config.php file, at the same level as the p4 entry:

<?php
// this block should be a peer of 'p4'
'security' => array(
'require_login' => false, // defaults to true
),

There is one exception: the /queue/worker endpoint is available to any user.

Note

Service and operator users are not permitted to login. For more information on these user types, see User types in Helix Core Server Administrator Guide.

Prevent login

When your Helix server has users that should not be able to log in to Swarm, for example service users involved with Helix server replicas, the prevent_login configuration item can be used to prevent successful authentication.

Add or update the following configuration block to the SWARM_ROOT/data/config.php file, at the same level as the p4 entry:

<?php
// this block should be a peer of 'p4'
'security' => array(
'prevent_login' => array(
'service_user1',
'service_user2',
),
),

prevent_login defaults to array(), which means no users in your Helix server are prevented from logging into Swarm.

For more information, see Service users in Helix Core Server Administrator Guide.

Auto-create new users

Swarm supports the automatic-creation of new users in Perforce on login if the Helix server is configured to allow it and the user exists in LDAP. This function is configured in the Helix server and no Swarm configuration is required. For instructions on how to configure Helix server to automatically create new users in Perforce on login, see auth.ldap.userautocreate and auth.default.method in the Defining LDAP-related configurables section of the Helix Core Server Administrator Guide.

Sessions

Swarm manages logged-in sessions using cookies in the browser, and PHP session storage on the server. Swarm uses reasonable defaults for the cookie and session lifetimes (measured in seconds); when the lifetime is exceeded users need to login again. To specify session lifetimes and garbage collection frequency, add the following configuration block to the SWARM_ROOT/data/config.php file, at the same level as the p4 entry:

<?php
// this block should be a peer of 'p4'
'session' => array(
'cookie_lifetime' => 0, // 0=expire when browser closed
'remembered_cookie_lifetime' => 60*60*24*30, // 30 days
'gc_maxlifetime' => 60*60*24*30, // 30 days
'gc_divisor' => 100, // 100 user requests
),
  • cookie_lifetime

    Optional: Limits the lifetime of session cookies. The default is 0, which causes the session cookie to expire when the user's browser is closed.

    Note

    When the Remember Me checkbox on the login dialog is checked, the remembered_cookie_lifetime value will be used for cookie_lifetime.

  • remembered_cookie_lifetime

    Optional: Limits the lifetime of session cookies when the Remember Me checkbox on the login dialog is checked. The default is 60*60*24*30 seconds (30 days).

  • gc_maxlifetime

    Optional: If a session is inactive for the specified number of seconds, the user is logged out. The default is 60*60*24*30 seconds (30 days). User sessions are stored in SWARM_ROOT/data/sessions/.

    Note

    By default, the user's Perforce ticket expires after 12 hours, which also causes them to be logged out.

  • gc_divisor

    Optional: Sets how often garbage collection is run based on the number of user requests that are made. The setting range is 1 to 100. Garbage collection deletes user session files that are older than the gc_maxlifetime setting from SWARM_ROOT/data/sessions/.

    • gc_divisor = 100: Garbage collection runs after every 100th user request. 100 is the default setting.
    • gc_divisor = 1: Garbage collection runs after every user request.
    Important

    If your Swarm system has a large number of users, setting gc_divisor to a low number can result in performance issues.

X-Frame-Options header

By default, Swarm emits a X-Frame-Options HTTP header set to SAMEORIGIN. This prevents embedding of the Swarm interface into other web pages, which avoids click-jacking attacks.

If your deployment of Swarm needs to be integrated into another web interface, you can adjust the X-Frame-Options header by adjusting the x_frame_options item within the security configuration block, found in the SWARM_ROOT/data/config.php file. For example:

<?php
// this block should be a peer of 'p4'
'security' => array(
'x_frame_options' => value,
),
),

Where value can be one of:

  • 'SAMEORIGIN' - Swarm can only be displayed in a frame hosted on the same domain.
  • 'DENY' - Swarm cannot be displayed in a frame.
  • 'ALLOW-FROM URI' - Swarm can only be displayed in a frame hosted on the specified URI.
  • false - The X-Frame-Options header is not emitted, so Swarm can be embedded without restriction.

For more information on the X-Frame-Options header, see this Mozilla Developer Network article.

For more information on click-jacking attacks, see this Wikipedia article.

Disable commit

Swarm provides the ability to commit reviews within the Swarm interface. You may want to disable this capability to prevent reviews from being committed by someone other than the review's author. When disabled, the Approve and Commit (and Commit if the review is already approved) option is removed from the list of states available to a code review.

To disable commits, set disable_commit to true within the reviews item in the SWARM_ROOT/data/config.php file. For example:

<?php
// this block should be a peer of 'p4'
'reviews' => array(
'disable_commit' => true,
),
),

Restricted Changes

The Helix server provides two changelist types: public (the default), and restricted. Swarm honors restricted changelists by preventing access to the changelist, and any associated comments or activity related to the changelist.

If a user has list-level privileges to at least one file in the changelist, Swarm allows the user to see the changelist and any of the files they have permission to see.

To prevent unintended disclosures, email notifications for restricted changes are disabled by default. To enable email notifications for restricted changes, set email_restricted_changes to true within the security item in the SWARM_ROOT/data/config.php file. For example:

<?php
// this block should be a peer of 'p4'
'security' => array(
'email_restricted_changes' => true,
),
),
Note

When email_restricted_changes is set to true, email notifications for restricted changes are sent to all interested parties with no permissions screening. These notifications might disclose sensitive information.

Swarm can only report on changes that the configured admin-level user has access to. When using restricted changes, we advise that you grant the Swarmadmin-level user access to the restricted files and set require_login = true to avoid leaking information to unauthenticated users.

Limit adding projects to administrators

Important

For Swarm 2016.1, the configuration item add_project_admin_only was moved from the security block to the projects block, and the item was renamed to add_admin_only. The functionality of this configuration item remains unchanged.

If you do not update your SWARM_ROOT/data/config.php configuration file, the old configuration for restricting project creation to administrators continues to work.

If you add the new configuration item add_admin_only to the projects block, it takes precedence over any remaining add_project_admin_only setting in the security block.

Limit adding projects to members of specific groups

Important

For Swarm 2016.1, the configuration item add_project_groups was moved from the security block to the projects block, and the item was renamed to add_groups_only. The functionality of this configuration item remains unchanged.

If you do not update your SWARM_ROOT/data/config.php configuration file, the old configuration for restricting project creation to specific groups continues to work.

If you add the new configuration item add_groups_only to the projects block, it takes precedence over any remaining add_project_groups setting in the security block.

IP address-based protections emulation

A Helix server can be configured via protections to restrict access to a depot in a variety of ways, including by IP address. As Swarm is a web application acting as a client to the Helix server, often with admin-level privileges, Swarm needs to emulate IP address-based restrictions. It does so by checking the user's IP address and applying any necessary restrictions during operations such as browsing files, viewing file content, viewing and adding comments on files.

Swarm also emulates proxy-based protections, in addition to regular IP-based protections emulation. However, Swarm does not detect whether it is connecting to a Helix Proxy or not; it merely attempts to emulate protections table entries that use proxy syntax.

IP address-based protections emulation is enabled by default. Swarm performs somewhat faster without this emulation; if you do not require them for your Swarm installation these can be disabled by setting the configuration:

<?php
// this block should be a peer of 'p4'
'security' => array(
'emulate_ip_protections' => false,
),
Tip

If Swarm is connected to multiple-Helix server instances, you have the following options for emulate_ip_protections:

  • To apply a global emulate_ip_protections setting to all Helix server instances that Swarm is connected to, set emulate_ip_protections in the security block as shown above.
  • To apply an individual emulate_ip_protections setting to a Helix server instance, set emulate_ip_protections in the serverid block for that server. This value overrides the global setting in the security block for the Helix server instance.

For more information about configuring Swarm for multiple-Helix server instances, see Set up the Swarm configuration file for the Helix servers.

Known limitations

  • Notification e-mails for reviews or commits include the list of affected files. Swarm cannot reliably know the IP address used to retrieve that e-mail, and makes no attempt to filter the files and their depot paths nor any details included in the description. However, when a user follows a link from the notification e-mail to a restricted resource, that access is denied.
  • Swarm filters comments from activity streams, but any comments created prior to upgrading to the 2013.3 release cannot be filtered and may leak sensitive information.
  • Swarm displays a comment count in code the review list, code reviews, jobs, and activity streams, but the count does not account for any comments that may be hidden from the user due to association with files the user is restricted from viewing.
  • Should Swarm users connect to Swarm via a proxy or VPN, the protections will generally use the IP address of the proxy/VPN.
  • When the user's IP address and Swarm's IP address both have restrictions applied, the user experiences the most constraining of the two IP address-based restrictions; Swarm cannot bypass restrictions applied to itself.
  • Swarm performs a variety of operations with admin-level privileges, on behalf of a user. Even if the Helix server has IP-based, or userid-based protections, installed to prevent access to some or most of its versioned data, Swarm typically does have access to this data. Therefore, Swarm cannot guarantee that no information leakage will occur, particularly when custom modules are in use, or Swarm source has been customized.

For more information, see Authorizing Access in Helix Core Server Administrator Guide.

Disable system info

Swarm provides a System Information page, available to users with admin or super privileges, which displays information about Helix server that Swarm is configured to use, as well as PHP information and the Swarm log file.

While this information can be invaluable when communicating with Perforce support engineers, you may wish to prevent disclosure of any system information. The System Information page can be disabled for all users by adding the following configuration block to the SWARM_ROOT/data/config.php file, at the same level as the p4 entry:

<?php
// this block should be a peer of 'p4'
'security' => array(
'disable_system_info' => true, // defaults to false
),

Once disabled, the System Information link disappears from the About Swarm dialog, and 403 errors are generated for any attempts to browse to the System Information page.

HTTP client options

Swarm permits configuration of options that are passed through to the underlying Laminas Framework HTTP client. These options can be used to specify SSL certificate locations, request timeouts, and more, and can be specified globally or per host.

Here is an example configuration:

<?php
// this block should be a peer of 'p4'
'http_client_options' => array(
'timeout' => 10, // default value is 10 seconds
// path to the SSL certificate directory
'sslcapath' => '',
// the path to a PEM-encoded SSL certificate
'sslcert' => '', // the path to Certificate Authority file 'sslcafile' => '',
// the passphrase for the SSL certificate file
'sslpassphrase' => '',
// optional, per-host overrides;
// host as key, array of options as value
'hosts' => array(
'jira.example.com' => array(
'sslcapath' => '/path/to/certs',
'sslcert' => 'jira.pem',
'sslpassphrase' => 'keep my JIRA secure',
'timeout' => 15,
), 'jenkins.example.com' => array( 'sslcafile' => '/path/to/certs/jenkins.pem', 'sslpassphrase' => 'keep my jenkins very secure', 'timeout' => 15, ),
),
),

See the Laminas Framework Socket Adapter documentation for more information.

Note

Swarm supports the Laminas component versions in the LICENSE.txt file, features and functions in the Laminas documentation that were introduced in later versions of Laminas will not work with Swarm. The LICENSE.txt file is in the readme folder of your Swarm installation.

Warning

While it is possible to use a self-signed SSL certificate, adding the configuration to do so disables certificate validity checks, making connections to the configured host less secure. We strongly recommend against using this configuration option.

However, if you need to configure continuous integration, deployment, or JIRA connections and those connections must use a self-signed SSL certificate, set the sslallowselfsigned item to true for the specific host that needs it, as in the following example:

<?php
// this block should be a peer of 'p4'
'http_client_options' => array(
'hosts' => array(
'jira.example.com' => array(
'sslallowselfsigned' => true,
),
),
),

Strict HTTPS

To improve the security when users work with Swarm, particularly if they need to do so outside of your network, Swarm provides a mechanism that tries to force web browsers to use HTTPS. When enabled, Swarm's behavior changes in the following ways:

  • HTTP requests to Swarm include a meta-refresh to the HTTPS version. If a load balancer handles encryption before requests reach Swarm, the meta-refresh should be disabled. See below.
  • A strict transport security header is included for all requests, which pins the browser to using HTTPS for your Swarm installation for 30 days.
  • All qualified URLs that Swarm produces use HTTPS for the scheme.
  • Cookies are flagged as HTTPS-only.

Here is an example of how to enable strict HTTPS:

<?php
// this block should be a peer of 'p4'
'security' => array(
'https_strict' => true,
'https_strict_redirect' => true, // optional; set false to avoid meta-refresh
'https_port' => null, // optional; specify if HTTPS is
// configured on a non-standard port
),

When the https_strict_redirect item is set to false, Swarm does not add a meta-refresh for HTTP clients. This prevents an endless redirect when a load balancer in front of Swarm applies HTTPS to the client-to-load balancer connection, but not the load balancer-to-Swarm connection.

Apache security

There are several Apache configuration changes that can improve security for Swarm:

  • Disable identification

    By default, each Apache response to a web request includes a list of tokens identifying Apache and its version, along with any installed modules and their versions. Also, Apache can add a signature line to each response it generates that includes similar information. By itself, this identification information is not a security risk, but it helps would-be attackers select attacks that could be successful.

    To disable Apache identification, add the following two lines to your Apache configuration:

    ServerSignature Off
    ServerTokens ProductOnly
  • Disable TRACE requests

    TRACE requests cause Apache to respond with all of the information it has received, which is useful in a debugging environment. TRACE can be tricked into divulging cookie information, which could compromise the credentials being used to login to Swarm.

    To disable TRACE requests, add the following line to your Apache configuration:

    TraceEnable off
  • Update SSL configuration

    Swarm works correctly with an SSL-enabled Apache. Several attacks on common SSL configurations have been published recently. We recommend that you update your Apache configuration with the following lines:

    <IfModule mod_ssl.c>
    SSLHonorCipherOrder On
    SSLCipherSuite ECDHE-RSA-AES128-SHA256:AES128-GCM-SHA256:RC4:HIGH:!MD5:!aNULL:!EDH
    SSLCompression Off
    </IfModule>

PHP security

There are several PHP configuration changes that can improve security for Swarm:

  • Disable identification

    By default, PHP provides information to Apache that identifies that it is participating in a web request, including its version.

    To disable PHP identification, edit your system's php.ini file and change the line setting expose_php to:

    expose_php = Off
  • Remove scripts containing phpinfo()

    During module development or other debugging, you may need to call phpinfo(), which displays PHP's active configuration, compilation details, included modules and their configuration. Typically, you would add a script to Swarm's public directory containing:

    <?php phpinfo() ?>

    Any such scripts should be removed from a production instance of Swarm.

proxy_mode

By default, Swarm works in proxy mode, passing the end-user's browser IP address to the Helix server. The Helix server checks the IP address against its IP protection table to work out what permissions the end-user has.

Set the Swarm proxy_mode in the p4 configuration block of the SWARM_ROOT/data/config.php file:

<?php
'p4' => array(
'proxy_mode' => true, // defaults to true
),
  • true: Swarm passes the end-user's browser IP address to the Helix server allowing the Helix server to work out the what permissions the end-user has. This is the default setting.
  • false: the Swarm server IP address is passed to the Helix server. The Helix server checks the Swarm IP address against its protections table to work out the permissions the end-user has. The result is that all of the Swarm users will have the same permissions.
Tip

If Swarm is connected to multiple-Helix server instances, you have the following options for proxy_mode:

  • To apply a global proxy_mode setting to all Helix server instances that Swarm is connected to, set proxy_mode in the p4 block as shown above.
  • To apply an individual proxy_mode setting to a Helix server instance, set proxy_mode in the serverid block for that server. This value overrides the global setting in the p4 block for the Helix server instance.

For more information about configuring Swarm for multiple-Helix server instances, see Set up the Swarm configuration file for the Helix servers.