documentation:2.1:security

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documentation:2.1:security [2019/09/10 15:03] (current)
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 +====== Security recommendation ======
  
 +===== Secure configuration access =====
 +
 +Configuration can be stored in several formats ([[sqlconfbackend|SQL]], [[fileconfbackend|File]], [[ldapconfbackend|LDAP]]) but must be shared over the network if you use more than 1 server. If some of your servers are not in the same (secured) network than the database, it is recommended to use [[soapconfbackend|SOAP access]] for those servers.
 +
 +<note tip>You can use different type of access: [[sqlconfbackend|SQL]], [[fileconfbackend|File]] or [[ldapconfbackend|LDAP]] for servers in secured network and [[soapconfbackend|SOAP]] for remote servers.</note>
 +
 +Next, you have to configure the SOAP access as described [[soapconfbackend#next_configure_soap_for_your_remote_servers|here]] since SOAP access is denied by default.
 +
 +===== Protect the Manager =====
 +
 +By default, the manager is restricted to the user 'dwho' (default backend is Demo). To protect the manager, you have to choose one or both of :
 +  * protect the manager by Apache configuration
 +  * protect the manager by LL::NG
 +
 +==== Protect the Manager by the web server ====
 +
 +You can use any of the mechanisms proposed by Apache: SSL, Auth-Basic, Kerberos,... Example
 +<code apache>
 +<VirtualHost *:443>
 +    ServerName manager.example.com
 +    # SSL parameters
 +    ...
 +    # DocumentRoot
 +    DocumentRoot /var/lib/lemonldap-ng/manager/
 +    <Location />
 +        AuthType Basic
 +        AuthName "Lemonldap::NG manager"
 +        AuthUserFile /usr/local/apache/passwd/passwords
 +        Require user rbowen
 +        Order allow,deny
 +        Deny from all
 +        Allow from 192.168.142.0/24
 +        Options +ExecCGI
 +    </Location>
 +</VirtualHost>
 +</code>
 +
 +==== Protect the Manager by LL::NG ====
 +
 +To protect the manager by LL::NG, you just have to set this in ''lemonldap-ng.ini'' configuration file (section [manager]):
 +<file ini>
 +[manager]
 +protection = manager
 +</file>
 +
 +<note important>Before, you have to create the virtual host ''manager.your.domain'' in the manager and set a [[writingrulesand_headers#rules|rules]], else access to the manager will be denied.</note>
 +
 +===== Portal =====
 +
 +LLNG portal now embeds the following features:
 +  * [[https://en.wikipedia.org/wiki/Cross-site_request_forgery|CSRF]] protection //(Cross-Site Request Forgery)//: a token is build for each form. To disable it, set '​require Token for forms' ​to Off //(portal security parameters in the manager)//. Token timeout can be defined via manager (default to 120 seconds)
 +  * [[https://en.wikipedia.org/wiki/Brute-force_attack|Brute-force attack]] protection: after some failed logins, user must wait before re-try to log into Portal
 +  * [[https://en.wikipedia.org/wiki/Content_Security_Policy|Content-Security-Policy]] header: portal builds dynamically this header. You can modify default values in the manager //(General parameters » Advanced parameters » Security » Content-Security-Policy)//
 +  * [[https://en.wikipedia.org/wiki/Cross-origin_resource_sharing|Cross-Origin Resource Sharing]] headers: CORS is a mechanism that allows restricted resources on a web page to be requested from another domain outside the domain from which the first resource was served. A web page may freely embed cross-origin images, stylesheets, scripts, iframes, and videos. Certain "cross-domain" requests, notably Ajax requests, are forbidden by default by the same-origin security policy. You can modify default values in the manager //(General parameters » Advanced parameters » Security » Cross-Origin Resource Sharing)//
 +
 +<note important>
 +  * Brute-force attack protection is DISABLED by default
 +  * Browser implementations of formAction directive are inconsistent (e.g. Firefox doesn't block the redirects whereas Chrome does). Administrators may have to modify formAction value with wildcard likes ''*''.
 +</note>
 +==== Split portal when using SOAP/REST ====
 +
 +If you use [[soapsessionbackend|SOAP]] or [[restsessionbackend|REST]] session backend, dedicate a portal especially for these internal requests.
 +
 +===== Write good rules =====
 +
 +==== Order your rules ====
 +
 +[[writingrulesand_headers#rules|Rules]] are applied in alphabetical order (comment and regular expression). The first matching rule is applied.
 +
 +<note important>The "default" rule is only applied if no other rule matchs</note>
 +
 +The Manager let you define comments in rules, to order them:
 +
 +{{ :documentation:manager-rule.png |}}
 +
 +For example, if these rules are used without comments:
 +^  Regular expression  ^  Rule  ^ Comment  ^
 +| %%^/pub/admin/%% | $uid eq "root" | |
 +| %%^/pub/%% | accept | |
 +
 +Then the second rule will be applied first, so every authenticated user will access to ''/pub/admin'' directory.
 +
 +Use comment to correct this:
 +^  Regular expression  ^  Rule  ^ Comment  ^
 +| %%^/pub/admin/%% | $uid eq "root" | 1_admin |
 +| %%^/pub/%% | accept | 2_pub |
 +
 +<note tip>
 +  * Reload the Manager to see the effective order
 +  * Use rule comments to order your rules
 +</note>
 +
 +==== Be careful with URL parameters ====
 +
 +You can write [[writingrulesand_headers#rules|rules]] matching any component of URL to protect including GET parameters, but be careful.
 +
 +For example with this rule on the ''access'' parameter:
 +^  Regular expression  ^  Rule  ^ Comment  ^
 +| %%^/index.php\?.*access=admin%% | %%$groups =~ /\badmin\b/%% | |
 +| default | accept | |
 +
 +Then a user that try to access to one of the following __will be granted__ !
 +  * %%/index.php?access=admin&access=other%%
 +  * %%/index.php?Access=admin%%
 +
 +You can use the following rules instead:
 +^  Regular expression  ^  Rule  ^ Comment  ^
 +| %%^/(?i)index.php\?.*access.*access%% | deny | 0_bad |
 +| %%^/(?i)index.php\?.*access=admin%% | %%$groups =~ /\badmin\b/%% | 1_admin |
 +| default | accept | |
 +
 +<note tip>**(?i)** means case no sensitive.</note>
 +
 +<note warning>Remember that rules written on GET parameters must be tested.</note>
 +
 +==== Encoded characters ====
 +
 +Some characters are encoded in URLs by the browser (such as space,...). To avoid problems, LL::NG decode them using [[https://metacpan.org/pod/Apache2::URI#unescape_url]]. So write your rules using normal characters.
 +
 +===== Secure reverse-proxies =====
 +
 +LL::NG can protect any Apache hosted application including Apache reverse-proxy mechanism. Example:
 +
 +<code apache>
 +PerlOptions +GlobalRequest
 +PerlRequire /var/lib/lemonldap-ng/handler/MyHandler.pm
 +<VirtualHost *:443>
 +    SSLEngine On
 +    ... other SSL parameters ...
 +    PerlInitHandler My::Handler
 +    ServerName appl1.example.com
 +    ProxyPass / http://hiddenappl1.example.com/
 +    ProxyPassReverse / http://hiddenappl1.example.com/
 +    ProxyPassReverseCookieDomain / http://hiddenappl1.example.com/
 +</VirtualHost>
 +</code>
 +
 +See [[http://httpd.apache.org/docs/2.2/mod/mod_proxy.html|mod_proxy]] and [[http://httpd.apache.org/docs/2.2/mod/mod_rewrite.html|mod_rewrite]] documentation for more about configuring Apache reverse-proxies.
 +
 +Such configuration can have some security problems:
 +  * if a user can access directly to the hidden application, it can bypass LL::NG protection
 +  * if many hidden applications are on the same private network, if one is corrupted (by SQL injection, or another attack), the hacker will be able to access to other applications without using reverse-proxies so it can bypass LL::NG protection
 +
 +It is recommended to secure the channel between reverse-proxies and application to be sure that only request coming from the LL::NG protected reverse-proxies are allowed. You can use one or a combination of:
 +  * firewalls (but be careful if more than 1 server is behind the firewall)
 +  * server based restriction (like Apache "allow/deny" mechanism)
 +  * SSL client certificate for the reverse-proxy (see SSLProxy* parameters in [[http://httpd.apache.org/docs/2.2/mod/mod_ssl.html|mod_ssl documentation]])
 +
 +===== Configure security settings =====
 +
 +Go in Manager, ''General parameters'' » ''Advanced parameters'' » ''Security'':
 +  * **Username control**: Regular expression used to check user login syntax.
 +  * **Avoid browsers to store users password**: Enable this option to prevent browsers from prompting users to save passwords.
 +  * **Force authentication**: set to 'On' to force authentication when user connects to portal, even if he has a valid session.
 +  * **Force authentication interval**: time interval (in seconds) when an authentication renewal cannot be forced, used to prevent to loose the current authentication during the main process. If you experience slow network performances, you can increase this value.
 +  * **Encryption key**: key used to crypt some data, should not be known by other applications
 +  * **Trusted domains**: domains on which the user can be redirected after login on portal.
 +    * Example: ''myapp.example.com .subdomain.example.com''
 +    * ''*'' allows redirections to any external domain (DANGEROUS)
 +  * **Use Safe jail**: set to 'Off' to disable Safe jail. Safe module is used to eval expressions in headers, rules, etc. Disabling it can lead to security issues.
 +  * **Check XSS Attacks**: Set to 'Off' to disable XSS checks. XSS checks will still be done with warning in logs, but this will not prevent the process to continue.
 +  * **Brute-Force Attack protection**: set to 'On' to enable it. The aim of a brute force attack is to gain access to user accounts by repeatedly trying to guess the password of a user. If it is disabled, automated tools may submit thousands of password attempts in a matter of seconds, making it easy for an attacker to beat a password-based authentication system.
 +  * **Required token for forms**: To prevent CSRF attack, a token is build for each form. To disable it, set this parameter to 'Off' or set a special rule
 +  * **Form timeout**: Form token timeout (default to 120 seconds)
 +  * **Use global storage**: Local cache is used by default for one time tokens. To use global storage, set it to 'On'
 +  * **LWP::UserAgent and SSL options**: insert here options to pass to LWP::UserAgent object (used by SAML or OpenID-Connect to query partners and AuthSSL or AuthBasic handler to request Portal URL). Example: ''verify_hostname => 0'', ''SSL_verify_mode => 0''
 +  * **Content Security Policy**:  Portal builds dynamically this header. You can modify default values. Browser implementations of formAction directive are inconsistent (e.g. Firefox doesn't block the redirects whereas Chrome does). Administrators may have to modify ''formAction'' value with wildcard likes *.
 +  * **Cross-Origin Resource Sharing**:  Portal builds those headers. You can modify default values. Administrators may have to modify ''Access-Control-Allow-Origin'' value with ' '.
 +
 +<note important>If URLs are protected with AuthBasic handler, you have to disable CSRF token by setting a special rule based on callers IP address like this :
 +
 +requireToken => $env->{REMOTE_ADDR} !~ /^127\.0\.[1-3]\.1$/
 +</note>
 +<note warning>Enable global storage for one time tokens will downgrade Portal performance!!!
 +
 +Must ONLY be use with outdated or low performance Load Balancer.</note>
 +===== Fail2ban =====
 +To prevent brute force attack with fail2ban
 +
 +Edit /etc/fail2ban/jail.conf
 +<code>[lemonldap-ng]
 +enabled = true
 +port    = http,https
 +filter  = lemonldap
 +action   = iptables-multiport[name=lemonldap, port="http,https"]
 +logpath = /var/log/apache*/error*.log
 +maxretry = 3
 +</code>
 +
 +and edit /etc/fail2ban/filter.d/lemonldap.conf
 +
 +<code>
 +# Fail2Ban configuration file
 +#
 +# Author: Adrien Beudin
 +#
 +# $Revision: 2 $
 +#
 +
 +[Definition]
 +
 +# Option:  failregex
 +# Notes.:  regex to match the password failure messages in the logfile. The
 +#          host must be matched by a group named "host". The tag "<HOST>" can
 +#          be used for standard IP/hostname matching and is only an alias for
 +#          (?:::f{4,6}:)?(?P<host>[\w\-.^_]+)
 +# Values:  TEXT
 +#
 +failregex = Lemonldap\:\:NG \: .* was not found in LDAP directory \(<HOST>\)
 +            Lemonldap\:\:NG \: Bad password for .* \(<HOST>\)
 +
 +# Option:  ignoreregex
 +# Notes.:  regex to ignore. If this regex matches, the line is ignored.
 +# Values:  TEXT
 +#
 +ignoreregex =
 +</code>
 +
 +Restart fail2ban
 +
 +===== Sessions identifier =====
 +
 +You can change the module used for sessions identifier generation. To do, add ''generateModule'' key in the configured session backend options.
 +
 +We recommend to use : ''Lemonldap::NG::Common::Apache::Session::Generate::SHA256''.
 +
 +===== SAML =====
 +
 +See [[samlservice#security_parameters]]