--- loncom/auth/lonshibauth.pm 2021/11/03 01:04:02 1.12 +++ loncom/auth/lonshibauth.pm 2021/12/06 03:31:54 1.13 @@ -1,7 +1,8 @@ # The LearningOnline Network -# Redirect Shibboleth authentication to designated URL (/adm/sso). +# Redirect Single Sign On authentication to designated URL: +# /adm/sso, by default. # -# $Id: lonshibauth.pm,v 1.12 2021/11/03 01:04:02 raeburn Exp $ +# $Id: lonshibauth.pm,v 1.13 2021/12/06 03:31:54 raeburn Exp $ # # Copyright Michigan State University Board of Trustees # @@ -28,14 +29,15 @@ =head1 NAME -Apache::lonshibauth - Redirect Shibboleth authentication +Apache::lonshibauth - Redirect Single Sign On authentication =head1 SYNOPSIS -Invoked when lonOtherAuthen is set to yes, and type is Shibboleth +Invoked when an Apache config file includes: +PerlAuthenHandler Apache::lonshibauth If server is configured as a Shibboleth SP, the main Apache -configuration file, e.g., /etc/httpd/conf/httpd.conf +configuration file, e.g., /etc/httpd/conf/httpd.conf (for RHEL/CentOS/Scentific Linux/Fedora) should contain: LoadModule mod_shib /usr/lib/shibboleth/mod_shib_22.so @@ -43,10 +45,99 @@ LoadModule mod_shib /usr/lib/shibboleth/ or equivalent (depending on Apache version) before the line to include conf/loncapa_apache.conf +If some other Apache module is in use for Single Sign On +authentication e.g., mod_auth_cas or mod_sentinel, +then a separate config file should be created which +includes settings for the authentication module. + =head1 INTRODUCTION -Redirects a user requiring Single Sign On via Shibboleth to a -URL -- /adm/sso -- on the server which is configured to use that service. +Redirects a user requiring Single Sign On to a URL on the server +which is configured to use that service. The default URL is: +/adm/sso. + +If this is to be used with a Single Sign On service other Shibboleth +then an Apache config file needs to be loaded which: + +(a) loads the corresponding Apache module, and +(b) sets appropriate values for perl vars in +an block, and +(c) sets an appropriate value for AuthType in a + + block, which also contains + +require valid-user + +PerlAuthzHandler Apache::lonshibacc + +PerlAuthzHandler Apache::lonacc + +In the case of Shibboleth no additional file is needed +because loncapa_apache.conf already contains: + + + PerlAuthenHandler Apache::lonshibauth + PerlSetVar lonOtherAuthen yes + PerlSetVar lonOtherAuthenType Shibboleth + + + +and + + + Header set Cache-Control "private,no-store,no-cache,max-age=0" + + AuthType shibboleth + ShibUseEnvironment On + ShibRequestSetting requireSession 1 + ShibRequestSetting redirectToSSL 443 + require valid-user + PerlAuthzHandler Apache::lonshibacc + PerlAuthzHandler Apache::lonacc + ErrorDocument 403 /adm/login + ErrorDocument 500 /adm/errorhandler + + + PerlTypeHandler Apache::lonnoshib + + + + +If the service is not Shibboleth, then (optionally) a URL that is +not /adm/sso can be used as the URL for the service, e.g., /adm/cas +or /adm/sentinel, by setting a lonOtherAuthenUrl perl var +in an Apache config file containing (for example): + +PerlSetVar lonOtherAuthenUrl /adm/sentinel + + + PerlAuthenHandler Apache::lonshibauth + PerlSetVar lonOtherAuthen yes + PerlSetVar lonOtherAuthenType Sentinel + + + + + Header set Cache-Control "private,no-store,no-cache,max-age=0" + + AuthType Sentinel + require valid-user + PerlAuthzHandler Apache::lonshibacc + PerlAuthzHandler Apache::lonacc + ErrorDocument 403 /adm/login + ErrorDocument 500 /adm/errorhandler + + + PerlTypeHandler Apache::lonnoshib + + + + +In the example above for Sentinel SSO, it would also be possible to +use /adm/sso instead of /adm/sentinel, in which case (i) there would be +no need to define lonOtherAuthenUrl, (ii) there would be +and (iii) the block would not be needed as +it is already present in /etc/httpd/conf/loncapa_apache.conf. =head1 HANDLER SUBROUTINE @@ -54,10 +145,62 @@ This routine is called by Apache and mod =over 4 -If $r->user defined and requested uri not /adm/sso -redirect to /adm/sso +If $r->user is defined and requested URL is not /adm/sso or +other specific URL as set by a lonOtherAuthenUrl perlvar, +then redirect to /adm/sso (or to the specific URL). + +Otherwise return DECLINED. + +In the case of redirection a query string is appended, +which will contain either (a) the originally requested URL, +if not /adm/sso (or lonOtherAuthenUrl URL), and +any existing query string in the original request, or +(b) if original request was for /tiny/domain/uniqueID, +or if redirect is to /adm/login to support dual SSO and +non-SSO, a query string which contains sso=tokenID, where the +token contains information for deep-linking to course/resource. + +Support is included for use of LON-CAPA's standard log-in +page -- /adm/login -- to support dual SSO and non-SSO +authentication from that "landing" page. + +To enable dual SSO and non-SSO access from /adm/login +a Domain Coordinator will use the web GUI: +Main Menu > Set domain configuration > Display +("Log-in page options" checked) +and for any of the LON-CAPA domain's servers which +will offer dual login will check "Yes" and then set: +(a) SSO Text, Image, Alt Text, URL, Tool Tip +(b) non-SSO: Text + +The value in the URL field should be /adm/sso, +or the same URL as set for the lonOtherAuthenUrl +perl var, e.g., /adm/sentinel. -Otherwise return DECLINED +=back + +=head1 NOTABLE SUBROUTINES + +=over 4 + +=item set_token() + +Inputs: 2 +$r - request object +$lonhost - hostID of current server + +Output: 1 +$querystring - query string to append to URL +when redirecting. + +If any of the following items are present in the original query string: +role, symb, and linkkey, then they will be stored in the token file +on the server, for access later to support deep-linking. If the ltoken +item is available, from successful launch from an LTI Consumer where +LON-CAPA is the LTI Provider, but not configured to accept user +information, and the destination is a deep-link URL /tiny/domain/uniqueiD, +then the LTI number, type (c or d), and tiny URL will be saved as the +linkprot item in a token file. =back @@ -75,11 +218,15 @@ use LONCAPA qw(:DEFAULT :match); sub handler { my $r = shift; - my $target = '/adm/sso'; + my $ssourl = '/adm/sso'; + if ($r->dir_config('lonOtherAuthenUrl') ne '') { + $ssourl = $r->dir_config('lonOtherAuthenUrl'); + } + my $target = $ssourl; if (&Apache::lonnet::get_saml_landing()) { $target = '/adm/login'; } - if (($r->user eq '') && ($r->uri ne $target) && ($r->uri ne '/adm/sso')) { + if (($r->user eq '') && ($r->uri ne $target) && ($r->uri ne $ssourl)) { my $lonhost = $Apache::lonnet::perlvar{'lonHostID'}; my $hostname = &Apache::lonnet::hostname($lonhost); if (!$hostname) { $hostname = $r->hostname(); }