Update OmniAuth Shibboleth gem to latest to gain support

for handling multi-valued SAML assertions. Add documentation
of label argument for omniauth provider to override text
in login button.

Gemfile

@@ -47,7 +47,7 @@ gem 'omniauth-google-oauth2', '~> 0.5.3'
 gem 'omniauth-kerberos', '~> 0.3.0', group: :kerberos
 gem 'omniauth-oauth2-generic', '~> 0.2.2'
 gem 'omniauth-saml', '~> 1.10'
-gem 'omniauth-shibboleth', '~> 1.2.0'
+gem 'omniauth-shibboleth', '~> 1.3.0'
 gem 'omniauth-twitter', '~> 1.4'
 gem 'omniauth_crowd', '~> 2.2.0'
 gem 'omniauth-authentiq', '~> 0.3.3'

Gemfile.lock

@@ -568,7 +568,7 @@ GEM
     omniauth-saml (1.10.0)
       omniauth (~> 1.3, >= 1.3.2)
       ruby-saml (~> 1.7)
-    omniauth-shibboleth (1.2.1)
+    omniauth-shibboleth (1.3.0)
       omniauth (>= 1.0.0)
     omniauth-twitter (1.4.0)
       omniauth-oauth (~> 1.1)
@@ -1101,7 +1101,7 @@ DEPENDENCIES
   omniauth-kerberos (~> 0.3.0)
   omniauth-oauth2-generic (~> 0.2.2)
   omniauth-saml (~> 1.10)
-  omniauth-shibboleth (~> 1.2.0)
+  omniauth-shibboleth (~> 1.3.0)
   omniauth-twitter (~> 1.4)
   omniauth_crowd (~> 2.2.0)
   org-ruby (~> 0.9.12)

Gemfile.rails5.lock

@@ -572,7 +572,7 @@ GEM
     omniauth-saml (1.10.0)
       omniauth (~> 1.3, >= 1.3.2)
       ruby-saml (~> 1.7)
-    omniauth-shibboleth (1.2.1)
+    omniauth-shibboleth (1.3.0)
       omniauth (>= 1.0.0)
     omniauth-twitter (1.4.0)
       omniauth-oauth (~> 1.1)
@@ -1111,7 +1111,7 @@ DEPENDENCIES
   omniauth-kerberos (~> 0.3.0)
   omniauth-oauth2-generic (~> 0.2.2)
   omniauth-saml (~> 1.10)
-  omniauth-shibboleth (~> 1.2.0)
+  omniauth-shibboleth (~> 1.3.0)
   omniauth-twitter (~> 1.4)
   omniauth_crowd (~> 2.2.0)
   org-ruby (~> 0.9.12)

doc/integration/shibboleth.md

@@ -43,7 +43,19 @@ exclude shibboleth URLs from rewriting, add "RewriteCond %{REQUEST_URI} !/Shibbo
   RequestHeader set X_FORWARDED_PROTO 'https'
 ```
 
-1.  Edit /etc/gitlab/gitlab.rb configuration file, your shibboleth attributes should be in form of "HTTP_ATTRIBUTE" and you should adjust them to your need and environment. Add any other configuration you need.
+1. Edit /etc/gitlab/gitlab.rb configuration file to enable OmniAuth and add
+Shibboleth as an OmniAuth provider. User attributes will be sent from the
+Apache reverse proxy to GitLab as headers with the names from the Shibboleth
+attribute mapping. Therefore the values of the `args` hash
+should be in the form of `"HTTP_ATTRIBUTE"`. The keys in the hash are arguments
+to the [OmniAuth::Strategies::Shibboleth class](https://github.com/toyokazu/omniauth-shibboleth/blob/master/lib/omniauth/strategies/shibboleth.rb)
+and are documented by the [omniauth-shibboleth gem](https://github.com/toyokazu/omniauth-shibboleth)
+(take care to note the version of the gem packaged with GitLab). If some of
+your users appear to be authenticated by Shibboleth and Apache, but GitLab
+rejects their account with a URI that contains "e-mail is invalid" then your
+Shibboleth Identity Provider or Attribute Authority may be asserting multiple
+e-mail addresses. In this instance, you might consider setting the
+`multi_values` argument to `first`.
 
 File should look like this:
 ```
@@ -58,7 +70,8 @@ gitlab_rails['omniauth_block_auto_created_users'] = false
 gitlab_rails['omniauth_enabled'] = true
 gitlab_rails['omniauth_providers'] = [
   {
-    "name" => 'shibboleth',
+    "name"  => "'shibboleth"',
+    "label" => "Text for Login Button",
     "args"  => {
         "shib_session_id_field"     => "HTTP_SHIB_SESSION_ID",
         "shib_application_id_field" => "HTTP_SHIB_APPLICATION_ID",