Allow SAML plugin to have custom auth error message - like Xmlrpc

[Robert Lyon]

With Xml-rpc auth method there is an admin field that allows the admin to set an error message that shows if a person tries to login internally alerting them of how to login properly.

This looks to be a useful feature of that auth plugin

This patch adds the same functionality to the SAML plugin. So if a user tries to login internally instead of via IdP it will alert the message set by admin

[Mahara Bot (dev-mahara)]

Patch for "master" branch: https://reviews.mahara.org/8309

[Niranjan (niranjan528)]

Environment to be tested: Master
Browser to be tested: Any browser

Precondition:

1. A user with 'Site admin' access exists.
2. ‘Institution A' exists.

Steps to reproduce:

1. Log in as ‘Site admin’.
2. Navigate to Administration menu > Institutions > Settings.
3. Click the ‘Settings’ button for ‘Institution A’.
4. Select ‘SAML’ from the ‘Authentication plugin’ drop-down menu.
5. Add ‘SAML’ meta data and make sure the 'Authentication login message' is set up with the text ‘This is an error message’.
6. Click the ‘Submit’ button.
7. Click the 'Save' button.
8. Set up a new user that has SAML as authentication method in that institution and make sure you set a remote username for them.
9. Log out as ‘Site admin’.
10. Now try to log in as ‘User one’ using the regular login fields and not the SSO button.

Expected result: ‘User one’ is not able to log in and the authentication login error message box is displayed: ‘This is an error message’.

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/8309
Committed: https://git.mahara.org/mahara/mahara/commit/c642e6aa8df31bb15db630d13d18468a8197b31b
Submitter: Robert Lyon (<email address hidden>)
Branch: master

commit c642e6aa8df31bb15db630d13d18468a8197b31b
Author: Robert Lyon <email address hidden>
Date: Mon Nov 27 07:38:52 2017 +1300

Bug 1734557: Allow SAML to show custom login error msg

Similar to what xml-rpc does, so allowing admin to set a message about
how to properly login

behatnotneeded

Change-Id: Ib4a85571dccf0fcf719785481645777c506687da
Signed-off-by: Robert Lyon <email address hidden>