ElectronicCourseReserve Plugin

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.

Table of Contents

• Requirements
• Install
• Logging
• Dependencies
  • GnuPG
    • Key Pair Generation
    • Public Key Export
• Interfaces
• License

Requirements

• PHP:
• ILIAS:

Install

This plugin MUST be installed as a User Interface Plugin.

The files MUST be saved in the following directory:

<ILIAS>/Customizing/global/plugins/Services/UIComponent/UserInterfaceHook/ElectronicCourseReserve

Correct file and folder permissions MUST be ensured by the responsible system administrator.

The plugin's files and folder SHOULD NOT be created, as root.

Logging

The ILIAS log file is used whenever the plugin considers something to be important to log.

Dependencies

• CronElectronicCourseReserve Plugin (https://github.com/DatabayAG/CronElectronicCourseReserve)
• GnuPG (https://wiki.ubuntuusers.de/GnuPG/)
  • Important: For newer GnuPG versions, please follow the steps mentioned here: https://d.sb/2016/11/gpg-inappropriate-ioctl-for-device-errors

GnuPG

The plugin uses GnuPG for token generation. Therefore you MUST create a public/private key pair, located in a keyring of an arbitrary server directory you MUST define in the plugin administration.

In the following examples, /srv/www/esa.invorbereitung.de/data/esainvorbe/.esa is used as directory, and [email protected] is used as email address. A directory of your choice MAY be used. This directory MUST be readable by the operating system user the PHP interpreter is executed with (www-data, www-run, etc.),

Key Pair Generation

gpg --homedir /srv/www/esa.invorbereitung.de/data/esainvorbe/.esa --gen-key

• If you get asked for selecting a kind, choose: DSA and Elgamal
• Keysize: 2048
• Key Expiration: 0
• Realname und Comment (Example): Elektronischer Semesterapparat
• Email Address (Example): [email protected]
• Passphrase (Your Secret): *****

Public Key Export

gpg --homedir /srv/www/esa.invorbereitung.de/data/esainvorbe/.esa --armor --export [email protected] > esa_pub_key.asc

The public key file esa_pub_key.asc has to be shared with the library.

In the ILIAS configuration screen you'll have to enter the following values in regards of the key:

• Absolute Server Path/HomeDirectory: /srv/www/esa.invorbereitung.de/data/esainvorbe/.esa
• Fingerprint (Key): Enter the unique fingerprint of the relevant private key. A list of possible keys will be provided on the configuration screen if ILIAS is able to read/analyze the GnuPG files.
• Passphrase: *****

Known Issues

If you are using new gpg versions, e.g. v. 2.2.x in Ubuntu 18.04 or above, please ensure the following configuration files exists with the respective settings:

cat gpg-agent.conf

allow-loopback-pinentry

cat gpg.conf

use-agent
pinentry-mode loopback

The configuration files MUST be located within the gpg directory configured in ILIAS.

The PHP wrapper for gpg requires a running gpg agent, which provides interfaces via UNIX sockets. Please make sure your file system supports UNIX sockets. If you notice any issues, the following links might be useful:

• https://askubuntu.com/questions/777900/how-to-configure-gnupgs-s-gpg-agent-socket-location
• https://michaelheap.com/gpg-cant-connect-to-the-agent-ipc-connect-call-failed/

Interfaces

Signature Creation/Verification

When redirecting the actor (mostly a course admin or tutor) to the research system of the library (to order digitized media), ILIAS appends some query parameters to the base URL configured in the global plugin administration.

1. ref_id: The ILIAS ref_id of the current course
2. usr_id: The current login/username of the actor
3. ts: A unix timestamp base on the current point in time
4. email: The current email address of the actor
5. iltitle (optional): An optional title of the current course
6. iltoken: A cryptographic signature of the data above

Algorithm:

1. Parameters 1 - 5 are joined with an empty string.
   • Example: -1root1585137094mjansen[at]databay[dot]deExample
2. A (detached) GnuPG signature is created with this string (created in 1.) used as message.
3. The built signature is base64 encoded.
4. The encoded signature is appended to the research system URL as "iltoken".

The search system has to verify the signature accordingly.

Delivery of Digitized Media an Links to ILIAS

The library has to push it's generated files to the folder configured in the global plugin administration.

It is up to the concrete institutions and libraries how the files will be transferred (SCP, FTP, ...).

There MUST be a XML file describing a delivery. The file MUST be based on the XML schema file here.

License

See LICENSE file in this repository.