Databases

Authentication Users Password

Presentation

Drivers

LL::NG can use a lot of databases as authentication, users and password backend:

  • MariaDB/MySQL
  • PostGreSQL
  • Oracle

Indeed, any Perl DBD driver can be used.

Schema

LL::NG can use two tables:

  • Authentication table: where login and password are stored
  • User table: where user data are stored (mail, name, etc.)
Authentication table and user table can be the same.

The password can be in plain text, or encoded with a standard SQL method:

  • SHA
  • SHA1
  • MD5

Example 1: two tables

Authentication table
id login password
0 coudot 1f777a6581e478499f4284e54fe2d4a4e513dfff
1 xguimard a15a18c8bb17e6f67886a9af1898c018b9f5a072
2 tchemineau 1f777a6581e478499f4284e54fe2d4a4e513dfff
User table
id user name mail
0 coudot Clément OUDOT coudot@example.com
1 tchemineau Thomas CHEMINEAU tchemineau@example.com
2 xguimard Xavier GUIMARD xguimard@example.com

Example 2: single table

id user password name mail
0 coudot 1f777a6581e478499f4284e54fe2d4a4e513dfff Clément OUDOT coudot@example.com
1 tchemineau 1f777a6581e478499f4284e54fe2d4a4e513dfff Thomas CHEMINEAU tchemineau@example.com
2 xguimard a15a18c8bb17e6f67886a9af1898c018b9f5a072 Xavier GUIMARD xguimard@example.com

SQL

LL::NG will operate some SQL queries:

  • Authentication: select row in authentication table matching user and password
  • Search user: select row in user table matching user
  • Change password: update password column in authentication table matching user

Configuration

In Manager, go in General Parameters > Authentication modules and choose Database (DBI) for authentication, users and/or password modules.

Authentication level

The authentication level given to users authenticated with this module.

As DBI is a login/password based module, the authentication level can be:
  • increased (+1) if portal is protected by SSL (HTTPS)
  • decreased (-1) if the portal autocompletion is allowed (see portal customization)

Exported variables

List of columns to query to fill user session. See also exported variables configuration.

Connection

Connection settings can be configured differently for authentication process and user process. This allows one to use different databases for these process. By default, if user process connection settings are empty, authentication process connection settings will be used.
  • Chain: DBI chain, including database driver name and database name (for example: dbi:mysql:database=lemonldapng;host=localhost).
  • User: Connection user
  • Password: Connection password

Schema

  • Authentication table: authentication table name
  • User table: user table name
  • Login field name: name of authentication table column hosting login
  • Password field name: name of authentication table column hosting password
  • Mail field name: name of authentication table column hosting mail (for password reset)
  • Login field name in user table: name of user table column hosting login

Password

  • Hash schema: SQL method for hashing password. Can be left blank for plain text passwords.
  • Dynamic hash activation: Activate dynamic hashing. With dynamic hashing, the hash scheme is recovered from the user password in the database during authentication.
  • Supported non-salted schemes: List of whitespace separated hash schemes. Every hash scheme MUST match a non-salted hash function in the database. LemonLDAP::NG relies on this hashing function for computing user password hashes. These hashes MUST NOT be salted (no random data used in conjunction with the password).
  • Supported salted schemes: List of whitespace separated salted hash schemes, of the form “sscheme”, where scheme MUST match a non-salted hash function in the database. LemonLDAP::NG relies on this hashing function for computing user password hashes. Salted and non-salted scheme lists are not necessarily equivalent. (for example: non-salted=“sha256” and salted=“ssha ssha512” is valid)
  • Dynamic hash scheme for new passwords: LemonLDAP::NG is able to store new passwords in the database (while modifying or reinitializing the password). You can choose a salted or non salted dynamic hashed password. The value must be an element of “Supported non-salted schemes” or “Supported salted schemes”.
The SQL function MUST have hexadecimal values as input AND output
Here is an example for creating a postgreSQL SHA256 function. 1. Install postgresql-contrib. 2. Activate extension:
CREATE EXTENSION pgcrypto;

3. Create the hash function:

CREATE OR REPLACE FUNCTION sha256(varchar) returns text AS $$
SELECT encode(digest(decode($1, 'hex'), 'sha256'), 'hex')
$$ LANGUAGE SQL STRICT IMMUTABLE;