security: User Account Naming Security

[alexskr]

This request addresses several security concerns regarding user account naming. The proposed changes aim to reduce potential vulnerabilities and ensure a consistent, secure handling of usernames across the system.

Proposed Changes:

• Restrict usernames to alphanumeric characters plus a limited set of extra characters deemed safe.
  Period (.)
  Plus (+)
  Underscore (_)
  Dash (-)
  At symbol (@)
  Space ( )?
  Note: Further review may refine this list based on security best practices.

• Case-Insensitive Uniqueness
  Usernames must be treated in a case-insensitive manner to prevent accounts such as Admin, admin and ADMIN from being considered distinct

• Maximum Length Restriction

• Blacklist of Reserved or Unsafe Usernames
  Prevent the registration of usernames that are known to be sensitive or prone to abuse, such as "admin", "root", "support", etc, that cannot be registered by end users.

[jonquet]

@muhammedBkf opinion?
(Mohamed is working in the security area)