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Revision as of 08:30, 1 September 2023 by Ipedrosa (talk | contribs)

Switch pam_userdb from BerkeleyDB to GDBM

This is a proposed Change for Fedora Linux.
This document represents a proposed Change. As part of the Changes process, proposals are publicly announced in order to receive community feedback. This proposal will only be implemented if approved by the Fedora Engineering Steering Committee.

Summary

pam_userdb was built with support for BerkeleyDB, but this project is no longer maintained as open source, so it is replaced by GDBM.

Owner


Current status

  • Targeted release: Fedora Linux 40
  • Last updated: 2023-09-01
  • [<will be assigned by the Wrangler> devel thread]
  • FESCo issue: <will be assigned by the Wrangler>
  • Tracker bug: <will be assigned by the Wrangler>
  • Release notes tracker: <will be assigned by the Wrangler>

Detailed Description

Currently, the Fedora provided BerkeleyDB versions is 5.x, which has been unmaintained upstream for several years. BerkeleyDB v6.x is license incompatible, so moving to that version is not an option.

The proposal is to switch to GDBM, which has upstream support and whose license is compatible with Fedora.

Feedback

Benefit to Fedora

  • This change uses a database that is Fedora license compatible.
  • This changes uses an upstream maintained database version, with new features and bug fixing. pam_userdb controls user authentication, and a bug in the database could lead to a security vulnerability.

Scope

  • Proposal owners:
    • libdb provides a program to port a BerkeleyDB database to GDBM.
    • Change PAM database build option to GDBM.
  • Other developers: N/A
  • Policies and guidelines: N/A (not needed for this Change)
  • Trademark approval: N/A
  • Alignment with Community Initiatives: N/A

Upgrade/compatibility impact

Upgrade

  • If the pam_userdb module is used by the system, then the user/sysadmin will have to run the conversion tool. This can't be done automatically because the database location is configurable, and the conversion tool will need manual intervention.

Compatibility

  • pam_userdb module is mainly used in vsftpd environments. If this module is used by the system and the database isn't converted, then the user won't be able to authenticate in vsftpd environments. The user would still be able to authenticate using other methods (i.e. su, ssh) and run the conversion tool.


How To Test

  • Run db_converter to convert the database. Example

db_converter --src /etc/vsftpd/login.db --dest /etc/vsftpd/login.gdbm

  • vsftpd login
  • Check that the user is authenticated


User Experience

Users won't experience any change.

Dependencies

vsftpd depends on this change, but nothing needs to be done in this package.

Contingency Plan

  • Contingency mechanism: Postpone to the next release.
  • Contingency deadline: Beta freeze.
  • Blocks release? No.


Documentation

N/A (not a System Wide Change)

Release Notes

pam_userdb switches database provider to GDM.