Linux-PAM release 1.5.1
* pam_unix: fixed CVE-2020-27780 - authentication bypass when a user
            doesn't exist and root password is blank
* pam_faillock: added nodelay option to not set pam_fail_delay
* pam_wheel: use pam_modutil_user_in_group to check for the group membership
             with getgrouplist where it is available

Linux-PAM release 1.5.0
* Multiple minor bug fixes, portability fixes, and documentation improvements.
* Extended libpam API with pam_modutil_check_user_in_passwd function.
* configure: added --disable-unix option to disable build of pam_unix module.
* pam_faillock: changed /run/faillock/$USER permissions from 0600 to 0660.
* pam_limits: added support for nonewprivs item.
* pam_motd: read motd files with target user credentials skipping unreadable ones.
* pam_pwhistory: added a SELinux helper executable.
* pam_unix, pam_usertype: implemented avoidance of certain timing attacks.
* pam_wheel: implemented PAM_RUSER fallback for the case when getlogin fails.
* Removed deprecated pam_cracklib module, use pam_passwdqc (from passwdqc project)
  or pam_pwquality (from libpwquality project) instead.
* Removed deprecated pam_tally and pam_tally2 modules, use pam_faillock instead.
* pam_env: Reading of the user environment is deprecated and will be removed
	   at some point in the future.
* libpam: pam_modutil_drop_priv() now correctly sets the target user's
          supplementary groups, allowing pam_motd to filter messages accordingly


Linux-PAM release 1.4.0
* Multiple minor bug fixes and documentation improvements
* Fixed grammar of messages printed via pam_prompt
* Added support for a vendor directory and libeconf
* configure: Added --enable-Werror option to enable -Werror build
* configure: Allowed disabling documentation through --disable-doc
* pam_get_authtok_verify: Avoid duplicate password verification
* pam_cracklib: Fixed parsing of options without arguments
* pam_env: Changed the default to not read the user .pam_environment file
* pam_exec: Require a user name to be specified before the command is executed
* pam_faillock: New module for locking after multiple auth failures
* pam_group, pam_time: Fixed logical error with multiple ! operators
* pam_keyinit: In pam_sm_setcred do the same as in pam_sm_open_session
* pam_lastlog: Do not log info about failed login if the session was opened
	       with PAM_SILENT flag
* pam_lastlog: Limit lastlog file use by LASTLOG_UID_MAX option in login.defs
* pam_lastlog: With 'unlimited' option prevent SIGXFSZ due to reduced 'fsize'
	       limit
* pam_mkhomedir: Fixed return value when the user is unknown
* pam_motd: Export MOTD_SHOWN=pam after showing MOTD
* pam_motd: Support multiple motd paths specified, with filename overrides
* pam_namespace: Added a systemd service, which creates the namespaced
		 instance parent directories during boot
* pam_namespace: Support for noexec, nosuid and nodev flags for tmpfs mounts
* pam_selinux: Check unknown object classes or permissions in current policy
* pam_selinux: Fall back to log to syslog if audit logging fails
* pam_setquota: New module to set or modify disk quotas on session start
* pam_shells: Recognize /bin/sh as the default shell
* pam_succeed_if: Fixed potential override of the default prompt
* pam_succeed_if: Support lists in group membership checks
* pam_time: Added conffile= option to specify an alternative configuration file
* pam_tty_audit: If kernel audit is disabled return PAM_IGNORE
* pam_umask: Added new 'nousergroups' module argument and allowed specifying
	     the default for usergroups at build-time
* pam_unix: Added 'nullresetok' option to allow resetting blank passwords
* pam_unix: Report unusable hashes found by checksalt to syslog
* pam_unix: Return PAM_AUTHINFO_UNAVAIL when shadow entry is unavailable
* pam_unix: Support for (gost-)yescrypt hashing methods
* pam_unix: Use bcrypt b-variant when it bcrypt is chosen
* pam_usertype: New module to tell if uid is in login.defs ranges
* Fixed and documented possible values returned by pam_get_user()
* Added new API call pam_start_confdir() for special applications that
  cannot use the system-default PAM configuration paths and need to
  explicitly specify another path
* Deprecated pam_cracklib: this module is no longer built by default and will
  be removed in the next release, use pam_passwdqc (from passwdqc project)
  or pam_pwquality (from libpwquality project) instead
* Deprecated pam_tally and pam_tally2: these modules are no longer built
  by default and will be removed in the next release, use pam_faillock instead