Update to libpam 1.5.2
This updates to libpam 1.5.2. This version removes support for
pam_cracklib and pam_tally2. They are replaced by pam_pwquality and
pam_faillock respectively.
Since parameters of pam_cracklb and pam_tally2 are configurable through
Redfish, it's possible that they will remain in the overlay of
/etc/pam.d with the old module names preventing PAM from working
correctly. To avoid this, this commit includes a script that will detect
if the old modules are in the overlay and update the overlay with the
new modules and configuration.
The script will allow updates from libpam 1.3.1 to libpam 1.5.2, but if there
are configured parameters during a downgrade from libpam 1.5.2 to libpam
1.3.1, it will require a factory reset before the downgrade.
pam_pwquality was selected over pam_passwdqc because of better security
and compatibility with pam_cracklib.
Note pam_faillock is necessarily configured into the pam module stack
differently than pam_tally2.
This patchset causes a BMC operational change:
- The pam_tally2 command (invoked from the BMC's command line) is no
longer present. If you used the "pam_tally2 -u USER -r" command
to unlock a user after repeated authentication failures, change to
use: faillock --user USER --reset
Compatibility note / migration issue. If your BMC cannot authenticate
users after installing this change, the cause might be an overlayfs file
hiding the new /etc/pam.d/common-auth file. To find out, use
`grep deny= /etc/pam.d/common-auth` on your BMC. If it shows "tally2"
then your BMC is affected. The recovery is to delete the overlay file,
to factory reset the BMC, or manually-install the changed files.
The convert-pam-configs service is intended to handle this problem.
Tested: as follows, for local users only (not tested with LDAP)
Note OpenBMC configuration defaults to an AccountLockoutThreshold
value of 0 which does not lock account passwords no matter how many
consecutive failed authentication attempts. To configure this on
the BMC, for example, use:
curl -X PATCH https://${bmc}/redfish/v1/AccountService
-d '{"AccountLockoutThreshold": 3, "AccountLockoutDuration": 60}'
Tested update scenarios:
1. Install from scratch. Success.
2. Install over firmware which had old PAM configs. Success.
Tested update scenarios for the convert-pam-configs service.
Tested changing the password via various interfaces:
- the passwd command
- the PATCH Refish AccountService {Password: NEW}
- SSH (accessible only when the password is expired)
- IPMI user set password (accessible for unexpired password)
Tested both good and bad (unacceptable) passwords.
Tested account lockout after N bad passwords
Tested unlock via Redfish.
Also, because its implementation changed, ensure reading and writing the
D-Bus User AccountPolicy RememberOldPasswordTimes property continues to
work. There is no Redfish API for this.
Signed-off-by: Joseph Reynolds <joseph-reynolds@charter.net>
Signed-off-by: Jason M. Bills <jason.m.bills@linux.intel.com>
Change-Id: I7b712cf7cfbf7b0bc79da42f822540baee66ca4f
diff --git a/meta-phosphor/recipes-extended/pam/libpam/pam.d/common-auth b/meta-phosphor/recipes-extended/pam/libpam/pam.d/common-auth
index 8eef164..c051ab7 100644
--- a/meta-phosphor/recipes-extended/pam/libpam/pam.d/common-auth
+++ b/meta-phosphor/recipes-extended/pam/libpam/pam.d/common-auth
@@ -8,14 +8,19 @@
# traditional Unix authentication mechanisms.
# here are the per-package modules (the "Primary" block)
-auth [success=ok user_unknown=ignore default=2] pam_tally2.so deny=0 unlock_time=0
# Try for local user first, and then try for ldap
auth [success=2 default=ignore] pam_unix.so quiet
-auth [success=1 default=ignore] pam_ldap.so ignore_unknown_user ignore_authinfo_unavail
-# here's the fallback if no module succeeds
-auth requisite pam_deny.so
+# Control gets here when no authentication module succeeds. Increment the
+# failure tally and return failure status to PAM.
+auth [default=die] pam_faillock.so authfail
+# Control gets here when authentication succeeds. Check if the user is locked
+# out due to consecutive authentication failures and return status accordingly.
+auth sufficient pam_faillock.so authsucc
+# If authsucc failed, deny access
+auth requisite pam_deny.so
# prime the stack with a positive return value if there isn't one already;
# this avoids us returning an error just because nothing sets a success code
# since the modules above will each just jump around
-auth required pam_permit.so
+auth required pam_permit.so
# and here are more per-package modules (the "Additional" block)