shadow/etc/login.defs
Iker Pedrosa b8cbc2c113 login.defs: include HMAC_CRYPTO_ALGO key
Include the new HMAC_CRYPTO_ALGO key that is needed by pam_timestamp to
select the algorithm that is going to be used to calculate the message
authentication code.

pam_timestamp is currently using an embedded algorithm to calculate the
HMAC message, but the idea is to improve this behaviour by relying on
openssl's implementation. On top of that, the ability to change the
algorithm with a simple configuration change allows to simplify the
process of removing unsecure algorithms.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1947294
2021-05-06 17:31:53 +02:00

480 lines
13 KiB
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#
# /etc/login.defs - Configuration control definitions for the shadow package.
#
# $Id$
#
#
# Delay in seconds before being allowed another attempt after a login failure
# Note: When PAM is used, some modules may enforce a minimum delay (e.g.
# pam_unix(8) enforces a 2s delay)
#
FAIL_DELAY 3
#
# Enable logging and display of /var/log/faillog login(1) failure info.
#
FAILLOG_ENAB yes
#
# Enable display of unknown usernames when login(1) failures are recorded.
#
LOG_UNKFAIL_ENAB no
#
# Enable logging of successful logins
#
LOG_OK_LOGINS no
#
# Enable logging and display of /var/log/lastlog login(1) time info.
#
LASTLOG_ENAB yes
#
# Limit the highest user ID number for which the lastlog entries should
# be updated.
#
# No LASTLOG_UID_MAX means that there is no user ID limit for writing
# lastlog entries.
#
#LASTLOG_UID_MAX
#
# Enable checking and display of mailbox status upon login.
#
# Disable if the shell startup files already check for mail
# ("mailx -e" or equivalent).
#
MAIL_CHECK_ENAB yes
#
# Enable additional checks upon password changes.
#
OBSCURE_CHECKS_ENAB yes
#
# Enable checking of time restrictions specified in /etc/porttime.
#
PORTTIME_CHECKS_ENAB yes
#
# Enable setting of ulimit, umask, and niceness from passwd(5) gecos field.
#
QUOTAS_ENAB yes
#
# Enable "syslog" logging of su(1) activity - in addition to sulog file logging.
# SYSLOG_SG_ENAB does the same for newgrp(1) and sg(1).
#
SYSLOG_SU_ENAB yes
SYSLOG_SG_ENAB yes
#
# If defined, either full pathname of a file containing device names or
# a ":" delimited list of device names. Root logins will be allowed only
# from these devices.
#
CONSOLE /etc/securetty
#CONSOLE console:tty01:tty02:tty03:tty04
#
# If defined, all su(1) activity is logged to this file.
#
#SULOG_FILE /var/log/sulog
#
# If defined, ":" delimited list of "message of the day" files to
# be displayed upon login.
#
MOTD_FILE /etc/motd
#MOTD_FILE /etc/motd:/usr/lib/news/news-motd
#
# If defined, this file will be output before each login(1) prompt.
#
#ISSUE_FILE /etc/issue
#
# If defined, file which maps tty line to TERM environment parameter.
# Each line of the file is in a format similar to "vt100 tty01".
#
#TTYTYPE_FILE /etc/ttytype
#
# If defined, login(1) failures will be logged here in a utmp format.
# last(1), when invoked as lastb(1), will read /var/log/btmp, so...
#
FTMP_FILE /var/log/btmp
#
# If defined, name of file whose presence will inhibit non-root
# logins. The content of this file should be a message indicating
# why logins are inhibited.
#
NOLOGINS_FILE /etc/nologin
#
# If defined, the command name to display when running "su -". For
# example, if this is defined as "su" then ps(1) will display the
# command as "-su". If not defined, then ps(1) will display the
# name of the shell actually being run, e.g. something like "-sh".
#
SU_NAME su
#
# *REQUIRED*
# Directory where mailboxes reside, _or_ name of file, relative to the
# home directory. If you _do_ define both, MAIL_DIR takes precedence.
#
MAIL_DIR /var/spool/mail
#MAIL_FILE .mail
#
# If defined, file which inhibits all the usual chatter during the login
# sequence. If a full pathname, then hushed mode will be enabled if the
# user's name or shell are found in the file. If not a full pathname, then
# hushed mode will be enabled if the file exists in the user's home directory.
#
HUSHLOGIN_FILE .hushlogin
#HUSHLOGIN_FILE /etc/hushlogins
#
# If defined, either a TZ environment parameter spec or the
# fully-rooted pathname of a file containing such a spec.
#
#ENV_TZ TZ=CST6CDT
#ENV_TZ /etc/tzname
#
# If defined, an HZ environment parameter spec.
#
# for Linux/x86
ENV_HZ HZ=100
# For Linux/Alpha...
#ENV_HZ HZ=1024
#
# *REQUIRED* The default PATH settings, for superuser and normal users.
#
# (they are minimal, add the rest in the shell startup files)
ENV_SUPATH PATH=/sbin:/bin:/usr/sbin:/usr/bin
ENV_PATH PATH=/bin:/usr/bin
#
# Terminal permissions
#
# TTYGROUP Login tty will be assigned this group ownership.
# TTYPERM Login tty will be set to this permission.
#
# If you have a write(1) program which is "setgid" to a special group
# which owns the terminals, define TTYGROUP as the number of such group
# and TTYPERM as 0620. Otherwise leave TTYGROUP commented out and
# set TTYPERM to either 622 or 600.
#
TTYGROUP tty
TTYPERM 0600
#
# Login configuration initializations:
#
# ERASECHAR Terminal ERASE character ('\010' = backspace).
# KILLCHAR Terminal KILL character ('\025' = CTRL/U).
# ULIMIT Default "ulimit" value.
#
# The ERASECHAR and KILLCHAR are used only on System V machines.
# The ULIMIT is used only if the system supports it.
# (now it works with setrlimit too; ulimit is in 512-byte units)
#
# Prefix these values with "0" to get octal, "0x" to get hexadecimal.
#
ERASECHAR 0177
KILLCHAR 025
#ULIMIT 2097152
# Default initial "umask" value used by login(1) on non-PAM enabled systems.
# Default "umask" value for pam_umask(8) on PAM enabled systems.
# UMASK is also used by useradd(8) and newusers(8) to set the mode for new
# home directories if HOME_MODE is not set.
# 022 is the default value, but 027, or even 077, could be considered
# for increased privacy. There is no One True Answer here: each sysadmin
# must make up their mind.
UMASK 022
# HOME_MODE is used by useradd(8) and newusers(8) to set the mode for new
# home directories.
# If HOME_MODE is not set, the value of UMASK is used to create the mode.
#HOME_MODE 0700
#
# Password aging controls:
#
# PASS_MAX_DAYS Maximum number of days a password may be used.
# PASS_MIN_DAYS Minimum number of days allowed between password changes.
# PASS_MIN_LEN Minimum acceptable password length.
# PASS_WARN_AGE Number of days warning given before a password expires.
#
PASS_MAX_DAYS 99999
PASS_MIN_DAYS 0
PASS_MIN_LEN 5
PASS_WARN_AGE 7
#
# If "yes", the user must be listed as a member of the first gid 0 group
# in /etc/group (called "root" on most Linux systems) to be able to "su"
# to uid 0 accounts. If the group doesn't exist or is empty, no one
# will be able to "su" to uid 0.
#
SU_WHEEL_ONLY no
#
# If compiled with cracklib support, sets the path to the dictionaries
#
CRACKLIB_DICTPATH /var/cache/cracklib/cracklib_dict
#
# Min/max values for automatic uid selection in useradd(8)
#
UID_MIN 1000
UID_MAX 60000
# System accounts
SYS_UID_MIN 101
SYS_UID_MAX 999
# Extra per user uids
SUB_UID_MIN 100000
SUB_UID_MAX 600100000
SUB_UID_COUNT 65536
#
# Min/max values for automatic gid selection in groupadd(8)
#
GID_MIN 1000
GID_MAX 60000
# System accounts
SYS_GID_MIN 101
SYS_GID_MAX 999
# Extra per user group ids
SUB_GID_MIN 100000
SUB_GID_MAX 600100000
SUB_GID_COUNT 65536
#
# Max number of login(1) retries if password is bad
#
LOGIN_RETRIES 5
#
# Max time in seconds for login(1)
#
LOGIN_TIMEOUT 60
#
# Maximum number of attempts to change password if rejected (too easy)
#
PASS_CHANGE_TRIES 5
#
# Warn about weak passwords (but still allow them) if you are root.
#
PASS_ALWAYS_WARN yes
#
# Number of significant characters in the password for crypt().
# Default is 8, don't change unless your crypt() is better.
# Ignored if MD5_CRYPT_ENAB set to "yes".
#
#PASS_MAX_LEN 8
#
# Require password before chfn(1)/chsh(1) can make any changes.
#
CHFN_AUTH yes
#
# Which fields may be changed by regular users using chfn(1) - use
# any combination of letters "frwh" (full name, room number, work
# phone, home phone). If not defined, no changes are allowed.
# For backward compatibility, "yes" = "rwh" and "no" = "frwh".
#
CHFN_RESTRICT rwh
#
# Password prompt (%s will be replaced by user name).
#
# XXX - it doesn't work correctly yet, for now leave it commented out
# to use the default which is just "Password: ".
#LOGIN_STRING "%s's Password: "
#
# Only works if compiled with MD5_CRYPT defined:
# If set to "yes", new passwords will be encrypted using the MD5-based
# algorithm compatible with the one used by recent releases of FreeBSD.
# It supports passwords of unlimited length and longer salt strings.
# Set to "no" if you need to copy encrypted passwords to other systems
# which don't understand the new algorithm. Default is "no".
#
# Note: If you use PAM, it is recommended to use a value consistent with
# the PAM modules configuration.
#
# This variable is deprecated. You should use ENCRYPT_METHOD instead.
#
#MD5_CRYPT_ENAB no
#
# Only works if compiled with ENCRYPTMETHOD_SELECT defined:
# If set to MD5, MD5-based algorithm will be used for encrypting password
# If set to SHA256, SHA256-based algorithm will be used for encrypting password
# If set to SHA512, SHA512-based algorithm will be used for encrypting password
# If set to BCRYPT, BCRYPT-based algorithm will be used for encrypting password
# If set to YESCRYPT, YESCRYPT-based algorithm will be used for encrypting password
# If set to DES, DES-based algorithm will be used for encrypting password (default)
# MD5 and DES should not be used for new hashes, see crypt(5) for recommendations.
# Overrides the MD5_CRYPT_ENAB option
#
# Note: If you use PAM, it is recommended to use a value consistent with
# the PAM modules configuration.
#
#ENCRYPT_METHOD DES
#
# Only works if ENCRYPT_METHOD is set to SHA256 or SHA512.
#
# Define the number of SHA rounds.
# With a lot of rounds, it is more difficult to brute-force the password.
# However, more CPU resources will be needed to authenticate users if
# this value is increased.
#
# If not specified, the libc will choose the default number of rounds (5000),
# which is orders of magnitude too low for modern hardware.
# The values must be within the 1000-999999999 range.
# If only one of the MIN or MAX values is set, then this value will be used.
# If MIN > MAX, the highest value will be used.
#
#SHA_CRYPT_MIN_ROUNDS 5000
#SHA_CRYPT_MAX_ROUNDS 5000
#
# Only works if ENCRYPT_METHOD is set to BCRYPT.
#
# Define the number of BCRYPT rounds.
# With a lot of rounds, it is more difficult to brute-force the password.
# However, more CPU resources will be needed to authenticate users if
# this value is increased.
#
# If not specified, 13 rounds will be attempted.
# If only one of the MIN or MAX values is set, then this value will be used.
# If MIN > MAX, the highest value will be used.
#
#BCRYPT_MIN_ROUNDS 13
#BCRYPT_MAX_ROUNDS 13
#
# Only works if ENCRYPT_METHOD is set to YESCRYPT.
#
# Define the YESCRYPT cost factor.
# With a higher cost factor, it is more difficult to brute-force the password.
# However, more CPU time and more memory will be needed to authenticate users
# if this value is increased.
#
# If not specified, a cost factor of 5 will be used.
# The value must be within the 1-11 range.
#
#YESCRYPT_COST_FACTOR 5
#
# List of groups to add to the user's supplementary group set
# when logging in from the console (as determined by the CONSOLE
# setting). Default is none.
#
# Use with caution - it is possible for users to gain permanent
# access to these groups, even when not logged in from the console.
# How to do it is left as an exercise for the reader...
#
#CONSOLE_GROUPS floppy:audio:cdrom
#
# Should login be allowed if we can't cd to the home directory?
# Default is no.
#
DEFAULT_HOME yes
#
# The pwck(8) utility emits a warning for any system account with a home
# directory that does not exist. Some system accounts intentionally do
# not have a home directory. Such accounts may have this string as
# their home directory in /etc/passwd to avoid a spurious warning.
#
NONEXISTENT /nonexistent
#
# If this file exists and is readable, login environment will be
# read from it. Every line should be in the form name=value.
#
ENVIRON_FILE /etc/environment
#
# If defined, this command is run when removing a user.
# It should remove any at/cron/print jobs etc. owned by
# the user to be removed (passed as the first argument).
#
#USERDEL_CMD /usr/sbin/userdel_local
#
# Enable setting of the umask group bits to be the same as owner bits
# (examples: 022 -> 002, 077 -> 007) for non-root users, if the uid is
# the same as gid, and username is the same as the primary group name.
#
# This also enables userdel(8) to remove user groups if no members exist.
#
USERGROUPS_ENAB yes
#
# If set to a non-zero number, the shadow utilities will make sure that
# groups never have more than this number of users on one line.
# This permits to support split groups (groups split into multiple lines,
# with the same group ID, to avoid limitation of the line length in the
# group file).
#
# 0 is the default value and disables this feature.
#
#MAX_MEMBERS_PER_GROUP 0
#
# If useradd(8) should create home directories for users by default (non
# system users only).
# This option is overridden with the -M or -m flags on the useradd(8)
# command-line.
#
#CREATE_HOME yes
#
# Force use shadow, even if shadow passwd & shadow group files are
# missing.
#
#FORCE_SHADOW yes
#
# Allow newuidmap and newgidmap when running under an alternative
# primary group.
#
#GRANT_AUX_GROUP_SUBIDS yes
#
# Prevents an empty password field to be interpreted as "no authentication
# required".
# Set to "yes" to prevent for all accounts
# Set to "superuser" to prevent for UID 0 / root (default)
# Set to "no" to not prevent for any account (dangerous, historical default)
PREVENT_NO_AUTH superuser
#
# Select the HMAC cryptography algorithm.
# Used in pam_timestamp module to calculate the keyed-hash message
# authentication code.
#
# Note: It is recommended to check hmac(3) to see the possible algorithms
# that are available in your system.
#
#HMAC_CRYPTO_ALGO SHA512