Edit File: login.defs
# # /etc/login.defs - Configuration control definitions for the login package. # # Three items must be defined: MAIL_DIR, ENV_SUPATH, and ENV_PATH. # If unspecified, some arbitrary (and possibly incorrect) value will # be assumed. All other items are optional - if not specified then # the described action or option will be inhibited. # # Comment lines (lines beginning with "#") and blank lines are ignored. # # Modified for Linux. --marekm # REQUIRED for useradd/userdel/usermod # Directory where mailboxes reside, _or_ name of file, relative to the # home directory. If you _do_ define MAIL_DIR and MAIL_FILE, # MAIL_DIR takes precedence. # # Essentially: # - MAIL_DIR defines the location of users mail spool files # (for mbox use) by appending the username to MAIL_DIR as defined # below. # - MAIL_FILE defines the location of the users mail spool files as the # fully-qualified filename obtained by prepending the user home # directory before $MAIL_FILE # # NOTE: This is no more used for setting up users MAIL environment variable # which is, starting from shadow 4.0.12-1 in Debian, entirely the # job of the pam_mail PAM modules # See default PAM configuration files provided for # login, su, etc. # # This is a temporary situation: setting these variables will soon # move to /etc/default/useradd and the variables will then be # no more supported MAIL_DIR /var/mail #MAIL_FILE .mail # # Enable logging and display of /var/log/faillog login failure info. # This option conflicts with the pam_tally PAM module. # FAILLOG_ENAB yes # # Enable display of unknown usernames when login failures are recorded. # # WARNING: Unknown usernames may become world readable. # See #290803 and #298773 for details about how this could become a security # concern LOG_UNKFAIL_ENAB no # # Enable logging of successful logins # LOG_OK_LOGINS no # # Enable "syslog" logging of su activity - in addition to sulog file logging. # SYSLOG_SG_ENAB does the same for newgrp and sg. # SYSLOG_SU_ENAB yes SYSLOG_SG_ENAB yes # # If defined, all su activity is logged to this file. # #SULOG_FILE /var/log/sulog # # If defined, file which maps tty line to TERM environment parameter. # Each line of the file is in a format something like "vt100 tty01". # #TTYTYPE_FILE /etc/ttytype # # If defined, login failures will be logged here in a utmp format # last, when invoked as lastb, will read /var/log/btmp, so... # FTMP_FILE /var/log/btmp # # If defined, the command name to display when running "su -". For # example, if this is defined as "su" then a "ps" will display the # command is "-su". If not defined, then "ps" would display the # name of the shell actually being run, e.g. something like "-sh". # SU_NAME su # # 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 # # *REQUIRED* The default PATH settings, for superuser and normal users. # # (they are minimal, add the rest in the shell startup files) ENV_SUPATH PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin ENV_PATH PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games # # 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" program which is "setgid" to a special group # which owns the terminals, define TTYGROUP to the group number and # TTYPERM to 0620. Otherwise leave TTYGROUP commented out and assign # TTYPERM to either 622 or 600. # # In Debian /usr/bin/bsd-write or similar programs are setgid tty # However, the default and recommended value for TTYPERM is still 0600 # to not allow anyone to write to anyone else console or terminal # Users can still allow other people to write them by issuing # the "mesg y" command. TTYGROUP tty TTYPERM 0600 # # Login configuration initializations: # # ERASECHAR Terminal ERASE character ('\010' = backspace). # KILLCHAR Terminal KILL character ('\025' = CTRL/U). # UMASK Default "umask" value. # # The ERASECHAR and KILLCHAR are used only on System V machines. # # UMASK is the default umask value for pam_umask and is used by # useradd and newusers to set the mode of the new home directories. # 022 is the "historical" value in Debian for UMASK # 027, or even 077, could be considered better for privacy # There is no One True Answer here : each sysadmin must make up his/her # mind. # # If USERGROUPS_ENAB is set to "yes", that will modify this UMASK default value # for private user groups, i. e. the uid is the same as gid, and username is # the same as the primary group name: for these, the user permissions will be # used as group permissions, e. g. 022 will become 002. # # Prefix these values with "0" to get octal, "0x" to get hexadecimal. # ERASECHAR 0177 KILLCHAR 025 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 0750 # # 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_WARN_AGE Number of days warning given before a password expires. # PASS_MAX_DAYS 99999 PASS_MIN_DAYS 0 PASS_WARN_AGE 7 # # Min/max values for automatic uid selection in useradd # UID_MIN 1000 UID_MAX 60000 # System accounts #SYS_UID_MIN 100 #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 # GID_MIN 1000 GID_MAX 60000 # System accounts #SYS_GID_MIN 100 #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 retries if password is bad. This will most likely be # overriden by PAM, since the default pam_unix module has it's own built # in of 3 retries. However, this is a safe fallback in case you are using # an authentication module that does not enforce PAM_MAXTRIES. # LOGIN_RETRIES 5 # # Max time in seconds for login # LOGIN_TIMEOUT 60 # # Which fields may be changed by regular users using chfn - 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 # # Should login be allowed if we can't cd to the home directory? # Default is no. # DEFAULT_HOME yes # # 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. # # If set to yes, userdel will remove the user's group if it contains no # more members, and useradd will create by default a group with the name # of the user. # USERGROUPS_ENAB yes # # Instead of the real user shell, the program specified by this parameter # will be launched, although its visible name (argv[0]) will be the shell's. # The program may do whatever it wants (logging, additional authentification, # banner, ...) before running the actual shell. # # FAKE_SHELL /bin/fakeshell # # If defined, either full pathname of a file containing device names or # a ":" delimited list of device names. Root logins will be allowed only # upon these devices. # # This variable is used by login and su. # #CONSOLE /etc/consoles #CONSOLE console:tty01:tty02:tty03:tty04 # # List of groups to add to the user's supplementary group set # when logging in on 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 on the console. # How to do it is left as an exercise for the reader... # # This variable is used by login and su. # #CONSOLE_GROUPS floppy:audio:cdrom # # 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". # # This variable is deprecated. You should use ENCRYPT_METHOD. # #MD5_CRYPT_ENAB no # # 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: It is recommended to use a value consistent with # the PAM modules configuration. # ENCRYPT_METHOD SHA512 # # 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 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 # # 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 # # Allow newuidmap and newgidmap when running under an alternative # primary group. # #GRANT_AUX_GROUP_SUBIDS yes # # 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 ################# OBSOLETED BY PAM ############## # # # These options are now handled by PAM. Please # # edit the appropriate file in /etc/pam.d/ to # # enable the equivelants of them. # ############### #MOTD_FILE #DIALUPS_CHECK_ENAB #LASTLOG_ENAB #MAIL_CHECK_ENAB #OBSCURE_CHECKS_ENAB #PORTTIME_CHECKS_ENAB #SU_WHEEL_ONLY #CRACKLIB_DICTPATH #PASS_CHANGE_TRIES #PASS_ALWAYS_WARN #ENVIRON_FILE #NOLOGINS_FILE #ISSUE_FILE #PASS_MIN_LEN #PASS_MAX_LEN #ULIMIT #ENV_HZ #CHFN_AUTH #CHSH_AUTH #FAIL_DELAY ################# OBSOLETED ####################### # # # These options are no more handled by shadow. # # # # Shadow utilities will display a warning if they # # still appear. # # # ################################################### # CLOSE_SESSIONS # LOGIN_STRING # NO_PASSWORD_CONSOLE # QMAIL_DIR