'\" t
.\"     Title: login.defs
.\"    Author: Julianne Frances Haugh
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 2020-02-07
.\"    Manual: 文件格式和转化
.\"    Source: shadow-utils 4.8.1
.\"  Language: Chinese Simplified
.\"
.TH "LOGIN\&.DEFS" "5" "2020-02-07" "shadow\-utils 4\&.8\&.1" "文件格式和转化"
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.SH "名称"
login.defs \- 影子密码套件配置
.SH "描述"
.PP
The
/etc/login\&.defs
file defines the site\-specific configuration for the shadow password suite\&. This file is required\&. Absence of this file will not prevent system operation, but will probably result in undesirable operation\&.
.PP
This file is a readable text file, each line of the file describing one configuration parameter\&. The lines consist of a configuration name and value, separated by whitespace\&. Blank lines and comment lines are ignored\&. Comments are introduced with a "#" pound sign and the pound sign must be the first non\-white character of the line\&.
.PP
Parameter values may be of four types: strings, booleans, numbers, and long numbers\&. A string is comprised of any printable characters\&. A boolean should be either the value
\fIyes\fR
or
\fIno\fR\&. An undefined boolean parameter or one with a value other than these will be given a
\fIno\fR
value\&. Numbers (both regular and long) may be either decimal values, octal values (precede the value with
\fI0\fR) or hexadecimal values (precede the value with
\fI0x\fR)\&. The maximum value of the regular and long numeric parameters is machine\-dependent\&.
.PP
提供如下配置项：
.PP
\fBCHFN_RESTRICT\fR (string)
.RS 4
This parameter specifies which values in the
\fIgecos\fR
field of the
/etc/passwd
file may be changed by regular users using the
\fBchfn\fR
program\&. It can be any combination of letters
\fIf\fR,
\fIr\fR,
\fIw\fR,
\fIh\fR, for Full name, Room number, Work phone, and Home phone, respectively\&. For backward compatibility,
\fIyes\fR
is equivalent to
\fIrwh\fR
and
\fIno\fR
is equivalent to
\fIfrwh\fR\&. If not specified, only the superuser can make any changes\&. The most restrictive setting is better achieved by not installing
\fBchfn\fR
SUID\&.
.RE
.PP
\fBCONSOLE_GROUPS\fR (string)
.RS 4
List of groups to add to the user\*(Aqs supplementary groups 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\&.
.RE
.PP
\fBCREATE_HOME\fR (boolean)
.RS 4
指示是否应该为新用户默认创建主目录。
.sp
此设置并不应用到系统用户，并且可以使用命令行覆盖。
.RE
.PP
\fBDEFAULT_HOME\fR (boolean)
.RS 4
如果不能 cd 到主目录时，说明是否允许登录。默认是否。
.sp
If set to
\fIyes\fR, the user will login in the root (/) directory if it is not possible to cd to her home directory\&.
.RE
.PP
\fBENCRYPT_METHOD\fR (string)
.RS 4
这定义了系统加密密码的默认算法(如果没有在命令行上指定算法)。
.sp
It can take one of these values:
\fIDES\fR
(default),
\fIMD5\fR, \fISHA256\fR, \fISHA512\fR\&.
.sp
Note: this parameter overrides the
\fBMD5_CRYPT_ENAB\fR
variable\&.
.sp
注意：这只影响组密码的产生。用户密码的产生是由 PAM 和 PAM 配置负责的。建议设置此变量和 PAM 配置一致。
.RE
.PP
\fBENV_HZ\fR (string)
.RS 4
If set, it will be used to define the HZ environment variable when a user login\&. The value must be preceded by
\fIHZ=\fR\&. A common value on Linux is
\fIHZ=100\fR\&.
.sp
The
\fBHZ\fR
environment variable is only set when the user (the superuser) logs in with
\fBsulogin\fR\&.
.RE
.PP
\fBENV_PATH\fR (string)
.RS 4
If set, it will be used to define the PATH environment variable when a regular user login\&. The value is a colon separated list of paths (for example
\fI/bin:/usr/bin\fR) and can be preceded by
\fIPATH=\fR\&. The default value is
\fIPATH=/bin:/usr/bin\fR\&.
.RE
.PP
\fBENV_SUPATH\fR (string)
.RS 4
If set, it will be used to define the PATH environment variable when the superuser login\&. The value is a colon separated list of paths (for example
\fI/sbin:/bin:/usr/sbin:/usr/bin\fR) and can be preceded by
\fIPATH=\fR\&. The default value is
\fIPATH=/sbin:/bin:/usr/sbin:/usr/bin\fR\&.
.RE
.PP
\fBERASECHAR\fR (number)
.RS 4
Terminal ERASE character (\fI010\fR
= backspace,
\fI0177\fR
= DEL)\&.
.sp
此值可以使用前缀\(lq0\(rq表示八进制，\(lq0x\(rq表示十六进制。
.RE
.PP
\fBFAIL_DELAY\fR (number)
.RS 4
登录失败后，等待多少秒才再允许登录。
.RE
.PP
\fBFAKE_SHELL\fR (string)
.RS 4
If set,
\fBlogin\fR
will execute this shell instead of the users\*(Aq shell specified in
/etc/passwd\&.
.RE
.PP
\fBGID_MAX\fR (number), \fBGID_MIN\fR (number)
.RS 4
Range of group IDs used for the creation of regular groups by
\fBuseradd\fR,
\fBgroupadd\fR, or
\fBnewusers\fR\&.
.sp
The default value for
\fBGID_MIN\fR
(resp\&.
\fBGID_MAX\fR) is 1000 (resp\&. 60000)\&.
.RE
.PP
\fBHOME_MODE\fR (number)
.RS 4
The mode for new home directories\&. If not specified, the
\fBUMASK\fR
is used to create the mode\&.
.sp
\fBuseradd\fR
and
\fBnewusers\fR
use this to set the mode of the home directory they create\&.
.RE
.PP
\fBHUSHLOGIN_FILE\fR (string)
.RS 4
If defined, this file can inhibit all the usual chatter during the login sequence\&. If a full pathname is specified, then hushed mode will be enabled if the user\*(Aqs 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\*(Aqs home directory\&.
.RE
.PP
\fBKILLCHAR\fR (number)
.RS 4
Terminal KILL character (\fI025\fR
= CTRL/U)\&.
.sp
此值可以使用前缀\(lq0\(rq表示八进制，\(lq0x\(rq表示十六进制。
.RE
.PP
\fBLASTLOG_UID_MAX\fR (number)
.RS 4
Highest user ID number for which the lastlog entries should be updated\&. As higher user IDs are usually tracked by remote user identity and authentication services there is no need to create a huge sparse lastlog file for them\&.
.sp
No
\fBLASTLOG_UID_MAX\fR
option present in the configuration means that there is no user ID limit for writing lastlog entries\&.
.RE
.PP
\fBLOG_OK_LOGINS\fR (boolean)
.RS 4
允许记录成功登录。
.RE
.PP
\fBLOG_UNKFAIL_ENAB\fR (boolean)
.RS 4
在记录到登录失败时，允许记录未知用户名。
.sp
注意：如果用户不小心将密码输入到了登录名中，记录未知用户名可能是一个安全隐患。
.RE
.PP
\fBLOGIN_RETRIES\fR (number)
.RS 4
密码错误时，重试的最大次数。
.sp
This will most likely be overridden by PAM, since the default pam_unix module has its 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\&.
.RE
.PP
\fBLOGIN_TIMEOUT\fR (number)
.RS 4
最大登录时间(以秒为单位)。
.RE
.PP
\fBMAIL_DIR\fR (string)
.RS 4
邮箱目录。修改或删除用户账户时需要处理邮箱，如果没有指定，将使用编译时指定的默认值。
.RE
.PP
\fBMAIL_FILE\fR (string)
.RS 4
定义用户邮箱文件的位置(相对于主目录)。
.RE
.PP
The
\fBMAIL_DIR\fR
and
\fBMAIL_FILE\fR
variables are used by
\fBuseradd\fR,
\fBusermod\fR, and
\fBuserdel\fR
to create, move, or delete the user\*(Aqs mail spool\&.
.PP
\fBMAX_MEMBERS_PER_GROUP\fR (number)
.RS 4
Maximum members per group entry\&. When the maximum is reached, a new group entry (line) is started in
/etc/group
(with the same name, same password, and same GID)\&.
.sp
默认值是 0，意味着组中的成员数没有限制。
.sp
此功能(分割组)允许限制组文件中的行长度。这对于确保 NIS 组的行比长于 1024 字符。
.sp
如果要强制这个限制，可以使用 25。
.sp
注意：分割组可能不受所有工具的支持(甚至在 Shadow 工具集中)。您不应该使用这个变量，除非真的需要。
.RE
.PP
\fBMD5_CRYPT_ENAB\fR (boolean)
.RS 4
Indicate if passwords must be encrypted using the MD5\-based algorithm\&. If set to
\fIyes\fR, 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
\fIno\fR
if you need to copy encrypted passwords to other systems which don\*(Aqt understand the new algorithm\&. Default is
\fIno\fR\&.
.sp
This variable is superseded by the
\fBENCRYPT_METHOD\fR
variable or by any command line option used to configure the encryption algorithm\&.
.sp
This variable is deprecated\&. You should use
\fBENCRYPT_METHOD\fR\&.
.sp
注意：这只影响组密码的产生。用户密码的产生是由 PAM 和 PAM 配置负责的。建议设置此变量和 PAM 配置一致。
.RE
.PP
\fBPASS_MAX_DAYS\fR (number)
.RS 4
一个密码可以使用的最大天数。如果密码比这旧，将会强迫更改密码。如果不指定，就假定为 \-1，这会禁用这个限制。
.RE
.PP
\fBPASS_MIN_DAYS\fR (number)
.RS 4
两次更改密码时间的最小间隔。将会拒绝任何早于此的更改密码的尝试。如果不指定，假定为 \-1，将会禁用这个限制。
.RE
.PP
\fBPASS_WARN_AGE\fR (number)
.RS 4
密码过期之前给出警告的天数。0 表示只有只在过期的当天警告，负值表示不警告。如果没有指定，不会给警告。
.RE
.PP
\fBPASS_MAX_DAYS\fR,
\fBPASS_MIN_DAYS\fR
and
\fBPASS_WARN_AGE\fR
are only used at the time of account creation\&. Any changes to these settings won\*(Aqt affect existing accounts\&.
.PP
\fBSHA_CRYPT_MIN_ROUNDS\fR (number), \fBSHA_CRYPT_MAX_ROUNDS\fR (number)
.RS 4
When
\fBENCRYPT_METHOD\fR
is set to
\fISHA256\fR
or
\fISHA512\fR, this defines the number of SHA rounds used by the encryption algorithm by default (when the number of rounds is not specified on the command line)\&.
.sp
使用很多轮转，会让暴力破解更加困难。但是需要注意，认证用户时也会需要更多的 CPU 资源。
.sp
如果没有指定，libc 会选择默认的轮转数(5000)。
.sp
值必须在 1000 \- 999,999,999 之间。
.sp
If only one of the
\fBSHA_CRYPT_MIN_ROUNDS\fR
or
\fBSHA_CRYPT_MAX_ROUNDS\fR
values is set, then this value will be used\&.
.sp
If
\fBSHA_CRYPT_MIN_ROUNDS\fR
>
\fBSHA_CRYPT_MAX_ROUNDS\fR, the highest value will be used\&.
.sp
注意：这只影响组密码的产生。用户密码的产生是由 PAM 和 PAM 配置负责的。建议设置此变量和 PAM 配置一致。
.RE
.PP
\fBSULOG_FILE\fR (string)
.RS 4
如果定义了，所有的 su 活动都会记录到此文件。
.RE
.PP
\fBSU_NAME\fR (string)
.RS 4
如果定义了，就是运行\(lqsu \-\(rq时显示的命令名称。例如，如果定义为\(lqsu\(rq，那么\(lqps\(rq会显示此命令为\(lq\-su\(rq。如果没有定义，\(lqps\(rq将会显示实际执行的 shell，例如类似于\(lq\-sh\(rq。
.RE
.PP
\fBSUB_GID_MIN\fR (number), \fBSUB_GID_MAX\fR (number), \fBSUB_GID_COUNT\fR (number)
.RS 4
If
/etc/subuid
exists, the commands
\fBuseradd\fR
and
\fBnewusers\fR
(unless the user already have subordinate group IDs) allocate
\fBSUB_GID_COUNT\fR
unused group IDs from the range
\fBSUB_GID_MIN\fR
to
\fBSUB_GID_MAX\fR
for each new user\&.
.sp
The default values for
\fBSUB_GID_MIN\fR,
\fBSUB_GID_MAX\fR,
\fBSUB_GID_COUNT\fR
are respectively 100000, 600100000 and 65536\&.
.RE
.PP
\fBSUB_UID_MIN\fR (number), \fBSUB_UID_MAX\fR (number), \fBSUB_UID_COUNT\fR (number)
.RS 4
If
/etc/subuid
exists, the commands
\fBuseradd\fR
and
\fBnewusers\fR
(unless the user already have subordinate user IDs) allocate
\fBSUB_UID_COUNT\fR
unused user IDs from the range
\fBSUB_UID_MIN\fR
to
\fBSUB_UID_MAX\fR
for each new user\&.
.sp
The default values for
\fBSUB_UID_MIN\fR,
\fBSUB_UID_MAX\fR,
\fBSUB_UID_COUNT\fR
are respectively 100000, 600100000 and 65536\&.
.RE
.PP
\fBSYS_GID_MAX\fR (number), \fBSYS_GID_MIN\fR (number)
.RS 4
Range of group IDs used for the creation of system groups by
\fBuseradd\fR,
\fBgroupadd\fR, or
\fBnewusers\fR\&.
.sp
The default value for
\fBSYS_GID_MIN\fR
(resp\&.
\fBSYS_GID_MAX\fR) is 101 (resp\&.
\fBGID_MIN\fR\-1)\&.
.RE
.PP
\fBSYS_UID_MAX\fR (number), \fBSYS_UID_MIN\fR (number)
.RS 4
Range of user IDs used for the creation of system users by
\fBuseradd\fR
or
\fBnewusers\fR\&.
.sp
The default value for
\fBSYS_UID_MIN\fR
(resp\&.
\fBSYS_UID_MAX\fR) is 101 (resp\&.
\fBUID_MIN\fR\-1)\&.
.RE
.PP
\fBSYSLOG_SG_ENAB\fR (boolean)
.RS 4
Enable "syslog" logging of
\fBsg\fR
activity\&.
.RE
.PP
\fBSYSLOG_SU_ENAB\fR (boolean)
.RS 4
Enable "syslog" logging of
\fBsu\fR
activity \- in addition to sulog file logging\&.
.RE
.PP
\fBTTYGROUP\fR (string), \fBTTYPERM\fR (string)
.RS 4
The terminal permissions: the login tty will be owned by the
\fBTTYGROUP\fR
group, and the permissions will be set to
\fBTTYPERM\fR\&.
.sp
By default, the ownership of the terminal is set to the user\*(Aqs primary group and the permissions are set to
\fI0600\fR\&.
.sp
\fBTTYGROUP\fR
can be either the name of a group or a numeric group identifier\&.
.sp
If you have a
\fBwrite\fR
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\&.
.RE
.PP
\fBTTYTYPE_FILE\fR (string)
.RS 4
If defined, file which maps tty line to TERM environment parameter\&. Each line of the file is in a format something like "vt100 tty01"\&.
.RE
.PP
\fBUID_MAX\fR (number), \fBUID_MIN\fR (number)
.RS 4
Range of user IDs used for the creation of regular users by
\fBuseradd\fR
or
\fBnewusers\fR\&.
.sp
The default value for
\fBUID_MIN\fR
(resp\&.
\fBUID_MAX\fR) is 1000 (resp\&. 60000)\&.
.RE
.PP
\fBUMASK\fR (number)
.RS 4
文件模式创建掩码初始化为此值。如果没有指定，掩码初始化为 022。
.sp
\fBuseradd\fR
and
\fBnewusers\fR
use this mask to set the mode of the home directory they create if
\fBHOME_MODE\fR
is not set\&.
.sp
It is also used by
\fBpam_umask\fR
as the default umask value\&.
.RE
.PP
\fBUSERDEL_CMD\fR (string)
.RS 4
如果定义了，这是删除账户时执行的命令。它应该移除所有属于此用户的的 at/cron/print 等作业(作为第一个参数传递)。
.sp
这个脚本的返回值并不被带到账户中去。
.sp
Here is an example script, which removes the user\*(Aqs cron, at and print jobs:
.sp
.if n \{\
.RS 4
.\}
.nf
#! /bin/sh

# Check for the required argument\&.
if [ $# != 1 ]; then
	echo "Usage: $0 username"
	exit 1
fi

# Remove cron jobs\&.
crontab \-r \-u $1

# Remove at jobs\&.
# Note that it will remove any jobs owned by the same UID,
# even if it was shared by a different username\&.
AT_SPOOL_DIR=/var/spool/cron/atjobs
find $AT_SPOOL_DIR \-name "[^\&.]*" \-type f \-user $1 \-delete \e;

# Remove print jobs\&.
lprm $1

# All done\&.
exit 0
      
.fi
.if n \{\
.RE
.\}
.sp
.RE
.PP
\fBUSERGROUPS_ENAB\fR (boolean)
.RS 4
If set to
\fIyes\fR,
\fBuserdel\fR
will remove the user\*(Aqs group if it contains no more members, and
\fBuseradd\fR
will create by default a group with the name of the user\&.
.RE
.SH "交叉引用"
.PP
如下交叉引用显示影子密码套件哪个程序使用哪个参数。
.PP
chfn
.RS 4
CHFN_RESTRICT
.RE
.PP
chgpasswd
.RS 4
ENCRYPT_METHOD MAX_MEMBERS_PER_GROUP MD5_CRYPT_ENAB
SHA_CRYPT_MAX_ROUNDS SHA_CRYPT_MIN_ROUNDS
.RE
.PP
chpasswd
.RS 4
SHA_CRYPT_MAX_ROUNDS SHA_CRYPT_MIN_ROUNDS
.RE
.PP
gpasswd
.RS 4
ENCRYPT_METHOD MAX_MEMBERS_PER_GROUP MD5_CRYPT_ENAB
SHA_CRYPT_MAX_ROUNDS SHA_CRYPT_MIN_ROUNDS
.RE
.PP
groupadd
.RS 4
GID_MAX GID_MIN MAX_MEMBERS_PER_GROUP SYS_GID_MAX SYS_GID_MIN
.RE
.PP
groupdel
.RS 4
MAX_MEMBERS_PER_GROUP
.RE
.PP
groupmems
.RS 4
MAX_MEMBERS_PER_GROUP
.RE
.PP
groupmod
.RS 4
MAX_MEMBERS_PER_GROUP
.RE
.PP
grpck
.RS 4
MAX_MEMBERS_PER_GROUP
.RE
.PP
grpconv
.RS 4
MAX_MEMBERS_PER_GROUP
.RE
.PP
grpunconv
.RS 4
MAX_MEMBERS_PER_GROUP
.RE
.PP
lastlog
.RS 4
LASTLOG_UID_MAX
.RE
.PP
login
.RS 4
CONSOLE_GROUPS DEFAULT_HOME ERASECHAR FAIL_DELAY FAKE_SHELL HUSHLOGIN_FILE KILLCHAR LOGIN_RETRIES LOGIN_TIMEOUT LOG_OK_LOGINS LOG_UNKFAIL_ENAB TTYGROUP TTYPERM TTYTYPE_FILE USERGROUPS_ENAB
.RE
.PP
newgrp / sg
.RS 4
SYSLOG_SG_ENAB
.RE
.PP
newusers
.RS 4
ENCRYPT_METHOD GID_MAX GID_MIN MAX_MEMBERS_PER_GROUP MD5_CRYPT_ENAB HOME_MODE PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE
SHA_CRYPT_MAX_ROUNDS SHA_CRYPT_MIN_ROUNDS
SUB_GID_COUNT SUB_GID_MAX SUB_GID_MIN SUB_UID_COUNT SUB_UID_MAX SUB_UID_MIN SYS_GID_MAX SYS_GID_MIN SYS_UID_MAX SYS_UID_MIN UID_MAX UID_MIN UMASK
.RE
.PP
pwck
.RS 4
PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE
.RE
.PP
pwconv
.RS 4
PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE
.RE
.PP
su
.RS 4
CONSOLE_GROUPS DEFAULT_HOME ENV_PATH ENV_SUPATH SULOG_FILE SU_NAME SYSLOG_SU_ENAB
.RE
.PP
sulogin
.RS 4
ENV_HZ
.RE
.PP
useradd
.RS 4
CREATE_HOME GID_MAX GID_MIN HOME_MODE LASTLOG_UID_MAX MAIL_DIR MAX_MEMBERS_PER_GROUP PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE SUB_GID_COUNT SUB_GID_MAX SUB_GID_MIN SUB_UID_COUNT SUB_UID_MAX SUB_UID_MIN SYS_GID_MAX SYS_GID_MIN SYS_UID_MAX SYS_UID_MIN UID_MAX UID_MIN UMASK
.RE
.PP
userdel
.RS 4
MAIL_DIR MAIL_FILE MAX_MEMBERS_PER_GROUP USERDEL_CMD USERGROUPS_ENAB
.RE
.PP
usermod
.RS 4
LASTLOG_UID_MAX MAIL_DIR MAIL_FILE MAX_MEMBERS_PER_GROUP
.RE
.SH "缺陷"
.PP
Much of the functionality that used to be provided by the shadow password suite is now handled by PAM\&. Thus,
/etc/login\&.defs
is no longer used by
\fBpasswd\fR(1), or less used by
\fBlogin\fR(1), and
\fBsu\fR(1)\&. Please refer to the corresponding PAM configuration files instead\&.
.SH "参见"
.PP
\fBlogin\fR(1),
\fBpasswd\fR(1),
\fBsu\fR(1),
\fBpasswd\fR(5),
\fBshadow\fR(5),
\fBpam\fR(8)\&.