名称

       chpasswd - 批量更新密码

大纲

       chpasswd [options]

描述

       The chpasswd command reads a list of user name and password pairs from standard input and uses this
       information to update a group of existing users. Each line is of the format:

       user_name:password

       By default the passwords must be supplied in clear-text, and are encrypted by chpasswd. Also the password
       age will be updated, if present.

       By default, passwords are encrypted by PAM, but (even if not recommended) you can select a different
       encryption method with the -e, -m, or -c options.

       Except when PAM is used to encrypt the passwords, chpasswd first updates all the passwords in memory, and
       then commits all the changes to disk if no errors occurred for any user.

       When PAM is used to encrypt the passwords (and update the passwords in the system database) then if a
       password cannot be updated chpasswd continues updating the passwords of the next users, and will return
       an error code on exit.

       此命令一般用于需要一次创建很多用户的大型系统。

选项

       The options which apply to the chpasswd command are:

       -c, --crypt-method METHOD
           使用指定的方法加密密码。

           The available methods are DES, MD5, SHA256, SHA512, YESCRYPT and NONE if your libc supports these
           methods.

           默认，使用 PAM 来加密密码。

       -e, --encrypted
           提供的密码是已经加密了的

       -h, --help
           显示帮助信息并退出。

       -m, --md5
           如果提供的密码没有加密，则使用 MD5 加密而不是 DES。

       -R, --root CHROOT_DIR
           Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR
           directory. Only absolute paths are supported.

       -P, --prefix PREFIX_DIR
           Apply changes to configuration files under the root filesystem found under the directory PREFIX_DIR.
           This option does not chroot and is intended for preparing a cross-compilation target. Some
           limitations: NIS and LDAP users/groups are not verified. PAM authentication is using the host files.
           No SELINUX support.

       -s, --sha-rounds ROUNDS
           使用指定次数的轮转来加密密码。

           You can only use this option with crypt method: SHA256 SHA512 YESCRYPT

           By default, the number of rounds for SHA256 or SHA512 is defined by the SHA_CRYPT_MIN_ROUNDS and
           SHA_CRYPT_MAX_ROUNDS variables in /etc/login.defs.

           A minimal value of 1000 and a maximal value of 999,999,999 will be enforced for SHA256 and SHA512.
           The default number of rounds is 5000.

           By default, the number of rounds for YESCRYPT is defined by the YESCRYPT_COST_FACTOR in
           /etc/login.defs.

           A minimal value of 1 and a maximal value of 11 will be enforced for YESCRYPT. The default number of
           rounds is 5.

CAVEATS

       记住要设置权限或者掩码来阻止其它用户对未加密文件的读取。

配置文件

       The following configuration variables in /etc/login.defs change the behavior of this tool:

文件

       /etc/passwd
           用户账户信息。

       /etc/shadow
           安全用户账户信息。

       /etc/login.defs
           Shadow 密码套件配置。

       /etc/pam.d/chpasswd
           PAM configuration for chpasswd.

参见

       passwd(1), newusers(8), login.defs(5), useradd(8).

shadow-utils 4.17.4                                2025-05-07                                        CHPASSWD(8)