newusers(8)

НАЗВАНИЕ
newusers - обновляет и создаёт новые учётные записи пользователей в пакетном режиме

СИНТАКСИС

newusers [options] [file]

ОПИСАНИЕ

The newusers command reads a file (or the standard input by default) and uses this information to update a set of existing users or to create new users. Each line is in the same format as the standard password file (see passwd(5)) with the exceptions explained below:

pw_name:pw_passwd:pw_uid:pw_gid:pw_gecos:pw_dir:pw_shell

pw_name
    Имя пользователя.

    It can be the name of a new user or the name of an existing user (or a user created before by newusers). In case of an existing user, the user's information will be changed, otherwise a new user will be created.

pw_passwd
    If this field is not empty, it will be encrypted and used as the new value of the encrypted password.

pw_uid
    Это поле используется для определения UID пользователя.

    If the field is empty, a new (unused) UID will be defined automatically by newusers.

    Если в этом поле указано число, то оно будет использовано в качестве UID.

    If this field contains the name of an existing user (or the name of a user created before by newusers), the UID of the specified user will be used.

    Если изменяется UID существующего пользователя, то у файлов, которыми владел этот пользователь, нужно вручную переопределить владельца.

pw_gid
    Это поле используется для определения ID первичной группы пользователя.

    If this field contains the name of an existing group (or a group created before by newusers), the GID of this group will be used as the primary group ID for the user.

    Если в этом поле содержится число, то это число будет использовано как ID первичной группы пользователя. Если с таким GID не существует, то будет создана новая группа с этим GID и именем пользователя.

    If this field is empty, a new group will be created with the name of the user and a GID will be automatically defined by newusers to be used as the primary group ID for the user and as the GID for the new group.

    If this field contains the name of a group which does not exist (and was not created before by newusers), a new group will be created with the specified name and a GID will be automatically defined by newusers to be used as the primary group ID for the user and GID for the new group.

pw_gecos
    Это поле копируется в поле GECOS записи пользователя.

pw_dir
    Это поле используется для определения домашнего каталога пользователя.

    If this field does not specify an existing directory, the specified directory is created, with ownership set to the user being created or updated and its primary group. Note that newusers does not create parent directories of the new user's home directory. The newusers command will fail to create the home directory if the parent directories do not exist, and will send a message to stderr informing the user of the failure. The newusers command will not halt or return a failure to the calling shell if it fails to create the home directory, it will continue to process the batch of new users specified.

    If the home directory of an existing user is changed, newusers does not move or copy the content of the old directory to the new location. This should be done manually.

pw_shell
    В этом поле задаётся пользовательская оболочка. Никаких проверок поля не делается.

newusers first tries to create or change all the specified users, and then write these changes to the user or group databases. If an error occurs (except in the final writes to the databases), no changes are committed to the databases.

Данная команда предназначена для работы в крупных системных средах, где за один раз обновляется несколько учётных записей.

ПАРАМЕТРЫ

The options which apply to the newusers command are:

--badname
    Allow names that do not conform to standards.

-c, --crypt-method
    Использовать указанный метод для шифрования паролей.

    The available methods are NONE, and SHA256 or SHA512 if your libc support these methods.

-h, --help
    Показать краткую справку и закончить работу.

-r, --system
    Создать системную учётную запись.

    System users will be created with no aging information in /etc/shadow, and their numeric identifiers are chosen in the SYS_UID_MIN-SYS_UID_MAX range, defined in login.defs, instead of UID_MIN-UID_MAX (and their GID counterparts for the creation of groups).

-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. No SELINUX support.

-s, --sha-rounds
    Использовать указанное количество раундов шифрования паролей.

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

    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 is 5000.

ПРЕДОСТЕРЕЖЕНИЯ

Файл с входными данными должен быть защищён, так как в нём содержатся не шифрованные пароли.

Вы должны проверить, что пароль и метод шифрования соответствует политике системных паролей.

НАСТРОЙКА

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

ENCRYPT_METHOD (string)
    This defines the system default encryption algorithm for encrypting passwords (if no algorithm is specified on the command line).

    It can take one of these values: SHA256, SHA512 (default), . See crypt(5) for recommendations.

    History: This variable is used by other programs, which may still default to unsafe algorithms such as DES. To avoid using unsafe algorithms, the variable should always be specified.

GID_MAX (number), GID_MIN (number)
    Range of group IDs used for the creation of regular groups by useradd, groupadd, or newusers.

    The default value for GID_MIN (resp. GID_MAX) is 1000 (resp. 60000).

HOME_MODE (number)
    The mode for new home directories. If not specified, the UMASK is used to create the mode.

    useradd and newusers use this to set the mode of the home directory they create.

MAX_MEMBERS_PER_GROUP (number)
    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).

    Значение по умолчанию равно 0, означающее, что ограничения на количество членов в группе нет.

    Данная возможность (разделение группы) позволяет ограничить длину строк в файле групп. Это полезно для ограничения длины строк групп NIS в 1024 символа.

    Если вам нужно такое ограничение, укажите значение 25.

    Замечание: разделение групп поддерживается не всеми инструментами (даже в наборе инструментов Shadow). Вы не должны использовать эту переменную, если вам действительно это ненужно.

PASS_MAX_DAYS (number)
    Максимальное число дней использования пароля. Если пароль старее этого числа, то будет запущена процедура смены пароля. Если значение не задано, то предполагается значение -1 (то есть возможность ограничения не используется).

PASS_WARN_AGE (number)
    The number of days warning given before a password expires. A zero means warning is given only upon the day of expiration, a value of -1 means no warning is given. If not specified, no warning will be provided.

SHA_CRYPT_MIN_ROUNDS (number), SHA_CRYPT_MAX_ROUNDS (number)
    When ENCRYPT_METHOD is set to SHA256 or SHA512, 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).

    With a lot of rounds, it is more difficult to brute force the password. But note also that more CPU resources will be needed to authenticate users.

    If not specified, the libc will choose the default number of rounds (5000), which is orders of magnitude too low for modern hardware.

    Значения должны лежать в диапазоне 1000-999999999.

    If only one of the SHA_CRYPT_MIN_ROUNDS or SHA_CRYPT_MAX_ROUNDS values is set, then this value will be used.

    If SHA_CRYPT_MIN_ROUNDS > SHA_CRYPT_MAX_ROUNDS, the highest value will be used.

SUB_GID_MIN (number), SUB_GID_MAX (number), SUB_GID_COUNT (number)
    If /etc/subuid exists, the commands useradd and newusers (unless the user already have subordinate group IDs) allocate SUB_GID_COUNT unused group IDs from the range SUB_GID_MIN to SUB_GID_MAX for each new user.

    The default values for SUB_GID_MIN, SUB_GID_MAX, SUB_GID_COUNT are respectively 100000, 600100000 and 65536.

SUB_GID_DETERMINISTIC (boolean)
    If set to yes, the commands useradd, usermod, and newusers will calculate subordinate GID ranges deterministically based on the user's UID instead of searching for the next free range. The formula used is:

              start = SUB_GID_MIN + ((UID - UID_MIN) * SUB_GID_COUNT)
              end   = start + SUB_GID_COUNT - 1

    This ensures the same UID always receives the same subordinate GID range on every system, making it suitable for environments with centralized user management (LDAP, NIS, etc.) or synchronized UIDs across systems.

    If SUB_GID_DETERMINISTIC is enabled, you can use usermod --add-subgids -S to produce deterministic subgids.

    WARNING: Because UID_MIN is used to calculate the ranges, any change of UID_MIN will change the ranges calculated. SUB_GID_COUNT is used to calculate the ranges, any change of SUB_GID_COUNT will change the ranges calculated. Users with identities less than UID_MIN are incompatible with SUB_GID_DETERMINISTIC, but can still be set manually.

    WARNING: Do not mix deterministic and linear (default) allocation on the same system or across systems sharing /etc/subgid via network storage (NFS, etc.). Mixing allocation methods will cause subordinate ID range conflicts and overlaps .

    The default value for SUB_GID_DETERMINISTIC is no.

  Range Calculation Examples
With default configuration (UID_MIN=1000, SUB_GID_MIN=100000, SUB_GID_COUNT=65536):
UID | Calculation | Subordinate GID Range
1000 | 100000 + ((1000-1000) * 65536) | 100000-165535
1001 | 100000 + ((1001-1000) * 65536) | 165536-231071
1002 | 100000 + ((1002-1000) * 65536) | 231072-296607
1100 | 100000 + ((1100-1000) * 65536) | 6653600-6719135

  Subordinate ID Space Planning
When planning subordinate ID allocation, calculate the maximum number of users the space can accommodate:

          capacity = (SUB_GID_MAX - SUB_GID_MIN) / SUB_GID_COUNT

With default values: (600100000 - 100000) / 65536 ≈ 9155 users.

For high-density environments with many users and smaller allocations:

            SUB_GID_COUNT  4096
            SUB_GID_MIN    100000
            SUB_GID_MAX    10000000

This gives: (10000000 - 100000) / 4096 ≈ 2417 users.

UNSAFE_SUB_GID_DETERMINISTIC_WRAP (boolean)
    WARNING: SECURITY RISK - MAY CAUSE RANGE OVERLAPS AND PRIVILEGE ESCALATION!

    Only effective when SUB_GID_DETERMINISTIC is set to yes.

    When set to yes (WRAP MODE), allows the deterministic range calculation to wrap around using modulo arithmetic when a UID would overflow the configured subordinate ID space. The subordinate ID space is treated as a ring buffer.

    WARNING: Range overlaps can lead to container escapes and privilege escalation. For example, with SUB_GID_MIN=100000, SUB_GID_MAX=200000, SUB_GID_COUNT=65536, User A (UID 1000) gets range [100000, 165535] and User B (UID 1001) wraps and overlaps with User A. User B's container can now access files from User A's containers.

    Use only in development, testing, or tightly constrained lab environments.

    When set to no (default), any arithmetic overflow or range exceeding SUB_GID_MAX is a hard error. This guarantees non-overlapping, monotonic allocation.

    The default value for UNSAFE_SUB_GID_DETERMINISTIC_WRAP is no.

SUB_UID_MIN (number), SUB_UID_MAX (number), SUB_UID_COUNT (number)
    If /etc/subuid exists, the commands useradd and newusers (unless the user already have subordinate user IDs) allocate SUB_UID_COUNT unused user IDs from the range SUB_UID_MIN to SUB_UID_MAX for each new user.

    The default values for SUB_UID_MIN, SUB_UID_MAX, SUB_UID_COUNT are respectively 100000, 600100000 and 65536.

SUB_UID_DETERMINISTIC (boolean)
    If set to yes, the commands useradd, usermod, and newusers will calculate subordinate UID ranges deterministically based on the user's UID instead of searching for the next free range. The formula used is:

              start = SUB_UID_MIN + ((UID - UID_MIN) * SUB_UID_COUNT)
              end   = start + SUB_UID_COUNT - 1

    This ensures the same UID always receives the same subordinate UID range on every system, making it suitable for environments with centralized user management (LDAP, NIS, etc.) or synchronized UIDs across systems.

    If SUB_UID_DETERMINISTIC is enabled, you can use usermod --add-subuids -S to produce deterministic subuids.

    WARNING: Because UID_MIN is used to calculate the ranges, any change of UID_MIN will change the ranges calculated. SUB_UID_COUNT is used to calculate the ranges, any change of SUB_UID_COUNT will change the ranges calculated. Users with identities less than UID_MIN are incompatible with SUB_UID_DETERMINISTIC, but can still be set manually.

    WARNING: Do not mix deterministic and linear (default) allocation on the same system or across systems sharing /etc/subuid via network storage (NFS, etc.). Mixing allocation methods will cause subordinate ID range conflicts and overlaps .

    The default value for SUB_UID_DETERMINISTIC is no.

  Range Calculation Examples
With default configuration (UID_MIN=1000, SUB_UID_MIN=100000, SUB_UID_COUNT=65536):
UID | Calculation | Subordinate UID Range
1000 | 100000 + ((1000-1000) * 65536) | 100000-165535
1001 | 100000 + ((1001-1000) * 65536) | 165536-231071
1002 | 100000 + ((1002-1000) * 65536) | 231072-296607
1100 | 100000 + ((1100-1000) * 65536) | 6653600-6719135

  Subordinate ID Space Planning
When planning subordinate ID allocation, calculate the maximum number of users the space can accommodate:

          capacity = (SUB_UID_MAX - SUB_UID_MIN) / SUB_UID_COUNT

With default values: (600100000 - 100000) / 65536 ≈ 9155 users.

For high-density environments with many users and smaller allocations:

            SUB_UID_COUNT  4096
            SUB_UID_MIN    100000
            SUB_UID_MAX    10000000

This gives: (10000000 - 100000) / 4096 ≈ 2417 users.

UNSAFE_SUB_UID_DETERMINISTIC_WRAP (boolean)
    WARNING: SECURITY RISK - MAY CAUSE RANGE OVERLAPS AND PRIVILEGE ESCALATION!

    Only effective when SUB_UID_DETERMINISTIC is set to yes.

    When set to yes (WRAP MODE), allows the deterministic range calculation to wrap around using modulo arithmetic when a UID would overflow the configured subordinate ID space. The subordinate ID space is treated as a ring buffer.

    WARNING: Range overlaps can lead to container escapes and privilege escalation. For example, with SUB_UID_MIN=100000, SUB_UID_MAX=200000, SUB_UID_COUNT=65536, User A (UID 1000) gets range [100000, 165535] and User B (UID 1001) wraps and overlaps with User A. User B's container can now access files from User A's containers.

    Use only in development, testing, or tightly constrained lab environments.

    When set to no (default), any arithmetic overflow or range exceeding SUB_UID_MAX is a hard error. This guarantees non-overlapping, monotonic allocation.

    The default value for UNSAFE_SUB_UID_DETERMINISTIC_WRAP is no.

SYS_GID_MAX (number), SYS_GID_MIN (number)
    Range of group IDs used for the creation of system groups by useradd, groupadd, or newusers.

    The default value for SYS_GID_MIN (resp. SYS_GID_MAX) is 101 (resp. GID_MIN-1).

SYS_UID_MAX (number), SYS_UID_MIN (number)
    Range of user IDs used for the creation of system users by useradd or newusers.

    The default value for SYS_UID_MIN (resp. SYS_UID_MAX) is 101 (resp. UID_MIN-1).

UID_MAX (number), UID_MIN (number)
    Range of user IDs used for the creation of regular users by useradd or newusers.

    The default value for UID_MIN (resp. UID_MAX) is 1000 (resp. 60000).

UMASK (number)
    Задаёт начальное значение маски доступа для создаваемых файлов. Если не указано, то маска устанавливается в 022.

    useradd and newusers use this mask to set the mode of the home directory they create if HOME_MODE is not set.

    It is also used by login to define users' initial umask. Note that this mask can be overridden by the user's GECOS line (if QUOTAS_ENAB is set) or by the specification of a limit with the K identifier in limits(5).

ФАЙЛЫ

/etc/passwd
    содержит информацию о пользователях

/etc/shadow
    содержит защищаемую информацию о пользователях

/etc/group
    содержит информацию о группах

/etc/gshadow
    содержит защищаемую информацию о группах

/etc/login.defs
    содержит конфигурацию подсистемы теневых паролей

/etc/subgid
    Per user subordinate group IDs.

/etc/subuid
    Per user subordinate user IDs.

СМОТРИТЕ ТАКЖЕ

login.defs(5), passwd(1), subgid(5), subuid(5), useradd(8).