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'\" t
.\" Title: passwd
.\" Author: Julianne Frances Haugh
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\" Date: 01/02/2026
.\" Manual: User Commands
.\" Source: shadow-utils 4.19.3
.\" Language: Ukrainian
.\"
.TH "passwd" "1" "01/02/2026" "shadow\-utils 4\&.19\&.3" "User Commands"
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.SH "НАЗВА"
passwd \- зміна пароля користувача
.SH "КОРОТКИЙ ОГЛЯД"
.HP \w'\fBpasswd\fR\ 'u
\fBpasswd\fR [\fIoptions\fR] [\fILOGIN\fR]
.SH "ОПИС"
.PP
The
\fBpasswd\fR
command changes passwords for user accounts\&. A regular user can only change the password for their own account, while the superuser can change the password for any account\&. The
\fBpasswd\fR
also changes the account or associated password validity period\&.
.SS "Зміни паролів"
.PP
If the account has a non\-empty password, the user is first prompted to enter their current password\&. The entered password is encrypted and compared to the stored value\&. The user has only one attempt to enter the correct password\&. The superuser can bypass this step to allow changing forgotten passwords\&.
.PP
After the password has been entered, password aging information is checked to determine if the user is permitted to change the password at this time\&. If not,
\fBpasswd\fR
refuses to change the password and exits\&.
.PP
The user is then prompted twice for a replacement password\&. The second entry is compared against the first and both are required to match for the password to be changed\&.
.PP
Then, the password is tested for complexity\&.
\fBpasswd\fR
rejects passwords that do not meet the complexity requirements\&. Do not include the system default erase or kill characters\&.
.SS "Підказки для паролів користувача"
.PP
The security of a password depends on the strength of the encryption algorithm and the size of the key space\&. The legacy
\fIUNIX\fR
System encryption method is based on the NBS DES algorithm\&. More recent methods are now recommended (see
\fBENCRYPT_METHOD\fR)\&. The size of the key space depends on the randomness of the selected password\&.
.PP
Compromises in password security normally result from careless password selection or handling\&. For this reason, you should not select a password which appears in a dictionary or one that must be written down\&. The password should also not be a proper name, your license number, birth date, or street address\&. Any of these may be used as guesses to violate system security\&.
.PP
As a general guideline, passwords should be long and random\&. It\*(Aqs fine to use simple character sets, such as passwords consisting only of lowercase letters, if that helps memorizing longer passwords\&. For a password consisting only of lowercase English letters randomly chosen, and a length of 32, there are 26^32 (approximately 2^150) different possible combinations\&. Being an exponential equation, it\*(Aqs apparent that the exponent (the length) is more important than the base (the size of the character set)\&.
.PP
You can find advice on how to choose a strong password on https://en\&.wikipedia\&.org/wiki/Password_strength
.SH "ПАРАМЕТРИ"
.PP
The options which apply to the
\fBpasswd\fR
command are:
.PP
\fB\-a\fR, \fB\-\-all\fR
.RS 4
This option can be used only with
\fB\-S\fR
and causes show status for all users\&.
.RE
.PP
\fB\-d\fR, \fB\-\-delete\fR
.RS 4
Deletes a user\*(Aqs password, making it empty\&. This command sets the account to be passwordless\&.
.RE
.PP
\fB\-e\fR, \fB\-\-expire\fR
.RS 4
Негайно завершити строк дії пароля облікового запису\&. Результатом є те, що система вимагатиме від користувача змінити пароль під час наступного входу до системи\&.
.RE
.PP
\fB\-h\fR, \fB\-\-help\fR
.RS 4
Показати довідкове повідомлення і завершити роботу\&.
.RE
.PP
\fB\-i\fR, \fB\-\-inactive\fR\ \&\fIINACTIVE\fR
.RS 4
This option is used to disable an account after the password has been expired for a number of days\&. After a user account has had an expired password for
\fIINACTIVE\fR
days, the user may no longer sign on to the account\&.
.RE
.PP
\fB\-k\fR, \fB\-\-keep\-tokens\fR
.RS 4
Вказати, що зміну пароля має бути виконано лише для жетонів (паролів) розпізнавання, строк дії яких вичерпано\&. Користувач бажає зберегти попередню дію жетонів, строк дії яких не вичерпано\&.
.RE
.PP
\fB\-l\fR, \fB\-\-lock\fR
.RS 4
Заблокувати пароль іменованого облікового запису\&. За допомогою цього параметра можна вимкнути пароль, змінивши його на значення, яке не відповідає зашифрованому значенню (буде додано \(aa!\(aa на початку пароля)\&.
.sp
Note that this does not disable the account\&. The user may still be able to login using another authentication token (e\&.g\&. an SSH key)\&. To disable the account, administrators should use
\fBusermod \-\-expiredate 1\fR
(this sets the account\*(Aqs expire date to 1970\-01\-02)\&.
.sp
Користувачі із заблокованим паролем не зможуть змінювати власний пароль\&.
.RE
.PP
\fB\-n\fR, \fB\-\-mindays\fR\ \&\fIMIN_DAYS\fR
.RS 4
Set the minimum number of days between password changes to
\fIMIN_DAYS\fR\&. A value of zero for this field indicates that the user may change their password at any time\&.
.RE
.PP
\fB\-q\fR, \fB\-\-quiet\fR
.RS 4
Режим без повідомлень\&.
.RE
.PP
\fB\-r\fR, \fB\-\-repository\fR\ \&\fIREPOSITORY\fR
.RS 4
change password in
\fIREPOSITORY\fR
repository
.RE
.PP
\fB\-R\fR, \fB\-\-root\fR\ \&\fICHROOT_DIR\fR
.RS 4
Apply changes in the
\fICHROOT_DIR\fR
directory and use the configuration files from the
\fICHROOT_DIR\fR
directory\&. Only absolute paths are supported\&. No SELINUX support\&.
.RE
.PP
\fB\-P\fR, \fB\-\-prefix\fR\ \&\fIPREFIX_DIR\fR
.RS 4
Apply changes to configuration files under the root filesystem found under the directory
\fIPREFIX_DIR\fR\&. This option does not chroot and is intended for preparing a cross\-compilation target\&. Some limitations: NIS and LDAP users/groups are not verified\&. No PAM support\&. No SELINUX support\&.
.RE
.PP
\fB\-S\fR, \fB\-\-status\fR
.RS 4
Вивести дані щодо стану облікового запису\&. Дані щодо стану складаються з 7 полів\&. Першим полем є назва облікового запису користувача\&. Друге поле вказує на те, чи є обліковий запис таким, для якого заблоковано пароль (L), немає пароля (NP) або має придатний до користування пароль (P)\&. Третє поле задає дату останньої зміни пароля\&. Наступними чотирма полями є мінімальний вік, максимальний вік, період попередження та період неактивності для пароля\&. Ці значення віку виражаються у днях\&.
.RE
.PP
\fB\-u\fR, \fB\-\-unlock\fR
.RS 4
Unlock the password of the named account\&. This option re\-enables a password by changing the password back to its previous value (to the value before using the
\fB\-l\fR
option)\&.
.RE
.PP
\fB\-w\fR, \fB\-\-warndays\fR\ \&\fIWARN_DAYS\fR
.RS 4
Set the number of days of warning before a password change is required\&. The
\fIWARN_DAYS\fR
option is the number of days prior to password expiration during which the user is warned that their password is about to expire\&.
.RE
.PP
\fB\-x\fR, \fB\-\-maxdays\fR\ \&\fIMAX_DAYS\fR
.RS 4
Set the maximum number of days a password remains valid\&. After
\fIMAX_DAYS\fR, the password is required to be changed\&.
.sp
Passing the number
\fI\-1\fR
as
\fIMAX_DAYS\fR
will remove checking a password\*(Aqs validity\&.
.RE
.PP
\fB\-s\fR, \fB\-\-stdin\fR
.RS 4
This option is used to indicate that passwd should read the new password from standard input, which can be a pipe\&.
.RE
.SH "ЗАСТЕРЕЖЕННЯ"
.PP
Перевірка складності пароля може бути різною у різних системах\&. Система вимагатиме вибрати пароль, який буде достатньо складним на думку її розробників\&.
.PP
Можливо, користувачі не зможуть змінити свій пароль у системі, якщо увімкнено NIS, і користувачі не увійшли до сервера NIS\&.
.SH "НАЛАШТУВАННЯ"
.PP
The following configuration variables in
/etc/login\&.defs
change the behavior of this tool:
.PP
\fBENCRYPT_METHOD\fR (string)
.RS 4
This defines the system default encryption algorithm for encrypting passwords (if no algorithm is specified on the command line)\&.
.sp
It can take one of these values:
\fIDES\fR
(default),
\fIMD5\fR, \fISHA256\fR, \fISHA512\fR\&. MD5 and DES should not be used for new hashes, see
crypt(5)
for recommendations\&.
.sp
Note: this parameter overrides the
\fBMD5_CRYPT_ENAB\fR
variable\&.
.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\&.
.RE
.PP
\fBOBSCURE_CHECKS_ENAB\fR (boolean)
.RS 4
Enable additional checks upon password changes\&.
.RE
.PP
\fBPASS_ALWAYS_WARN\fR (boolean)
.RS 4
Warn about weak passwords (but still allow them) if you are root\&.
.RE
.PP
\fBPASS_CHANGE_TRIES\fR (number)
.RS 4
Maximum number of attempts to change password if rejected (too easy)\&.
.RE
.PP
\fBPASS_MAX_LEN\fR (number), \fBPASS_MIN_LEN\fR (number)
.RS 4
Number of significant characters in the password for crypt()\&.
.sp
\fBPASS_MAX_LEN\fR
is 8 by default\&. Don\*(Aqt change unless your crypt() is better\&.
.sp
\fBPASS_MAX_LEN\fR
is only used for DES\&. It is ignored if an encryption algorithm other than DES is used, either because
\fBMD5_CRYPT_ENAB\fR
set to
\fIyes\fR
or
\fBENCRYPT_METHOD\fR
set to an algorithm other than
\fIDES\fR\&.
.sp
In addition,
\fBPASS_MAX_LEN\fR
is only used if
\fBOBSCURE_CHECKS_ENAB\fR
set to
\fIyes\fR\&.
.sp
Note: This only affects the generation of user passwords\&. Group password lengths are not checked\&.
.RE
.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
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\&.
.sp
If not specified, the libc will choose the default number of rounds (5000), which is orders of magnitude too low for modern hardware\&.
.sp
The values must be inside the 1000\-999,999,999 range\&.
.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\&.
.RE
.SH "ФАЙЛИ"
.PP
/etc/passwd
.RS 4
Відомості щодо облікових записів користувача\&.
.RE
.PP
/etc/shadow
.RS 4
Відомості щодо захищених облікових записів користувачів\&.
.RE
.PP
/etc/login\&.defs
.RS 4
Налаштування комплексу для роботи з прихованими паролями\&.
.RE
.SH "ЗНАЧЕННЯ ВИХОДУ"
.PP
The
\fBpasswd\fR
command exits with the following values:
.PP
\fI0\fR
.RS 4
success
.RE
.PP
\fI1\fR
.RS 4
permission denied
.RE
.PP
\fI2\fR
.RS 4
invalid combination of options
.RE
.PP
\fI3\fR
.RS 4
unexpected failure, nothing done
.RE
.PP
\fI4\fR
.RS 4
unexpected failure,
passwd
file missing
.RE
.PP
\fI5\fR
.RS 4
passwd
file busy, try again
.RE
.PP
\fI6\fR
.RS 4
invalid argument to option
.RE
.PP
\fI10\fR
.RS 4
an error was returned by
pam(3)
.RE
.SH "ДИВ\&. ТАКОЖ"
.PP
\fBchpasswd\fR(8),
\fBmakepasswd\fR(1),
\fBpasswd\fR(5),
\fBshadow\fR(5),
\fBlogin.defs\fR(5),
\fBusermod\fR(8)\&.
.PP
The following web page comically (yet correctly) compares the strength of two different methods for choosing a password: "https://xkcd\&.com/936/"