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ftpasswd: tool for ProFTPD's AuthUserFile, AuthGroupFile, UserPassword
ftpasswd: tool for ProFTPD's AuthUserFile, AuthGroupFile, UserPassword
This program is used to create and manage files, correctly formatted, suitable
for use with ProFTPD's AuthUserFile and AuthGroupFile
configuration directives. It can also generate password hashes for ProFTPD's
UserPassword directive.
The most current version of ftpasswd is distributed with the
ProFTPD source code.
Author
Please contact TJ Saunders <tj at castaglia.org> with any
questions, concerns, or suggestions regarding this program.
The following describes the common usage of the ftpasswd tool.
The options supported are described in more detail
later.
This script is intended to replace the genuser.pl script that
is currently distributed with proftpd. That script can
generate DES-hashed passwords, suitable for use with the UserPassword
configuration directive, but it is not quite right for
AuthUserFiles. Another common mistake is to use the
htpasswd program from Apache to create files for
proftpd. Apache and ProFTPD both have the same
AuthUserFile and AuthGroupFile directives; the format
of the files used by each server is different.
Creating Files
The ftpasswd program can create and update files for both
AuthUserFile and AuthGroupFile. When it is used
for the first time, the program will create the necessary file. If that
file already exists, ftpasswd will update it with the new
information.
ftpasswd must first know what type of file to create. Use either
the --passwd option (for handling AuthUserFiles), or
the --group option (for handling AuthGroupFiles);
this is required.
When creating an AuthUserFile, the following options are also
required: --name, --uid, --home, and
--shell. This information is required by proftpd to
authenticate a user. The optional parameters for an AuthUserFile
include --gid (defaults to the given --uid argument
when not provided) and --gecos (not used by proftpd
at all). For example:
ftpasswd --passwd --name=bob --uid=1001 --home=/home/bob --shell=/bin/false
creates an account for user bob. To create a file with a name or
location other than the default (which, for --passwd mode is
ftpd.passwd), use the --file option. For example, to create the alternate password file in /usr/local/etc/ftpd/passwd:
ftpasswd --passwd --file=/usr/local/etc/ftpd/passwd --name=bob --uid=1001 --home=/home/bob \
--shell=/bin/false
For AuthGroupFiles, use --group:
ftpasswd --group --name=group-name --gid=group-id --member=user-member1 \
--member=user-member2 ... --member=user-memberN
The most common change to these files is made to AuthUserFiles, to
change a user's password. The --change-password option was
provided just for this scenario:
ftpasswd --passwd --name=user --change-password
Creating Hashes
A less common need is to generate a password hash for some user, to be used
in a UserPassword directive in the proftpd.conf.
One could generate a file using --passwd and then extract the
password hash from the file. Easier, though, is to use ftpasswd's
--hash option:
ftpasswd --hash
The password will either be prompted for, or it can be given on standard in
using --stdin.
Automated Use
The ftpasswd provides a useful command-line interface to
interacting with the authentication files. Many sites would like to be able
to remotely manipulate these files, just as ftpasswd does, only
using a web-based mechanism, perhaps even providing a page to users to change
their passwords, instead of requiring use of a shell. Wrapping a shell
or Perl script around ftpasswd is the logical solution.
To aid such automated wrapper scripts, ftpasswd has two features:
its return value, and a specific option. The program returns 0 if the
requested change was successful, and 1 if there was an error (no such
user/group, password matched system password and the
--not-system-password option was used, etc.). The specific
option is --stdin: this allows scripts to provide a password to
ftpasswd without prompting for a password. For example:
echo passwd-variable | ftpasswd opts --stdin
Note that the --stdin option does not allow passwords to
be passed to the script on the command line, but on stdin. This
is done as a security measure: the standard Unix ps command can
be used to show all the processes running on a system including their
command line parameters. This means that any user could use
ps to watch passwords given to ftpasswd, if those
passwords were to be passed on the command line. Some operating systems
(e.g. FreeBSD) allow the sysadmin to prevent users from seeing all
processes in this manner; consult your operating system documentation for
more information.
There are other issues that arise when using AuthUserFiles.
This document discusses these issues in greater detail.
The following is the output from running ftpasswd --help:
usage: ftpasswd [--help] [--hash|--group|--passwd]
REQUIRED: --passwd, --group, or --hash. These specify whether ftpasswd is to
operate on a passwd(5) format file, on a group(5) format file, or simply
to generate a password hash, respectively.
If used with --passwd, ftpasswd creates a file in the passwd(5) format,
suitable for use with proftpd's AuthUserFile configuration directive.
You will be prompted for the password to use of the user, which will be
encrypted, and written out as the encrypted string. New entries are
appended to the file by default.
By default, using --passwd will write output to "./ftpd.passwd".
Error exit values:
To make it easier for wrapper scripts to interact with ftpasswd, ftpasswd
will exit with the following error values for the reasons described:
1 no such user
2 password matches current password
4 password matches system password
8 relative path given for home directory
Options:
--file Write output to specified file, rather than "./ftpd.passwd"
-F If the file to be used already exists, delete it and write a
--force new one. By default, new entries will be appended to the file.
--gecos Descriptive string for the given user (usually the user's
full name).
--gid Primary group ID for this user (optional, will default to
given --uid value if absent)
-h Displays this message
--help
--home Home directory for the user (required)
--des Use the DES algorithm for encrypting passwords. The default
is the MD5 algorithm.
--md5 Use the MD5 algorithm for encrypting passwords. This is the
default.
--name Name of the user account (required). If the name does not
exist in the specified output-file, an entry will be created
for her. Otherwise, the given fields will be updated.
--shell Shell for the user (required). Recommended: /bin/false
--uid Numerical user ID (required)
--change-home
Update only the home directory field for a user. This option
requires that the --name and --passwd options be used, but no
others.
--change-password
Update only the password field for a user. This option
requires that the --name and --passwd options be used, but no
others. This also double-checks the given password against
the user's current password in the existing passwd file, and
requests that a new password be given if the entered password
is the same as the current password.
--delete-user
Remove the entry for the given user name from the file.
-l Lock the password of the named account. This option disables a
--lock password by changing it to a value which matches no possible
encrypted value (it adds a '!' at the beginning of the
password).
--not-previous-password
Double-checks the given password against the previous password
for the user, and requests that a new password be given if
the entered password is the same as the previous password.
--not-system-password
Double-checks the given password against the system password
for the user, and requests that a new password be given if
the entered password is the same as the system password. This
helps to enforce different passwords for different types of
access.
--sha256 Use the SHA-256 algorithm for encrypting passwords.
--sha512 Use the SHA-512 algorithm for encrypting passwords.
--stdin
Read the password directly from standard in rather than
prompting for it. This is useful for writing scripts that
automate use of ftpasswd.
-u Unlock the password of the named account. This option
--unlock re-enables a password by changing the password back to its
previous value (to the value before using the -l option).
--use-cracklib
Causes ftpasswd to use Alec Muffet's cracklib routines in
order to determine and prevent the use of bad or weak
passwords. The optional path to this option specifies
the path to the dictionary files to use -- default path
is "/usr/lib/cracklib_dict". This requires the Perl
Crypt::Cracklib module to be installed on your system.
--version
Displays the version of ftpasswd.
If used with --group, ftpasswd creates a file in the group(5) format,
suitable for use with proftpd's AuthGroupFile configuration directive.
By default, using --group will write output to "./ftpd.group".
Options:
--add-member
Add the named member to the given group name from the file.
Example:
$ ftpasswd --group --file=... --name=ftpd --add-member=bob
--delete-group
Remove the entry for the given group name from the file.
--delete-member
Remove the named member from the given group name from the file.
Example:
$ ftpasswd --group --file=... --name=ftpd --delete-member=bob
--enable-group-passwd
Prompt for a group password. This is disabled by default,
as group passwords are not usually a good idea at all.
--file Write output to specified file, rather than "./ftpd.group"
-F If the file be used already exists, delete it and write a new
--force one. By default, new entries will be appended to the file.
--gid Numerical group ID (required)
-h
--help Displays this message
-m
--member User to be a member of the group. This argument may be used
multiple times to specify the full list of users to be members
of this group.
--des Use the DES algorithm for encrypting passwords. The default
is the MD5 algorithm.
--md5 Use the MD5 algorithm for encrypting passwords. This is the
default.
--name Name of the group (required). If the name does not exist in
the specified output-file, an entry will be created for them.
Otherwise, the given fields will be updated.
--sha256 Use the SHA-256 algorithm for encrypting passwords.
--sha512 Use the SHA-512 algorithm for encrypting passwords.
--stdin
Read the password directly from standard in rather than
prompting for it. This is useful for writing scripts that
automate use of ftpasswd.
--use-cracklib
Causes ftpasswd to use Alec Muffet's cracklib routines in
order to determine and prevent the use of bad or weak
passwords. The optional path to this option specifies
the path to the dictionary files to use -- default path
is "/usr/lib/cracklib_dict". This requires the Perl
Crypt::Cracklib module to be installed on your system.
--version
Displays the version of ftpasswd.
If used with --hash, ftpasswd generates a hash of a password, as would
appear in an AuthUserFile. The hash is written to standard out.
This hash is suitable for use with proftpd's UserPassword directive.
Options:
--des Use the DES algorithm for encrypting passwords. The default
is the MD5 algorithm.
--md5 Use the MD5 algorithm for encrypting passwords. This is the
default.
--sha256 Use the SHA-256 algorithm for encrypting passwords.
--sha512 Use the SHA-512 algorithm for encrypting passwords.
--stdin
Read the password directly from standard in rather than
prompting for it. This is useful for writing scripts that
automate use of ftpasswd.
--use-cracklib
Causes ftpasswd to use Alec Muffet's cracklib routines in
order to determine and prevent the use of bad or weak
passwords. The optional path to this option specifies
the path to the dictionary files to use -- default path
is "/usr/lib/cracklib_dict". This requires the Perl
Crypt::Cracklib module to be installed on your system.
© Copyright 2000-2017 TJ Saunders
All Rights Reserved
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