Apache HTTP Server Version 2.4
htpasswd - Manage user files for basic authentication
htpasswd
is used to create and update the flat-files used to
store usernames and password for basic authentication of HTTP users. If
htpasswd
cannot access a file, such as not being able to write
to the output file or not being able to read the file in order to update it,
it returns an error status and makes no changes.
Resources available from the Apache HTTP server can be restricted to
just the users listed in the files created by htpasswd
. This
program can only manage usernames and passwords stored in a flat-file. It
can encrypt and display password information for use in other types of data
stores, though. To use a DBM database see dbmmanage
or
htdbm
.
htpasswd
encrypts passwords using either bcrypt,
a version of MD5 modified for Apache, SHA1, or the system's
crypt()
routine. Files
managed by htpasswd
may contain a mixture of different encoding
types of passwords; some
user records may have bcrypt or MD5-encrypted passwords while others in the
same file may have passwords encrypted with crypt()
.
This manual page only lists the command line arguments. For details of
the directives necessary to configure user authentication in
httpd
see the Apache manual, which is part of the
Apache distribution or can be found at http://httpd.apache.org/.
Synopsis
htpasswd
[ -c ]
[ -i ]
[ -m |
-B |
-d |
-s |
-p ]
[ -C cost ]
[ -D ]
[ -v ] passwdfile username
htpasswd -b
[ -c ]
[ -m |
-B |
-d |
-s |
-p ]
[ -C cost ]
[ -D ]
[ -v ] passwdfile username
password
htpasswd -n
[ -i ]
[ -m |
-B |
-d |
-s |
-p ]
[ -C cost ] username
htpasswd -nb
[ -m |
-B |
-d |
-s |
-p ]
[ -C cost ] username
password
Options
-b
- Use batch mode; i.e., get the password from the command line
rather than prompting for it. This option should be used with extreme care,
since the password is clearly visible on the command
line. For script use see the
-i
option. Available in 2.4.4 and later. -i
- Read the password from stdin without verification (for script usage).
-c
- Create the passwdfile. If passwdfile already
exists, it is rewritten and truncated. This option cannot be combined with
the
-n
option. -n
- Display the results on standard output rather than updating a file.
This is useful for generating password records acceptable to Apache for
inclusion in non-text data stores. This option changes the syntax of the
command line, since the passwdfile argument (usually the first
one) is omitted. It cannot be combined with the
-c
option. -m
- Use MD5 encryption for passwords. This is the default (since version 2.2.18).
-B
- Use bcrypt encryption for passwords. This is currently considered to be very secure.
-C
- This flag is only allowed in combination with
-B
(bcrypt encryption). It sets the computing time used for the bcrypt algorithm (higher is more secure but slower, default: 5, valid: 4 to 31). -d
- Use
crypt()
encryption for passwords. This is not supported by thehttpd
server on Windows and Netware. This algorithm limits the password length to 8 characters. This algorithm is insecure by today's standards. It used to be the default algorithm until version 2.2.17. -s
- Use SHA encryption for passwords. Facilitates migration from/to Netscape servers using the LDAP Directory Interchange Format (ldif). This algorithm is insecure by today's standards.
-p
- Use plaintext passwords. Though
htpasswd
will support creation on all platforms, thehttpd
daemon will only accept plain text passwords on Windows and Netware. -D
- Delete user. If the username exists in the specified htpasswd file, it will be deleted.
-v
- Verify password. Verify that the given password matches the password of the user stored in the specified htpasswd file. Available in 2.4.5 and later.
passwdfile
- Name of the file to contain the user name and password. If
-c
is given, this file is created if it does not already exist, or rewritten and truncated if it does exist. username
- The username to create or update in passwdfile. If username does not exist in this file, an entry is added. If it does exist, the password is changed.
password
- The plaintext password to be encrypted and stored in the file. Only
used with the
-b
flag.
Exit Status
htpasswd
returns a zero status ("true") if the username and
password have been successfully added or updated in the
passwdfile. htpasswd
returns 1
if it
encounters some problem accessing files, 2
if there was a
syntax problem with the command line, 3
if the password was
entered interactively and the verification entry didn't match,
4
if its operation was interrupted, 5
if a value
is too long (username, filename, password, or final computed record),
6
if the username contains illegal characters (see the
Restrictions section), and 7
if the file is not a valid password file.
Examples
htpasswd /usr/local/etc/apache/.htpasswd-users jsmith
Adds or modifies the password for user jsmith
. The user
is prompted for the password. The password will be encrypted using the
modified Apache MD5 algorithm. If the file does not exist,
htpasswd
will do nothing except return an error.
htpasswd -c /home/doe/public_html/.htpasswd jane
Creates a new file and stores a record in it for user jane
.
The user is prompted for the password. If the file exists and cannot be
read, or cannot be written, it is not altered and htpasswd
will display a message and return an error status.
htpasswd -db /usr/web/.htpasswd-all jones Pwd4Steve
Encrypts the password from the command line (Pwd4Steve
)
using the crypt()
algorithm, and stores it in the specified
file.
Security Considerations
Web password files such as those managed by htpasswd
should
not be within the Web server's URI space -- that is, they should
not be fetchable with a browser.
This program is not safe as a setuid executable. Do not make it setuid.
The use of the -b
option is discouraged, since when it is
used the unencrypted password appears on the command line.
When using the crypt()
algorithm, note that only the first
8 characters of the password are used to form the password. If the supplied
password is longer, the extra characters will be silently discarded.
The SHA encryption format does not use salting: for a given password,
there is only one encrypted representation. The crypt()
and
MD5 formats permute the representation by prepending a random salt string,
to make dictionary attacks against the passwords more difficult.
The SHA and crypt()
formats are insecure by today's
standards.
Restrictions
On the Windows platform, passwords encrypted with
htpasswd
are limited to no more than 255
characters in length. Longer passwords will be truncated to 255
characters.
The MD5 algorithm used by htpasswd
is specific to the Apache
software; passwords encrypted using it will not be usable with other Web
servers.
Usernames are limited to 255
bytes and may not include the
character :
.