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.
htpasswd encrypts passwords using either a version of MD5
modified for Apache, or the system's crypt() routine. Files
managed by htpasswd may contain both types of passwords; some
user records may have 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/.
See also
httpd- The scripts in support/SHA1 which come with the distribution.
Synopsis
htpasswd
[ -c ]
[ -m ]
[ -D ] passwdfile username
htpasswd -b
[ -c ]
[ -m |
-d |
-p |
-s ]
[ -D ] passwdfile username
password
htpasswd -n
[ -m |
-d |
-s |
-p ] username
htpasswd -nb
[ -m |
-d |
-s |
-p ] 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.
-c- Create the passwdfile. If passwdfile already
exists, it is rewritten and truncated. This option cannot be combined with
the
-noption. -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
-coption. -m- Use MD5 encryption for passwords. This is the default (since version 2.2.18).
-d- Use
crypt()encryption for passwords. This is not supported by thehttpdserver on Windows and Netware and TPF. 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).
-p- Use plaintext passwords. Though
htpasswdwill support creation on all platforms, thehttpddaemon will only accept plain text passwords on Windows, Netware and TPF. -D- Delete user. If the username exists in the specified htpasswd file, it will be deleted.
passwdfile- Name of the file to contain the user name and password. If
-cis 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
-bflag.
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.
Restrictions
On the Windows and MPE platforms, 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 :.