htpasswd
Manage user files for basic authentication
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
add an example, a script, a trick and tips
examples
source
htpasswd -D ../../.htpasswd $1
source
sudo htpasswd /var/lib/trac/.htpasswd
$1 $2
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.
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 -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.
-d
Use crypt() encryption for passwords. This is not
supported by the httpd server on Windows and Netware and
TPF.
-s
Use SHA encryption for passwords. Facilitates migration
from/to Netscape servers using the LDAP Directory
Interchange Format (ldif).
-p
Use plaintext passwords. Though htpasswd will support
creation on all platforms, the httpd daemon 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 -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.
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 :.
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.
summary
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/.