HTPASSWD(1) htpasswd HTPASSWD(1)
NAME
htpasswd - Manage user files for basic authentication
SYNOPSIS
htpasswd [ -c ] [ -i ] [ -m | -B | -d | -s | -p ] [ -r rounds ] [ -C
cost ] [ -D ] [ -v ] passwdfile username
htpasswd -b [ -c ] [ -m | -B | -d | -s | -p ] [ -r rounds ] [ -C cost ]
[ -D ] [ -v ] passwdfile username password
htpasswd -n [ -i ] [ -m | -B | -d | -s | -p ] [ -r rounds ] [ -C cost ]
username
htpasswd -nb [ -m | -B | -d | -s | -p ] [ -r rounds ] [ -C cost ] user-
name password
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 or htdbm.
+htpasswd encrypts passwords using either bcrypt, a version of MD5 mod-
ified for Apache, SHA-1, or the system's crypt() routine. SHA-2-based
hashes (SHA-256 and SHA-512) are supported for crypt(). Files managed
by htpasswd may contain a mixture of different encoding types of pass-
words; 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/.
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 com-
mand line. For script use see the -i option.
-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 com-
bined with the -c option.
-m Use MD5 encryption for passwords. This is the default (since
version 2.2.18).
-2 Use SHA-256 crypt() based hashes for passwords. This is sup-
ported on most Unix platforms.
-5 Use SHA-512 crypt() based hashes for passwords. This is sup-
ported on most Unix platforms.
-B Use bcrypt encryption for passwords. This is currently consid-
ered to be very secure.
-C This flag is only allowed in combination with -B (bcrypt encryp-
tion). It sets the computing time used for the bcrypt algorithm
(higher is more secure but slower, default: 5, valid: 4 to 31).
-r This flag is only allowed in combination with -2 or -5. It sets
the number of hash rounds used for the SHA-2 algorithms (higher
is more secure but slower; the default is 5,000).
-d Use crypt() encryption for passwords. This is not supported by
the httpd 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-1 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, the httpd 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.
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 opera-
tion 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 mes-
sage 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 fetch-
able 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-1 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-1 and crypt() formats are insecure by today's standards.
The SHA-2-based crypt() formats (SHA-256 and SHA-512) are supported on
most modern Unix systems, and follow the specification at
https://www.akkadia.org/drepper/SHA-crypt.txt
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 :.
Apache HTTP Server 2013-07-06 HTPASSWD(1)
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