HTPASSWD(1) htpasswd HTPASSWD(1)
NAME
htpasswd - Manage user files for basic authentication
SYNOPSIS
htpasswd [ -c ] [ -i ] [ -m | -B | -2 | -5 | -d | -s | -p ] [ -r rounds
] [ -C cost ] [ -D ] [ -v ] passwdfile username
htpasswd -b [ -c ] [ -m | -B | -2 | -5 | -d | -s | -p ] [ -r rounds ] [
-C cost ] [ -D ] [ -v ] passwdfile username password
htpasswd -n [ -i ] [ -m | -B | -2 | -5 | -d | -s | -p ] [ -r rounds ] [
-C cost ] username
htpasswd -nb [ -m | -B | -2 | -5 | -d | -s | -p ] [ -r rounds ] [ -C
cost ] username 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 ht-
passwd 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
hash and display password information for use in other types of data
stores, though. To use a DBM database see dbmmanage or htdbm.
htpasswd hashes passwords using either bcrypt, a version of MD5 modi-
fied 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-hashed passwords while
others in the same file may have passwords hashed 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. 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 ar-
gument (usually the first one) is omitted. It cannot be combined
with the -c option.
-m Use MD5 hashing for passwords. This is the default (since ver-
sion 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 hashing for passwords. This is currently considered
to be very secure.
-C This flag is only allowed in combination with -B (bcrypt hash-
ing). It sets the computing time used for the bcrypt algorithm
(higher is more secure but slower, default: 5, valid: 4 to 17).
-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() hashing 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 (160-bit) hashing 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.
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 hashed 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 re-
turns 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 in-
teractively and the verification entry didn't match, 4 if its operation
was interrupted, 5 if a value is too long (username, filename, pass-
word, 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 hashed 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
plaintext 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 hashing format does not use salting: for a given password,
there is only one hashed 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 hashed with htpasswd are limited to
no more than 255 characters in length. Longer passwords will be trun-
cated to 255 characters.
The MD5 algorithm used by htpasswd is specific to the Apache software;
passwords hashed using it will not be usable with other Web servers.
Usernames are limited to 255 bytes and may not include the character :.
The cost of computing a bcrypt password hash value increases with the
number of rounds specified by the -C option. The apr-util library en-
forces a maximum number of rounds of 17 in version 1.6.0 and later.
Apache HTTP Server 2024-04-02 HTPASSWD(1)
Generated by dwww version 1.15 on Thu Jun 20 14:14:58 CEST 2024.