NAME¶
htpasswd - Manage user files for basic authentication
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
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 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/.
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 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 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. 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 :.