|The Apache HTTP Server Reference Manual
by Apache Software Foundation
Paperback (6"x9"), 862 pages
RRP £19.95 ($29.95)
htpasswd is used to create and update the flat-files used to store usernames and passwords 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().
- httpd (p. 10)
- The scripts in support/SHA1 which come with the distribution.
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
- 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.
- Create the passwdfile. If passwdfile already exists, it is rewritten and truncated. This option cannot be combined with the -n option.
- 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.
- Use MD5 encryption for passwords. On Windows, Netware and TPF, this is the default.
- Use crypt() encryption for passwords. The default on all platforms but Windows, Netware and TPF. Though possibly supported by htpasswd on all platforms, it is not supported by the httpd server on Windows, Netware and TPF.
- Use SHA encryption for passwords. Facilitates migration from/to Netscape servers using the LDAP Directory Interchange Format (ldif).
- 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.
- Delete user. If the username exists in the specified htpasswd file, it will be deleted.
- 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.
- 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.
- The plaintext password to be encrypted and stored in the file. Only used with the -b flag.
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.
htpasswd /usr/local/etc/apache/.htpasswd-users jsmith
Adds or modifies the password for user jsmith. The user is prompted for the password. If executed on a Windows system, the password will be encrypted using the modified Apache MD5 algorithm; otherwise, the system’s crypt() routine will be used. 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 -mb /usr/web/.htpasswd-all jones Pwd4Steve
Encrypts the password from the command line (Pwd4Steve) using the MD5 algorithm, and stores it in the specified file.
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.
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 :.
|ISBN 9781906966034||The Apache HTTP Server Reference Manual||See the print edition|