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 17).

       -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 :.

       The  cost  of computing a bcrypt password hash value increases with the number of rounds specified by the
       -C option. The apr-util library enforces a maximum number of rounds of 17 in version 1.6.0 and later.