Provided by: apache2-utils_2.4.34-1ubuntu2_amd64 bug

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 :.