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HTDBM(1)			     htdbm			      HTDBM(1)

NAME
       htdbm - Manipulate DBM password databases

SYNOPSIS
       htdbm [ -TDBTYPE	] [ -i ] [ -c ]	[ -m | -B | -d | -s | -p ] [ -C	cost ]
       [ -t ] [	-v ] filename username

       htdbm -b	[ -TDBTYPE ] [ -c ] [ -m | -B |	-d | -s	| -p ] [ -C cost  ]  [
       -t ] [ -v ] filename username password

       htdbm  -n [ -i ]	[ -c ] [ -m | -B | -d |	-s | -p	] [ -C cost ] [	-t ] [
       -v ] username

       htdbm -nb [ -c ]	[ -m | -B | -d | -s | -p ] [ -C	cost ] [ -t ] [	 -v  ]
       username	password

       htdbm  -v  [  -TDBTYPE  ] [ -i ]	[ -c ] [ -m | -B | -d |	-s | -p	] [ -C
       cost ] [	-t ] [ -v ] filename username

       htdbm -vb [ -TDBTYPE ] [	-c ] [ -m | -B | -d | -s | -p ]	[ -C cost ]  [
       -t ] [ -v ] filename username password

       htdbm -x	[ -TDBTYPE ] filename username

       htdbm -l	[ -TDBTYPE ]

SUMMARY
       htdbm  is  used	to manipulate the DBM format files used	to store user-
       names and password for basic authentication of HTTP users  via  mod_au-
       thn_dbm.	 See  the  dbmmanage  documentation for	more information about
       these DBM files.

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.

       -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
	      database.	 This  option  changes the syntax of the command line,
	      since the	passwdfile argument (usually the first one)  is	 omit-
	      ted. It cannot be	combined with the -c option.

       -m     Use  MD5	encryption for passwords. On Windows and Netware, this
	      is the default.

       -B     Use bcrypt encryption for	passwords. This	is  currently  consid-
	      ered to be very secure.

       -C     This flag	is only	allowed	in combination with -B (bcrypt encryp-
	      tion). 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. The default on all plat-
	      forms but	Windows	and Netware. Though possibly supported by  ht-
	      dbm on all platforms, it is not supported	by the httpd server on
	      Windows and Netware. This	algorithm is insecure by today's stan-
	      dards.

       -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	htdbm will support creation on
	      all platforms, the httpd daemon  will  only  accept  plain  text
	      passwords	on Windows and Netware.

       -l     Print  each  of  the usernames and comments from the database on
	      stdout.

       -v     Verify the username and password.	The program will print a  mes-
	      sage  indicating	whether	the supplied password is valid.	If the
	      password is invalid, the program exits with error	code 3.

       -x     Delete user. If the username exists in the specified  DBM	 file,
	      it will be deleted.

       -t     Interpret	 the final parameter as	a comment. When	this option is
	      specified, an additional string can be appended to  the  command
	      line;  this  string will be stored in the	"Comment" field	of the
	      database,	associated with	the specified username.

       filename
	      The filename of the DBM format file. Usually without the	exten-
	      sion .db,	.pag, or .dir. If -c is	given, the DBM file is created
	      if it does not already exist, or updated 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  DBM
	      file. Used only with the -b flag.

       -TDBTYPE
	      Type of DBM file (SDBM, GDBM, DB,	or "default").

BUGS
       One  should be aware that there are a number of different DBM file for-
       mats in existence, and with all likelihood, libraries for more than one
       format  may  exist on your system. The three primary examples are SDBM,
       NDBM, GNU GDBM, and Berkeley/Sleepycat  DB  2/3/4.  Unfortunately,  all
       these libraries use different file formats, and you must	make sure that
       the file	format used by filename	is the same format that	htdbm  expects
       to see. htdbm currently has no way of determining what type of DBM file
       it is looking at. If used against the wrong format, will	simply	return
       nothing,	 or  may create	a different DBM	file with a different name, or
       at worst, it may	corrupt	the DBM	file if	you were attempting  to	 write
       to it.

       One can usually use the file program supplied with most Unix systems to
       see what	format a DBM file is in.

EXIT STATUS
       htdbm returns a zero status ("true") if the username and	password  have
       been  successfully added	or updated in the DBM File. htdbm 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 interac-
       tively 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 DBM
       password	file.

EXAMPLES
	     htdbm /usr/local/etc/apache/.htdbm-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 en-
       crypted using the modified Apache MD5 algorithm;	 otherwise,  the  sys-
       tem's  crypt()  routine will be used. If	the file does not exist, htdbm
       will do nothing except return an	error.

	     htdbm -c /home/doe/public_html/.htdbm 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	htdbm will display  a  message
       and return an error status.

	     htdbm -mb /usr/web/.htdbm-all jones Pwd4Steve

       Encrypts	 the  password from the	command	line (Pwd4Steve) using the MD5
       algorithm, and stores it	in the specified file.

SECURITY CONSIDERATIONS
       Web password files such as those	managed	by htdbm should	not be	within
       the  Web	 server's  URI	space -- that is, they should not be fetchable
       with a browser.

       The use of the -b option	is discouraged,	since when it is used the  un-
       encrypted 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 htdbm are limited  to
       no  more	 than 255 characters in	length.	Longer passwords will be trun-
       cated to	255 characters.

       The MD5 algorithm used by htdbm 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 :.

Apache HTTP Server		  2012-12-12			      HTDBM(1)

NAME | SYNOPSIS | SUMMARY | OPTIONS | BUGS | EXIT STATUS | EXAMPLES | SECURITY CONSIDERATIONS | RESTRICTIONS

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