htdbm - Manipulate DBM databases 464y1y

Synopsis 5j6t5r

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

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

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

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

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

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

htdbm -x [ -TDBTYPE ] filename name

htdbm -l [ -TDBTYPE ]

Options 4y664e

-b

Use batch mode; i.e., get the from the command line rather than prompting for it. This option should be used with extreme care, since the is clearly visible on the command line. For script use see the -i option.

-i

Read the from stdin without verification (for script usage).

-c

Create the wdfile. If wdfile 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 wdfile argument (usually the first one) is omitted. It cannot be combined with the -c option.

-m

Use MD5 encryption for s. On Windows and Netware, this is the default.

-B

Use bcrypt encryption for s. 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 s. The default on all platforms but Windows and Netware. Though possibly ed by htdbm on all platforms, it is not ed by the httpd server on Windows and Netware. This algorithm is insecure by today's standards.

-s

Use SHA encryption for s. Facilitates migration from/to Netscape servers using the LDAP Directory Interchange Format (ldif). This algorithm is insecure by today's standards.

-p

Use plaintext s. Though htdbm will creation on all platforms, the httpd daemon will only accept plain text s on Windows and Netware.

-l

Print each of the names and comments from the database on stdout.

-v

the name and . The program will print a message indicating whether the supplied is valid. If the is invalid, the program exits with error code 3.

-x

Delete . If the name 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 name.

filename

The filename of the DBM format file. Usually without the extension .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.

name

The name to create or update in wdfile. If name does not exist in this file, an entry is added. If it does exist, the is changed.

The plaintext 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 a157

One should be aware that there are a number of different DBM file formats 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 1wa41

htdbm returns a zero status ("true") if the name and 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 was entered interactively and the verification entry didn't match, 4 if its operation was interrupted, 5 if a value is too long (name, filename, , or final computed record), 6 if the name contains illegal characters (see the Restrictions section), and 7 if the file is not a valid DBM file.

Examples 412u42

Adds or modifies the for jsmith. The is prompted for the . If executed on a Windows system, the will be encrypted using the modified Apache MD5 algorithm; otherwise, the system's crypt() routine will be used. If the file does not exist, htdbm will do nothing except return an error.

Creates a new file and stores a record in it for jane. The is prompted for the . 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.

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

Security Considerations 636c3h

Web 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 unencrypted appears on the command line.

When using the crypt() algorithm, note that only the first 8 characters of the are used to form the . If the supplied is longer, the extra characters will be silently discarded.

The SHA encryption format does not use salting: for a given , 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 s more difficult.

The SHA and crypt() formats are insecure by today's standards.

Restrictions 1w4k1q

On the Windows platform, s encrypted with htdbm are limited to no more than 255 characters in length. Longer s will be truncated to 255 characters.

The MD5 algorithm used by htdbm is specific to the Apache software; s encrypted using it will not be usable with other Web servers.

names are limited to 255 bytes and may not include the character :.