NAME

       krb5-strength-wordlist - Create a krb5-strength database from a word list

SYNOPSIS

       krb5-strength-wordlist [-am] [-c output-cdb] [-l min-length]
           [-L max-length] [-o output-wordlist] [-s output-sqlite]
           [-x exclude ...] wordlist

DESCRIPTION

       krb5-strength-wordlist converts a word list (a file containing one word per line) into a database that
       can be used by the krb5-strength plugin or heimdal-strength command for checking passwords.  Two database
       formats are supported, with different features.  CDB is more space-efficient and possibly faster, but
       supports checking passwords only against exact matches or simple transformations (removing small numbers
       of leading and trailing characters).  SQLite creates a much larger database, but supports rejecting any
       password within edit distance one of a word in the word list.

       CDB is a format invented by Dan Bernstein for fast, constant databases.  The database is fixed during
       creation and cannot be changed without rebuilding it, and is optimized for very fast access.  For cdb,
       the database generated by this program will have keys for each word in the word list and the constant 1
       as the value.

       SQLite stores the word list in a single table containing both each word and each word reversed.  This
       allows the krb5-strength plugin or heimdal-strength command to reject passwords within edit distance one
       of any word in the word list.  (Edit distance one means that the word list entry can be formed by
       changing a single character of the password, either by adding one character, removing one character, or
       changing one character to a different character.)  However, the SQLite database will be much larger and
       lookups may be somewhat slower.

       krb5-strength-wordlist takes one argument, the input word list file.  Use the -c option to specify an
       output CDB file, -s to specify an output SQLite file, or -o to just filter the word list against the
       criteria given on the command line and generate a new word list.  The input word list file does not have
       to be sorted.  See the individual option descriptions for more information.

OPTIONS

       -a, --ascii
           Filter all words that contain non-ASCII characters or control characters from the resulting cdb file,
           leaving only words that consist solely of ASCII non-control characters.

       -c output-cdb, --cdb=output-cdb
           Create a CDB database in output-cdb.  A temporary file named after output-cdb with ".data" appended
           will be created in the same directory and used to stage the database contents.  The actual CDB file
           will be built using the cdb command, which must be on the user's path.  If either file already
           exists, krb5-strength-wordlist will abort with an error.

           This option cannot be used with -o or -s.

       -L maximum, --max-length=maximum
           Filter all words of length greater than maximum from the resulting cdb database.  The length of each
           line (minus the separating newline) in the input word list will be checked against minimum and will
           be filtered out of the resulting database if it is shorter.  Useful for generating password
           dictionaries from word lists that contain random noise that's highly unlikely to be used as a
           password.

           The default is to not filter out any words for maximum length.

       -l minimum, --min-length=minimum
           Filter all words of length less than minimum from the resulting cdb database.  The length of each
           line (minus the separating newline) in the input word list will be checked against minimum and will
           be filtered out of the resulting database if it is shorter.  Useful for generating password
           dictionaries where shorter passwords will be rejected by a generic length check and no dictionary
           lookup will be done for a transform of the password shorter than the specified minimum.

           The default is not to filter out any words for minimum length.

       -m, --man, --manual
           Print out this documentation (which is done simply by feeding the script to "perldoc -t").

       -o wordlist, --output=wordlist
           Rather than creating a database, apply the filter rules given by the other command-line arguments and
           generate a new word list in the file name given by the wordlist option.  This can be used to reduce
           the size of a raw word list file (such as one taken from Internet sources) by removing the words that
           will be filtered out of the dictionary anyway, thus reducing the size of the source required to
           regenerate the dictionary.

           This option cannot be used with -c or -s.

       -s output-sqlite, --sqlite=output-sqlite
           Create a SQLite database in output-sqlite.  If this file already exists, krb5-strength-wordlist will
           abort with an error.  The resulting SQLite database will have one table, "passwords", with two
           columns, "password" and "drowssap".  The first holds a word from the word list, and the second holds
           the same word reversed.

           Using this option requires the DBI and DBD::SQLite Perl modules be installed.

           This option cannot be used with -c or -o.

       -x exclude, --exclude=exclude
           Filter all words matching the regular expression exclude from the resulting cdb database.  This
           regular expression will be matched against each line of the source word list after the trailing
           newline is removed.  This option may be given repeatedly to add multiple exclusion regexes.

AUTHOR

       Russ Allbery <eagle@eyrie.org>

COPYRIGHT AND LICENSE

       Copyright 2016 Russ Allbery <eagle@eyrie.org>

       Copyright 2013, 2014 The Board of Trustees of the Leland Stanford Junior University

       Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
       associated documentation files (the "Software"), to deal in the Software without restriction, including
       without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
       copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the
       following conditions:

       The above copyright notice and this permission notice shall be included in all copies or substantial
       portions of the Software.

       THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
       LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN
       NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
       WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
       SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

SEE ALSO

       cdb(1), DBI, DBD::SQLite

       The cdb file format is defined at <http://cr.yp.to/cdb.html>.

       The current version of this program is available from its web page at
       <https://www.eyrie.org/~eagle/software/krb5-strength/> as part of the krb5-strength package.