# Package metadata for krb5-strength. # # This file contains configuration for DocKnot used to generate # documentation files (like README.md) and web pages. Other documentation # in this package is generated automatically from these files as part of # the release process. For more information, see DocKnot's documentation. # # DocKnot is available from . # # Copyright 2007, 2009-2010, 2012-2014, 2016-2017, 2020, 2023 # Russ Allbery # # SPDX-License-Identifier: MIT format: v1 name: krb5-strength maintainer: Russ Allbery version: '3.3' synopsis: Kerberos password strength checking plugin license: name: Expat notices: | Developed by Daria Phoebe Brashear and Ken Hornstein of Sine Nomine Associates, on behalf of Stanford University. The embedded version of CrackLib (all files in the `cracklib` subdirectory) is covered by the Artistic license. See the file `cracklib/LICENCE` for more information. Combined derivative works that include this code, such as binaries built with the embedded CrackLib, will need to follow the terms of the Artistic license as well as the above license. copyrights: - holder: Russ Allbery years: 2016, 2020, 2023 - holder: The Board of Trustees of the Leland Stanford Junior University years: 2006-2007, 2009-2010, 2012-2014 - holder: Alec Muffett years: '1993' build: autoconf: '2.64' automake: '1.11' autotools: true kerberos: true manpages: true reduced_depends: true bootstrap: | You will also need Perl 5.010 or later and the Const::Fast, DBI, DBD::SQLite, JSON::MaybeXS, and Perl6::Slurp modules (from CPAN) to bootstrap the test suite data from a Git checkout. middle: | By default, the Heimdal external password check function is installed as `/usr/local/bin/heimdal-strength`, and the plugin is installed as `/usr/local/lib/krb5/plugins/pwqual/strength.so`. You can change these paths with the `--prefix`, `--libdir`, and `--bindir` options to `configure`. By default, the embedded version of CrackLib will be used. To build with the system version of CrackLib, pass `--with-cracklib` to `configure`. You can optionally add a directory, giving the root directory where CrackLib was installed, or separately set the include and library path with `--with-cracklib-include` and `--with-cracklib-lib`. You can also build without any CrackLib support by passing `--without-cracklib` to `configure`. krb5-strength will automatically build with TinyCDB if it is found. To specify the installation path of TinyCDB, use `--with-tinycdb`. You can also separately set the include and library path with `--with-tinycdb-include` and `--with-tinycdb-lib`. Similarly, krb5-strength will automatically build with SQLite if it is found. To specify the installation path of SQLite, use `--with-sqlite`. You can also separately set the include and library path with `--with-sqlite-include` and `--with-sqlite-lib`. suffix: | After installing this software, see the man pages for krb5-strength, heimdal-strength, and heimdal-history for configuration information. type: Autoconf valgrind: true distribution: section: kerberos tarname: krb5-strength version: krb5-strength packaging: debian: package: krb5-strength summary: | A Debian package is included in Debian 8.0 (jessie) and later releases. support: email: eagle@eyrie.org github: rra/krb5-strength web: https://www.eyrie.org/~eagle/software/krb5-strength/ vcs: browse: https://git.eyrie.org/?p=kerberos/krb5-strength.git github: rra/krb5-strength openhub: https://www.openhub.net/p/krb5-strength status: workflow: build type: Git url: https://git.eyrie.org/git/kerberos/krb5-strength.git docs: user: - name: heimdal-history title: heimdal-history - name: heimdal-strength title: heimdal-strength - name: krb5-strength title: krb5-strength plugin - name: wordlist title: krb5-strength-wordlist developer: - name: todo title: To-do list blurb: | krb5-strength provides a password quality plugin for the MIT Kerberos KDC (specifically the kadmind server) and Heimdal KDC, an external password quality program for use with Heimdal, and a per-principal password history implementation for Heimdal. Passwords can be tested with CrackLib, checked against a CDB or SQLite database of known weak passwords with some transformations, checked for length, checked for non-printable or non-ASCII characters that may be difficult to enter reproducibly, required to contain particular character classes, or any combination of these tests. description: | Heimdal includes a capability to plug in external password quality checks and comes with an example that checks passwords against CrackLib. However, in testing at Stanford, we found that CrackLib with its default transform rules does not catch passwords that can be guessed using the same dictionary with other tools, such as Jack the Ripper. We then discovered other issues with CrackLib with longer passwords, such as some bad assumptions about how certain measures of complexity will scale, and wanted to impose other limitations that it didn't support. This plugin provides the ability to check password quality against the standard version of CrackLib, or against a modified version of CrackLib that only passes passwords that resist attacks from both Crack and Jack the Ripper using the same rule sets. It also supports doing simpler dictionary checks against a CDB database, which is fast with very large dictionaries, or a SQLite database, which can reject all passwords within edit distance one of a dictionary word. It can also impose other programmatic checks on passwords such as character class requirements. If you're just now starting with password checking, I recommend using the SQLite database with a large wordlist and minimum password lengths. We found this produced the best results with the least user frustration. For Heimdal, krb5-strength includes both a program usable as an external password quality check and a plugin that implements the dynamic module API. For MIT Kerberos (1.9 or later), it includes a plugin for the password quality (pwqual) plugin API. krb5-strength can be built with either the system CrackLib or with the modified version of CrackLib included in this package. Note, however, that if you're building against the system CrackLib, Heimdal includes in the distribution a strength-checking plugin and an external password check program that use the system CrackLib. With Heimdal, it would probably be easier to use that plugin or program than build this package unless you want the modified CrackLib, one of the other dictionary types, or the additional character class and length checks. For information about the changes to the CrackLib included in this toolkit, see `cracklib/HISTORY`. The primary changes are tighter rules, which are more aggressive at finding dictionary words with characters appended and prepended, which tighten the requirements for password entropy, and which add stricter rules for longer passwords. They are also minor changes to fix portability issues, remove some code that doesn't make sense in the kadmind context, and close a few security issues. The standard CrackLib distribution on at least some Linux distributions now supports an additional interface to configure its behavior, and krb5-strength should change in the future to use that interface and drop the embedded copy. krb5-strength also includes a password history implementation for Heimdal. This is separate from the password strength implementation but can be stacked with it so that both strength and history checks are performed. This history implementation is available only via the Heimdal external password quality interface. MIT Kerberos includes its own password history implementation. requirements: | For Heimdal, you may use either the external password quality check tool, installed as heimdal-strength, or the plugin as you choose. It has been tested with Heimdal 1.2.1 and later, but has not recently been tested with versions prior to 7.0. For MIT Kerberos, version 1.9 or higher is required for the password quality plugin interface. MIT Kerberos does not support an external password quality check tool directly, so you will need to install the plugin. You can optionally build against the system CrackLib library. Any version should be supported, but note that some versions, particularly older versions close to the original code, do things like printing diagnostics to stderr, calling exit, and otherwise not being well-behaved for use inside plugins or libraries. They also have known security vulnerabilities. If using a system CrackLib library, use version 2.8.22 or later to avoid these problems. You can also optionally build against the TinyCDB library, which provides support for simpler and faster password checking against a CDB dictionary file, and the SQLite library (a version new enough to support the `sqlite3_open_v2` API; 3.7 should be more than sufficient), which provides support for checking whether passwords are within edit distance one of a dictionary word. For this module to be effective for either Heimdal or MIT Kerberos, you will also need to construct a dictionary. The `mkdict` and `packer` utilities to build a CrackLib dictionary from a word list are included in this toolkit but not installed by default. You can run them out of the `cracklib` directory after building. You can also use the utilities that come with the stock CrackLib package (often already packaged in a Linux distribution); the database format is compatible. For building a CDB or SQLite dictionary, use the provided `krb5-strength-wordlist` program. For CDB dictionries, the `cdb` utility must be on your `PATH`. For SQLite, the DBI and DBD::SQLite Perl modules are required. `krb5-strength-wordlist` requires Perl 5.010 or later. For a word list to use as source for the dictionary, you can use `/usr/share/dict/words` if it's available on your system, but it would be better to find a more comprehensive word list. Since word lists are bulky, often covered by murky copyrights, and easily locatable on the Internet with a modicum of searching, none are included in this toolkit. The password history program, heimdal-history, requires Perl 5.010 or later plus the following CPAN modules: * Const::Fast * Crypt::PBKDF2 * DB_File::Lock * Getopt::Long::Descriptive * IPC::Run * JSON::MaybeXS and their dependencies. test: lancaster: true suffix: | To run the test suite, you will need Perl 5.010 or later and the dependencies of the `heimdal-history` program. The following additional Perl modules will also be used by the test suite if present: * Perl6::Slurp * Test::MinimumVersion * Test::Perl::Critic * Test::Pod * Test::Spelling * Test::Strict All are available on CPAN. Some tests will be skipped if the modules are not available.