Add packages/passwdqc.md

docs/index.md

@@ -39,7 +39,7 @@ You'll normally install packages from the mirrors, which should just work. Howev
 ### Extra packages (for EL8 and EL9)
 
 - [lkrg](packages/lkrg.md) (Linux Kernel Runtime Guard)
-- [passwdqc](https://www.openwall.com/passwdqc/) (Password/passphrase strength checking and policy enforcement)
+- [passwdqc](packages/passwdqc.md) (Password/passphrase strength checking and policy enforcement)
 
 ### Extra packages (currently only for EL9)
 

docs/packages/passwdqc.md

@@ -0,0 +1,36 @@
+# Extra package: passwdqc
+
+## EL8 and EL9
+
+- Version `2.0.3-2.el9_2.security`
+- Based on upstream version `2.0.3-2` as packaged in Fedora
+
+### Package summary
+
+`passwdqc` is a password/passphrase strength checking and policy enforcement toolset, including a PAM module (`pam_passwdqc`), command-line programs (`pwqcheck`, `pwqfilter`, and `pwqgen`), and a library (`libpasswdqc`).
+
+More information is available on the [passwdqc homepage](https://www.openwall.com/passwdqc/) and in the documentation files (man pages and a README) included in the sub-packages below.
+
+### Usage in Rocky Linux
+
+There are 4 sub-packages:
+
+#### pam_passwdqc
+
+`pam_passwdqc` is a PAM module that is normally invoked on password changes by programs such as `passwd(1)`. It is capable of checking password or passphrase strength, enforcing a policy, and offering randomly-generated passphrases, with all of these features being optional and easily (re-)configurable.
+
+Merely installing this sub-package does not yet configure the system to use the PAM module. To do so, please edit PAM configuration files e.g. like [shown here](https://github.com/openwall/passwdqc/issues/19#issuecomment-1140262371).
+
+#### passwdqc-utils
+
+`pwqcheck` and `pwqgen` are standalone password/passphrase strength checking and random passphrase generator programs, respectively, which are usable from scripts.
+
+The `pwqfilter` program searches, creates, or updates binary passphrase filter files, which can also be used with `pwqcheck` and `pam_passwdqc`. This can be used for checking of user-provided passwords against existing data breaches, which is recommended in the current NIST guidance, specifically in publication 800-63B sections 5.1.1.2 and A.3. Paid pre-generated filter files are available from Openwall at the project homepage above, but with this tool you can also generate your own.
+
+#### libpasswdqc
+
+`libpasswdqc` is the underlying library, which may also be used from third-party programs.
+
+#### passwdqc
+
+`passwdqc` is a meta sub-package that installs (via dependencies) all 3 actual sub-packages above.