gnu: Add oath-toolkit.

* gnu/packages/authentication.scm: New file.
(oath-toolkit): New public variable.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add the new file.

gnu/local.mk

@@ -68,6 +68,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/packages/attr.scm				\
   %D%/packages/audio.scm			\
   %D%/packages/augeas.scm			\
+  %D%/packages/authentication.scm		\
   %D%/packages/autogen.scm			\
   %D%/packages/autotools.scm			\
   %D%/packages/avahi.scm			\

gnu/packages/authentication.scm

@@ -0,0 +1,77 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2018 Tobias Geerinckx-Rice <me@tobias.gr>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (gnu packages authentication)
+  #:use-module (gnu packages linux)
+  #:use-module (gnu packages pkg-config)
+  #:use-module (guix build-system gnu)
+  #:use-module (guix download)
+  #:use-module ((guix licenses) #:prefix license:)
+  #:use-module (guix packages))
+
+(define-public oath-toolkit
+  ;; If gcc@7 breaks this package before its next release, try patching it:
+  ;; <https://gitlab.com/oath-toolkit/oath-toolkit/issues/2#note_52958748>.
+  (package
+    (name "oath-toolkit")
+    (version "2.6.2")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (string-append "https://download.savannah.nongnu.org/releases/"
+                           name "/" name "-" version ".tar.gz"))
+       (sha256
+        (base32 "182ah8vfbg0yhv6mh1b6ap944d0na6x7lpfkwkmzb6jl9gx4cd5h"))))
+    (build-system gnu-build-system)
+    (arguments
+     ;; TODO ‘--enable-pskc’ causes xmlsec-related test suite failures.
+     `(#:configure-flags
+       (list "--enable-pam")
+       #:phases
+       (modify-phases %standard-phases
+         (add-after 'install 'delete-static-libraries
+           (lambda* (#:key outputs #:allow-other-keys)
+             (let* ((out (assoc-ref outputs "out"))
+                    (lib (string-append out "/lib")))
+               (for-each delete-file (find-files lib "\\.a$"))
+               #t))))))
+    (native-inputs
+     `(("pkg-config" ,pkg-config)))
+    (inputs
+     `(("linux-pam" ,linux-pam)))       ; for --enable-pam
+    (home-page "https://www.nongnu.org/oath-toolkit/")
+    (synopsis "One-time password (OTP) components")
+    ;; TODO Add the following items after they've been enabled.
+    ;; @item @command{pskctool}, a command-line tool for manipulating secret key
+    ;; files in the Portable Symmetric Key Container (@dfn{PSKC}) format
+    ;; described in RFC6030.
+    ;; @item @code{libpskc}, a shared and static C library for PSKC handling.
+    (description
+     "The @dfn{OATH} (Open AuTHentication) Toolkit provides various components
+for building one-time password (@dfn{OTP}) authentication systems:
+
+@itemize
+@item @command{oathtool}, a command-line tool for generating & validating OTPs.
+@item @code{liboath}, a C library for OATH handling.
+@item @code{pam_oath}, a PAM module for pluggable login authentication.
+@end itemize
+
+Supported technologies include the event-based @dfn{HOTP} algorithm (RFC4226)
+and the time-based @dfn{TOTP} algorithm (RFC6238).")
+    (license (list license:lgpl2.1+     ; the libraries (liboath/ & libpskc/)
+                   license:gpl3+))))    ; the tools (everything else)