Add (guix gcrypt).

* guix/gcrypt.scm: New file.
* Makefile.am (MODULES): Add it.
* guix/pk-crypto.scm: Use it.
  (libgcrypt-func, gcrypt-version): Remove.

Makefile.am

@@ -30,6 +30,7 @@ MODULES =					\
   guix/base32.scm				\
   guix/base64.scm				\
   guix/records.scm				\
+  guix/gcrypt.scm				\
   guix/hash.scm					\
   guix/pk-crypto.scm				\
   guix/pki.scm					\

guix/gcrypt.scm

+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;; 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 (guix gcrypt)
+  #:use-module (guix config)
+  #:use-module (system foreign)
+  #:export (gcrypt-version
+            libgcrypt-func))
+
+;;; Commentary:
+;;;
+;;; Common code for the GNU Libgcrypt bindings.  Loading this module
+;;; initializes Libgcrypt as a side effect.
+;;;
+;;; Code:
+
+(define libgcrypt-func
+  (let ((lib (dynamic-link %libgcrypt)))
+    (lambda (func)
+      "Return a pointer to symbol FUNC in libgcrypt."
+      (dynamic-func func lib))))
+
+(define gcrypt-version
+  ;; According to the manual, this function must be called before any other,
+  ;; and it's not clear whether it can be called more than once.  So call it
+  ;; right here from the top level.
+  (let* ((ptr     (libgcrypt-func "gcry_check_version"))
+         (proc    (pointer->procedure '* ptr '(*)))
+         (version (pointer->string (proc %null-pointer))))
+    (lambda ()
+      "Return the version number of libgcrypt as a string."
+      version)))
+
+;;; gcrypt.scm ends here

guix/pk-crypto.scm

@@ -17,15 +17,15 @@
 ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
 
 (define-module (guix pk-crypto)
-  #:use-module (guix config)
   #:use-module ((guix utils)
                 #:select (bytevector->base16-string
                           base16-string->bytevector))
+  #:use-module (guix gcrypt)
+
   #:use-module (system foreign)
   #:use-module (rnrs bytevectors)
   #:use-module (ice-9 match)
-  #:export (gcrypt-version
-            canonical-sexp?
+  #:export (canonical-sexp?
             error-source
             error-string
             string->canonical-sexp
@@ -46,7 +46,8 @@ (define-module (guix pk-crypto)
             generate-key
             find-sexp-token
             canonical-sexp->sexp
-            sexp->canonical-sexp))
+            sexp->canonical-sexp)
+  #:re-export (gcrypt-version))
 
 
 ;;; Commentary:
@@ -81,23 +82,6 @@ (define-wrapped-pointer-type <canonical-sexp>
             (number->string (pointer-address (canonical-sexp->pointer obj))
                             16))))
 
-(define libgcrypt-func
-  (let ((lib (dynamic-link %libgcrypt)))
-    (lambda (func)
-      "Return a pointer to symbol FUNC in libgcrypt."
-      (dynamic-func func lib))))
-
-(define gcrypt-version
-  ;; According to the manual, this function must be called before any other,
-  ;; and it's not clear whether it can be called more than once.  So call it
-  ;; right here from the top level.
-  (let* ((ptr     (libgcrypt-func "gcry_check_version"))
-         (proc    (pointer->procedure '* ptr '(*)))
-         (version (pointer->string (proc %null-pointer))))
-    (lambda ()
-      "Return the version number of libgcrypt as a string."
-      version)))
-
 (define finalize-canonical-sexp!
   (libgcrypt-func "gcry_sexp_release"))