guix/hash.scm

   1 ;;; GNU Guix --- Functional package management for GNU
   2 ;;; Copyright © 2012, 2013 Ludovic Courtès <ludo@gnu.org>
   3 ;;;
   4 ;;; This file is part of GNU Guix.
   5 ;;;
   6 ;;; GNU Guix is free software; you can redistribute it and/or modify it
   7 ;;; under the terms of the GNU General Public License as published by
   8 ;;; the Free Software Foundation; either version 3 of the License, or (at
   9 ;;; your option) any later version.
  10 ;;;
  11 ;;; GNU Guix is distributed in the hope that it will be useful, but
  12 ;;; WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ;;; GNU General Public License for more details.
  15 ;;;
  16 ;;; You should have received a copy of the GNU General Public License
  17 ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 (define-module (guix hash)
  20   #:use-module (guix config)
  21   #:use-module (rnrs bytevectors)
  22   #:use-module (system foreign)
  23   #:export (sha256))
  24
  25 ;;; Commentary:
  26 ;;;
  27 ;;; Cryptographic hashes.
  28 ;;;
  29 ;;; Code:
  30
  31 \f
  32 ;;;
  33 ;;; Hash.
  34 ;;;
  35
  36 (define sha256
  37   (let ((hash   (pointer->procedure void
  38                                     (dynamic-func "gcry_md_hash_buffer"
  39                                                   (dynamic-link %libgcrypt))
  40                                     `(,int * * ,size_t)))
  41         (sha256 8))                        ; GCRY_MD_SHA256, as of 1.5.0
  42     (lambda (bv)
  43       "Return the SHA256 of BV as a bytevector."
  44       (let ((digest (make-bytevector (/ 256 8))))
  45         (hash sha256 (bytevector->pointer digest)
  46               (bytevector->pointer bv) (bytevector-length bv))
  47         digest))))
  48
  49 ;;; hash.scm ends here