guix-devel/guix/scripts/authenticate.scm

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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014 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 scripts authenticate)
#:use-module (guix config)
#:use-module (guix utils)
#:use-module (guix pk-crypto)
#:use-module (guix pki)
#:use-module (guix ui)
#:use-module (rnrs io ports)
#:use-module (ice-9 match)
#:export (guix-authenticate))
;;; Commentary:
;;;
;;; This program is used internally by the daemon to sign exported archive
;;; (the 'export-paths' RPC), and to authenticate imported archives (the
;;; 'import-paths' RPC.)
;;;
;;; Code:
(define (read-canonical-sexp file)
"Read a gcrypt sexp from FILE and return it."
(call-with-input-file file
(compose string->canonical-sexp get-string-all)))
(define (read-hash-data file)
"Read sha256 hash data from FILE and return it as a gcrypt sexp."
(let* ((hex (call-with-input-file file get-string-all))
(bv (base16-string->bytevector (string-trim-both hex))))
(bytevector->hash-data bv)))
;;;
;;; Entry point with 'openssl'-compatible interface. We support this
;;; interface because that's what the daemon expects, and we want to leave it
;;; unmodified currently.
;;;
(define (guix-authenticate . args)
(match args
(("rsautl" "-sign" "-inkey" key "-in" hash-file)
;; Sign the hash in HASH-FILE with KEY, and return an sexp that includes
;; both the hash and the actual signature.
(let* ((secret-key (read-canonical-sexp key))
(public-key (if (string-suffix? ".sec" key)
(read-canonical-sexp
(string-append (string-drop-right key 4) ".pub"))
(leave
(_ "cannot find public key for secret key '~a'~%")
key)))
(data (read-hash-data hash-file))
(signature (signature-sexp data secret-key public-key)))
(display (canonical-sexp->string signature))
#t))
(("rsautl" "-verify" "-inkey" _ "-pubin" "-in" signature-file)
;; Read the signature as produced above, check whether its public key is
;; authorized, and verify the signature, and print the signed data to
;; stdout upon success.
(let* ((signature (read-canonical-sexp signature-file))
(subject (signature-subject signature))
(data (signature-signed-data signature)))
(if (and data subject)
(if (authorized-key? subject)
(if (valid-signature? signature)
(let ((hash (hash-data->bytevector data)))
(display (bytevector->base16-string hash))
#t) ; success
(leave (_ "error: invalid signature: ~a~%")
(canonical-sexp->string signature)))
(leave (_ "error: unauthorized public key: ~a~%")
(canonical-sexp->string subject)))
(leave (_ "error: corrupt signature data: ~a~%")
(canonical-sexp->string signature)))))
(("--help")
(display (_ "Usage: guix authenticate OPTION...
Sign or verify the signature on the given file. This tool is meant to
be used internally by 'guix-daemon'.\n")))
(("--version")
(show-version-and-exit "guix authenticate"))
(else
(leave (_ "wrong arguments")))))
;;; authenticate.scm ends here