diff options
| -rw-r--r-- | doc/guix.texi | 11 | ||||
| -rw-r--r-- | gnu/services/base.scm | 62 |
2 files changed, 72 insertions, 1 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index bb75425a9f..01363c1d13 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -7355,6 +7355,17 @@ Return a service that runs the Guix build daemon according to Run @var{udev}, which populates the @file{/dev} directory dynamically. @end deffn +@deffn {Scheme Procedure} urandom-seed-service @var{#f} +Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom} +when rebooting. +@end deffn + +@defvr {Scheme Variable} %random-seed-file +This is the name of the file where some random bytes are saved by +@var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting. +It defaults to @file{/var/lib/random-seed}. +@end defvr + @deffn {Scheme Procedure} console-keymap-service @var{files} ... @cindex keyboard layout Return a service to load console keymaps from @var{files} using diff --git a/gnu/services/base.scm b/gnu/services/base.scm index 96bf8da02a..a45f219643 100644 --- a/gnu/services/base.scm +++ b/gnu/services/base.scm @@ -3,6 +3,7 @@ ;;; Copyright © 2015, 2016 Alex Kost <alezost@gmail.com> ;;; Copyright © 2015 Mark H Weaver <mhw@netris.org> ;;; Copyright © 2015 Sou Bunnbu <iyzsong@gmail.com> +;;; Copyright © 2016 Leo Famulari <leo@famulari.name> ;;; ;;; This file is part of GNU Guix. ;;; @@ -93,6 +94,8 @@ gpm-service-type gpm-service + urandom-seed-service + %base-services)) ;;; Commentary: @@ -422,6 +425,63 @@ stopped before 'kill' is called." ;;; +;;; Preserve entropy to seed /dev/urandom on boot. +;;; + +(define %random-seed-file + "/var/lib/random-seed") + +(define %urandom-seed-activation + ;; Activation gexp for the urandom seed + #~(begin + (use-modules (guix build utils)) + + (mkdir-p (dirname #$%random-seed-file)) + (close-port (open-file #$%random-seed-file "a0b")) + (chmod #$%random-seed-file #o600))) + +(define (urandom-seed-shepherd-service _) + "Return a shepherd service for the /dev/urandom seed." + (list (shepherd-service + (documentation "Preserve entropy across reboots for /dev/urandom.") + (provision '(urandom-seed)) + (requirement '(user-processes)) + (start #~(lambda _ + ;; On boot, write random seed into /dev/urandom. + (when (file-exists? #$%random-seed-file) + (call-with-input-file #$%random-seed-file + (lambda (seed) + (call-with-output-file "/dev/urandom" + (lambda (urandom) + (dump-port seed urandom)))))) + #t)) + (stop #~(lambda _ + ;; During shutdown, write from /dev/urandom into random seed. + (let ((buf (make-bytevector 512))) + (call-with-input-file "/dev/urandom" + (lambda (urandom) + (get-bytevector-n! urandom buf 0 512) + (call-with-output-file #$%random-seed-file + (lambda (seed) + (put-bytevector seed buf))) + #t))))) + (modules `((rnrs bytevectors) + (rnrs io ports) + ,@%default-modules))))) + +(define urandom-seed-service-type + (service-type (name 'urandom-seed) + (extensions + (list (service-extension shepherd-root-service-type + urandom-seed-shepherd-service) + (service-extension activation-service-type + (const %urandom-seed-activation)))))) + +(define (urandom-seed-service) + (service urandom-seed-service-type #f)) + + +;;; ;;; System-wide environment variables. ;;; @@ -1200,7 +1260,6 @@ extra rules from the packages listed in @var{rules}." "Return a service that uses @var{device} as a swap device." (service swap-service-type device)) - (define-record-type* <gpm-configuration> gpm-configuration make-gpm-configuration gpm-configuration? (gpm gpm-configuration-gpm) ;package @@ -1281,6 +1340,7 @@ This is the GNU operating system, welcome!\n\n"))) (static-networking-service "lo" "127.0.0.1" #:provision '(loopback)) (syslog-service) + (urandom-seed-service) (guix-service) (nscd-service) |