Re: [PATCH] openssh service

[Julien Lepiller <julien@lepiller.eu>]

[-- Attachment #1: Type: text/plain, Size: 2104 bytes --]

On Fri, 26 Aug 2016 12:51:56 +0200
Andy Wingo <wingo@igalia.com> wrote:

> Hi Julien,
> 
> Thanks for the documentation update!
> 
> On Fri 19 Aug 2016 16:31, Julien Lepiller <julien@lepiller.eu> writes:
> 
> > +@deffn {Scheme Procedure} openssh-service [#:pidfile
> > "/var/run/sshd.pid"] @
> > +       [#:port-number 22] [#:root-login "without-password"] @
> > +       [#:allow-empty-passwords #f] [#:password-authentication?
> > #t] @
> > +       [#:pubkey-authentication? #t] [#:rsa-authentication? #t] @
> > +       [#:x11-forwarding? #f] [#:protocol-number "2"]
> > +"Run the @command{sshd} program from @var{openssh} on port
> > @var{port-number}. +@command{sshd} runs an ssh daemon and writes
> > its PID to @var{pidfile}. It +understands ssh protocol
> > @var{protocol-number}. The @var{protocol-number} can +be one of
> > \"1\", \"2\" or \"1,2\". +
> > +@var{PermitRootLogin} takes one of @var{yes},
> > @var{without-password} and +@var{no}. It is used to allow root
> > login through ssh. @var{without-password} +means that root login is
> > allowed, except when loging with a password (eg: a +public key).  
> 
> The variable needs to be changed to @var{root-login} (and I think
> probably @var{permit-root-login} would be more expected), and probably
> "without-password" should be a symbol rather than a string.  In
> general I think naming the keywords after the upstream options is
> going to be the least confusing thing for users.  Consider changing
> from yes/no/without-password to #t/#f/without-password, and renaming
> the option to #:permit-root-login?.  Consider requiring that the
> protocol number be either 1 or 2.  In general we want to make errors
> happen early, when building the OS, rather than when the OS is booted.

Sorry for the delay, here is a new version of the patch.

Meanwhile, sysconfdir was set to /etc, but I changed this for /etc/ssh,
because openssh looks for its configuration and other files (about 10)
directly in sysconfdir, not a subdirectory. Also, I fixed a mistake in
openssh-service (it was not following what the doc said).

> 
> WDYT?
> 
> Andy


[-- Attachment #2: 0001-services-Add-openssh.patch --]
[-- Type: text/x-patch, Size: 9701 bytes --]

From cf879a47c8f9b0733fac906cd4bd28dc646aa9fb Mon Sep 17 00:00:00 2001
From: Julien Lepiller <julien@lepiller.eu>
Date: Fri, 5 Aug 2016 15:20:15 +0200
Subject: [PATCH] services: Add openssh

* gnu/packages/ssh.scm: Openssh reads its configuration from /etc
* gnu/services/ssh.scm: Add openssh-service
* doc/guix.texi (Networking Services): Document 'openssh-services'.
---
 doc/guix.texi        |  34 ++++++++++++++
 gnu/packages/ssh.scm |   2 +-
 gnu/services/ssh.scm | 127 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 161 insertions(+), 2 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index 808fbdc..bcd8b6b 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -8199,6 +8199,40 @@ root.
 The other options should be self-descriptive.
 @end deffn
 
+@deffn {Scheme Procedure} openssh-service [#:pidfile "/var/run/sshd.pid"] @
+       [#:port-number 22] [#:permit-root-login 'without-password] @
+       [#:allow-empty-passwords #f] [#:password-authentication? #t] @
+       [#:pubkey-authentication? #t] [#:rsa-authentication? #t] @
+       [#:x11-forwarding? #f] [#:protocol-number "2"]
+"Run the @command{sshd} program from @var{openssh} on port @var{port-number}.
+@command{sshd} runs an ssh daemon and writes its PID to @var{pidfile}. It
+understands ssh protocol @var{protocol-number}. The @var{protocol-number} can
+be either 1 or 2.
+
+@var{permit-root-login} takes one of @var{yes}, @var{without-password} and
+@var{no}. It is used to allow root login through ssh. @var{without-password}
+means that root login is allowed, except when loging with a password (eg: a
+public key).
+
+When @var{allow-empty-passwords?} is true, users with empty passwords may log
+in. When false, they may not.
+
+When @var{password-authentication?} is true, users may log in with their
+password. When false, they have to use other means of authentication.
+
+When @var{pubkey-authentication?} is true, users may log in using public key
+authentication. When false, users have to use other means of authentication.
+Authorized public keys are stored in ~/.ssh/authorized_keys. This is used only
+by protocol 2.
+
+When @var{rsa-authentication?} is true, users may log in using pure RSA
+authentication. When false, users have to use other means of authentication.
+This is used only by protocol 1.
+
+When @var{x11-forwarding} is true, @command{ssh} options -X and -Y will work.
+
+@end deffn
+
 @deffn {Scheme Procedure} dropbear-service [@var{config}]
 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
diff --git a/gnu/packages/ssh.scm b/gnu/packages/ssh.scm
index b2612a4..88bfd06 100644
--- a/gnu/packages/ssh.scm
+++ b/gnu/packages/ssh.scm
@@ -144,7 +144,7 @@ a server that supports the SSH-2 protocol.")
              ("xauth" ,xauth)))                   ;for 'ssh -X' and 'ssh -Y'
    (arguments
     `(#:test-target "tests"
-      #:configure-flags '("--sysconfdir=/etc"
+      #:configure-flags '("--sysconfdir=/etc/ssh"
 
                           ;; Default value of 'PATH' used by sshd.
                           "--with-default-path=/run/current-system/profile/bin"
diff --git a/gnu/services/ssh.scm b/gnu/services/ssh.scm
index 462988c..5484463 100644
--- a/gnu/services/ssh.scm
+++ b/gnu/services/ssh.scm
@@ -19,9 +19,11 @@
 
 (define-module (gnu services ssh)
   #:use-module (gnu packages ssh)
+  #:use-module (gnu packages admin)
   #:use-module (gnu services)
   #:use-module (gnu services shepherd)
   #:use-module (gnu system pam)
+  #:use-module (gnu system shadow)
   #:use-module (guix gexp)
   #:use-module (guix records)
   #:use-module (srfi srfi-26)
@@ -30,6 +32,11 @@
             lsh-service
             lsh-service-type
 
+            openssh-configuration
+            openssh-configuration?
+            openssh-service-type
+            openssh-service
+
             dropbear-configuration
             dropbear-configuration?
             dropbear-service-type
@@ -244,7 +251,125 @@ The other options should be self-descriptive."
                                public-key-authentication?)
                               (initialize? initialize?))))
 
-\f
+;;;
+;;; OpenSSH.
+;;;
+
+(define-record-type* <openssh-configuration>
+  openssh-configuration make-openssh-configuration
+  openssh-configuration?
+  (pidfile               openssh-configuration-pidfile)
+  (port-number           openssh-configuration-port-number)
+  (permit-root-login?    openssh-configuration-permit-root-login)
+  (allow-empty-passwords? openssh-configuration-allow-empty-passwords?)
+  (password-authentication? openssh-configuration-password-authentication?)
+  (pubkey-authentication? openssh-configuration-pubkey-authentication?)
+  (rsa-authentication?   openssh-configuration-rsa-authentication?)
+  (x11-forwarding?       openssh-configuration-x11-forwarding?)
+  (protocol-number       openssh-configuration-protocol-number))
+
+(define %openssh-accounts
+  (list (user-group (name "sshd") (system? #t))
+        (user-account
+          (name "sshd")
+          (group "sshd")
+          (system? #t)
+          (comment "sshd privilege separation user")
+          (home-directory "/var/run/sshd")
+          (shell #~(string-append #$shadow "/sbin/nologin")))))
+
+(define (openssh-activation config)
+  "Return the activation GEXP for CONFIG."
+  #~(begin
+      (mkdir-p "/etc/ssh")
+      (mkdir-p (basename #$(openssh-configuration-pidfile config)))
+      (system* (string-append #$openssh "/bin/ssh-keygen") "-A")
+      (call-with-output-file "/etc/ssh/sshd_config"
+         (lambda (port)
+           (display
+             "# Generated by 'openssh-service'.\n"
+             port)
+           (format port "Protocol ~a\n"
+              #$(if (eq? (openssh-configuration-protocol-number config) 1)
+                     "1" "2"))
+           (format port "Port ~a\n" 
+              #$(number->string (openssh-configuration-port-number config)))
+           (format port "PermitRootLogin ~a\n"
+              #$(if (eq? (openssh-configuration-permit-root-login config) #t)
+                    "yes" (if (eq?
+                              (openssh-configuration-permit-root-login config)
+                               #f)
+                               "no" "without-password")))
+           (format port "PermitEmptyPasswords ~a\n"
+              #$(if (openssh-configuration-allow-empty-passwords? config)
+                    "yes" "no"))
+           (format port "PasswordAuthentication ~a\n"
+              #$(if (openssh-configuration-password-authentication? config)
+                    "yes" "no"))
+           (format port "PubkeyAuthentication ~a\n"
+              #$(if (openssh-configuration-pubkey-authentication? config)
+                    "yes" "no"))
+           (format port "RSAAuthentication ~a\n"
+              #$(if (openssh-configuration-rsa-authentication? config)
+                    "yes" "no"))
+           (format port "X11Forwarding ~a\n"
+              #$(if (openssh-configuration-x11-forwarding? config)
+                    "yes" "no"))
+           (format port "PidFile ~a\n"
+              #$(openssh-configuration-pidfile config))))))
+
+(define (openssh-shepherd-service config)
+  "Return a <shepherd-service> for openssh with CONFIG."
+
+  (define pid-file
+    (openssh-configuration-pidfile config))
+
+  (define openssh-command
+    #~(list (string-append #$openssh "/sbin/sshd")
+            "-D"))
+
+  (define requires
+        '(networking syslogd))
+
+  (list (shepherd-service
+         (documentation "Openssh SSH server.")
+         (requirement requires)
+         (provision '(ssh-daemon))
+         (start #~(make-forkexec-constructor #$openssh-command
+                                             #:pid-file #$pid-file))
+         (stop #~(make-kill-destructor)))))
+
+(define openssh-service-type
+  (service-type (name 'openssh)
+                (extensions
+                 (list (service-extension shepherd-root-service-type
+                                          openssh-shepherd-service)
+                       (service-extension activation-service-type
+                                          openssh-activation)
+                       (service-extension account-service-type
+                                          (const %openssh-accounts))))))
+
+(define* (openssh-service #:key 
+                          (pidfile "/var/run/sshd.pid")
+                          (port-number 22)
+                          (permit-root-login? 'without-password)
+                          (allow-empty-passwords? #f)
+                          (password-authentication? #t)
+                          (pubkey-authentication? #t)
+                          (rsa-authentication? #t)
+                          (x11-forwarding? #f)
+                          (protocol-number 2))
+  (service openssh-service-type (openssh-configuration (pidfile pidfile)
+                                 (port-number port-number)
+                                 (permit-root-login? permit-root-login?)
+                                 (allow-empty-passwords? allow-empty-passwords?)
+                                 (password-authentication? password-authentication?)
+                                 (pubkey-authentication? pubkey-authentication?)
+                                 (rsa-authentication? rsa-authentication?)
+                                 (x11-forwarding? x11-forwarding?)
+                                 (protocol-number protocol-number))))
+
+                                                                                
 ;;;
 ;;; Dropbear.
 ;;;
-- 
2.10.0