From 4892eb7c6a21416f3a18e18ca17984e2b66050ad Mon Sep 17 00:00:00 2001 From: Ludovic Courtès Date: Tue, 25 Jul 2017 15:27:58 +0200 Subject: services: openssh: Add 'authorized-keys' field. * gnu/services/ssh.scm ()[authorized-keys]: New field. (authorized-key-directory): New procedure. (openssh-config-file): Honor 'authorized-keys'. (openssh-activation): Use 'with-imported-modules'. Make /etc/ssh 755. Create /etc/ssh/authorized_keys.d. * doc/guix.texi (Networking Services): Document it. --- doc/guix.texi | 29 ++++++++++++++++-- gnu/services/ssh.scm | 86 +++++++++++++++++++++++++++++++++++++++++----------- 2 files changed, 96 insertions(+), 19 deletions(-) diff --git a/doc/guix.texi b/doc/guix.texi index 4d2c45e8a4..962bdc17f9 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -10203,7 +10203,10 @@ shell daemon, @command{sshd}. Its value must be an (service openssh-service-type (openssh-configuration (x11-forwarding? #t) - (permit-root-login 'without-password))) + (permit-root-login 'without-password) + (authorized-keys + `(("alice" ,(local-file "alice.pub")) + ("bob" ,(local-file "bob.pub")))))) @end example See below for details about @code{openssh-configuration}. @@ -10278,8 +10281,30 @@ server. Alternately, one can specify the @command{sftp-server} command: (service openssh-service-type (openssh-configuration (subsystems - '(("sftp" ,(file-append openssh "/libexec/sftp-server")))))) + `(("sftp" ,(file-append openssh "/libexec/sftp-server")))))) @end example + +@item @code{authorized-keys} (default: @code{'()}) +@cindex authorized keys, SSH +@cindex SSH authorized keys +This is the list of authorized keys. Each element of the list is a user +name followed by one or more file-like objects that represent SSH public +keys. For example: + +@example +(openssh-configuration + (authorized-keys + `(("rekado" ,(local-file "rekado.pub")) + ("chris" ,(local-file "chris.pub")) + ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub"))))) +@end example + +@noindent +registers the specified public keys for user accounts @code{rekado}, +@code{chris}, and @code{root}. + +Note that this does @emph{not} interfere with the use of +@file{~/.ssh/authorized_keys}. @end table @end deftp diff --git a/gnu/services/ssh.scm b/gnu/services/ssh.scm index 2a6c8d45c2..08635af16d 100644 --- a/gnu/services/ssh.scm +++ b/gnu/services/ssh.scm @@ -28,6 +28,7 @@ #:use-module (gnu system shadow) #:use-module (guix gexp) #:use-module (guix records) + #:use-module (guix modules) #:use-module (srfi srfi-26) #:use-module (ice-9 match) #:export (lsh-configuration @@ -295,7 +296,11 @@ The other options should be self-descriptive." (default #t)) ;; list of two-element lists (subsystems openssh-configuration-subsystems - (default '(("sftp" "internal-sftp"))))) + (default '(("sftp" "internal-sftp")))) + + ;; list of user-name/file-like tuples + (authorized-keys openssh-authorized-keys + (default '()))) (define %openssh-accounts (list (user-group (name "sshd") (system? #t)) @@ -309,22 +314,64 @@ The other options should be self-descriptive." (define (openssh-activation config) "Return the activation GEXP for CONFIG." - #~(begin - (use-modules (guix build utils)) - (mkdir-p "/etc/ssh") - (mkdir-p (dirname #$(openssh-configuration-pid-file config))) - - (define (touch file-name) - (call-with-output-file file-name (const #t))) - - (let ((lastlog "/var/log/lastlog")) - (when #$(openssh-configuration-print-last-log? config) - (unless (file-exists? lastlog) - (touch lastlog)))) - - ;; Generate missing host keys. - (system* (string-append #$(openssh-configuration-openssh config) - "/bin/ssh-keygen") "-A"))) + (with-imported-modules '((guix build utils)) + #~(begin + (use-modules (guix build utils)) + + (define (touch file-name) + (call-with-output-file file-name (const #t))) + + ;; Make sure /etc/ssh can be read by the 'sshd' user. + (mkdir-p "/etc/ssh") + (chmod "/etc/ssh" #o755) + (mkdir-p (dirname #$(openssh-configuration-pid-file config))) + + ;; 'sshd' complains if the authorized-key directory and its parents + ;; are group-writable, which rules out /gnu/store. Thus we copy the + ;; authorized-key directory to /etc. + (catch 'system-error + (lambda () + (delete-file-recursively "/etc/authorized_keys.d")) + (lambda args + (unless (= ENOENT (system-error-errno args)) + (apply throw args)))) + (copy-recursively #$(authorized-key-directory + (openssh-authorized-keys config)) + "/etc/ssh/authorized_keys.d") + + (chmod "/etc/ssh/authorized_keys.d" #o555) + + (let ((lastlog "/var/log/lastlog")) + (when #$(openssh-configuration-print-last-log? config) + (unless (file-exists? lastlog) + (touch lastlog)))) + + ;; Generate missing host keys. + (system* (string-append #$(openssh-configuration-openssh config) + "/bin/ssh-keygen") "-A")))) + +(define (authorized-key-directory keys) + "Return a directory containing the authorized keys specified in KEYS, a list +of user-name/file-like tuples." + (define build + (with-imported-modules (source-module-closure '((guix build utils))) + #~(begin + (use-modules (ice-9 match) (srfi srfi-26) + (guix build utils)) + + (mkdir #$output) + (for-each (match-lambda + ((user keys ...) + (let ((file (string-append #$output "/" user))) + (call-with-output-file file + (lambda (port) + (for-each (lambda (key) + (call-with-input-file key + (cut dump-port <> port))) + keys)))))) + '#$keys)))) + + (computed-file "openssh-authorized-keys" build)) (define (openssh-config-file config) "Return the sshd configuration file corresponding to CONFIG." @@ -367,6 +414,11 @@ The other options should be self-descriptive." (format port "PrintLastLog ~a\n" #$(if (openssh-configuration-print-last-log? config) "yes" "no")) + + ;; Add '/etc/authorized_keys.d/%u', which we populate. + (format port "AuthorizedKeysFile \ + .ssh/authorized_keys .ssh/authorized_keys2 /etc/ssh/authorized_keys.d/%u\n") + (for-each (match-lambda ((name command) (format port "Subsystem\t~a\t~a\n" name command))) -- cgit v1.2.3