;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2022 Ludovic Courtès ;;; ;;; 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 . (define-module (gnu home services ssh) #:use-module (guix gexp) #:use-module (guix records) #:use-module (guix diagnostics) #:use-module (guix i18n) #:use-module (gnu services) #:use-module (gnu services configuration) #:use-module (guix modules) #:use-module (gnu home services) #:use-module ((gnu home services utils) #:select (object->camel-case-string)) #:autoload (gnu packages base) (glibc-utf8-locales) #:use-module (srfi srfi-1) #:use-module (srfi srfi-34) #:use-module (srfi srfi-35) #:use-module (ice-9 match) #:export (home-openssh-configuration home-openssh-configuration-authorized-keys home-openssh-configuration-known-hosts home-openssh-configuration-hosts openssh-host openssh-host-host-name openssh-host-identity-file openssh-host-name openssh-host-port openssh-host-user openssh-host-forward-x11? openssh-host-forward-x11-trusted? openssh-host-forward-agent? openssh-host-compression? openssh-host-proxy-command openssh-host-host-key-algorithms openssh-host-accepted-key-types openssh-host-extra-content home-openssh-service-type)) (define (serialize-field-name name) (match name ('accepted-key-types "PubkeyAcceptedKeyTypes") (_ (let ((name (let ((str (symbol->string name))) (if (string-suffix? "?" str) (string->symbol (string-drop-right str 1)) name)))) (object->camel-case-string name 'upper))))) (define (serialize-string field value) (string-append " " (serialize-field-name field) " " value "\n")) (define (address-family? obj) (memv obj (list AF_INET AF_INET6))) (define-maybe address-family) (define (serialize-address-family field family) (if (maybe-value-set? family) (string-append " " (serialize-field-name field) " " (cond ((= family AF_INET) "inet") ((= family AF_INET6) "inet6") ;; The 'else' branch is unreachable. (else (raise (condition (&error))))) "\n") "")) (define (natural-number? obj) (and (integer? obj) (exact? obj) (> obj 0))) (define (serialize-natural-number field value) (string-append " " (serialize-field-name field) " " (number->string value) "\n")) (define (serialize-boolean field value) (string-append " " (serialize-field-name field) " " (if value "yes" "no") "\n")) (define-maybe string) (define-maybe natural-number) (define (serialize-raw-configuration-string field value) (string-append value "\n")) (define raw-configuration-string? string?) (define (string-list? lst) (and (pair? lst) (every string? lst))) (define (serialize-string-list field lst) (string-append " " (serialize-field-name field) " " (string-join lst ",") "\n")) (define-maybe string-list) (define-configuration openssh-host (name (string) "Name of this host declaration.") (host-name maybe-string "Host name---e.g., @code{\"foo.example.org\"} or @code{\"192.168.1.2\"}.") (address-family maybe-address-family "Address family to use when connecting to this host: one of @code{AF_INET} (for IPv4 only), @code{AF_INET6} (for IPv6 only). Additionally, the field can be left unset to allow any address family.") (identity-file maybe-string "The identity file to use---e.g., @code{\"/home/charlie/.ssh/id_ed25519\"}.") (port maybe-natural-number "TCP port number to connect to.") (user maybe-string "User name on the remote host.") (forward-x11? (boolean #f) "Whether to forward remote client connections to the local X11 graphical display.") (forward-x11-trusted? (boolean #f) "Whether remote X11 clients have full access to the original X11 graphical display.") (forward-agent? (boolean #f) "Whether the authentication agent (if any) is forwarded to the remote machine.") (compression? (boolean #f) "Whether to compress data in transit.") (proxy-command maybe-string "The command to use to connect to the server. As an example, a command to connect via an HTTP proxy at 192.0.2.0 would be: @code{\"nc -X connect -x 192.0.2.0:8080 %h %p\"}.") (host-key-algorithms maybe-string-list "The list of accepted host key algorithms---e.g., @code{'(\"ssh-ed25519\")}.") (accepted-key-types maybe-string-list "The list of accepted user public key types.") (extra-content (raw-configuration-string "") "Extra content appended as-is to this @code{Host} block in @file{~/.ssh/config}.")) (define (serialize-openssh-host config) (define (openssh-host-name-field? field) (eq? (configuration-field-name field) 'name)) (string-append "Host " (openssh-host-name config) "\n" (string-concatenate (map (lambda (field) ((configuration-field-serializer field) (configuration-field-name field) ((configuration-field-getter field) config))) (remove openssh-host-name-field? openssh-host-fields))))) (define-record-type* home-openssh-configuration make-home-openssh-configuration home-openssh-configuration? (authorized-keys home-openssh-configuration-authorized-keys ;list of file-like (default '())) (known-hosts home-openssh-configuration-known-hosts ;unspec | list of file-like (default *unspecified*)) (hosts home-openssh-configuration-hosts ;list of (default '()))) (define (openssh-configuration->string config) (string-join (map serialize-openssh-host (home-openssh-configuration-hosts config)) "\n")) (define* (file-join name files #:optional (delimiter " ")) "Return a file in the store called @var{name} that is the concatenation of all the file-like objects listed in @var{files}, with @var{delimited} inserted after each of them." (computed-file name (with-imported-modules '((guix build utils)) #~(begin (use-modules (guix build utils)) ;; Support non-ASCII file names. (setenv "GUIX_LOCPATH" #+(file-append glibc-utf8-locales "/lib/locale")) (setlocale LC_ALL "en_US.utf8") (call-with-output-file #$output (lambda (output) (for-each (lambda (file) (call-with-input-file file (lambda (input) (dump-port input output))) (display #$delimiter output)) '#$files))))))) (define (openssh-configuration-files config) (let ((config (plain-file "ssh.conf" (openssh-configuration->string config))) (known-hosts (home-openssh-configuration-known-hosts config)) (authorized-keys (file-join "authorized_keys" (home-openssh-configuration-authorized-keys config) "\n"))) `((".ssh/authorized_keys" ,authorized-keys) ,@(if (unspecified? known-hosts) '() `((".ssh/known_hosts" ,(file-join "known_hosts" known-hosts "\n")))) (".ssh/config" ,config)))) (define openssh-activation (with-imported-modules (source-module-closure '((gnu build activation))) #~(begin (use-modules (gnu build activation)) ;; Make sure ~/.ssh is #o700. (let* ((home (getenv "HOME")) (dot-ssh (string-append home "/.ssh"))) (mkdir-p/perms dot-ssh (getpw (getuid)) #o700))))) (define home-openssh-service-type (service-type (name 'home-openssh) (extensions (list (service-extension home-files-service-type openssh-configuration-files) (service-extension home-activation-service-type (const openssh-activation)))) (description "Configure the OpenSSH @acronym{SSH, secure shell} client by providing a @file{~/.ssh/config} file, which is honored by the OpenSSH client,@command{ssh}, and by other tools such as @command{guix deploy}.") (default-value (home-openssh-configuration))))