aboutsummaryrefslogtreecommitdiff
path: root/gnu/build/bootloader.scm
diff options
context:
space:
mode:
Diffstat (limited to 'gnu/build/bootloader.scm')
0 files changed, 0 insertions, 0 deletions
56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014-2019, 2022 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016 David Craven <david@craven.ch>
;;; Copyright © 2016 Julien Lepiller <julien@lepiller.eu>
;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org>
;;; Copyright © 2019 Ricardo Wurmus <rekado@elephly.net>
;;; Copyright © 2020 pinoaffe <pinoaffe@airmail.cc>
;;; Copyright © 2020 Oleg Pykhalov <go.wigust@gmail.com>
;;; Copyright © 2020 Brice Waegeneire <brice@waegenei.re>
;;; Copyright © 2021 Tobias Geerinckx-Rice <me@tobias.gr>
;;;
;;; 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 (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 services web)
  #:use-module (gnu system pam)
  #:use-module (gnu system shadow)
  #:use-module (guix deprecation)
  #:use-module (guix gexp)
  #:use-module (guix records)
  #:use-module (guix modules)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-26)
  #:use-module (ice-9 match)
  #:use-module (ice-9 vlist)
  #:export (lsh-configuration
            lsh-configuration?
            lsh-service
            lsh-service-type

            openssh-configuration
            openssh-configuration?
            openssh-service-type

            dropbear-configuration
            dropbear-configuration?
            dropbear-service-type
            dropbear-service

            autossh-configuration
            autossh-configuration?
            autossh-service-type

            webssh-configuration
            webssh-configuration?
            webssh-service-type
            %webssh-configuration-nginx))

;;; Commentary:
;;;
;;; This module implements secure shell (SSH) services.
;;;
;;; Code:

(define-record-type* <lsh-configuration>
  lsh-configuration make-lsh-configuration
  lsh-configuration?
  (lsh lsh-configuration-lsh
       (default lsh))
  (daemonic? lsh-configuration-daemonic?)
  (host-key lsh-configuration-host-key)
  (interfaces lsh-configuration-interfaces)
  (port-number lsh-configuration-port-number)
  (allow-empty-passwords? lsh-configuration-allow-empty-passwords?)
  (root-login? lsh-configuration-root-login?)
  (syslog-output? lsh-configuration-syslog-output?)
  (pid-file? lsh-configuration-pid-file?)
  (pid-file lsh-configuration-pid-file)
  (x11-forwarding? lsh-configuration-x11-forwarding?)
  (tcp/ip-forwarding? lsh-configuration-tcp/ip-forwarding?)
  (password-authentication? lsh-configuration-password-authentication?)
  (public-key-authentication? lsh-configuration-public-key-authentication?)
  (initialize? lsh-configuration-initialize?))

(define %yarrow-seed
  "/var/spool/lsh/yarrow-seed-file")

(define (lsh-initialization lsh host-key)
  "Return the gexp to initialize the LSH service for HOST-KEY."
  #~(begin
      (unless (file-exists? #$%yarrow-seed)
        (system* (string-append #$lsh "/bin/lsh-make-seed")
                 "--sloppy" "-o" #$%yarrow-seed))

      (unless (file-exists? #$host-key)
        (mkdir-p (dirname #$host-key))
        (format #t "creating SSH host key '~a'...~%" #$host-key)

        ;; FIXME: We're just doing a simple pipeline, but 'system' cannot be
        ;; used yet because /bin/sh might be dangling; factorize this somehow.
        (let* ((in+out (pipe))
               (keygen (primitive-fork)))
          (case keygen
            ((0)
             (close-port (car in+out))
             (close-fdes 1)
             (dup2 (fileno (cdr in+out)) 1)
             (execl (string-append #$lsh "/bin/lsh-keygen")
                    "lsh-keygen" "--server"))
            (else
             (let ((write-key (primitive-fork)))
               (case write-key
                 ((0)
                  (close-port (cdr in+out))
                  (close-fdes 0)
                  (dup2 (fileno (car in+out)) 0)
                  (execl (string-append #$lsh "/bin/lsh-writekey")
                         "lsh-writekey" "--server" "-o" #$host-key))
                 (else
                  (close-port (car in+out))
                  (close-port (cdr in+out))
                  (waitpid keygen)
                  (waitpid write-key))))))))))

(define (lsh-activation config)
  "Return the activation gexp for CONFIG."
  #~(begin
      (use-modules (guix build utils))
      (mkdir-p "/var/spool/lsh")
      #$(if (lsh-configuration-initialize? config)
            (lsh-initialization (lsh-configuration-lsh config)
                                (lsh-configuration-host-key config))
            #t)))

(define (lsh-shepherd-service config)
  "Return a <shepherd-service> for lsh with CONFIG."
  (define lsh (lsh-configuration-lsh config))
  (define pid-file (lsh-configuration-pid-file config))
  (define pid-file? (lsh-configuration-pid-file? config))
  (define daemonic? (lsh-configuration-daemonic? config))
  (define interfaces (lsh-configuration-interfaces config))

  (define lsh-command
    (append
     (cons (file-append lsh "/sbin/lshd")
           (if daemonic?
               (let ((syslog (if (lsh-configuration-syslog-output? config)
                                 '()
                                 (list "--no-syslog"))))
                 (cons "--daemonic"
                       (if pid-file?
                           (cons #~(string-append "--pid-file=" #$pid-file)
                                 syslog)
                           (cons "--no-pid-file" syslog))))
               (if pid-file?
                   (list #~(string-append "--pid-file=" #$pid-file))
                   '())))
     (cons* #~(string-append "--host-key="
                             #$(lsh-configuration-host-key config))
            #~(string-append "--password-helper=" #$lsh "/sbin/lsh-pam-checkpw")
            #~(string-append "--subsystems=sftp=" #$lsh "/sbin/sftp-server")
            "-p" (number->string (lsh-configuration-port-number config))
            (if (lsh-configuration-password-authentication? config)
                "--password" "--no-password")
            (if (lsh-configuration-public-key-authentication? config)
                "--publickey" "--no-publickey")
            (if (lsh-configuration-root-login? config)
                "--root-login" "--no-root-login")
            (if (lsh-configuration-x11-forwarding? config)
                "--x11-forward" "--no-x11-forward")
            (if (lsh-configuration-tcp/ip-forwarding? config)
                "--tcpip-forward" "--no-tcpip-forward")
            (if (null? interfaces)
                '()
                (map (cut string-append "--interface=" <>)
                     interfaces)))))

  (define requires
    (if (and daemonic? (lsh-configuration-syslog-output? config))
        '(networking syslogd)
        '(networking)))

  (list (shepherd-service
         (documentation "GNU lsh SSH server")
         (provision '(ssh-daemon ssh sshd))
         (requirement requires)
         (start #~(make-forkexec-constructor (list #$@lsh-command)))
         (stop  #~(make-kill-destructor)))))

(define (lsh-pam-services config)
  "Return a list of <pam-services> for lshd with CONFIG."
  (list (unix-pam-service
         "lshd"
         #:login-uid? #t
         #:allow-empty-passwords?
         (lsh-configuration-allow-empty-passwords? config))))

(define lsh-service-type
  (service-type (name 'lsh)
                (description
                 "Run the GNU@tie{}lsh secure shell (SSH) daemon,
@command{lshd}.")
                (extensions
                 (list (service-extension shepherd-root-service-type
                                          lsh-shepherd-service)
                       (service-extension pam-root-service-type
                                          lsh-pam-services)
                       (service-extension activation-service-type
                                          lsh-activation)))))

(define* (lsh-service #:key
                      (lsh lsh)
                      (daemonic? #t)
                      (host-key "/etc/lsh/host-key")
                      (interfaces '())
                      (port-number 22)
                      (allow-empty-passwords? #f)
                      (root-login? #f)
                      (syslog-output? #t)
                      (pid-file? #f)
                      (pid-file "/var/run/lshd.pid")
                      (x11-forwarding? #t)
                      (tcp/ip-forwarding? #t)
                      (password-authentication? #t)
                      (public-key-authentication? #t)
                      (initialize? #t))
  "Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
@var{host-key} must designate a file containing the host key, and readable
only by root.

When @var{daemonic?} is true, @command{lshd} will detach from the
controlling terminal and log its output to syslogd, unless one sets
@var{syslog-output?} to false.  Obviously, it also makes lsh-service
depend on existence of syslogd service.  When @var{pid-file?} is true,
@command{lshd} writes its PID to the file called @var{pid-file}.

When @var{initialize?} is true, automatically create the seed and host key
upon service activation if they do not exist yet.  This may take long and
require interaction.

When @var{initialize?} is false, it is up to the user to initialize the
randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
a key pair with the private key stored in file @var{host-key} (@pxref{lshd
basics,,, lsh, LSH Manual}).

When @var{interfaces} is empty, lshd listens for connections on all the
network interfaces; otherwise, @var{interfaces} must be a list of host names
or addresses.

@var{allow-empty-passwords?} specifies whether to accept log-ins with empty
passwords, and @var{root-login?} specifies whether to accept log-ins as
root.

The other options should be self-descriptive."
  (service lsh-service-type
           (lsh-configuration (lsh lsh) (daemonic? daemonic?)
                              (host-key host-key) (interfaces interfaces)
                              (port-number port-number)
                              (allow-empty-passwords? allow-empty-passwords?)
                              (root-login? root-login?)
                              (syslog-output? syslog-output?)
                              (pid-file? pid-file?) (pid-file pid-file)
                              (x11-forwarding? x11-forwarding?)
                              (tcp/ip-forwarding? tcp/ip-forwarding?)
                              (password-authentication?
                               password-authentication?)
                              (public-key-authentication?
                               public-key-authentication?)
                              (initialize? initialize?))))


;;;
;;; OpenSSH.
;;;

(define-record-type* <openssh-configuration>
  openssh-configuration make-openssh-configuration
  openssh-configuration?
  ;; file-like object
  (openssh               openssh-configuration-openssh
                         (default openssh))
  ;; string
  (pid-file              openssh-configuration-pid-file
                         (default "/var/run/sshd.pid"))
  ;; integer
  (port-number           openssh-configuration-port-number
                         (default 22))
  ;; integer
  (max-connections       openssh-configuration-max-connections
                         (default 200))
  ;; Boolean | 'prohibit-password
  (permit-root-login     openssh-configuration-permit-root-login
                         (default #f))
  ;; Boolean
  (allow-empty-passwords? openssh-configuration-allow-empty-passwords?
                          (default #f))
  ;; Boolean
  (password-authentication? openssh-configuration-password-authentication?
                            (default #t))
  ;; Boolean
  (public-key-authentication? openssh-configuration-public-key-authentication?
                              (default #t))
  ;; Boolean
  (x11-forwarding?       openssh-configuration-x11-forwarding?
                         (default #f))

  ;; Boolean
  (allow-agent-forwarding? openssh-configuration-allow-agent-forwarding?
                           (default #t))

  ;; Boolean
  (allow-tcp-forwarding? openssh-configuration-allow-tcp-forwarding?
                         (default #t))

  ;; Boolean
  (gateway-ports? openssh-configuration-gateway-ports?
                         (default #f))

  ;; Boolean
  (challenge-response-authentication? openssh-challenge-response-authentication?
                                      (default #f))
  ;; Boolean
  (use-pam?              openssh-configuration-use-pam?
                         (default #t))
  ;; Boolean
  (print-last-log?       openssh-configuration-print-last-log?
                         (default #t))
  ;; list of two-element lists
  (subsystems            openssh-configuration-subsystems
                         (default '(("sftp" "internal-sftp"))))

  ;; list of strings
  (accepted-environment  openssh-configuration-accepted-environment
                         (default '()))

  ;; symbol
  (log-level             openssh-configuration-log-level
                         (default 'info))

  ;; String
  ;; This is an "escape hatch" to provide configuration that isn't yet
  ;; supported by this configuration record.
  (extra-content         openssh-configuration-extra-content
                         (default ""))

  ;; list of user-name/file-like tuples
  (authorized-keys       openssh-configuration-authorized-keys
                         (default '()))

  ;; Boolean
  (generate-host-keys?   openssh-configuration-generate-host-keys?
                         (default #t))

  ;; Boolean
  ;; XXX: This should really be handled in an orthogonal way, for instance as
  ;; proposed in <https://bugs.gnu.org/27155>.  Keep it internal/undocumented
  ;; for now.
  (%auto-start?          openssh-auto-start?
                         (default #t)))

(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 (file-append shadow "/sbin/nologin")))))

(define (openssh-activation config)
  "Return the activation GEXP for CONFIG."
  (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-configuration-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))))

        (when #$(openssh-configuration-generate-host-keys? config)
          ;; Generate missing host keys.
          (system* (string-append #$(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."
  (computed-file
   "sshd_config"
   #~(begin
       (use-modules (ice-9 match))
       (call-with-output-file #$output
         (lambda (port)
           (display "# Generated by 'openssh-service'.\n" port)
           (format port "Port ~a\n"
                   #$(number->string
                      (openssh-configuration-port-number config)))
           (format port "PermitRootLogin ~a\n"
                   #$(match (openssh-configuration-permit-root-login config)
                       (#t "yes")
                       (#f "no")
                       ('without-password (warn-about-deprecation
                                           'without-password #f
                                           #:replacement 'prohibit-password)
                                          "prohibit-password")
                       ('prohibit-password "prohibit-password")))
           (format port "PermitEmptyPasswords ~a\n"
                   #$(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-public-key-authentication?
                          config)
                         "yes" "no"))
           (format port "X11Forwarding ~a\n"
                   #$(if (openssh-configuration-x11-forwarding? config)
                         "yes" "no"))
           (format port "AllowAgentForwarding ~a\n"
                   #$(if (openssh-configuration-allow-agent-forwarding? config)
                         "yes" "no"))
           (format port "AllowTcpForwarding ~a\n"
                   #$(if (openssh-configuration-allow-tcp-forwarding? config)
                         "yes" "no"))
           (format port "GatewayPorts ~a\n"
                   #$(if (openssh-configuration-gateway-ports? config)
                         "yes" "no"))
           (format port "PidFile ~a\n"
                   #$(openssh-configuration-pid-file config))
           (format port "ChallengeResponseAuthentication ~a\n"
                   #$(if (openssh-challenge-response-authentication? config)
                         "yes" "no"))
           (format port "UsePAM ~a\n"
                   #$(if (openssh-configuration-use-pam? config)
                         "yes" "no"))
           (format port "PrintLastLog ~a\n"
                   #$(if (openssh-configuration-print-last-log? config)
                         "yes" "no"))
           (format port "LogLevel ~a\n"
                   #$(string-upcase
                      (symbol->string
                       (openssh-configuration-log-level config))))

           ;; 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 (lambda (s) (format port "AcceptEnv ~a\n" s))
                     '#$(openssh-configuration-accepted-environment config))

           (for-each
            (match-lambda
              ((name command) (format port "Subsystem\t~a\t~a\n" name command)))
            '#$(openssh-configuration-subsystems config))

           (format port "~a\n"
                   #$(openssh-configuration-extra-content config))
           #t)))))

(define (openssh-shepherd-service config)
  "Return a <shepherd-service> for openssh with CONFIG."

  (define pid-file
    (openssh-configuration-pid-file config))

  (define port-number
    (openssh-configuration-port-number config))

  (define max-connections
    (openssh-configuration-max-connections config))

  (define openssh-command
    #~(list (string-append #$(openssh-configuration-openssh config) "/sbin/sshd")
            "-D" "-f" #$(openssh-config-file config)))

  (list (shepherd-service
         (documentation "OpenSSH server.")
         (requirement '(syslogd loopback))
         (provision '(ssh-daemon ssh sshd))
         (start #~(if (defined? 'make-inetd-constructor)
                      (make-inetd-constructor
                       (append #$openssh-command '("-i"))
                       (make-socket-address AF_INET INADDR_ANY
                                            #$port-number)
                       #:max-connections #$max-connections)
                      (make-forkexec-constructor #$openssh-command
                                                 #:pid-file #$pid-file)))
         (stop #~(if (defined? 'make-inetd-destructor)
                     (make-inetd-destructor)
                     (make-kill-destructor)))
         (auto-start? (openssh-auto-start? config)))))

(define (openssh-pam-services config)
  "Return a list of <pam-services> for sshd with CONFIG."
  (list (unix-pam-service
         "sshd"
         #:login-uid? #t
         #:allow-empty-passwords?
         (openssh-configuration-allow-empty-passwords? config))))

(define (extend-openssh-authorized-keys config keys)
  "Extend CONFIG with the extra authorized keys listed in KEYS."
  (openssh-configuration
   (inherit config)
   (authorized-keys
    (match (openssh-configuration-authorized-keys config)
      (((users _ ...) ...)
       ;; Build a user/key-list mapping.
       (let ((user-keys (alist->vhash
                         (openssh-configuration-authorized-keys config))))
         ;; Coalesce the key lists associated with each user.
         (map (lambda (user)
                `(,user
                  ,@(concatenate (vhash-fold* cons '() user user-keys))))
              users)))))))

(define openssh-service-type
  (service-type (name 'openssh)
                (description
                 "Run the OpenSSH secure shell (SSH) server, @command{sshd}.")
                (extensions
                 (list (service-extension shepherd-root-service-type
                                          openssh-shepherd-service)
                       (service-extension pam-root-service-type
                                          openssh-pam-services)
                       (service-extension activation-service-type
                                          openssh-activation)
                       (service-extension account-service-type
                                          (const %openssh-accounts))

                       ;; Install OpenSSH in the system profile.  That way,
                       ;; 'scp' is found when someone tries to copy to or from
                       ;; this machine.
                       (service-extension profile-service-type
                                          (lambda (config)
                                            (list (openssh-configuration-openssh
                                                   config))))))
                (compose concatenate)
                (extend extend-openssh-authorized-keys)
                (default-value (openssh-configuration))))


;;;
;;; Dropbear.
;;;

(define-record-type* <dropbear-configuration>
  dropbear-configuration make-dropbear-configuration
  dropbear-configuration?
  (dropbear               dropbear-configuration-dropbear
                          (default dropbear))
  (port-number            dropbear-configuration-port-number
                          (default 22))
  (syslog-output?         dropbear-configuration-syslog-output?
                          (default #t))
  (pid-file               dropbear-configuration-pid-file
                          (default "/var/run/dropbear.pid"))
  (root-login?            dropbear-configuration-root-login?
                          (default #f))
  (allow-empty-passwords? dropbear-configuration-allow-empty-passwords?
                          (default #f))
  (password-authentication? dropbear-configuration-password-authentication?
                            (default #t)))

(define (dropbear-activation config)
  "Return the activation gexp for CONFIG."
  #~(begin
      (use-modules (guix build utils))
      (mkdir-p "/etc/dropbear")))

(define (dropbear-shepherd-service config)
  "Return a <shepherd-service> for dropbear with CONFIG."
  (define dropbear
    (dropbear-configuration-dropbear config))

  (define pid-file
    (dropbear-configuration-pid-file config))

  (define dropbear-command
    #~(list (string-append #$dropbear "/sbin/dropbear")

            ;; '-R' allows host keys to be automatically generated upon first
            ;; connection, at a time when /dev/urandom is more likely securely
            ;; seeded.
            "-F" "-R"

            "-p" #$(number->string (dropbear-configuration-port-number config))
            "-P" #$pid-file
            #$@(if (dropbear-configuration-syslog-output? config) '() '("-E"))
            #$@(if (dropbear-configuration-root-login? config) '() '("-w"))
            #$@(if (dropbear-configuration-password-authentication? config)
                   '()
                   '("-s" "-g"))
            #$@(if (dropbear-configuration-allow-empty-passwords? config)
                   '("-B")
                   '())))

  (define requires
    (if (dropbear-configuration-syslog-output? config)
        '(networking syslogd) '(networking)))

  (list (shepherd-service
         (documentation "Dropbear SSH server.")
         (requirement requires)
         (provision '(ssh-daemon ssh sshd))
         (start #~(make-forkexec-constructor #$dropbear-command
                                             #:pid-file #$pid-file))
         (stop #~(make-kill-destructor)))))

(define dropbear-service-type
  (service-type (name 'dropbear)
                (description
                 "Run the Dropbear secure shell (SSH) server.")
                (extensions
                 (list (service-extension shepherd-root-service-type
                                          dropbear-shepherd-service)
                       (service-extension activation-service-type
                                          dropbear-activation)))
                (default-value (dropbear-configuration))))

(define* (dropbear-service #:optional (config (dropbear-configuration)))
  "Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
daemon} with the given @var{config}, a @code{<dropbear-configuration>}
object."
  (service dropbear-service-type config))


;;;
;;; AutoSSH.
;;;


(define-record-type* <autossh-configuration>
  autossh-configuration make-autossh-configuration
  autossh-configuration?
  (user            autossh-configuration-user
                   (default "autossh"))
  (poll            autossh-configuration-poll
                   (default 600))
  (first-poll      autossh-configuration-first-poll
                   (default #f))
  (gate-time       autossh-configuration-gate-time
                   (default 30))
  (log-level       autossh-configuration-log-level
                   (default 1))
  (max-start       autossh-configuration-max-start
                   (default #f))
  (message         autossh-configuration-message
                   (default ""))
  (port            autossh-configuration-port
                   (default "0"))
  (ssh-options     autossh-configuration-ssh-options
                   (default '())))

(define (autossh-file-name config file)
  "Return a path in /var/run/autossh/ that is writable
   by @code{user} from @code{config}."
  (string-append "/var/run/autossh/"
                 (autossh-configuration-user config)
                 "/" file))

(define (autossh-shepherd-service config)
  (shepherd-service
   (documentation "Automatically set up ssh connections (and keep them alive).")
   (provision '(autossh))
   (start #~(make-forkexec-constructor
             (list #$(file-append autossh "/bin/autossh")
                   #$@(autossh-configuration-ssh-options config))
             #:user #$(autossh-configuration-user config)
             #:group (passwd:gid (getpw #$(autossh-configuration-user config)))
             #:pid-file #$(autossh-file-name config "pid")
             #:log-file #$(autossh-file-name config "log")
             #:environment-variables
             '(#$(string-append "AUTOSSH_PIDFILE="
                                (autossh-file-name config "pid"))
               #$(string-append "AUTOSSH_LOGFILE="
                                (autossh-file-name config "log"))
               #$(string-append "AUTOSSH_POLL="
                                (number->string
                                 (autossh-configuration-poll config)))
               #$(string-append "AUTOSSH_FIRST_POLL="
                                (number->string
                                 (or
                                  (autossh-configuration-first-poll config)
                                  (autossh-configuration-poll config))))
               #$(string-append "AUTOSSH_GATETIME="
                                (number->string
                                 (autossh-configuration-gate-time config)))
               #$(string-append "AUTOSSH_LOGLEVEL="
                                (number->string
                                 (autossh-configuration-log-level config)))
               #$(string-append "AUTOSSH_MAXSTART="
                                (number->string
                                 (or (autossh-configuration-max-start config)
                                     -1)))
               #$(string-append "AUTOSSH_MESSAGE="
                                (autossh-configuration-message config))
               #$(string-append "AUTOSSH_PORT="
                                (autossh-configuration-port config)))))
   (stop #~(make-kill-destructor))))

(define (autossh-service-activation config)
  (with-imported-modules '((guix build utils))
    #~(begin
        (use-modules (guix build utils))
        (define %user
          (getpw #$(autossh-configuration-user config)))
        (let* ((directory #$(autossh-file-name config ""))
               (log (string-append directory "/log")))
          (mkdir-p directory)
          (chown directory (passwd:uid %user) (passwd:gid %user))
          (call-with-output-file log (const #t))
          (chown log (passwd:uid %user) (passwd:gid %user))))))

(define autossh-service-type
  (service-type
   (name 'autossh)
   (description "Automatically set up ssh connections (and keep them alive).")
   (extensions
    (list (service-extension shepherd-root-service-type
                             (compose list autossh-shepherd-service))
          (service-extension activation-service-type
                             autossh-service-activation)))
   (default-value (autossh-configuration))))


;;;
;;; WebSSH
;;;

(define-record-type* <webssh-configuration>
  webssh-configuration make-webssh-configuration
  webssh-configuration?
  (package     webssh-configuration-package     ;file-like
               (default webssh))
  (user-name   webssh-configuration-user-name   ;string
               (default "webssh"))
  (group-name  webssh-configuration-group-name  ;string
               (default "webssh"))
  (policy      webssh-configuration-policy      ;symbol
               (default #f))
  (known-hosts webssh-configuration-known-hosts ;list of strings
               (default #f))
  (port        webssh-configuration-port        ;number
               (default #f))
  (address     webssh-configuration-address     ;string
               (default #f))
  (log-file    webssh-configuration-log-file    ;string
               (default "/var/log/webssh.log"))
  (log-level   webssh-configuration-log-level   ;symbol
               (default #f)))

(define %webssh-configuration-nginx
  (nginx-server-configuration
   (listen '("80"))
   (locations
    (list (nginx-location-configuration
           (uri "/")
           (body '("proxy_pass http://127.0.0.1:8888;"
                   "proxy_http_version 1.1;"
                   "proxy_read_timeout 300;"
                   "proxy_set_header Upgrade $http_upgrade;"
                   "proxy_set_header Connection \"upgrade\";"
                   "proxy_set_header Host $http_host;"
                   "proxy_set_header X-Real-IP $remote_addr;"
                   "proxy_set_header X-Real-PORT $remote_port;")))))))

(define webssh-account
  ;; Return the user accounts and user groups for CONFIG.
  (match-lambda
    (($ <webssh-configuration> _ user-name group-name _ _ _ _ _ _)
     (list (user-group
            (name group-name))
           (user-account
            (name user-name)
            (group group-name)
            (comment "webssh privilege separation user")
            (home-directory (string-append "/var/run/" user-name))
            (shell #~(string-append #$shadow "/sbin/nologin")))))))

(define webssh-activation
  ;; Return the activation GEXP for CONFIG.
  (match-lambda
    (($ <webssh-configuration> _ user-name group-name policy known-hosts _ _
                               log-file _)
     (with-imported-modules '((guix build utils))
       #~(begin
           (let* ((home-dir (string-append "/var/run/" #$user-name))
                  (ssh-dir (string-append home-dir "/.ssh"))
                  (known-hosts-file (string-append ssh-dir "/known_hosts")))
             (call-with-output-file #$log-file (const #t))
             (mkdir-p ssh-dir)
             (case '#$policy
               ((reject)
                (if '#$known-hosts
                    (call-with-output-file known-hosts-file
                      (lambda (port)
                        (for-each (lambda (host) (display host port) (newline port))
                                  '#$known-hosts)))
                    (display-hint (G_ "webssh: reject policy requires `known-hosts'.")))))
             (for-each (lambda (file)
                         (chown file
                                (passwd:uid (getpw #$user-name))
                                (group:gid (getpw #$group-name))))
                       (list #$log-file ssh-dir known-hosts-file))
             (chmod ssh-dir #o700)))))))

(define webssh-shepherd-service
  (match-lambda
    (($ <webssh-configuration> package user-name group-name policy _ port
                               address log-file log-level)
     (list (shepherd-service
            (provision '(webssh))
            (documentation "Run webssh daemon.")
            (start #~(make-forkexec-constructor
                      `(,(string-append #$webssh "/bin/wssh")
                        ,(string-append "--log-file-prefix=" #$log-file)
                        ,@(case '#$log-level
                            ((debug) '("--logging=debug"))
                            (else '()))
                        ,@(case '#$policy
                            ((reject) '("--policy=reject"))
                            (else '()))
                        ,@(if #$port
                              (list (string-append "--port=" (number->string #$port)))
                              '())
                        ,@(if #$address
                              (list (string-append "--address=" #$address))
                              '()))
                      #:user #$user-name
                      #:group #$group-name))
            (stop #~(make-kill-destructor)))))))

(define webssh-service-type
  (service-type
   (name 'webssh)
   (extensions
    (list (service-extension shepherd-root-service-type
                             webssh-shepherd-service)
          (service-extension account-service-type
                             webssh-account)
          (service-extension activation-service-type
                             webssh-activation)))
   (default-value (webssh-configuration))
   (description
    "Run the webssh.")))

;;; ssh.scm ends here