1 files changed, 23 insertions, 17 deletions
diff --git a/nixos/modules/services/misc/nix-ssh-serve.nix b/nixos/modules/services/misc/nix-ssh-serve.nix
index 80e7961b1f82..d70bd855c7ff 100644
--- a/nixos/modules/services/misc/nix-ssh-serve.nix
+++ b/nixos/modules/services/misc/nix-ssh-serve.nix
@@ -1,32 +1,35 @@
 { config, lib, pkgs, ... }:
 
-let
-  serveOnly = pkgs.writeScript "nix-store-serve" ''
-    #!${pkgs.stdenv.shell}
-    if [ "$SSH_ORIGINAL_COMMAND" != "nix-store --serve" ]; then
-      echo 'Error: You are only allowed to run `nix-store --serve'\'''!' >&2
-      exit 1
-    fi
-    exec /run/current-system/sw/bin/nix-store --serve
-  '';
-
-  inherit (lib) mkIf mkOption types;
-in {
+with lib;
+
+{
   options = {
+
     nix.sshServe = {
+
       enable = mkOption {
-        description = "Whether to enable serving the nix store over ssh.";
-        default = false;
         type = types.bool;
+        default = false;
+        description = "Whether to enable serving the Nix store as a binary cache via SSH.";
+      };
+
+      keys = mkOption {
+        type = types.listOf types.str;
+        default = [];
+        example = [ "ssh-dss AAAAB3NzaC1k... alice@example.org" ];
+        description = "A list of SSH public keys allowed to access the binary cache via SSH.";
       };
+
     };
+
   };
 
   config = mkIf config.nix.sshServe.enable {
+
     users.extraUsers.nix-ssh = {
-      description = "User for running nix-store --serve.";
+      description = "Nix SSH substituter user";
       uid = config.ids.uids.nix-ssh;
-      shell = pkgs.stdenv.shell;
+      useDefaultShell = true;
     };
 
     services.openssh.enable = true;
@@ -38,8 +41,11 @@ in {
         PermitTTY no
         PermitTunnel no
         X11Forwarding no
-        ForceCommand ${serveOnly}
+        ForceCommand ${config.nix.package}/bin/nix-store --serve
       Match All
     '';
+
+    users.extraUsers.nix-ssh.openssh.authorizedKeys.keys = config.nix.sshServe.keys;
+
   };
 }