nixos/browserpass: update for v3

See browserpass/browserpass-native#31

Additionally browserpass was removed from systemPackages, because it
doesn't need to be installed, browsers will get the path to the binary
from the native messaging host JSON.

(cherry picked from commit e98ee8d)

nixos/modules/programs/browserpass.nix

@@ -4,15 +4,34 @@ with lib;
 
 {
 
-  ###### interface
-  options = {
-    programs.browserpass.enable = mkEnableOption "the NativeMessaging configuration for Chromium, Chrome, and Vivaldi.";
-  };
+  options.programs.browserpass.enable = mkEnableOption "Browserpass native messaging host";
 
-  ###### implementation
   config = mkIf config.programs.browserpass.enable {
-    environment.systemPackages = [ pkgs.browserpass ];
-    environment.etc = {
+    environment.etc = let
+      appId = "com.github.browserpass.native.json";
+      source = part: "${pkgs.browserpass}/lib/browserpass/${part}/${appId}";
+    in {
+      # chromium
+      "chromium/native-messaging-hosts/${appId}".source = source "hosts/chromium";
+      "chromium/policies/managed/${appId}".source = source "policies/chromium";
+
+      # chrome
+      "opt/chrome/native-messaging-hosts/${appId}".source = source "hosts/chromium";
+      "opt/chrome/policies/managed/${appId}".source = source "policies/chromium";
+
+      # vivaldi
+      "opt/vivaldi/native-messaging-hosts/${appId}".source = source "hosts/chromium";
+      "opt/vivaldi/policies/managed/${appId}".source = source "policies/chromium";
+
+      # brave
+      "opt/brave/native-messaging-hosts/${appId}".source = source "hosts/chromium";
+      "opt/brave/policies/managed/${appId}".source = source "policies/chromium";
+    }
+    # As with the v2 backwards compatibility in the pkgs.browserpass
+    # declaration, this part can be removed once the browser extension
+    # auto-updates to v3 (planned 2019-04-13, see
+    # https://github.com/browserpass/browserpass-native/issues/31)
+    // {
       "chromium/native-messaging-hosts/com.dannyvankooten.browserpass.json".source = "${pkgs.browserpass}/etc/chrome-host.json";
       "chromium/policies/managed/com.dannyvankooten.browserpass.json".source = "${pkgs.browserpass}/etc/chrome-policy.json";
       "opt/chrome/native-messaging-hosts/com.dannyvankooten.browserpass.json".source = "${pkgs.browserpass}/etc/chrome-host.json";