mautrix-{meta,signal,whatsapp}: Optionally build against goolm

After olm gained knownVulnerabilities in #334638, allow building these
bridges using the pure-Go goolm library instead of libolm bindings.

(cherry picked from commit 8b17835)

pkgs/by-name/ma/mautrix-meta/package.nix

@@ -4,6 +4,12 @@
 , lib
 , nixosTests
 , olm
+# This option enables the use of an experimental pure-Go implementation of the
+# Olm protocol instead of libolm for end-to-end encryption. Using goolm is not
+# recommended by the mautrix developers, but they are interested in people
+# trying it out in non-production-critical environments and reporting any
+# issues they run into.
+, withGoolm ? false
 }:
 
 buildGoModule rec {
@@ -19,7 +25,8 @@ buildGoModule rec {
     hash = "sha256-whBqhdB2FSFfrbtGtq8v3pjXW7QMt+I0baHTXVGPWVg=";
   };
 
-  buildInputs = [ olm ];
+  buildInputs = lib.optional (!withGoolm) olm;
+  tags = lib.optional withGoolm "goolm";
 
   vendorHash = "sha256-rP9wvF6yYW0TdQ+vQV6ZcVMxnCtqz8xRcd9v+4pYYio=";
 

pkgs/servers/mautrix-signal/default.nix

@@ -1,4 +1,16 @@
-{ lib, buildGoModule, fetchFromGitHub, olm, libsignal-ffi }:
+{
+  lib,
+  buildGoModule,
+  fetchFromGitHub,
+  olm,
+  libsignal-ffi,
+  # This option enables the use of an experimental pure-Go implementation of
+  # the Olm protocol instead of libolm for end-to-end encryption. Using goolm
+  # is not recommended by the mautrix developers, but they are interested in
+  # people trying it out in non-production-critical environments and reporting
+  # any issues they run into.
+  withGoolm ? false,
+}:
 
 buildGoModule rec {
   pname = "mautrix-signal";
@@ -11,12 +23,12 @@ buildGoModule rec {
     hash = "sha256-KBb/rLYM2ne4VD/bPy/lcXD0avCx3J74e3zDcmg+Dzs=";
   };
 
-  buildInputs = [
-    olm
+  buildInputs = (lib.optional (!withGoolm) olm) ++ [
     # must match the version used in https://github.com/mautrix/signal/tree/main/pkg/libsignalgo
     # see https://github.com/mautrix/signal/issues/401
     libsignal-ffi
   ];
+  tags = lib.optional withGoolm "goolm";
 
   vendorHash = "sha256-DDcz4O3RhV6OVI+qC/LkDW/UsE5jOAn5t/gmILxHx1s=";
 

pkgs/servers/mautrix-whatsapp/default.nix

@@ -1,4 +1,15 @@
-{ lib, buildGoModule, fetchFromGitHub, olm }:
+{
+  lib,
+  buildGoModule,
+  fetchFromGitHub,
+  olm,
+  # This option enables the use of an experimental pure-Go implementation of
+  # the Olm protocol instead of libolm for end-to-end encryption. Using goolm
+  # is not recommended by the mautrix developers, but they are interested in
+  # people trying it out in non-production-critical environments and reporting
+  # any issues they run into.
+  withGoolm ? false,
+}:
 
 buildGoModule rec {
   pname = "mautrix-whatsapp";
@@ -11,7 +22,8 @@ buildGoModule rec {
     hash = "sha256-iVILI6OGndnxIVmgNcIwHA64tkv9V3OTH3YtrCyeYx4=";
   };
 
-  buildInputs = [ olm ];
+  buildInputs = lib.optional (!withGoolm) olm;
+  tags = lib.optional withGoolm "goolm";
 
   vendorHash = "sha256-DpgkSXSLF+U6zIzJ4AF2uTcFWQQYsRgkaUTG9F+bnVk=";