Harden Switch OTA install with TLS verification and reliable NRO replace.

Enable HTTPS peer checks via a romfs CA bundle, remove existing NROs before rename on sdmc, and surface launcher replace failures before writing version.txt.

native/switch-ota-launcher/Makefile

@@ -135,9 +135,15 @@ endif
 #---------------------------------------------------------------------------------
 all: sync-romfs $(BUILD)
 
+CACERT_URL	:=	https://curl.se/ca/cacert.pem
+CACERT_ROMFS	:=	$(CURDIR)/$(ROMFS)/cacert.pem
+
 sync-romfs:
 	@mkdir -p $(CURDIR)/$(ROMFS)
 	@cp -f $(LOGO_SRC) $(CURDIR)/$(ROMFS)/logo.png
+	@if ! curl -sfL --time-cond $(CACERT_ROMFS) -o $(CACERT_ROMFS) $(CACERT_URL); then \
+		[ -f $(CACERT_ROMFS) ] || (echo "sync-romfs: failed to fetch cacert.pem" && exit 1); \
+	fi
 
 $(BUILD): sync-romfs
 	@[ -d $@ ] || mkdir -p $@

native/switch-ota-launcher/README.md

@@ -69,5 +69,6 @@ Manifest: `scripts/switch/ota_launcher.manifest`.
 
 - Zip extraction uses `switch-zziplib` (`ota_unzip.c`) on device.
 - OTA replaces launcher + game from the install zip (NACP versions stay aligned).
+- HTTPS uses Mozilla CA bundle in romfs (`cacert.pem`, fetched at build time).
 - Sphaira HOME forwarders cache metadata until reinstalled (see docs/switch-install.md).
 - Release runner: `switch-dev` + (`install_devkitpro_deps.sh` **or** Docker)

native/switch-ota-launcher/src/main.c

@@ -185,14 +185,29 @@ static int run_update_flow(const char *install_dir) {
   }
   remove(extracted);
 
+  int have_launcher = 0;
   if (ota_unzip_extract_file(zip_path, LAUNCHER_MEMBER_IN_ZIP, extracted_launcher, err,
                              sizeof(err)) == 0 ||
       ota_unzip_extract_file(zip_path, OTA_LAUNCHER_NRO_NAME, extracted_launcher, err,
                              sizeof(err)) == 0) {
-    (void)ota_fs_atomic_replace_nro(install_dir, OTA_LAUNCHER_NRO_NAME, extracted_launcher, err,
-                                    sizeof(err));
-    remove(extracted_launcher);
+    have_launcher = 1;
   }
+  if (!have_launcher) {
+    remove(zip_path);
+    show_update_error("Could not extract",
+                      "Update zip is missing launcher files.", err, installed);
+    return 0;
+  }
+  if (ota_fs_atomic_replace_nro(install_dir, OTA_LAUNCHER_NRO_NAME, extracted_launcher, err,
+                                sizeof(err)) != 0) {
+    remove(extracted_launcher);
+    remove(zip_path);
+    show_update_error("Could not install",
+                      "Game updated but launcher could not be replaced. Reinstall from the SD zip.",
+                      err, installed);
+    return 0;
+  }
+  remove(extracted_launcher);
 
   char vpath[192];
   snprintf(vpath, sizeof(vpath), "%s/version.txt", install_dir);

native/switch-ota-launcher/src/ota_fs.c

@@ -104,9 +104,8 @@ int ota_fs_atomic_replace_nro(const char *install_dir, const char *nro_name,
     if (err && err_len) snprintf(err, err_len, "copy to .part failed (%s)", nro_name);
     return -1;
   }
-#ifdef _WIN32
+  /* sdmc/FAT (Switch) and Windows do not replace an existing dest on rename. */
   remove(dest);
-#endif
   if (rename(part, dest) != 0) {
     if (err && err_len) snprintf(err, err_len, "rename .part -> %s failed", nro_name);
     remove(part);

native/switch-ota-launcher/src/ota_net.c

@@ -10,6 +10,14 @@
 #endif
 
 #if defined(__SWITCH__)
+#define OTA_CA_BUNDLE "romfs:/cacert.pem"
+
+static void ota_net_configure_tls(CURL *curl) {
+  curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 1L);
+  curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 2L);
+  curl_easy_setopt(curl, CURLOPT_CAINFO, OTA_CA_BUNDLE);
+}
+
 struct mem_buf {
   char *data;
   size_t len;
@@ -76,8 +84,7 @@ int ota_net_download_buffer(const char *url, long timeout_ms, char **out, size_t
   curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS, timeout_ms);
   curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_mem);
   curl_easy_setopt(curl, CURLOPT_WRITEDATA, &mem);
-  curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
-  curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
+  ota_net_configure_tls(curl);
   CURLcode rc = curl_easy_perform(curl);
   curl_easy_cleanup(curl);
   if (rc != CURLE_OK) {
@@ -122,8 +129,7 @@ int ota_net_download_file(const char *url, const char *path, long timeout_ms, ch
   curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS, timeout_ms);
   curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_file);
   curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp);
-  curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
-  curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
+  ota_net_configure_tls(curl);
   if (progress) {
     curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0L);
     curl_easy_setopt(curl, CURLOPT_XFERINFOFUNCTION, xfer_progress);