Allow HTTP connections to fetch database

Introduce a new config option to allow requests over HTTP when fetching
a database from a URL.

extensions/ql-vscode/package.json

@@ -293,6 +293,11 @@
           "scope": "window",
           "minimum": 0,
           "description": "Report a warning for any join order whose metric exceeds this value."
+        },
+        "codeQL.allowHttp": {
+          "type": "boolean",
+          "default": false,
+          "description": "Allow databased to be downloaded via HTTP"
         }
       }
     },

extensions/ql-vscode/src/config.ts

@@ -608,3 +608,12 @@ export const CODESPACES_TEMPLATE = new Setting(
 export function isCodespacesTemplate() {
   return !!CODESPACES_TEMPLATE.getValue<boolean>();
 }
+
+export const ALLOW_HTTP = new Setting(
+  "allowHttp",
+  ROOT_SETTING,
+);
+
+export function allowHttp(): boolean {
+  return ALLOW_HTTP.getValue<boolean>() || false;
+}

extensions/ql-vscode/src/databaseFetcher.ts

@@ -27,6 +27,7 @@ import {
 } from "./common/github-url-identifier-helper";
 import { Credentials } from "./common/authentication";
 import { AppCommandManager } from "./common/commands";
+import { ALLOW_HTTP } from "./config";
 
 /**
  * Prompts a user to fetch a database from a remote location. Database is assumed to be an archive file.
@@ -49,7 +50,9 @@ export async function promptImportInternetDatabase(
     return;
   }
 
-  validateHttpsUrl(databaseUrl);
+  if (!ALLOW_HTTP.getValue()) {
+    validateHttpsUrl(databaseUrl);
+  }
 
   const item = await databaseArchiveFetcher(
     databaseUrl,