feat(snaps-utils): Allow overriding allowed protocols in validateLink

packages/snaps-controllers/src/interface/SnapInterfaceController.ts

@@ -272,6 +272,7 @@ export class SnapInterfaceController extends BaseController<
     );
 
     await this.#triggerPhishingListUpdate();
+    // TODO: Expose configuration for allowedProtocols in validateJsxLinks
     validateJsxLinks(element, this.#checkPhishingList.bind(this));
   }
 }

packages/snaps-rpc-methods/src/restricted/notify.ts

@@ -111,15 +111,19 @@ export const notifyBuilder = Object.freeze({
  * @param hooks.showInAppNotification - A function that shows a notification in the MetaMask UI.
  * @param hooks.isOnPhishingList - A function that checks for links against the phishing list.
  * @param hooks.maybeUpdatePhishingList - A function that updates the phishing list if needed.
+ * @param allowedProtocols - Allowed protocols for links (example: ['https:']).
  * @returns The method implementation which returns `null` on success.
  * @throws If the params are invalid.
  */
-export function getImplementation({
-  showNativeNotification,
-  showInAppNotification,
-  isOnPhishingList,
-  maybeUpdatePhishingList,
-}: NotifyMethodHooks) {
+export function getImplementation(
+  {
+    showNativeNotification,
+    showInAppNotification,
+    isOnPhishingList,
+    maybeUpdatePhishingList,
+  }: NotifyMethodHooks,
+  allowedProtocols?: string[],
+) {
   return async function implementation(
     args: RestrictedMethodOptions<NotifyParams>,
   ): Promise<NotifyResult> {
@@ -132,7 +136,11 @@ export function getImplementation({
 
     await maybeUpdatePhishingList();
 
-    validateTextLinks(validatedParams.message, isOnPhishingList);
+    validateTextLinks(
+      validatedParams.message,
+      isOnPhishingList,
+      allowedProtocols,
+    );
 
     switch (validatedParams.type) {
       case NotificationType.Native:

packages/snaps-utils/coverage.json

@@ -1,5 +1,5 @@
 {
-  "branches": 96.7,
+  "branches": 96.72,
   "functions": 98.72,
   "lines": 98.81,
   "statements": 94.79

packages/snaps-utils/src/ui.test.tsx

@@ -615,6 +615,31 @@ describe('validateTextLinks', () => {
       'Invalid URL: Unable to parse URL.',
     );
   });
+
+  it('handles custom protocols', () => {
+    const allowedProtocols = ['http:', 'file:'];
+    expect(() =>
+      validateTextLinks(
+        '[test](http://foo.bar)',
+        () => false,
+        allowedProtocols,
+      ),
+    ).not.toThrow();
+    expect(() =>
+      validateTextLinks(
+        '[test](https://foo.bar)',
+        () => false,
+        allowedProtocols,
+      ),
+    ).toThrow('Invalid URL: Protocol must be one of: http:, file:.');
+    expect(() =>
+      validateTextLinks(
+        '<file:///var/www/index.html>',
+        () => false,
+        allowedProtocols,
+      ),
+    ).not.toThrow();
+  });
 });
 
 describe('validateJsxLinks', () => {

packages/snaps-utils/src/ui.tsx

@@ -40,7 +40,7 @@ import { lexer, walkTokens } from 'marked';
 import type { Token, Tokens } from 'marked';
 
 const MAX_TEXT_LENGTH = 50_000; // 50 kb
-const ALLOWED_PROTOCOLS = ['https:', 'mailto:'];
+const DEFAULT_ALLOWED_PROTOCOLS = ['https:', 'mailto:'];
 
 /**
  * Get the button variant from a legacy button component variant.
@@ -320,16 +320,18 @@ function getMarkdownLinks(text: string) {
  * @param link - The link to validate.
  * @param isOnPhishingList - The function that checks the link against the
  * phishing list.
+ * @param allowedProtocols - Allowed protocols (example: ['https:']).
  */
 function validateLink(
   link: string,
   isOnPhishingList: (url: string) => boolean,
+  allowedProtocols: string[],
 ) {
   try {
     const url = new URL(link);
     assert(
-      ALLOWED_PROTOCOLS.includes(url.protocol),
-      `Protocol must be one of: ${ALLOWED_PROTOCOLS.join(', ')}.`,
+      allowedProtocols.includes(url.protocol),
+      `Protocol must be one of: ${allowedProtocols.join(', ')}.`,
     );
 
     const hostname =
@@ -352,16 +354,18 @@ function validateLink(
  * @param text - The text to verify.
  * @param isOnPhishingList - The function that checks the link against the
  * phishing list.
+ * @param allowedProtocols - Allowed protocols (example: ['https:']).
  * @throws If the text contains a link that is not allowed.
  */
 export function validateTextLinks(
   text: string,
   isOnPhishingList: (url: string) => boolean,
+  allowedProtocols: string[] = DEFAULT_ALLOWED_PROTOCOLS,
 ) {
   const links = getMarkdownLinks(text);
 
   for (const link of links) {
-    validateLink(link.href, isOnPhishingList);
+    validateLink(link.href, isOnPhishingList, allowedProtocols);
   }
 }
 
@@ -372,17 +376,19 @@ export function validateTextLinks(
  * @param node - The JSX node to walk.
  * @param isOnPhishingList - The function that checks the link against the
  * phishing list.
+ * @param allowedProtocols - Allowed protocols (example: ['https:']).
  */
 export function validateJsxLinks(
   node: JSXElement,
   isOnPhishingList: (url: string) => boolean,
+  allowedProtocols: string[] = DEFAULT_ALLOWED_PROTOCOLS,
 ) {
   walkJsx(node, (childNode) => {
     if (childNode.type !== 'Link') {
       return;
     }
 
-    validateLink(childNode.props.href, isOnPhishingList);
+    validateLink(childNode.props.href, isOnPhishingList, allowedProtocols);
   });
 }