feat: add Network URL non-ascii -> punycode warning

app/components/UI/NetworkVerificationInfo/NetworkVerificationInfo.test.tsx

@@ -97,4 +97,37 @@ describe('NetworkVerificationInfo', () => {
 
     expect(getByText('10')).toBeTruthy();
   });
+
+  it('should not render Network URL warning banner when the custom rpc url has all ascii characters', () => {
+    (useSelector as jest.Mock).mockReturnValue(true);
+    const { getByText } = render(
+      <NetworkVerificationInfo
+        customNetworkInformation={mockNetworkInfo}
+        onReject={() => undefined}
+        onConfirm={() => undefined}
+      />,
+    );
+
+    expect(() =>
+      getByText('Attackers sometimes mimic sites by making small changes to the site address. Make sure you\'re interacting with the intended Network URL before you continue. Punycode version: https://xn--ifura-dig.io/gnosis')
+    ).toThrow('Unable to find an element with text');
+  });
+
+  describe('when the custom rpc url has non-ascii characters', () => {
+    it('should render Network URL warning banner and display punycode encoded version', () => {
+      (useSelector as jest.Mock).mockReturnValue(true);
+      const { getByText } = render(
+        <NetworkVerificationInfo
+          customNetworkInformation={{
+            ...mockNetworkInfo,
+            rpcUrl: 'https://iոfura.io/gnosis',
+          }}
+          onReject={() => undefined}
+          onConfirm={() => undefined}
+        />,
+      );
+
+      expect(getByText('Attackers sometimes mimic sites by making small changes to the site address. Make sure you\'re interacting with the intended Network URL before you continue. Punycode version: https://xn--ifura-dig.io/gnosis')).toBeTruthy();
+    });
+  });
 });

app/components/UI/NetworkVerificationInfo/NetworkVerificationInfo.tsx

@@ -43,6 +43,7 @@ import { toggleUseSafeChainsListValidation } from '../../../util/networks/engine
 import { NetworkApprovalBottomSheetSelectorsIDs } from '../../../../e2e/selectors/Network/NetworkApprovalBottomSheet.selectors';
 import hideKeyFromUrl from '../../../util/hideKeyFromUrl';
 import { convertHexToDecimal } from '@metamask/controller-utils';
+import { isValidASCIIURL, toPunycodeURL } from '../../../util/url';
 
 interface Alert {
   alertError: string;
@@ -83,6 +84,8 @@ const NetworkVerificationInfo = ({
   const showReviewDefaultRpcUrlChangesModal = () =>
     setShowReviewDefaultRpcUrlChanges(!showReviewDefaultRpcUrlChanges);
 
+  const customRpcUrl = customNetworkInformation.rpcUrl;
+
   const goToLearnMore = () => {
     Linking.openURL(
       'https://support.metamask.io/networks-and-sidechains/managing-networks/verifying-custom-network-information/',
@@ -237,7 +240,7 @@ const NetworkVerificationInfo = ({
         </Text>
       )}
       <Text style={styles.textSection}>
-        {hideKeyFromUrl(customNetworkInformation.rpcUrl)}
+        {hideKeyFromUrl(customRpcUrl)}
       </Text>
 
       <Accordion
@@ -291,6 +294,25 @@ const NetworkVerificationInfo = ({
     return null;
   };
 
+  const renderBannerNetworkUrlNonAsciiDetected = () => {
+    if (!customRpcUrl || isValidASCIIURL(customRpcUrl)) { return null; }
+    const punycodeUrl = toPunycodeURL(customRpcUrl);
+
+    return (
+      <View style={styles.alertBar}>
+        <Banner
+          severity={BannerAlertSeverity.Warning}
+          variant={BannerVariant.Alert}
+          description={
+            strings('networks.network_rpc_url_warning_punycode') +
+            '\n' +
+            punycodeUrl
+          }
+        />
+      </View>
+    );
+  };
+
   const renderCustomNetworkBanner = () => (
     <View style={styles.alertBar}>
       <Banner
@@ -332,7 +354,7 @@ const NetworkVerificationInfo = ({
             {strings('networks.current_label')}
           </Text>
           <Text style={styles.textSection}>
-            {customNetworkInformation.rpcUrl}
+            {customRpcUrl}
           </Text>
           <Text variant={TextVariant.BodyMDBold}>
             {strings('networks.new_label')}
@@ -442,6 +464,7 @@ const NetworkVerificationInfo = ({
         />
         {renderAlerts()}
         {renderBanner()}
+        {renderBannerNetworkUrlNonAsciiDetected()}
         {isMultichainVersion1Enabled &&
           isCustomNetwork &&
           renderCustomNetworkBanner()}

app/util/url/index.ts

@@ -1,5 +1,13 @@
 import AppConstants from '../../core/AppConstants';
 
+/**
+ * "Use require('punycode/') to import userland modules rather than core modules."
+ * {@see {@link https://github.com/mathiasbynens/punycode.js?tab=readme-ov-file#installation}
+*/
+import { toASCII } from 'punycode/';
+
+const hostnameRegex = /^(?:[a-zA-Z][a-zA-Z0-9+.-]*:\/\/)?(?:www\.)?([^/?:]+)(?::\d+)?/;
+
 export function isPortfolioUrl(url: string) {
   try {
     const currentUrl = new URL(url);
@@ -24,6 +32,43 @@ export function isBridgeUrl(url: string) {
   }
 }
 
+/**
+ * This method does not use the URL library because it does not support punycode encoding in react native.
+ * It compares the original hostname to a punycode version of the hostname.
+ */
+export const isValidASCIIURL = (urlString?: string) => {
+  if (!urlString || urlString.length === 0) {
+    return false;
+  }
+
+  try {
+    const originalHostname = urlString.match(hostnameRegex);
+    const punycodeHostname = toASCII(originalHostname?.[1] || '');
+    return originalHostname?.[1] === punycodeHostname;
+  } catch (exp: unknown) {
+    console.error(`Failed to detect if URL hostname contains non-ASCII characters: ${urlString}. Error: ${exp}`);
+    return false;
+  }
+};
+
 function removePathTrailingSlash(path: string) {
   return path.endsWith('/') ? path.slice(0, -1) : path;
 }
+
+/**
+ * Note: We use the punycode library here because the URL library in react native doesn't support punycode encoding.
+ * We do have the 'react-native-url-polyfill' package which supports the URL library, but it doesn't support punycode encoding.
+ * The URL library is supported in node.js which allows tests to pass, but behavior differs in react-native runtime.
+ */
+export const toPunycodeURL = (urlString: string) => {
+  try {
+    const url = new URL(urlString);
+    const punycodeUrl = toASCII(url.href);
+    const isWithoutEndSlash = url.pathname === '/' && !urlString.endsWith('/');
+
+    return isWithoutEndSlash ? punycodeUrl.slice(0, -1) : punycodeUrl;
+  } catch (err: unknown) {
+    console.error(`Failed to convert URL to Punycode: ${err}`);
+    return urlString;
+  }
+};

app/util/url/url.test.ts

@@ -1,4 +1,4 @@
-import { isPortfolioUrl, isBridgeUrl } from './index';
+import { isPortfolioUrl, isBridgeUrl, isValidASCIIURL, toPunycodeURL } from './index';
 import AppConstants from '../../core/AppConstants';
 
 describe('URL Check Functions', () => {
@@ -60,4 +60,56 @@ describe('URL Check Functions', () => {
       expect(isBridgeUrl(url)).toBe(false);
     });
   });
+
+  describe('isValidASCIIURL', () => {
+    it('returns true for URL containing only ASCII characters in its hostname', () => {
+      expect(isValidASCIIURL('https://www.google.com')).toEqual(true);
+    });
+
+    it('returns true for URL with both its hostname and path containing ASCII characters', () => {
+      expect(
+        isValidASCIIURL('https://infura.io/gnosis?x=xn--ifura-dig.io'),
+      ).toStrictEqual(true);
+    });
+
+    it('returns true for URL with its hostname containing ASCII characters and its path containing non-ASCII characters', () => {
+      expect(isValidASCIIURL('https://infura.io/gnosis?x=iոfura.io')).toStrictEqual(true);
+      expect(isValidASCIIURL('infura.io:7777/gnosis?x=iոfura.io')).toStrictEqual(true);
+    });
+
+    it('returns false for URL with its hostname containing non-ASCII characters', () => {
+      expect(isValidASCIIURL('https://iոfura.io/gnosis')).toStrictEqual(false);
+      expect(isValidASCIIURL('iոfura.io:7777/gnosis?x=test')).toStrictEqual(false);
+    });
+
+    it('returns false for empty string', () => {
+      expect(isValidASCIIURL('')).toStrictEqual(false);
+    });
+  });
+
+  describe('toPunycodeURL', () => {
+    it('returns punycode version of URL', () => {
+      expect(toPunycodeURL('https://iոfura.io/gnosis')).toStrictEqual(
+        'https://xn--ifura-dig.io/gnosis',
+      );
+      expect(toPunycodeURL('https://iոfura.io')).toStrictEqual(
+        'https://xn--ifura-dig.io',
+      );
+      expect(toPunycodeURL('https://iոfura.io/')).toStrictEqual(
+        'https://xn--ifura-dig.io/',
+      );
+      expect(
+        toPunycodeURL('https://iոfura.io/gnosis:5050?test=iոfura&foo=bar'),
+      ).toStrictEqual(
+        'https://xn--ifura-dig.io/gnosis:5050?test=i%D5%B8fura&foo=bar',
+      );
+
+      expect(toPunycodeURL('https://www.google.com')).toStrictEqual(
+        'https://www.google.com',
+      );
+      expect(toPunycodeURL('https://opensea.io/language=français')).toStrictEqual(
+        'https://opensea.io/language=fran%C3%A7ais',
+      );
+    });
+  });
 });

locales/languages/en.json

@@ -1814,6 +1814,7 @@
     "network_chain_id": "Chain ID",
     "network_rpc_url": "Network URL",
     "network_rpc_url_label": "Network RPC URL",
+    "network_rpc_url_warning_punycode": "Attackers sometimes mimic sites by making small changes to the site address. Make sure you're interacting with the intended Network URL before you continue. Punycode version:",
     "new_default_network_url": "New default network URL",
     "current_label": "Current",
     "new_label": "New",