fix: validate EVM restore mnemonic checksum (#3498)

* fix: validate EVM restore mnemonics

* chore: drop test changes from this PR

Removes the test additions/modifications introduced by this branch so the
test design is left to the maintainers. Production code is unchanged.

lib/view_model/restore/wallet_restore_from_qr_code.dart

@@ -11,6 +11,7 @@ import 'package:cake_wallet/view_model/restore/restore_mode.dart';
 import 'package:cake_wallet/view_model/restore/restore_wallet.dart';
 import 'package:cw_core/currency_for_wallet_type.dart';
 import 'package:cw_core/wallet_type.dart';
+import 'package:bip39/bip39.dart' as bip39;
 import 'package:flutter/cupertino.dart';
 import 'package:cake_wallet/generated/i18n.dart';
 import 'package:collection/collection.dart';
@@ -89,9 +90,7 @@ class WalletRestoreFromQRCode {
     try {
       return AddressResolverUtils.extractAddressByType(
         raw: rawString,
-        type: walletTypeToCryptoCurrency(
-          type,
-        ),
+        type: walletTypeToCryptoCurrency(type),
         requireSurroundingWhitespaces: false,
       );
     } catch (_) {
@@ -127,8 +126,8 @@ class WalletRestoreFromQRCode {
     final prefix = code.startsWith('xpub')
         ? 'xpub'
         : code.startsWith('zpub')
-            ? 'zpub'
-            : '????';
+        ? 'zpub'
+        : '????';
     if (walletType == null) {
       await _specifyWalletAssets(context, "Can't determine wallet type, please pick it manually");
       walletType =
@@ -140,8 +139,8 @@ class WalletRestoreFromQRCode {
       formattedUri = seedPhrase != null
           ? '$walletType:?seed=$seedPhrase'
           : code.startsWith(prefix)
-              ? '$walletType:?$prefix=$code'
-              : throw Exception('Failed to determine valid seed phrase');
+          ? '$walletType:?$prefix=$code'
+          : throw Exception('Failed to determine valid seed phrase');
     } else {
       final index = code.indexOf(':');
       final query = code.substring(index + 1).replaceAll('?', '&');
@@ -202,9 +201,15 @@ class WalletRestoreFromQRCode {
       seedValue.split(' ').forEach((element) {
         if (!words.contains(element)) {
           throw Exception(
-              "Unexpected restore mode: mnemonic_seed is invalid or doesn't match wallet type");
+            "Unexpected restore mode: mnemonic_seed is invalid or doesn't match wallet type",
+          );
         }
       });
+      if (isEVMCompatibleChain(type) && !bip39.validateMnemonic(seedValue)) {
+        throw Exception(
+          'EVM mnemonic has an invalid checksum. Please check the seed phrase for typos.',
+        );
+      }
       return WalletRestoreMode.seed;
     }
 
@@ -268,12 +273,14 @@ class WalletRestoreFromQRCode {
 
 Future<void> _specifyWalletAssets(BuildContext context, String error) async {
   await showPopUp<void>(
-      context: context,
-      builder: (BuildContext context) {
-        return AlertWithOneAction(
-            alertTitle: S.current.error,
-            alertContent: error,
-            buttonText: S.of(context).ok,
-            buttonAction: () => Navigator.of(context).pop());
-      });
+    context: context,
+    builder: (BuildContext context) {
+      return AlertWithOneAction(
+        alertTitle: S.current.error,
+        alertContent: error,
+        buttonText: S.of(context).ok,
+        buttonAction: () => Navigator.of(context).pop(),
+      );
+    },
+  );
 }