1 files changed, 27 insertions, 5 deletions
diff --git a/Firebase/Auth/Source/FIRAuth.m b/Firebase/Auth/Source/FIRAuth.m
index d4ced9c..1930957 100644
--- a/Firebase/Auth/Source/FIRAuth.m
+++ b/Firebase/Auth/Source/FIRAuth.m
@@ -112,6 +112,10 @@ static NSString *const kHandleCodeInAppFalseExceptionReason =
     @"You must set handleCodeInApp in your ActionCodeSettings to true for Email-link "
     "Authentication.";
 
+static NSString *const kInvalidEmailSignInLinkExceptionMessage =
+    @"The link provided is not valid for email/link sign-in. Please check the link by calling "
+    "isSignInWithEmailLink:link: on Auth before attempting to use it for email/link sign-in.";
+
 /** @var kPasswordResetRequestType
     @brief The action code type value for resetting password in the check action code response.
  */
@@ -655,8 +659,16 @@ static NSMutableDictionary *gKeychainServiceNameForAppName;
 - (void)internalSignInWithEmail:(nonnull NSString *)email
                            link:(nonnull NSString *)link
                        callback:(nullable FIRAuthResultCallback)callback {
-  NSURLComponents *urlComponents = [NSURLComponents componentsWithString:link];
-  NSDictionary<NSString *, NSString *> *queryItems = FIRAuthParseURL(urlComponents.query);
+  if (![self isSignInWithEmailLink:link]) {
+    [FIRAuthExceptionUtils raiseInvalidParameterExceptionWithReason:
+        kInvalidEmailSignInLinkExceptionMessage];
+    return;
+  }
+  NSDictionary<NSString *, NSString *> *queryItems = FIRAuthParseURL(link);
+  if (![queryItems count]) {
+    NSURLComponents *urlComponents = [NSURLComponents componentsWithString:link];
+    queryItems = FIRAuthParseURL(urlComponents.query);
+  }
   NSString *actionCode = queryItems[@"oobCode"];
 
   FIREmailLinkSignInRequest *request =
@@ -1206,11 +1218,18 @@ static NSMutableDictionary *gKeychainServiceNameForAppName;
   if (link.length == 0) {
     return NO;
   }
-  NSURLComponents *urlComponents = [NSURLComponents componentsWithString:link];
-  if (!urlComponents.query) {
+  NSDictionary<NSString *, NSString *> *queryItems = FIRAuthParseURL(link);
+  if (![queryItems count]) {
+    NSURLComponents *urlComponents = [NSURLComponents componentsWithString:link];
+    if (!urlComponents.query) {
+      return NO;
+    }
+    queryItems = FIRAuthParseURL(urlComponents.query);
+  }
+
+  if (![queryItems count]) {
     return NO;
   }
-  NSDictionary<NSString *, NSString *> *queryItems = FIRAuthParseURL(urlComponents.query);
 
   NSString *actionCode = queryItems[@"oobCode"];
   NSString *mode = queryItems[@"mode"];
@@ -1228,6 +1247,9 @@ static NSMutableDictionary *gKeychainServiceNameForAppName;
  */
 static NSDictionary<NSString *, NSString *> *FIRAuthParseURL(NSString *urlString) {
   NSString *linkURL = [NSURLComponents componentsWithString:urlString].query;
+  if (!linkURL) {
+    return @{};
+  }
   NSArray<NSString *> *URLComponents = [linkURL componentsSeparatedByString:@"&"];
   NSMutableDictionary<NSString *, NSString *> *queryItems =
       [[NSMutableDictionary alloc] initWithCapacity:URLComponents.count];