Dropbox authentication on iPhone X

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Greg-DB wrote:

I'm not aware of any other reports like this, so we'll have to investigate. First, can you share:

• the version number of the Dropbox SDK you're using

Not sure exactly how to determine that (guessing 3.1.0), I found a plist file in the source, here it is:

 

• the version number of the official Dropbox for iOS app you have installed

This is a universal App, the Dropbox App version is the same for both iPad Air 2 and iPhone X:  70.2.2

 

• your code snippets for initiating and receiving the app authorization flow

 

- (BOOL) handleOpenURL:(NSURL *)url {
    
    // From a generic App sending us a document = file://localhost/private/var/mobile/Applications/***/Documents/Inbox/CoronaEarlyAccess-3.pdf
    // From Dropbox, in particular, for authentication = db-***://1/cancel?(null)
    //                                                 = db-***://1/connect?uid=***&oauth_token_secret=***&oauth_token=***
    
#ifdef kDEBUG
    NSLog(@"################ handleOpenURL=%@, absoluteString=%@", url, [url absoluteString]);
#endif
    
    NSString *dropboxKeyURLLeadin = [NSString stringWithFormat:@"db-%@", kDropboxKey];
    if ( [[url absoluteString] hasPrefix:dropboxKeyURLLeadin] ) {

        NSLog(@"handling URL: %@", url);
        static NSString *kDBLinkNonce = @"dropbox.sync.nonce";
        NSString *nonce = [[NSUserDefaults standardUserDefaults] objectForKey:kDBLinkNonce];
        NSLog(@"stored nonce: %@", nonce);
                           
        DBOAuthResult *authResult = [DBClientsManager handleRedirectURL:url];
        if (authResult != nil) {
            if ([authResult isSuccess]) {
                NSLog(@"Success! User is logged into Dropbox.");
                self.canUseDropbox = YES;
                [self performSelector:@selector(refreshDropbox) withObject:nil afterDelay:1.0];
                return YES;
            } else if ([authResult isCancel]) {
                NSLog(@"Authorization flow was manually canceled by user!");
                self.canUseDropbox = NO;
                [[NSNotificationCenter defaultCenter] postNotificationName:kKryptonTurnDropboxOffNotification object:nil];
            } else if ([authResult isError]) {
                NSLog(@"Auth Error: %@", authResult);
                self.canUseDropbox = NO;
                [self synchUserDefaults];
                [[NSNotificationCenter defaultCenter] postNotificationName:kKryptonTurnDropboxOffNotification object:nil];
                [[NSNotificationCenter defaultCenter] postNotificationName:kKryptonUnlinkDropboxNotification object:nil];
            }
        }
        return NO;
        
    } else {
        
        if ( self.openInURLs == nil ) {
            self.openInURLs = [[NSMutableArray alloc] initWithCapacity:10];
        }
        [self.openInURLs addObject:url];
        [self performSelector:@selector(handleOpenURL2) withObject:nil afterDelay:1.0];
        return YES;
        
    }
	
} // end handleOpenURL

 

• if this is only happening on iPhone X

This is difficult to answer.  In the simulator there is no Dropbox App and authentication works on all devices.  For real devices I have an iPad Air 2 and authentication via web and App works fine.  My iPhone 7 is now gone and all I have is iPhoneX.  Web authentication works for it but not via the Dropbox App. Authentication via the app used to work on the iPhone 7 though.

 

The "Unable to verify link request" error comes from here:

 

https://github.com/dropbox/dropbox-sdk-obj-c/blob/6f40607f7d558a04f1330b84d8c8a0c960412409/Source/ObjectiveDropboxOfficial/Platform/ObjectiveDropboxOfficial_iOS/DBOAuthMobileManager-iOS.m#L122

 

This error should indicate that the state value returned on the SDK auth URL doesn't match the one previously generated and stored in NSUserDefaults for this app authorization flow. 

 

To help debug that, you can try running this code inside application:openURL, just before you call handleRedirectURL:

    NSLog(@"handling URL: %@", url);
    static NSString *kDBLinkNonce = @"dropbox.sync.nonce";
    NSString *nonce = (NSString *)[[NSUserDefaults standardUserDefaults] objectForKey:kDBLinkNonce];
    NSLog(@"stored nonce: %@", nonce);

(Just be sure to redact the access token itself, if any, in the output before sharing.)

 

Ok, here are the log entries and including mine to help trace the authentication flow.  First the iPad Air 2, which works, then iPhone X, which does not.  What stands out to me is that for iPhone X several Dropbox operation appear twice.

 

Also note that you can ignore the log entries concerning biometrics, at least I think you can.  The authentication issue exists with and without Face ID enabled.

 

iPad:


2017-11-11 10:06:22.542097-0500 Krypton[531:143990] DBSDKReachability Flag Status: -R ------- networkStatusForFlags
2017-11-11 10:06:23.712286-0500 Krypton[531:143990] didEnterBackground
2017-11-11 10:06:25.991012-0500 Krypton[531:143990] +[CATransaction synchronize] called within transaction
2017-11-11 10:06:25.991841-0500 Krypton[531:143990] +[CATransaction synchronize] called within transaction
2017-11-11 10:06:25.992537-0500 Krypton[531:143990] +[CATransaction synchronize] called within transaction
2017-11-11 10:06:25.993148-0500 Krypton[531:143990] willEnterForeground
2017-11-11 10:06:26.009576-0500 Krypton[531:143990] DO BIOMETRICS IFF closed voew controller showing=<VaultClosedPadViewController: 0x13fd0b000>
2017-11-11 10:06:26.009722-0500 Krypton[531:143990]   OK DO BIOMETRICS
2017-11-11 10:06:26.033245-0500 Krypton[531:143990] handling URL: db-***://1/connect?oauth_token_secret=***&uid=***&oauth_token=oauth2%3A
2017-11-11 10:06:26.033338-0500 Krypton[531:143990] stored nonce: 56566428-71E4-4DA3-8629-A285598D9E50
2017-11-11 10:06:26.119131-0500 Krypton[531:143990] Success! User is logged into Dropbox.
2017-11-11 10:06:27.106473-0500 Krypton[531:143990] in doBiometrics touchIDInProgress=0
2017-11-11 10:06:27.116687-0500 Krypton[531:143990] evaluatePolicy now ...
2017-11-11 10:06:27.124749-0500 Krypton[531:144030] Biometrics failed, code=-1004, err=Error Domain=com.apple.LocalAuthentication Code=-1004 "User interaction is required." UserInfo={NSLocalizedDescription=User interaction is required.}

 OK, now for iPhone X:

 

iPhone:


2017-11-11 10:08:32.282149-0500 Krypton[3157:759519] DBSDKReachability Flag Status: -R ------- networkStatusForFlags
2017-11-11 10:08:33.093590-0500 Krypton[3157:759519] didEnterBackground
2017-11-11 10:08:33.118068-0500 Krypton[3157:759519] DBSDKReachability Flag Status: -R ------- networkStatusForFlags
2017-11-11 10:08:37.385070-0500 Krypton[3157:759519] willEnterForeground
2017-11-11 10:08:37.445841-0500 Krypton[3157:759519] DO BIOMETRICS IFF closed voew controller showing=<VaultClosedViewController: 0x101f2a9e0>
2017-11-11 10:08:37.445961-0500 Krypton[3157:759519]   OK DO BIOMETRICS
2017-11-11 10:08:37.459372-0500 Krypton[3157:759519] handling URL: db-***://1/connect?oauth_token_secret=***&uid=***&oauth_token=oauth2%3A
2017-11-11 10:08:37.459425-0500 Krypton[3157:759519] stored nonce: 8156E9C8-7C1C-4EA7-9CA7-B6E8D53E113F
2017-11-11 10:08:37.460354-0500 Krypton[3157:759519] Auth Error: Error:[ErrorType: 6 ErrorDescription: Unable to verify link request.]
2017-11-11 10:08:37.461598-0500 Krypton[3157:759519] handling URL: db-***://1/connect?oauth_token_secret=***&uid=***&oauth_token=oauth2%3A
2017-11-11 10:08:37.462183-0500 Krypton[3157:759519] stored nonce: 8156E9C8-7C1C-4EA7-9CA7-B6E8D53E113F
2017-11-11 10:08:37.462264-0500 Krypton[3157:759519] Auth Error: Error:[ErrorType: 6 ErrorDescription: Unable to verify link request.]
2017-11-11 10:08:38.543166-0500 Krypton[3157:759519] in doBiometrics touchIDInProgress=0
2017-11-11 10:08:38.558830-0500 Krypton[3157:759519] evaluatePolicy now ...
2017-11-11 10:08:38.566033-0500 Krypton[3157:759957] Biometrics failed, code=-1004, err=Error Domain=com.apple.LocalAuthentication Code=-1004 "User interaction is required." UserInfo={NSLocalizedDescription=User interaction is required.}

 

Thanks!

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Thank you.