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Sync API framework not connecting to Dropbox server?

New member | Level 1
New member | Level 1

Hi,

I’m using the Dropbox Sync API framework in my Mac app and I have had one user report problems enabling the Dropbox sync in my app.
The framework never connects to the Dropbox sync, but keeps on trying with this log:

23/03/2015 23:10:17.952 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:10:18.548 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api1.dropbox.com
23/03/2015 23:10:20.936 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:10:23.444 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:10:25.257 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api2.dropbox.com
23/03/2015 23:10:25.576 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:10:26.035 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api1.dropbox.com
23/03/2015 23:10:26.796 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:10:27.879 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:10:29.526 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:11.913 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:11.994 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api1.dropbox.com
23/03/2015 23:14.361 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:17.420 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:10:47.851 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:10:48.298 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:10:50.748 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:11:08.228 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:11:21.033 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
23/03/2015 23:11:23.451 [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
...

I’m unable to reproduce this myself. Other than that I didn’t have any complaints regarding the Dropbox sync in my app and it works fine on my test devices.

Do you have an hints what the log message could mean?

Thanks a bunch,
Niko

7 Replies 7
Highlighted

Re: Sync API framework not connecting to Dropbox server?

New member | Level 1
New member | Level 1

I just started getting this as well, has anyone been able to resolve this?

Highlighted

Re: Sync API framework not connecting to Dropbox server?

Dropboxer
Dropboxer

(moved to the API development forum)

Highlighted

Re: Sync API framework not connecting to Dropbox server?

Dropboxer
Dropboxer

Sorry for the delay! In the future, I'd recommend posting API questions in this forum, where responses are generally much faster.

My guess would be something about the networking set up for this particular user. Do you have any details about their environment? Perhaps they have an unusual set of trusted certs or they're going through an HTTPS proxy (and thus the cert doesn't match) or something like that. I expect it's going to be very hard to debug without a setup to reproduce the issue. :-(

Highlighted

Re: Sync API framework not connecting to Dropbox server?

Explorer | Level 3

I'm having the same issue now with a customer of mine using the Sync API.

5/31/15 8:14:01.042 AM Tap Forms[5788]: [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
5/31/15 8:14:01.068 AM Tap Forms[5788]: [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api1.dropbox.com
5/31/15 8:14:01.441 AM Tap Forms[5788]: [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
5/31/15 8:14:01.896 AM Tap Forms[5788]: [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com
5/31/15 8:14:02.714 AM Tap Forms[5788]: [WARNING] status: SSL: DBHTTPRequest.mm:535: Unknown authentication method NSURLAuthenticationMethodServerTrust for Dropbox host: api0.dropbox.com

and it goes on and on. I'll ask them to check their certificates to see if there are any expired ones.

Highlighted

Re: Sync API framework not connecting to Dropbox server?

Explorer | Level 3

So did this ever get resolved? I'm having the same issue now with a bunch of customers.

Highlighted

Re: Sync API framework not connecting to Dropbox server?

Dropboxer
Dropboxer

Did you ever learn anything from the first customer about their network setup?

Among the other customers who are seeing this issue, is there any commonality in their network setup? (Perhaps they all work at the same company, for example?) We haven't heard a lot of reports of this, so I assume it's not a widespread issue. Narrowing down what these customers have in common will be key to figuring out what's going on, so please let us know what you find out.

Highlighted

Re: Sync API framework not connecting to Dropbox server?

Explorer | Level 3

Unfortunately I haven't figured out from anyone who has this problem what the issue might be. Some have it on one Mac but not the other in the same office. I asked them to check their Keychain for expired certificates and proxy server configurations, but none had them. So I'm very puzzled by this. I've never seen it myself.

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