SSL validations randomly fails over a specific mobile internet service providers

[buguibu]

Working scenario

A pretty straightforward iOS 11 app that request contents to HTTPS servers using Alamofire 4.8.1 without NSAllowsArbitraryLoads enabled for security.

The app runs perfectly on Wifi and on Android works perfectly under any internet connection.

Failing scenario

The iOS app when used over mobile network of a specific IPS some request to a couple of servers fails, other doesn't.

Calling the server directly form Safari or an Postman like app fail.

The list of errors i'm getting:

• An SSL error has occurred and a secure connection to the server cannot be made.
• The request timed out.
• cancelled
• The Internet connection appears to be offline.
• NSURLSession/NSURLConnection HTTP load failed (kCFStreamErrorDomainSSL, -9816)

What i have tried

• ~URLSessionConfiguration~ let configuration: URLSessionConfiguration = URLSessionConfiguration.default configuration.allowsCellularAccess = true configuration.waitsForConnectivity = true configuration.timeoutIntervalForRequest = 120
• ~Remove SSL pinning~
• ~Set NSAllowsArbitraryLoads to true~
• How to Diagnose App Transport Security Issues using nscurl and OpenSSL

Links i followed

• iOS 9 App Transport Security

[buguibu]

Looking for server side errors

As the netowrking code is pretty simple and no fancy feature or customization is done, and as it works perfectly on Wifi and over the rest of mobile internet providers i have to abandon the app code issue and explore server side problems.

SSL possible errors

As logs above says, there is a random issues that bugs the SSL certificate and makes the client to invalidate the request.

Bt why it only happens on cellular and only on a specific career?

Links i Followed

• When Your Site’s SSL Works on WiFi but not Cellular
• SSL Checker

IPv6 possible errors

Links i've followed

• NSURLErrorDomain (SSL Error) on LTE, but not on Wifi
• Http calls not working ionic-webview (1.2.1) on iOS only on Cellular data

[buguibu]

Looking for network erros

Try to use another network like 3G or 2G doen't work.