Proof of concept for Connecting to the BMW Connect server using SSL certificate pinning. Assumes you have copied GlobalSignOrganizationValidationCA-SHA256-G2.cer from the Connected Drive iOS app bundle

NetworkManager.swift

import Foundation

final class NetworkManager: NSObject, URLSessionDelegate {
    
    func login() {
        var request = URLRequest(url: URL(string: "https://b2vapi.bmwgroup.com/webapi/oauth/token/")!)
        request.addValue("Content-Type", forHTTPHeaderField: "application/json")
        request.httpMethod = "GET"
        let session = URLSession(configuration: URLSessionConfiguration.default, delegate: self, delegateQueue: nil)
        
        session.dataTask(with: request) {data, response, err in
            print("=========================DATA===============================")
            if data != nil {
                print(data!)
            }
            print("=========================RESPONSE===========================")
            if response != nil {
                print(response!)
            }
            print("=========================ERR================================")
            if err != nil {
                print(err!)
            }
            }.resume()
    }
    
    func urlSession(_ session: URLSession, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
        
        if (challenge.protectionSpace.authenticationMethod == NSURLAuthenticationMethodServerTrust) {
            if let serverTrust = challenge.protectionSpace.serverTrust {
                var secresult = SecTrustResultType.invalid
                let status = SecTrustEvaluate(serverTrust, &secresult)
                
                if(errSecSuccess == status) {
                    let certificateIndex = 1 // Second certificate is the one we need
                    if let serverCertificate = SecTrustGetCertificateAtIndex(serverTrust, certificateIndex) {
                        // Is there a better way to compare certificates other than comparing NSData?
                        let serverCertificateData = SecCertificateCopyData(serverCertificate)
                        let serverCertData = CFDataGetBytePtr(serverCertificateData);
                        let serverCertSize = CFDataGetLength(serverCertificateData);
                        let serverCertData2 = NSData(bytes: serverCertData, length: serverCertSize)
                        let certificateFileName = "GlobalSignOrganizationValidationCA-SHA256-G2"
                        let file = Bundle.main.path(forResource: certificateFileName, ofType: "cer")!
                        let localCertificateData = NSData(contentsOfFile: file)!
                        if serverCertData2.isEqual(to: localCertificateData as Data) {
                            // Pinning succeeded
                            completionHandler(URLSession.AuthChallengeDisposition.useCredential, URLCredential(trust:serverTrust))
                            return
                        }
                    }
                }
            }
        }
        // Pinning failed
        completionHandler(URLSession.AuthChallengeDisposition.cancelAuthenticationChallenge, nil)
    }
}