Easiest way to perform a certificate or public key pining - ios

Question

I want to perform a certificate or public key pining in my iOS app. I am not using Alamofire only the standard requests Apple provide. How I can make this, I read how to do it with alomofire but I am not using it. I want the standard way apple giving us but if it’s possible someone to give me more examples of what is happening and how. What the is the best way, certificate or public key and how to implement it.

Answer 1

You can use pinning on iOS, is not so terrible but you must search on Appel docs:
(and I Opened a TSI with ADC for details...)
basically You have to implement delegate methods:
func urlSession(_: URLSession,
didReceive challenge: URLAuthenticationChallenge,
completionHandler: #escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void)
{
print("got Challenge")
let serverTrust = challenge.protectionSpace.serverTrust
let areEqual = CertificateHelper.certIsValid(CERT, serverTrust: serverTrust!)
// Set SSL policies for domain name check
let policies = NSMutableArray()
policies.add(SecPolicyCreateSSL(true, (challenge.protectionSpace.host as CFString?)))
SecTrustSetPolicies(serverTrust!, policies);
// Evaluate server certificate
var result = SecTrustResultType.invalid
SecTrustEvaluate(serverTrust!, &result)
let isServerTrusted: Bool = (
result == SecTrustResultType.unspecified // unspecified means implicitely go on (see help with alt click on SecTrustEvaluate)
|| result == SecTrustResultType.proceed
)
if isServerTrusted && areEqual {
let credential = URLCredential(trust: serverTrust!)
let certificate = credential.certificates // debug.
// ok
completionHandler(.useCredential, credential)
} else {
// fail:
completionHandler(.cancelAuthenticationChallenge, nil)
}
}