TrustKit is not working

Hello,

Below is the code we have written

`
public override func urlSession(_ session: URLSession, task: URLSessionTask, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
// Call into TrustKit here to do pinning validation
if NetworkUtil.isTrustKitInitialized {
if TrustKit.sharedInstance().pinningValidator.handle(challenge, completionHandler: completionHandler) == false {
// TrustKit did not handle this challenge: perhaps it was not for server trust
// or the domain was not pinned. Fall back to the default behavior
completionHandler(.performDefaultHandling, nil)
} else {
// TrustKit did successfully handled this challenge and took decision based on trust chain
DDLogDebug("SSL Pinning handled successfully")
}
} else {
completionHandler(.performDefaultHandling, nil)
}
}

//FILE: NetworkUtil.swift
static func initializeTrustKit(urlStr: String) {

    //urlStr is passed here as an argument based on the user's selection of environment
    if let sslKeys = Constants.SSLKeys(),
       let url = URL(string: urlStr),
       let domain = url.host {
        let trustKitConfig = [
            kTSKSwizzleNetworkDelegates: false,
            kTSKPinnedDomains: [
                domain: [
                    kTSKEnforcePinning: true,
                    kTSKIncludeSubdomains: true,
                    kTSKPublicKeyHashes: sslKeys
                ]
            ]
        ] as [String: Any]
        TrustKit.initSharedInstance(withConfiguration: trustKitConfig)
        isTrustKitInitialized = true
    }
}

`

We are using BurpSuite to trace the network (setting up a proxy server and routing iPhone to use a proxy) and we can read all communication in plaintext.

This code was working but looks like on the latest iOS it is not working. I request help here.

Start with the URLSession challenge handler and NetworkUtil.swift's initializeTrustKit function, then reproduce the report using the BurpSuite proxy setup described. Check whether the configured domain and SSL key hashes are used during challenge handling; done means intercepted traffic is rejected rather than readable in plaintext.