Demo source file for the Medium article - https://medium.com/lunasolutions/mastering-ssl-pinning-in-swift-no-third-party-libraries-required-42a377db80ff?source=friends_link&sk=b75e8720d528acfad013f0ec2f6901e6

SSLPinningDemo.swift

//
//  SSLPinningDemo.swift
//  SSLPinning
//
//  Created by Eugene Gordenstein on 11/04/2023.
//

import Foundation

struct DemoNetworkClient {
    let sessionDelegate: SessionDelegate
    let session: URLSession

    init() {
        sessionDelegate = SessionDelegate()
        session = URLSession(configuration: .default, delegate: sessionDelegate, delegateQueue: nil)
    }

    func demoURLRequest() {
        Task {
            do {
                let url = "https://stackoverflow.com"
                let data = try await makeURLRequest(urlString: url)

                print("Received data: \(data)")
            } catch {
                print("Error: \(error)")
            }
        }
    }

    private func makeURLRequest(urlString: String) async throws -> Data {
        guard let url = URL(string: urlString) else {
            throw URLError(.badURL)
        }
        let request = URLRequest(url: url)
        let (data, _) = try await session.data(for: request)
        return data
    }
}

class SessionDelegate: NSObject {
    let sslPinningManager: SSLPinningManager

    override init() {
        sslPinningManager = SSLPinningManager(pinnedKeyHashes: [
            "jQJTbIh0grw0/1TkHSumWb+Fs0Ggogr621gT3PvPKG0=" // Valid until 15 Sep 2025
        ])
    }
}

extension SessionDelegate: URLSessionTaskDelegate {
    func urlSession(_: URLSession,
                    didReceive challenge: URLAuthenticationChallenge,
                    completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
        sslPinningManager.validate(challenge: challenge, completionHandler: completionHandler)
    }
}