只需为NSURLSessionDelegate定义一个委托类并实现didReceiveChallenge函数(此代码改编自objective-c OWASP示例)：

class NSURLSessionPinningDelegate: NSObject,URLSessionDelegate {
 
    func urlSession(_ session: URLSession,didReceive challenge: URLAuthenticationChallenge,completionHandler: @escaping (URLSession.AuthChallengeDisposition,URLCredential?) -> Swift.Void) {
 
        // Adapted from OWASP https://www.owasp.org/index.PHP/Certificate_and_Public_Key_Pinning#iOS
 
        if (challenge.protectionSpace.authenticationMethod == NSURLAuthenticationMethodServerTrust) {
            if let serverTrust = challenge.protectionSpace.serverTrust {
                var secresult = SecTrustResultType.invalid
                let status = SecTrustEvaluate(serverTrust,&secresult)
 
                if(errSecSuccess == status) {
                    if let serverCertificate = SecTrustGetCertificateAtIndex(serverTrust,0) {
                        let serverCertificateData = SecCertificateCopyData(serverCertificate)
                        let data = CFDataGetBytePtr(serverCertificateData);
                        let size = CFDataGetLength(serverCertificateData);
                        let cert1 = NSData(bytes: data,length: size)
                        let file_der = Bundle.main.path(forResource: "certificateFile",ofType: "der")
 
                        if let file = file_der {
                            if let cert2 = NSData(contentsOfFile: file) {
                                if cert1.isEqual(to: cert2 as Data) {
                                    completionHandler(URLSession.AuthChallengeDisposition.useCredential,URLCredential(trust:serverTrust))
                                    return
                                }
                            }
                        }
                    }
                }
            }
        }
 
        // Pinning Failed
        completionHandler(URLSession.AuthChallengeDisposition.cancelAuthenticationChallenge,nil)
    }
 
}

(你可以找到一个Gist for Swift 2 here – from the initial answer)

然后使用openssl为您的网站创建.der文件

openssl s_client -connect my-https-website.com:443 -showcerts < /dev/null | openssl x509 -outform DER > my-https-website.der

并将其添加到xcode项目中.仔细检查它是否存在于“复制包资源”列表中的“构建阶段”选项卡中.否则将其拖放到此列表中.

最后在您的代码中使用它来发出URL请求：

if let url = NSURL(string: "https://my-https-website.com") {
 
    let session = URLSession(
            configuration: URLSessionConfiguration.ephemeral,delegate: NSURLSessionPinningDelegate(),delegateQueue: nil)
 
 
    let task = session.dataTask(with: url as URL,completionHandler: { (data,response,error) -> Void in
        if error != nil {
            print("error: \(error!.localizedDescription): \(error!)")
        } else if data != nil {
            if let str = NSString(data: data!,encoding: String.Encoding.utf8.rawValue) {
                print("Received data:\n\(str)")
            } else {
                print("Unable to convert data to text")
            }
        }
    })
 
    task.resume()
} else {
    print("Unable to create NSURL")
}