NSURLSession implements SSL/TLS request was written by Objective-C.

NSURLSession_SSL_TLS

#import "ViewController.h"

@interface ViewController ()<NSURLSessionDelegate>

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
    
    NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:[NSOperationQueue mainQueue]];
    
    NSURL *url = [NSURL URLWithString:@"https://www.domain.com/Home/LoginWithPass"];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    [request setHTTPMethod:@"POST"];
    
    NSURLSessionDataTask *data = [session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        
        NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response;
        NSString *str = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
        NSLog(@"%@ %ld",  str, (long)httpResponse.statusCode);
        
    }];
    
    [data resume];
}

/*
  摘要：适用于自签名证书，DV,OV,EV类型的证书
 
  作用：1.单向认证(One-way Authentication)
        此delegate方法会有一次调用，是NSURLAuthenticationMethodServerTrust
      2.双向认证(Bidirectional Authentication，或者Mutual Authentication，也有Two-way Authentication)
        此delegate方法会有两次调用，分别是NSURLAuthenticationMethodServerTrust和NSURLAuthenticationMethodClientCertificate

 */
- (void)URLSession:(NSURLSession *)session didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition, NSURLCredential * _Nullable))completionHandler
{
    //证书的处理方式
    NSURLSessionAuthChallengeDisposition disposition = NSURLSessionAuthChallengePerformDefaultHandling;
    
    NSURLCredential *credential = nil;
    
    //判断服务器返回的证书是否是服务器信任的
    if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) { //受信任的
        
        //获取服务器返回的证书
        credential = [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust];
        
        if (credential) {
            disposition = NSURLSessionAuthChallengeUseCredential;
        } else {
            disposition = NSURLSessionAuthChallengePerformDefaultHandling;
        }
        
    } else {
    
        //读取证书的私钥
        NSString *thePath = [[NSBundle mainBundle] pathForResource:@"webtest_ssl_Certificate" ofType:@"p12"];
        NSData *PKCS12Data = [[NSData alloc] initWithContentsOfFile:thePath];
        CFDataRef inPKCS12Data = (CFDataRef)CFBridgingRetain(PKCS12Data);
        SecIdentityRef identity = nil;
        
        //读取p12证书的私钥内容
        OSStatus result = [self extractP12Data:inPKCS12Data toIdentity:&identity];
        if(result != errSecSuccess){
            completionHandler(NSURLSessionAuthChallengeCancelAuthenticationChallenge, nil);
            return;
        }
        
        SecCertificateRef certificate = NULL;
        SecIdentityCopyCertificate(identity, &certificate);
        
        const void *certs[] = {certificate};
        CFArrayRef certArray = CFArrayCreate(kCFAllocatorDefault, certs, 1, NULL);
        
        credential = [NSURLCredential credentialWithIdentity:identity certificates:(NSArray*)CFBridgingRelease(certArray) persistence:NSURLCredentialPersistencePermanent];
        
        disposition = NSURLSessionAuthChallengeUseCredential;
    }
    
    //安装证书(即导入到iPhone的KeyChain)
    if (completionHandler) {
        completionHandler(disposition, credential);
    }
}

- (OSStatus)extractP12Data:(CFDataRef)inP12Data toIdentity:(SecIdentityRef *)identity {
    
    OSStatus securityError = errSecSuccess;
    
    CFStringRef password = CFSTR("Your Cert Password");
    const void *keys[] = { kSecImportExportPassphrase };
    const void *values[] = { password };
    
    CFDictionaryRef options = CFDictionaryCreate(NULL, keys, values, 1, NULL, NULL);
    
    CFArrayRef items = CFArrayCreate(NULL, 0, 0, NULL);
    securityError = SecPKCS12Import(inP12Data, options, &items);
    
    if (securityError == errSecSuccess) {
        CFDictionaryRef ident = CFArrayGetValueAtIndex(items, 0);
        const void *tempIdentity = NULL;
        tempIdentity = CFDictionaryGetValue(ident, kSecImportItemIdentity);
        *identity = (SecIdentityRef)tempIdentity;
    }
    
    if (options) CFRelease(options);
    if (password) CFRelease(password);
    
    return securityError;
}

@end