- (OSStatus)extractIdentity:(CFDataRef)inP12Data toIdentity:(SecIdentityRef*)identity { 
  OSStatus securityError = errSecSuccess;
  CFStringRef password = CFSTR("证书密码"); 
  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 == 0)   
  {
    CFDictionaryRef ident = CFArrayGetValueAtIndex(items,0); 
    const void *tempIdentity = NULL; 
    tempIdentity = CFDictionaryGetValue(ident, kSecImportItemIdentity);
    *identity = (SecIdentityRef)tempIdentity;  
  } 
  if (options) {  
    CFRelease(options);  
  }
  return securityError;
}

- (void)connection:(NSURLConnection *)connection
willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{
  NSString *thePath = [[NSBundle mainBundle] pathForResource:@"client" ofType:@"p12"];
  //倒入证书    NSLog(@"thePath===========%@",thePath);
  NSData *PKCS12Data = [[NSData alloc] initWithContentsOfFile:thePath];
  CFDataRef inPKCS12Data = (__bridge CFDataRef)PKCS12Data;

  SecIdentityRef identity = NULL;
  // extract the ideneity from the certificate
  [self extractIdentity :inPKCS12Data toIdentity:&identity];

  SecCertificateRef certificate = NULL;
  SecIdentityCopyCertificate (identity, &certificate);

  const void *certs[] = {certificate};
  //            CFArrayRef certArray = CFArrayCreate(kCFAllocatorDefault, certs, 1, NULL);
  // create a credential from the certificate and ideneity, then reply to the challenge with the credential
  //NSLog(@"identity=========%@",identity);
  NSURLCredential *credential = [NSURLCredential credentialWithIdentity:identity certificates:nil persistence:NSURLCredentialPersistencePermanent];

  //      credential = [NSURLCredential credentialWithIdentity:identity certificates:(__bridge NSArray*)certArray persistence:NSURLCredentialPersistencePermanent];

  [challenge.sender useCredential:credential forAuthenticationChallenge:challenge];

}

 NSString *url = @"xxxxxxxxxx";
  // 1.获得请求管理者
  AFHTTPRequestOperationManager *mgr = [AFHTTPRequestOperationManager manager];
  //2设置https 请求
  AFSecurityPolicy *securityPolicy = [AFSecurityPolicy policyWithPinningMode:AFSSLPinningModeCertificate];
  securityPolicy.allowInvalidCertificates = YES;
  mgr.securityPolicy = securityPolicy;
  // 3.发送POST请求

  [mgr POST:url parameters:nil success:^(AFHTTPRequestOperation * _Nonnull operation, id _Nonnull responseObject) {
    NSLog(@"responseObject: %@", responseObject);

  } failure:^(AFHTTPRequestOperation * _Nonnull operation, NSError * _Nonnull error) {
    NSLog(@"Error: %@", error);

  }];

 NSString *url = @"https://test.niuniuhaoguanjia.com/3.0.0/?service=City.GetCityList";

  NSString *certFilePath = [[NSBundle mainBundle] pathForResource:@"server" ofType:@"cer"];
  NSData *certData = [NSData dataWithContentsOfFile:certFilePath];
  NSSet *certSet = [NSSet setWithObject:certData];
  AFSecurityPolicy *policy = [AFSecurityPolicy policyWithPinningMode:AFSSLPinningModeCertificate withPinnedCertificates:certSet];
  policy.allowInvalidCertificates = YES;
  policy.validatesDomainName = NO;

  _manager = [AFHTTPSessionManager manager];
  _manager.securityPolicy = policy;
  _manager.requestSerializer = [AFHTTPRequestSerializer serializer];
  _manager.responseSerializer = [AFHTTPResponseSerializer serializer];
  _manager.responseSerializer.acceptableContentTypes = [NSSet setWithObjects:@"application/json", @"text/json", @"text/javascript",@"text/plain", nil];
  //关闭缓存避免干扰测试r
  _manager.requestSerializer.cachePolicy = NSURLRequestReloadIgnoringLocalCacheData;
  [_manager setSessionDidBecomeInvalidBlock:^(NSURLSession * _Nonnull session, NSError * _Nonnull error) {
    NSLog(@"setSessionDidBecomeInvalidBlock");
  }];
  //客户端请求验证 重写 setSessionDidReceiveAuthenticationChallengeBlock 方法
  __weak typeof(self)weakSelf = self;
  [_manager setSessionDidReceiveAuthenticationChallengeBlock:^NSURLSessionAuthChallengeDisposition(NSURLSession*session, NSURLAuthenticationChallenge *challenge, NSURLCredential *__autoreleasing*_credential) {
    NSURLSessionAuthChallengeDisposition disposition = NSURLSessionAuthChallengePerformDefaultHandling;
    __autoreleasing NSURLCredential *credential =nil;
    if([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) {
      if([weakSelf.manager.securityPolicy evaluateServerTrust:challenge.protectionSpace.serverTrust forDomain:challenge.protectionSpace.host]) {
        credential = [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust];
        if(credential) {
          disposition =NSURLSessionAuthChallengeUseCredential;
        } else {
          disposition =NSURLSessionAuthChallengePerformDefaultHandling;
        }
      } else {
        disposition = NSURLSessionAuthChallengeCancelAuthenticationChallenge;
      }
    } else {
      // client authentication
      SecIdentityRef identity = NULL;
      SecTrustRef trust = NULL;
      NSString *p12 = [[NSBundle mainBundle] pathForResource:@"client"ofType:@"p12"];
      NSFileManager *fileManager =[NSFileManager defaultManager];

      if(![fileManager fileExistsAtPath:p12])
      {
        NSLog(@"client.p12:not exist");
      }
      else
      {
        NSData *PKCS12Data = [NSData dataWithContentsOfFile:p12];

        if ([[weakSelf class]extractIdentity:&identity andTrust:&trust fromPKCS12Data:PKCS12Data])
        {
          SecCertificateRef certificate = NULL;
          SecIdentityCopyCertificate(identity, &certificate);
          const void*certs[] = {certificate};
          CFArrayRef certArray =CFArrayCreate(kCFAllocatorDefault, certs,1,NULL);
          credential =[NSURLCredential credentialWithIdentity:identity certificates:(__bridge NSArray*)certArray persistence:NSURLCredentialPersistencePermanent];
          disposition =NSURLSessionAuthChallengeUseCredential;
        }
      }
    }
    *_credential = credential;
    return disposition;
  }];

//第三步和这一步代码是放在一起的，请注意哦
  [_manager GET:url parameters:nil progress:^(NSProgress * _Nonnull downloadProgress) {

  } success:^(NSURLSessionDataTask * _Nonnull task, id _Nullable responseObject) {
    NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingMutableContainers error:nil];
    NSLog(@"JSON: %@", dic);
  } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
    NSLog(@"Error: %@", error);

    NSData *data = [error.userInfo objectForKey:@"com.alamofire.serialization.response.error.data"];
    NSString *str = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
    NSLog(@"%@",str);
  }];

+(BOOL)extractIdentity:(SecIdentityRef*)outIdentity andTrust:(SecTrustRef *)outTrust fromPKCS12Data:(NSData *)inPKCS12Data {
  OSStatus securityError = errSecSuccess;
  //client certificate password
  NSDictionary*optionsDictionary = [NSDictionary dictionaryWithObject:@"证书密码"
                                 forKey:(__bridge id)kSecImportExportPassphrase];

  CFArrayRef items = CFArrayCreate(NULL, 0, 0, NULL);
  securityError = SecPKCS12Import((__bridge CFDataRef)inPKCS12Data,(__bridge CFDictionaryRef)optionsDictionary,&items);

  if(securityError == 0) {
    CFDictionaryRef myIdentityAndTrust =CFArrayGetValueAtIndex(items,0);
    const void*tempIdentity =NULL;
    tempIdentity= CFDictionaryGetValue (myIdentityAndTrust,kSecImportItemIdentity);
    *outIdentity = (SecIdentityRef)tempIdentity;
    const void*tempTrust =NULL;
    tempTrust = CFDictionaryGetValue(myIdentityAndTrust,kSecImportItemTrust);
    *outTrust = (SecTrustRef)tempTrust;
  } else {
    NSLog(@"Failedwith error code %d",(int)securityError);
    return NO;
  }
  return YES;
}

//AF加上这句和下面的方法
  _manager.securityPolicy = [self customSecurityPolicy];



/**** SSL Pinning ****/
- (AFSecurityPolicy*)customSecurityPolicy {
  NSString *cerPath = [[NSBundle mainBundle] pathForResource:@"server" ofType:@"cer"];
  NSData *certData = [NSData dataWithContentsOfFile:cerPath];
  AFSecurityPolicy *securityPolicy = [AFSecurityPolicy policyWithPinningMode:AFSSLPinningModeCertificate];
  [securityPolicy setAllowInvalidCertificates:YES];
  NSSet *set = [NSSet setWithObjects:certData, nil];
  [securityPolicy setPinnedCertificates:@[certData]];
  /**** SSL Pinning ****/
  return securityPolicy;
}