1. 添加认证证书

    AFSecurityPolicy *securityPolicy = [AFSecurityPolicy policyWithPinningMode:AFSSLPinningModeCertificate];
    //tomcat1(1)
    NSString *cerPath = [[NSBundle mainBundle] pathForResource:@"认证证书.cer" ofType:nil];
    NSData *certData = [NSData dataWithContentsOfFile:cerPath];
    NSSet *dataSet = [NSSet setWithArray:@[certData]];
    [securityPolicy setAllowInvalidCertificates:YES];
    [securityPolicy setPinnedCertificates:dataSet];
    [securityPolicy setValidatesDomainName:YES];
    
    [manager setSecurityPolicy:securityPolicy];

2. 校验证书

+ (void)checkCredential:(AFURLSessionManager *)manager
{
    if (!manager) {
        return;
    }
    [manager setSessionDidBecomeInvalidBlock:^(NSURLSession * _Nonnull session, NSError * _Nonnull error) {
    }];
    __weak typeof(manager)weakManager = manager;
    [manager setSessionDidReceiveAuthenticationChallengeBlock:^NSURLSessionAuthChallengeDisposition(NSURLSession*session, NSURLAuthenticationChallenge *challenge, NSURLCredential *__autoreleasing*_credential) {
        NSURLSessionAuthChallengeDisposition disposition = NSURLSessionAuthChallengePerformDefaultHandling;
        __autoreleasing NSURLCredential *credential =nil;
        NSLog(@"authenticationMethod=%@",challenge.protectionSpace.authenticationMethod);
        //判断是核验客户端证书还是服务器证书
        if([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) {
            // 基于客户端的安全策略来决定是否信任该服务器，不信任的话，也就没必要响应挑战
            if([weakManager.securityPolicy evaluateServerTrust:challenge.protectionSpace.serverTrust forDomain:challenge.protectionSpace.host]) {
                // 创建挑战证书（注：挑战方式为UseCredential和PerformDefaultHandling都需要新建挑战证书）
                NSLog(@"serverTrust=%@",challenge.protectionSpace.serverTrust);
                credential = [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust];
                // 确定挑战的方式
                if (credential) {
                    //证书挑战  设计policy,none，则跑到这里
                    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 ([self 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;
    }];
}
//读取p12文件中的密码
+ (BOOL)extractIdentity:(SecIdentityRef*)outIdentity andTrust:(SecTrustRef *)outTrust fromPKCS12Data:(NSData *)inPKCS12Data {
    OSStatus securityError = errSecSuccess;
    //client certificate password
    NSDictionary *optionsDictionary = [NSDictionary dictionaryWithObject:@"123456"
                                                                  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;
}