httpdns_ios_demo/httpdns_ios_demo/Example/HttpsExample/HTTPSSimpleScenario.m

//
//  HTTPSScene.m
//  httpdns_ios_demo
//
//  Created by Miracle on 2024/7/22.
//

#import "HTTPSSimpleScenario.h"
#import <AlicloudHttpDNS/AlicloudHttpDNS.h>

@interface HTTPSSimpleScenario () <NSURLSessionTaskDelegate, NSURLSessionDataDelegate>

@end

@implementation HTTPSSimpleScenario

- (void)httpDnsQueryWithURL:(NSString *)originalUrl completionHandler:(void(^)(NSString * message))completionHandler {
    // 组装提示信息
    __block NSMutableString *tipsMessage = [NSMutableString string];

    NSURL *url = [NSURL URLWithString:originalUrl];
    NSMutableURLRequest *request;

    NSString *resolvedIpAddress = [self resolveAvailableIp:url.host];

    NSString *requestUrl = originalUrl;
    if (resolvedIpAddress) {
        // 通过HTTPDNS获取IP成功，进行URL替换和HOST头设置
        requestUrl = [originalUrl stringByReplacingOccurrencesOfString:url.host withString:resolvedIpAddress];

        NSString *log = [NSString stringWithFormat:@"Resolve host(%@) by HTTPDNS successfully, result ip: %@", url.host, resolvedIpAddress];
        NSLog(@"%@", log);
        [tipsMessage appendString:log];
    } else {
        NSString *log = [NSString stringWithFormat:@"Resolve host(%@) by HTTPDNS failed, keep original url to request", url.host];
        NSLog(@"%@", log);
        [tipsMessage appendString:log];
    }

    // 设置request
    request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:requestUrl]];
    [request setValue:url.host forHTTPHeaderField:@"host"];

    // 发送网络请求
    [self sendRequest:request completionHandler:^(NSString *message) {
        [tipsMessage appendFormat:@"\n\n %@",message];
        if (completionHandler) {
            completionHandler(tipsMessage);
        }
    }];
}

- (NSString *)resolveAvailableIp:(NSString *)host {
    HttpDnsService *httpDnsService = [HttpDnsService sharedInstance];
    HttpdnsResult *result = [httpDnsService resolveHostSyncNonBlocking:host byIpType:HttpdnsQueryIPTypeAuto];

    NSLog(@"resolve host result: %@", result);
    if (!result) {
        return nil;
    }

    if (result.hasIpv4Address) {
        return result.firstIpv4Address;
    } else if (result.hasIpv6Address) {
        return [NSString stringWithFormat:@"[%@]", result.firstIpv6Address];
    } else {
        return nil;
    }
}

- (void)sendRequest:(NSURLRequest *)request completionHandler:(void(^)(NSString * message))completionHandler {
    NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
    NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil];
    NSURLSessionTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
        if (error) {
            NSString *errorStr = [NSString stringWithFormat:@"Http request failed with error: %@", error];
            if (completionHandler) {
                completionHandler(errorStr);
            }
            return;
        }

        NSMutableString *message = [NSMutableString string];
        NSString *responseStr = [NSString stringWithFormat:@"HttpResponse: %@", response.description];

        [message appendFormat:@"\n\n%@", responseStr];

        NSString *dataStr = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
        [message appendFormat:@"\n\nHttpResponseData:\n %@", dataStr];

        if (completionHandler) {
            completionHandler(message);
        }
        NSLog(@"response data: %@", dataStr);
    }];
    [task resume];
}

- (BOOL)evaluateServerTrust:(SecTrustRef)serverTrust
                  forDomain:(NSString *)domain {
    // 创建证书校验策略
    NSMutableArray *policies = [NSMutableArray array];
    if (domain) {
        [policies addObject:(__bridge_transfer id) SecPolicyCreateSSL(true, (__bridge CFStringRef) domain)];
    } else {
        [policies addObject:(__bridge_transfer id) SecPolicyCreateBasicX509()];
    }

    // 绑定校验策略到服务端的证书上
    SecTrustSetPolicies(serverTrust, (__bridge CFArrayRef) policies);
    // 评估当前serverTrust是否可信任，官方建议在result = kSecTrustResultUnspecified 或 kSecTrustResultProceed的情况下serverTrust可以被验证通过，https://developer.apple.com/library/ios/technotes/tn2232/_index.html
    // 关于SecTrustResultType的详细信息请参考SecTrust.h
    SecTrustResultType result;
    SecTrustEvaluate(serverTrust, &result);
    return (result == kSecTrustResultUnspecified || result == kSecTrustResultProceed);
}

#pragma mark - NSURLSessionTaskDelegate
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition, NSURLCredential *_Nullable))completionHandler {
    if (!challenge) {
        return;
    }

    NSURLSessionAuthChallengeDisposition disposition = NSURLSessionAuthChallengePerformDefaultHandling;
    NSURLCredential *credential = nil;

    // 获取原始域名信息。
    NSString *host = [[task.currentRequest allHTTPHeaderFields] objectForKey:@"host"];
    if (!host) {
        host = task.currentRequest.URL.host;
    }

    if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) {
        if ([self evaluateServerTrust:challenge.protectionSpace.serverTrust forDomain:host]) {
            disposition = NSURLSessionAuthChallengeUseCredential;
            credential = [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust];
        } else {
            disposition = NSURLSessionAuthChallengePerformDefaultHandling;
        }
    } else {
        disposition = NSURLSessionAuthChallengePerformDefaultHandling;
    }

    // 对于其他的challenges直接使用默认的验证方案
    completionHandler(disposition, credential);
}

@end