HTTPDNS域名解析场景下如何使用Cookie？

1. Cookie

由于HTTP协议是无状态的，为了维护服务端和客户端的会话状态，客户端可存储服务端返回的Cookie，之后请求中可携带Cookie标识状态。

客户端根据服务端返回的携带Set-Cookie的HTTP Header来创建一个Cookie，Set-Cookie为字符串，主要字段如下：

Set-Cookie: [name1=value1, name2=value2;],[expires=date;],[path=path;],[domain=domain;] Cookie信息为形如name=value的字符串；expires，Cookie过期时间；domain，Cookie适用域名；path，请求资源URL中必须存在指定的路径时，才会发送该Cookie。

2. Cookie存储策略

基于iOS平台说明服务端Set-Cookie配置和客户端Cookie存储策略。

2.1 准备工作

访问域名test.com，假定HTTPDNS域名解析结果为201.87.1.125；Web服务器设置Cookie如下，domain字段待定： "Set-Cookie" = "name1=value1; expires=Wed, 15-Nov-17 15:41:02 GMT; path=/" 客户端发送普通HTTP请求： - (void)connectToUrlString:(NSString *)urlString { NSURL *url = [NSURL URLWithString:urlString]; NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration]; configuration.requestCachePolicy = NSURLRequestReloadIgnoringLocalCacheData; NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil]; NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url]; NSURLSessionTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { if (error) { NSLog(@"error: %@", error); } else { NSLog(@"response: %@", response); NSLog(@"data: %@", [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]); } }]; [task resume]; } 客户端使用HTTPDNS服务发送HTTP请求： - (void)connectToUrlStringUsingHTTPDNS:(NSString *)urlString { NSURL *url = [NSURL URLWithString:urlString]; NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration]; configuration.requestCachePolicy = NSURLRequestReloadIgnoringLocalCacheData; NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil]; NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url]; NSString *ip = [[HttpDnsService sharedInstance] getIpByHostAsync:url.host]; if (ip) { NSLog(@"Get IP(%@) for host(%@) from HTTPDNS Successfully!", ip, url.host); NSRange hostFirstRange = [urlString rangeOfString:url.host]; if (hostFirstRange.location != NSNotFound) { NSString * newUrlString = [urlString stringByReplacingCharactersInRange:hostFirstRange withString:ip]; request.URL = [NSURL URLWithString:newUrlString]; [request setValue:url.host forHTTPHeaderField:@"host"]; } } NSURLSessionTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { if (error) { NSLog(@"error: %@", error); } else { NSLog(@"response: %@", response); NSLog(@"data: %@", [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]); } }]; [task resume]; } 查询本App存储全部Cookie： NSHTTPCookieStorage *cookieStorage = [NSHTTPCookieStorage sharedHTTPCookieStorage]; for (NSHTTPCookie *cookie in [cookieStorage cookies]) { NSLog(@"cookie: %@", cookie); } 查询本App存储指定URL对应适配Cookie： NSHTTPCookieStorage *cookieStorage = [NSHTTPCookieStorage sharedHTTPCookieStorage]; NSDictionary *cookiesDic = [NSHTTPCookie requestHeaderFieldsWithCookies:[cookieStorage cookiesForURL:url]];

2.2 指定domain的Cookie

服务端配置Set-Cookie如下，domain设置为.test.com，

"Set-Cookie" = "name1=value1; expires=Wed, 15-Nov-17 15:41:02 GMT; path=/; domain=.test.com"

客户端调用[self connectToUrlString:@"http://test.com"];发送HTTP请求后查询本地Cookie如下；再次访问时，HTTP头部自动添加该Cookie并发送到服务端。

name1 = value1; expires = Wed, 15-Nov-17 15:41:02 GMT; path = /; domain = .test.com;

客户端调用[self connectToUrlStringUsingHTTPDNS:@"http://test.com"];，使用HTTPDNS服务发送HTTP请求，客户端同样收到上述domain为.test.com的Cookie，iOS网络库关于Cookie的默认存储策略为NSHTTPCookieAcceptPolicyOnlyFromMainDocumentDomain，domain与URL无法匹配时（使用HTTPDNS服务发送HTTP请求时，原生URL.host被替换为IP地址），该Cookie不会存储，因此再次发送请求时无法使用Cookie。

2.3 未指定domain的Cookie

若服务端配置Set-Cookie的domain不配置，

"Set-Cookie" = "name1=value1; expires=Wed, 15-Nov-17 15:41:02 GMT; path=/;

客户端发送HTTP请求返回Cookie如下，domain字段为空。

name1 = value1; expires = Wed, 15-Nov-17 15:41:02 GMT; path = /;

iOS网络库存储该Cookie时，自动填充Cookie的domain字段为HTTP请求的URL.host，即普通HTTP请求存储Cookie如下：

name1 = value1; expires = Wed, 15-Nov-17 15:41:02 GMT; path = /; domain = .test.com;

使用HTTPDNS访问的Cookie存储如下，再次使用HTTPDNS进行HTTP请求时，网络库默认Cookie匹配规则可以匹配到该Cookie。（此场景下使用HTTPDNS服务发送HTTP请求，虽然默认Cookie匹配规则可正确匹配Cookie，但是该场景依赖服务端Cookie的配置，为了安全性，通常服务端返回Set-Cookie的domain字段不为空。）

name1 = value1; expires = Wed, 15-Nov-17 15:41:02 GMT; path = /; domain = 201.87.1.125;

3. 适配策略

适配目的是在使用HTTPDNS服务，可以像通用HTTP请求对Cookie进行存储、匹配和发送，这就需要自行管理使用HTTPDNS服务的HTTP请求的Cookie。

存储，收到服务端返回的HTTP Header Set-Cookie，可以正确解析并存储； 匹配，发送HTTP请求前，可正确搜索匹配Cookie； 发送，将匹配的Cookie放入HTTP请求中发送到服务端。

3.1 iOS适配

根据苹果文档说明，按照以下方式可以改变Cookie接受策略，文档说明默认策略为NSHTTPCookieAcceptPolicyAlways，经测试发现默认策略其实为NSHTTPCookieAcceptPolicyOnlyFromMainDocumentDomain；使用以下方式手动将策略修改为NSHTTPCookieAcceptPolicyAlways，测试发现Accept Cookie Always没有生效，原因需要进一步确定。 NSHTTPCookieStorage *cookieStorage = [NSHTTPCookieStorage sharedHTTPCookieStorage]; [cookieStorage setCookieAcceptPolicy:NSHTTPCookieAcceptPolicyAlways]; 实现了简单的HTTPDNS专用的HTTPDNSCookieManager（【注意】此处仅提供Cookie管理的示例，Cookie管理细节如生命周期、匹配规则等不涉及，如有需要可参考RFC 2965），适用于使用HTTPDNS服务的HTTP请求，HTTPDNSCookieManager.h #ifndef HTTPDNSCookieManager_h #define HTTPDNSCookieManager_h // URL匹配Cookie规则 typedef BOOL (^HTTPDNSCookieFilter)(NSHTTPCookie *, NSURL *); @interface HTTPDNSCookieManager : NSObject + (instancetype)sharedInstance; /** 指定URL匹配Cookie策略 @param filter 匹配器 */ - (void)setCookieFilter:(HTTPDNSCookieFilter)filter; /** 处理HTTP Reponse携带的Cookie并存储 @param headerFields HTTP Header Fields @param URL 根据匹配策略获取查找URL关联的Cookie @return 返回添加到存储的Cookie */ - (NSArray<NSHTTPCookie *> *)handleHeaderFields:(NSDictionary *)headerFields forURL:(NSURL *)URL; /** 匹配本地Cookie存储，获取对应URL的request cookie字符串 @param URL 根据匹配策略指定查找URL关联的Cookie @return 返回对应URL的request Cookie字符串 */ - (NSString *)getRequestCookieHeaderForURL:(NSURL *)URL; /** 删除存储cookie @param URL 根据匹配策略查找URL关联的cookie @return 返回成功删除cookie数 */ - (NSInteger)deleteCookieForURL:(NSURL *)URL; @end #endif /* HTTPDNSCookieManager_h */ HTTPDNSCookieManager.m #import <Foundation/Foundation.h> #import "HTTPDNSCookieManager.h" @implementation HTTPDNSCookieManager { HTTPDNSCookieFilter cookieFilter; } - (instancetype)init { if (self = [super init]) { /** 此处设置的Cookie和URL匹配策略比较简单，检查URL.host是否包含Cookie的domain字段 通过调用setCookieFilter接口设定Cookie匹配策略， 比如可以设定Cookie的domain字段和URL.host的后缀匹配 | URL是否符合Cookie的path设定 细节匹配规则可参考RFC 2965 3.3节 */ cookieFilter = ^BOOL(NSHTTPCookie *cookie, NSURL *URL) { if ([URL.host containsString:cookie.domain]) { return YES; } return NO; }; } return self; } + (instancetype)sharedInstance { static id singletonInstance = nil; static dispatch_once_t onceToken; dispatch_once(&onceToken, ^{ if (!singletonInstance) { singletonInstance = [[super allocWithZone:NULL] init]; } }); return singletonInstance; } + (id)allocWithZone:(struct _NSZone *)zone { return [self sharedInstance]; } - (id)copyWithZone:(struct _NSZone *)zone { return self; } - (void)setCookieFilter:(HTTPDNSCookieFilter)filter { if (filter != nil) { cookieFilter = filter; } } - (NSArray<NSHTTPCookie *> *)handleHeaderFields:(NSDictionary *)headerFields forURL:(NSURL *)URL { NSArray *cookieArray = [NSHTTPCookie cookiesWithResponseHeaderFields:headerFields forURL:URL]; if (cookieArray != nil) { NSHTTPCookieStorage *cookieStorage = [NSHTTPCookieStorage sharedHTTPCookieStorage]; for (NSHTTPCookie *cookie in cookieArray) { if (cookieFilter(cookie, URL)) { NSLog(@"Add a cookie: %@", cookie); [cookieStorage setCookie:cookie]; } } } return cookieArray; } - (NSString *)getRequestCookieHeaderForURL:(NSURL *)URL { NSArray *cookieArray = [self searchAppropriateCookies:URL]; if (cookieArray != nil && cookieArray.count > 0) { NSDictionary *cookieDic = [NSHTTPCookie requestHeaderFieldsWithCookies:cookieArray]; if ([cookieDic objectForKey:@"Cookie"]) { return cookieDic[@"Cookie"]; } } return nil; } - (NSArray *)searchAppropriateCookies:(NSURL *)URL { NSMutableArray *cookieArray = [NSMutableArray array]; NSHTTPCookieStorage *cookieStorage = [NSHTTPCookieStorage sharedHTTPCookieStorage]; for (NSHTTPCookie *cookie in [cookieStorage cookies]) { if (cookieFilter(cookie, URL)) { NSLog(@"Search an appropriate cookie: %@", cookie); [cookieArray addObject:cookie]; } } return cookieArray; } - (NSInteger)deleteCookieForURL:(NSURL *)URL { int delCount = 0; NSHTTPCookieStorage *cookieStorage = [NSHTTPCookieStorage sharedHTTPCookieStorage]; for (NSHTTPCookie *cookie in [cookieStorage cookies]) { if (cookieFilter(cookie, URL)) { NSLog(@"Delete a cookie: %@", cookie); [cookieStorage deleteCookie:cookie]; delCount++; } } return delCount; } @end 使用HTTPDNS处理Cookie示例（使用上述默认简单匹配策略）： - (void)connectToUrlStringUsingHTTPDNS:(NSString *)urlString { NSURL *url = [NSURL URLWithString:urlString]; NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration]; configuration.requestCachePolicy = NSURLRequestReloadIgnoringLocalCacheData; NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil]; NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url]; NSString *ip = [[HttpDnsService sharedInstance] getIpByHostAsync:url.host]; if (ip) { NSLog(@"Get IP(%@) for host(%@) from HTTPDNS Successfully!", ip, url.host); NSRange hostFirstRange = [urlString rangeOfString:url.host]; if (hostFirstRange.location != NSNotFound) { NSString *newUrlString = [urlString stringByReplacingCharactersInRange:hostFirstRange withString:ip]; NSLog(@"New URL: %@", newUrlString); request.URL = [NSURL URLWithString:newUrlString]; [request setValue:url.host forHTTPHeaderField:@"host"]; // 匹配合适Cookie添加到request中，这里传入的是原生URL [request setValue:[[HTTPDNSCookieManager sharedInstance] getRequestCookieHeaderForURL:url] forHTTPHeaderField:@"Cookie"]; // 删除Cookie [[HTTPDNSCookieManager sharedInstance] deleteCookieForURL:url]; } } NSURLSessionTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { if (error) { NSLog(@"error: %@", error); } else { NSLog(@"response: %@", response); NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response; // 解析HTTP Response Header，存储cookie [[HTTPDNSCookieManager sharedInstance] handleHeaderFields:[httpResponse allHeaderFields] forURL:url]; NSLog(@"data: %@", [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]); NSHTTPCookieStorage *cookieStorage = [NSHTTPCookieStorage sharedHTTPCookieStorage]; } }]; [task resume]; }

3.2 Android适配

使用如下方式HTTPDNS解析"http://test.com" 域名进行访问， String urlStr = "http://test.com"; // HTTPDNS解析"test.com"域名，发HTTP请求访问 new DownloadWebPageTask().execute(urlStr); private class DownloadWebPageTask extends AsyncTask<String, Void, String> { @Override protected String doInBackground(String... params) { try { return downloadUrl(params[0]); } catch (IOException e) { e.printStackTrace(); } return null; } @Override protected void onPostExecute(String result) { if (result != null) { Log.e(TAG, "Get response: " + result); } else { Log.e(TAG, "Get response error."); } } } private String downloadUrl(String urlStr) throws IOException { try { URL url = new URL(urlStr); conn = (HttpURLConnection) url.openConnection(); String ip = httpDnsService.getIpByHostAsync(urlStr); if (urlStr.equals(url2)) { ip = IP; } if (ip != null) { Log.d(TAG, "Get IP: " + ip + " for host: " + url.getHost() + " from HTTPDNS successfully!"); String newUrlStr = urlStr.replaceFirst(url.getHost(), ip); conn = (HttpURLConnection) new URL(newUrlStr).openConnection(); conn.setRequestProperty("Host", url.getHost()); } conn.setConnectTimeout(1000 * 15); int responseCode = conn.getResponseCode(); if (responseCode == 200) { Log.i(TAG, "Reponse code is 200."); dis = new DataInputStream(conn.getInputStream()); int len; byte[] buff = new byte[4096]; StringBuilder response = new StringBuilder(); while ((len = dis.read(buff)) != -1) { response.append(new String(buff, 0, len)); } return response.toString(); } else { Log.e(TAG, "Response code is " + responseCode); return null; } } catch (MalformedURLException e) { e.printStackTrace(); } return null; } CookieManager配置如下： /** * 配置cookie manager */ private void setCookieHandler() { /** * 指定cookie存储policy * 系统已定义策略有： * CookiePolicy.ACCEPT_ALL，存储全部cookie * CookiePolicy.ACCEPT_NONE，不存储cookie * CookiePolicy.ACCEPT_ORIGINAL_SERVER，按照RFC 2965 3.3节标准域名匹配存储cookie * */ cookieManager.setCookiePolicy(new CookiePolicy() { @Override public boolean shouldAccept(URI uri, HttpCookie cookie) { // 为方便测试，此处都返回true，存储全部cookie Log.i(TAG, "Uri: " + uri.toString() + ", cookie: " + cookie.toString() + ", domain: " + cookie.getDomain()); return true; } }); CookieHandler.setDefault(cookieManager); } 使用CookieManager管理App的Cookie缓存，当对应Cookie满足策略存储到本地时，针对使用HTTPDNS域名解析进行HTTP访问的场景，不用修改即可完成适配。基于HTTPDNS访问http://test.com，获取到Cookie如下，shouldAccept()返回true后网络库自动缓存该Cookie； name1 = value1; expires = Wed, 15-Nov-17 15:41:02 GMT; path = /; domain = .test.com; Cookie存储时，该Cookie直接和访问的URL（http://201.87.1.125）相关联，并且Cookie的domain为test.com；所以，再次使用HTTPDNS服务防伪URL(http://201.87.1.125)时，系统可自动获取到该Cookie。Cookie存储后可按照下面代码测试，基于域名/IP的URL查询缓存Cookie，都可以正确获取该Cookie，因此使用HTTPDNS服务时可自动完成适配。 String url1 = "http://test.com"; String url2 = "http://201.87.1.125"; CookieStore cookieStore = cookieManager.getCookieStore(); try { Log.e(TAG, "store cookie is " + cookieStore.get(new URI(url1))); Log.e(TAG, "store cookie is " + cookieStore.get(new URI(url2))); } catch (URISyntaxException e) { e.printStackTrace(); } 相关资源：七夕情人节表白HTML源码(两款)