由于项目升级，在数据传输过程中需要经过OAuth2.0认证，访问服务器需要https协议。
首先，实现C++代码访问https 服务器，实现Get和post功能，在网上搜索一通，发现各种各样的都有，有的很简单，有的稍微复杂。结果MSDN介绍的比较简洁一点
官方网址：https://docs.microsoft.com/en-us/windows/desktop/WinHttp/ssl-in-winhttp
网友翻译：https://blog.csdn.net/edger2heaven/article/details/45664297
我们的要求还是相对比较简单，OAuth 采用客户端模式（client credentials）
参考阮一峰blog
http://www.ruanyifeng.com/blog/2014/05/oauth_2_0.html
客户端模式（Client Credentials Grant）指客户端以自己的名义，而不是以用户的名义，向"服务提供商"进行认证。严格地说，客户端模式并不属于OAuth框架所要解决的问题。在这种模式中，用户直接向客户端注册，客户端以自己的名义要求"服务提供商"提供服务，其实不存在授权问题。
它的步骤如下：
（A）客户端向认证服务器进行身份认证，并要求一个访问令牌。
（B）认证服务器确认无误后，向客户端提供访问令牌。
A步骤中，客户端发出的HTTP请求，包含以下参数：
- granttype：表示授权类型，此处的值固定为"clientcredentials"，必选项。
- scope：表示权限范围，可选项。
POST /token HTTP/1.1Host: server.example.comAuthorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JWContent-Type: application/x-www-form-urlencodedgrant_type=client_credentials
认证服务器必须以某种方式，验证客户端身份。
B步骤中，认证服务器向客户端发送访问令牌，下面是一个例子。
HTTP/1.1 200 OKContent-Type: application/json;charset=UTF-8Cache-Control: no-storePragma: no-cache{"access_token":"2YotnFZFEjr1zCsicMWpAA","token_type":"example","expires_in":3600,"example_parameter":"example_value"}
以下是POST的代码，代码有点瑕疵，不能通用于普通项目，但是流程是通用的。
GET的代码也是大同小异，只是https头部信息有所不用
#include "stdafx.h"
#include "windows.h"
#include "winhttp.h"
#include "wchar.h"
#include "wincrypt.h"
#include <comdef.h>#pragma comment(lib, "Winhttp.lib")
#pragma comment(lib, "Crypt32.lib")wstring string2wstring(const string &str)
{_bstr_t tmp = str.c_str();wchar_t* pwchar = (wchar_t*)tmp;wstring ret = pwchar;return ret;
}void winhttp_client_post(){LPSTR pszData = "WinHttpWriteData Example";
DWORD dwBytesWritten = 0;
BOOL bResults = FALSE;
HINTERNET hSession = NULL,hConnect = NULL,hRequest = NULL;// Use WinHttpOpen to obtain a session handle.
hSession = WinHttpOpen( L"A WinHTTP Example Program/1.0", WINHTTP_ACCESS_TYPE_DEFAULT_PROXY,WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);// Specify an HTTP server.
if (hSession)hConnect = WinHttpConnect( hSession, L"www.wingtiptoys.com",INTERNET_DEFAULT_HTTPS_PORT, 0);// Create an HTTP Request handle.
if (hConnect)hRequest = WinHttpOpenRequest( hConnect, L"POST", L"/token", NULL, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, 0);// Set HTTP Options
DWORD dwTimeOut = 3000;
DWORD dwFlags =SECURITY_FLAG_IGNORE_UNKNOWN_CA |SECURITY_FLAG_IGNORE_CERT_WRONG_USAGE |SECURITY_FLAG_IGNORE_CERT_CN_INVALID |SECURITY_FLAG_IGNORE_CERT_DATE_INVALID;BOOL bRet = WinHttpSetOption(hRequest, WINHTTP_OPTION_CONNECT_TIMEOUT, &dwTimeOut, sizeof(DWORD));
bRet = WinHttpSetOption(hRequest, WINHTTP_OPTION_SECURITY_FLAGS, &dwFlags, sizeof(dwFlags));
bRet = WinHttpSetOption(hRequest, WINHTTP_OPTION_CLIENT_CERT_CONTEXT, WINHTTP_NO_CLIENT_CERT_CONTEXT, 0);//加上OAuth认证需要的header信息：
std::string client_id = "test client id";
std::string client_secure = "test client security";
// client id and secure need base64 encode
std::wstring strHeader = L"Content-type:application/x-www-form-urlencoded\r\n";
strHeader += L"Authorization: Basic ";
//strHeader += string2wstring(tmsstring) +L"\r\n"; //tmsstring is client and secure after base64 encodingbRet = WinHttpAddRequestHeader(hRequest, strHeader.c_str(), strHeader.length(), WINHTTP_ADDREQ_FLAG_ADD|WINHTTP_ADDREQ_FLAG_REPLACE);
// Send a Request.std::string strTmp = "grant_type=client_credentials"; //OAuth认证模式是客户端模式
if (hRequest) bResults = WinHttpSendRequest( hRequest, WINHTTP_NO_ADDITIONAL_HEADERS,0, (LPVOID)strTmp.c_str(), strTmp.length(), strTmp.length(), 0);// Write data to the server. don't need this step
/*if (bResults)bResults = WinHttpWriteData( hRequest, pszData, (DWORD)strlen(pszData), &dwBytesWritten);
*/
// End the request.
if (bResults)bResults = WinHttpReceiveResponse( hRequest, NULL);// Report any errors.
if (!bResults)printf("Error %d has occurred.\n",GetLastError());//接收服务器返回数据
if(bRet)
{char *pszOutBuf;DWORD dwSize = 0;DWORD dwDownLoaded = 0;std::string strJson; //返回的是Json格式do{if (!WinHttpQueryDataAvailable(hRequest, &dwSize)){//error log}pszOutBuf = new char[dwSize+1];ZeroMemory(pszOutBuf, dwSize+1);if (!WinHttpReadData( hRequest, (LPVOID)pszOutBuf, dwSize, &dwDownLoaded) ){//error log}strJson += pszOutBuf;}while(dwSize > 0);
}// Close any open handles.
if (hRequest) WinHttpCloseHandle(hRequest);
if (hConnect) WinHttpCloseHandle(hConnect);
if (hSession) WinHttpCloseHandle(hSession);}
