IWinHttpRequest::SetCredentials method

Artikkel
01/07/2021

The SetCredentials method sets credentials to be used with an HTTP server, whether it is a proxy server or an originating server.

Syntax

HRESULT SetCredentials(
  [in] BSTR                             UserName,
  [in] BSTR                             Password,
  [in] HTTPREQUEST_SETCREDENTIALS_FLAGS Flags
);

Parameters

UserName [in]

Specifies the user name for authentication.

Password [in]

Specifies the password for authentication. This parameter is ignored if bstrUserName is NULL or missing.

Flags [in]

Specifies when IWinHttpRequest uses credentials. Can be one of the following values.

Value	Meaning
HTTPREQUEST_SETCREDENTIALS_FOR_SERVER	Credentials are passed to a server.
HTTPREQUEST_SETCREDENTIALS_FOR_PROXY	Credentials are passed to a proxy.

Return value

The return value is S_OK on success or an error value otherwise.

Remarks

This method returns an error value if a call to Open has not completed successfully. It is assumed that some measure of interaction with a proxy server or origin server must occur before users can set credentials for the session. Moreover, until users know which authentication scheme(s) are supported, they cannot format the credentials.

Note

For Windows XP and Windows 2000, see the Run-Time Requirements section of the WinHTTP Start Page.

To authenticate with both the server and the proxy, the application must call SetCredentials twice; first with the Flags parameter set to HTTPREQUEST_SETCREDENTIALS_FOR_SERVER, and second, with the Flags parameter set to HTTPREQUEST_SETCREDENTIALS_FOR_PROXY.

Examples

The following example shows how to open an HTTP connection, set credentials for the server, send an HTTP request, and read the response text. This example must be run from a command prompt.

#include <windows.h>
#include <stdio.h>
#include <objbase.h>

#include "httprequest.h"

#pragma comment(lib, "ole32.lib")
#pragma comment(lib, "oleaut32.lib")

// IID for IWinHttpRequest.
const IID IID_IWinHttpRequest =
{
  0x06f29373,
  0x5c5a,
  0x4b54,
  {0xb0, 0x25, 0x6e, 0xf1, 0xbf, 0x8a, 0xbf, 0x0e}
};

int main()
{
    // Variable for return value
    HRESULT    hr;

    // Initialize COM.
    hr = CoInitialize( NULL );

    IWinHttpRequest *  pIWinHttpRequest = NULL;

    BSTR            bstrResponse = NULL;
    VARIANT         varFalse;
    VARIANT         varEmpty;

    CLSID           clsid;

    VariantInit(&varFalse);
    V_VT(&varFalse)   = VT_BOOL;
    V_BOOL(&varFalse) = VARIANT_FALSE;

    VariantInit(&varEmpty);
    V_VT(&varEmpty) = VT_ERROR;

    hr = CLSIDFromProgID(L"WinHttp.WinHttpRequest.5.1", &clsid);

    if (SUCCEEDED(hr))
    {
        hr = CoCreateInstance(clsid, NULL,
                              CLSCTX_INPROC_SERVER,
                              IID_IWinHttpRequest,
                              (void **)&pIWinHttpRequest);
    }
    if (SUCCEEDED(hr))
    {    // Open WinHttpRequest.
        BSTR bstrMethod = SysAllocString(L"GET");
        BSTR bstrUrl = SysAllocString(L"https://microsoft.com");
        hr = pIWinHttpRequest->Open(bstrMethod, bstrUrl, varFalse);
        SysFreeString(bstrMethod);
        SysFreeString(bstrUrl);
    }
    if (SUCCEEDED(hr))
    {    // Set Credentials.
        BSTR bstrUserName = SysAllocString(L"User Name");
        BSTR bstrPassword = SysAllocString(L"Password");
        hr = pIWinHttpRequest->SetCredentials(
                               bstrUserName,
                               bstrPassword,
                               HTTPREQUEST_SETCREDENTIALS_FOR_SERVER);
        SysFreeString(bstrUserName);
        SysFreeString(bstrPassword);
    }
    if (SUCCEEDED(hr))
    {    // Send Request.
        hr = pIWinHttpRequest->Send(varEmpty);
    }
    if (SUCCEEDED(hr))
    {    // Get Response text.
        hr = pIWinHttpRequest->get_ResponseText(&bstrResponse);
    }
    if (SUCCEEDED(hr))
    {    // Print response to console.
        wprintf(L"%.256s",bstrResponse);
    }

    // Release memory.
    if (pIWinHttpRequest)
        pIWinHttpRequest->Release();
    if (bstrResponse)
        SysFreeString(bstrResponse);

    CoUninitialize();
    return 0;
}

The following scripting example shows how to open an HTTP connection, set credentials for the server, set credentials for a proxy if one is used, send an HTTP request, and read the response text.

// HttpRequest SetCredentials flags
HTTPREQUEST_SETCREDENTIALS_FOR_SERVER = 0;
HTTPREQUEST_SETCREDENTIALS_FOR_PROXY = 1;

// Instantiate a WinHttpRequest object.
var WinHttpReq = new ActiveXObject("WinHttp.WinHttpRequest.5.1");

// Specify the target resource.
var targURL = "https://msdn.microsoft.com/downloads/samples/"+
              "internet/winhttp/auth/authenticate.asp";    
WinHttpReq.open("GET", targURL, false);

var Done = false;
var LastStatus=0;
do {
    // Send a request to the server and wait for a response.                               
    WinHttpReq.send(); 
    
    // Obtain the status code from the response.
    var Status = WinHttpReq.Status;

    switch (Status){
        // A 200 status indicates that the resource was retrieved.
        case 200:
            Done = true;
            break;
                
        // A 401 status indicates that the server 
        // requires authentication.    
        case 401:
            WScript.Echo("Requires Server UserName and Password.");

            // Specify the target resource.
            WinHttpReq.open("GET", targURL, false);
                            
            // Set credentials for the server.
            WinHttpReq.SetCredentials("User Name", "Password", 
                        HTTPREQUEST_SETCREDENTIALS_FOR_SERVER);

            // If the same credentials are requested twice, abort 
            // the request.  For simplicity, this sample does not 
            // check for a repeated sequence of status codes.
            if (LastStatus==401)
                Done = true;
            break;

        // A 407 status indicates that the proxy 
        // requires authentication.    
        case 407:
            WScript.Echo("Requires Proxy UserName and Password.");
                
            // Specify the target resource.
            WinHttpReq.open("GET", targURL, false);
    
            // Set credentials for the proxy.
            WinHttpReq.SetCredentials("User Name", "Password", 
                HTTPREQUEST_SETCREDENTIALS_FOR_PROXY);

            // If the same credentials are requested twice, abort 
            // the request.  For simplicity, this sample does not 
            // check for a repeated sequence of status codes.
            if (LastStatus==407)
                Done = true;
            break;
        
        // Any other status is unexpected.
        default:
            WScript.Echo("Unexpected Status: "+Status);
            Done = true;
            break;
    }
    
    // Keep track of the last status code.
    LastStatus = Status;
    
} while (!Done);

// Display the results of the request.
WScript.Echo(WinHttpReq.Status + "   " + WinHttpReq.StatusText);
WScript.Echo(WinHttpReq.GetAllResponseHeaders());

Requirements

Requirement	Value
Minimum supported client	Windows XP, Windows 2000 Professional with SP3 [desktop apps only]
Minimum supported server	Windows Server 2003, Windows 2000 Server with SP3 [desktop apps only]
Redistributable	WinHTTP 5.0 and Internet Explorer 5.01 or later on Windows XP and Windows 2000.
IDL	HttpRequest.idl
Library	Winhttp.lib
DLL	Winhttp.dll

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