(C) Azure Storage: CORS Preflight Blob Request

Azure Storage Blob Service REST API: Sample code to send a CORS pre-flight blob request.

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#include <C_CkRest.h>
#include <C_CkAuthAzureStorage.h>

void ChilkatSample(void)
    {
    HCkRest rest;
    BOOL bTls;
    int port;
    BOOL bAutoReconnect;
    BOOL success;
    HCkAuthAzureStorage azAuth;
    const char *responseStr;

    // Azure Blob Service Example: CORS Preflight Blob Request
    // See also: https://msdn.microsoft.com/en-us/library/azure/dn535599.aspx

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    rest = CkRest_Create();

    // Connect to the Azure Storage Blob Service
    bTls = TRUE;
    port = 443;
    bAutoReconnect = TRUE;
    // In this example, the storage account name is "chilkat".
    success = CkRest_Connect(rest,"chilkat.blob.core.windows.net",port,bTls,bAutoReconnect);
    if (success != TRUE) {
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        return;
    }

    // Provide Azure Cloud credentials for the REST call.
    azAuth = CkAuthAzureStorage_Create();
    CkAuthAzureStorage_putAccessKey(azAuth,"AZURE_ACCESS_KEY");
    // The account name used here should match the 1st part of the domain passed in the call to Connect (above).
    CkAuthAzureStorage_putAccount(azAuth,"chilkat");
    CkAuthAzureStorage_putScheme(azAuth,"SharedKey");
    CkAuthAzureStorage_putService(azAuth,"Blob");
    // This causes the "x-ms-version: 2021-08-06" header to be automatically added.
    CkAuthAzureStorage_putXMsVersion(azAuth,"2021-08-06");
    success = CkRest_SetAuthAzureStorage(rest,azAuth);

    // Note: The application does not need to explicitly set the following
    // headers: x-ms-date, Authorization.  These headers
    // are automatically set by Chilkat.

    // The preflight blob request requires the following two HTTP headers.
    // The Origin is the domain from which the actual request will be issued.
    success = CkRest_AddHeader(rest,"Origin","www.contoso.com");
    // The Access-Control-Request-Method is the HTTP method (such as GET, POST, PUT, etc.) of the actual request.
    success = CkRest_AddHeader(rest,"Access-Control-Request-Method","PUT");

    // The expected response is a 202 response status code with no response body.
    // The name of the container or blob resource in this example is "test". (Replace "test" with your container name.)
    responseStr = CkRest_fullRequestNoBody(rest,"OPTIONS","/test");
    if (CkRest_getLastMethodSuccess(rest) != TRUE) {
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        CkAuthAzureStorage_Dispose(azAuth);
        return;
    }

    // When successful, the Azure Storage service will respond with a 200 response code,
    // with no response body.

    // If CORS is not enabled or no matching rule is found for the request, 
    // then a 403 status code is returned, with the following status text:
    // "CORS not enabled or no matching rule found for this request."
    if (CkRest_getResponseStatusCode(rest) != 200) {
        // Examine the request/response to see what happened.
        printf("response status code = %d\n",CkRest_getResponseStatusCode(rest));
        printf("response status text = %s\n",CkRest_responseStatusText(rest));
        printf("response header: %s\n",CkRest_responseHeader(rest));
        printf("response body (if any): %s\n",responseStr);
        printf("---\n");
        printf("LastRequestStartLine: %s\n",CkRest_lastRequestStartLine(rest));
        printf("LastRequestHeader: %s\n",CkRest_lastRequestHeader(rest));
        CkRest_Dispose(rest);
        CkAuthAzureStorage_Dispose(azAuth);
        return;
    }

    printf("Success: Preflight Blob Request is accepted.\n");


    CkRest_Dispose(rest);
    CkAuthAzureStorage_Dispose(azAuth);

    }