AzureCheckTest 0.1.23

IsAzureVM function (azurecheck.h)

The IsAzureVM function checks if the Windows Virtual Machine is on Azure using the attested metadata service.

This function uses the attested Azure IMDS Service which sends signed responses with trusted certificates. IsAzureVM will do attestation verifying those certificates and get the parameters decrypted from the response. For current Azure Instance Metadata Service (IMDS) attestation, refer here.

Syntax

HRESULT IsAzureVM (
    [in] DWORD flags, 
    [in, optional] LPCWSTR nonce, 
    [in, out] AZURE_HOST_TYPE azureHostType, 
    [in, out, optional] AZURE_METADATA* response, 
    [out] BOOL* isAzureVM
);

Parameters

[in] flags

Flags which determine additional validations.

[in, optional] nonce

A pointer to a string variable that contains the custom nonce which the calling application will validate with.

[in, out] azureHostType

A pointer to the AZURE_HOST_TYPE enumeration.

AZURE_HOST_TYPE

Syntax

typedef enum    
{ 
    AZURE_HOST_INVALID = 0, 
    AZURE_CLOUD, 
    AZURE_STACK, 
    AZURE_STACK_HCI, 
    AZURE_PRODUCT_MAX 
} AZURE_HOST_TYPE;

Members

If the value is AZURE_HOST_INVALID, then the API will determine the host product type and set the type accordingly.

If any other value is provided, then the API will attest if current VM is hosted on that specific host product.

[in, out, optional] response

A pointer to the AZURE_METADATA structure to be converted. It is a decrypted metadata from IMDS response. For more information, refer to Azure Instance Metadata Service for Windows - Azure Virtual Machines | Microsoft Docs

AZURE_METADATA

Syntax

typedef struct _tagAzureMetadataResponse
{   
    LPCWSTR nonce;
    LPCWSTR plan;
    LPCWSTR timeStampCreatedOn;
    LPCWSTR timeStampExpiresOn;
    LPCWSTR vmId;
    LPCWSTR subscriptionId;
    LPCWSTR sku;
    LPCWSTR licenseType;
} AZURE_METADATA;

Members

[out] isAzureVM

A pointer to Boolean value which indicates whether the VM is running in Azure.

Return value

Returns a HRESULT

Remarks

• Windows.h header file must be included.
• COM library must be initialized before the operation and closed after the operation.
• This function/API must always be used from its latest NuGet package Microsoft.Windows.AzureCheck

Example

#include <iostream>
#include <windows.h>
#include <azurecheck.h>

int main()
{
    HRESULT hr = CoInitializeEx(NULL, COINIT_MULTITHREADED);

    BOOL isAzureVM = FALSE;
    AZURE_HOST_TYPE host_type = AZURE_HOST_TYPE::AZURE_HOST_INVALID;
    AZURE_METADATA metadata = {};
    
    HRESULT hrResult = IsAzureVM(0, NULL, &host_type, &metadata, &isAzureVM);

    if (FAILED(hrResult)) {
        std::cerr << "Call to IsAzureVM failed with this error: 0x" << std::hex << hrResult << std::endl;
    }
    else {
        std::cout << "Is the code running in Azure? " << isAzureVM << std::endl;
        std::cout << "Host type: " << host_type << std::endl;
    }
    CoUninitialize();
}

Requirements