Codebeispiel für CNG-Anbieter

Das folgende Beispiel zeigt, wie Sie die registrierten Crypto-Anbieter auf Ihrem System auflisten, um den mit dem CloudHSM-Client für Windows installierten CNG-Anbieter zu finden. Das Beispiel zeigt außerdem, wie ein asymmetrisches Schlüsselpaar erstellt und zum Signieren von Daten verwendet wird.

// CloudHsmCngExampleConsole.cpp : Console application that demonstrates CNG capabilities.
// This example contains the following functions.
//
//   VerifyProvider()          - Enumerate the registered providers and retrieve Cavium KSP and CNG providers.
//   GenerateKeyPair()         - Create an RSA key pair.
//   SignData()                - Sign and verify data.
//

#include "stdafx.h"
#include <Windows.h>

#ifndef NT_SUCCESS
#define NT_SUCCESS(Status) ((NTSTATUS)(Status) >= 0)
#endif

#define CAVIUM_CNG_PROVIDER L"Cavium CNG Provider"
#define CAVIUM_KEYSTORE_PROVIDER L"Cavium Key Storage Provider"

// Enumerate the registered providers and determine whether the Cavium CNG provider
// and the Cavium KSP provider exist.
//
bool VerifyProvider()
{
  NTSTATUS status;
  ULONG cbBuffer = 0;
  PCRYPT_PROVIDERS pBuffer = NULL;
  bool foundCng = false;
  bool foundKeystore = false;

  // Retrieve information about the registered providers.
  //   cbBuffer - the size, in bytes, of the buffer pointed to by pBuffer.
  //   pBuffer - pointer to a buffer that contains a CRYPT_PROVIDERS structure.
  status = BCryptEnumRegisteredProviders(&cbBuffer, &pBuffer);

  // If registered providers exist, enumerate them and determine whether the
  // Cavium CNG provider and Cavium KSP provider have been registered.
  if (NT_SUCCESS(status))
  {
    if (pBuffer != NULL)
    {
      for (ULONG i = 0; i < pBuffer->cProviders; i++)
      {
        // Determine whether the Cavium CNG provider exists.
        if (wcscmp(CAVIUM_CNG_PROVIDER, pBuffer->rgpszProviders[i]) == 0)
        {
          printf("Found %S\n", CAVIUM_CNG_PROVIDER);
          foundCng = true;
        }

        // Determine whether the Cavium KSP provider exists.
        else if (wcscmp(CAVIUM_KEYSTORE_PROVIDER, pBuffer->rgpszProviders[i]) == 0)
        {
          printf("Found %S\n", CAVIUM_KEYSTORE_PROVIDER);
          foundKeystore = true;
        }
      }
    }
  }
  else
  {
    printf("BCryptEnumRegisteredProviders failed with error code 0x%08x\n", status);
  }

  // Free memory allocated for the CRYPT_PROVIDERS structure.
  if (NULL != pBuffer)
  {
    BCryptFreeBuffer(pBuffer);
  }

  return foundCng == foundKeystore == true;
}

// Generate an asymmetric key pair. As used here, this example generates an RSA key pair 
// and returns a handle. The handle is used in subsequent operations that use the key pair. 
// The key material is not available.
//
// The key pair is used in the SignData function.
//
NTSTATUS GenerateKeyPair(BCRYPT_ALG_HANDLE hAlgorithm, BCRYPT_KEY_HANDLE *hKey)
{
  NTSTATUS status;

  // Generate the key pair.
  status = BCryptGenerateKeyPair(hAlgorithm, hKey, 2048, 0);
  if (!NT_SUCCESS(status))
  {
    printf("BCryptGenerateKeyPair failed with code 0x%08x\n", status);
    return status;
  }

  // Finalize the key pair. The public/private key pair cannot be used until this 
  // function is called.
  status = BCryptFinalizeKeyPair(*hKey, 0);
  if (!NT_SUCCESS(status))
  {
    printf("BCryptFinalizeKeyPair failed with code 0x%08x\n", status);
    return status;
  }

  return status;
}

// Sign and verify data using the RSA key pair. The data in this function is hardcoded
// and is for example purposes only.
//
NTSTATUS SignData(BCRYPT_KEY_HANDLE hKey)
{
  NTSTATUS status;
  PBYTE sig;
  ULONG sigLen;
  ULONG resLen;
  BCRYPT_PKCS1_PADDING_INFO pInfo;

  // Hardcode the data to be signed (for demonstration purposes only).
  PBYTE message = (PBYTE)"d83e7716bed8a20343d8dc6845e57447";
  ULONG messageLen = strlen((char*)message);

  // Retrieve the size of the buffer needed for the signature.
  status = BCryptSignHash(hKey, NULL, message, messageLen, NULL, 0, &sigLen, 0);
  if (!NT_SUCCESS(status))
  {
    printf("BCryptSignHash failed with code 0x%08x\n", status);
    return status;
  }

  // Allocate a buffer for the signature.
  sig = (PBYTE)HeapAlloc(GetProcessHeap(), 0, sigLen);
  if (sig == NULL)
  {
    return -1;
  }

  // Use the SHA256 algorithm to create padding information.
  pInfo.pszAlgId = BCRYPT_SHA256_ALGORITHM;

  // Create a signature.
  status = BCryptSignHash(hKey, &pInfo, message, messageLen, sig, sigLen, &resLen, BCRYPT_PAD_PKCS1);
  if (!NT_SUCCESS(status))
  {
    printf("BCryptSignHash failed with code 0x%08x\n", status);
    return status;
  }

  // Verify the signature.
  status = BCryptVerifySignature(hKey, &pInfo, message, messageLen, sig, sigLen, BCRYPT_PAD_PKCS1);
  if (!NT_SUCCESS(status))
  {
    printf("BCryptVerifySignature failed with code 0x%08x\n", status);
    return status;
  }

  // Free the memory allocated for the signature.
  if (sig != NULL)
  {
    HeapFree(GetProcessHeap(), 0, sig);
    sig = NULL;
  }

  return 0;
}

// Main function.
//
int main()
{
  NTSTATUS status;
  BCRYPT_ALG_HANDLE hRsaAlg;
  BCRYPT_KEY_HANDLE hKey = NULL;

  // Enumerate the registered providers.
  printf("Searching for Cavium providers...\n");
  if (VerifyProvider() == false) {
    printf("Could not find the CNG and Keystore providers\n");
    return 1;
  }

  // Get the RSA algorithm provider from the Cavium CNG provider.
  printf("Opening RSA algorithm\n");
  status = BCryptOpenAlgorithmProvider(&hRsaAlg, BCRYPT_RSA_ALGORITHM, CAVIUM_CNG_PROVIDER, 0);
  if (!NT_SUCCESS(status))
  {
    printf("BCryptOpenAlgorithmProvider RSA failed with code 0x%08x\n", status);
    return status;
  }

  // Generate an asymmetric key pair using the RSA algorithm.
  printf("Generating RSA Keypair\n");
  GenerateKeyPair(hRsaAlg, &hKey);
  if (hKey == NULL)
  {
    printf("Invalid key handle returned\n");
    return 0;
  }
  printf("Done!\n");

  // Sign and verify [hardcoded] data using the RSA key pair.
  printf("Sign/Verify data with key\n");
  SignData(hKey);
  printf("Done!\n");

  // Remove the key handle from memory.
  status = BCryptDestroyKey(hKey);
  if (!NT_SUCCESS(status))
  {
    printf("BCryptDestroyKey failed with code 0x%08x\n", status);
    return status;
  }

  // Close the RSA algorithm provider.
  status = BCryptCloseAlgorithmProvider(hRsaAlg, NULL);
  if (!NT_SUCCESS(status))
  {
    printf("BCryptCloseAlgorithmProvider RSA failed with code 0x%08x\n", status);
    return status;
  }

  return 0;
}