#include <wincrypt.h>
HCRYPTPROV hProv = 0;
#define BUFFER_SIZE 256
BYTE pbBuffer[BUFFER_SIZE];
HCRYPTHASH hHash = 0;
HCRYPTKEY hPubKey = 0;
BYTE *pbSignature = NULL;
DWORD dwSigLen;
LPTSTR szDescription = NULL;
// Get a handle to the default provider using CryptAcquireContext.
// For sample code, see <A
HREF="wce50lrfcryptacquirecontext.htm">CryptAcquireContext</A>.
...
...
// Load 'pbBuffer' with 'BUFFER_SIZE' bytes of test data. This must
// be the same data that was originally signed.
...
// Point 'pbSignature' at the signature created by a previous call
// to CryptSignHash. Set 'dwSigLen' to the number of bytes in the
// signature.
...
// Point 'szDescription' at the text describing the data being 
// signed. This must be the same description text that was
originally
// passed to CryptSignHash.
...
// Get the public key of the user who created the digital signature

// and import it into the CSP by using CryptImportKey. This will
return
// a handle to the public key in 'hPubKey'.
...
// Create a hash object.
if(!CryptCreateHash(hProv, CALG_MD5, 0, 0, &hHash)) {
 printf("Error %x during CryptCreateHash!\n", GetLastError());
 goto done;
}
// Compute the cryptographic hash of the buffer.
if(!CryptHashData(hHash, pbBuffer, BUFFER_SIZE, 0)) {
 printf("Error %x during CryptHashData!\n", GetLastError());
 goto done;
}
// Validate the digital signature.
if(!CryptVerifySignature(hHash, pbSignature, dwSigLen, hPubKey, 
 szDescription, 0)) {
 if(GetLastError() == NTE_BAD_SIGNATURE) {
 printf("Signature not validated!\n");
 } else {
 printf("Error %x during CryptVerifySignature!\n", 
 GetLastError());
 }
} else {
 printf("Signature validated\n");
}
done:
...
// Free the public key.
if(hPubKey != 0) CryptDestroyKey(hPubKey);
// Destroy the hash object.
if(hHash != 0) CryptDestroyHash(hHash);
// Free the provider handle.
if(hProv != 0) CryptReleaseContext(hProv, 0);