Digital Signature SunMSCAPI provider & MS Crypto A

I want to sign file with the SunMSCAPI provider. As public key and signatures needs to be imported using MS Crypto API.

Generally generating signatures with SHA1withRSA, ends up with big-endian to little-endian (byte order) conversion.

//generate keystore with java keytool
$Keytool -genkey -alias tsign -keystore c:\test\tsignjks.p12 - keyalg rsa -storetype  pkcs12

In Java application:

//for signing and getting keystore, assuming windows certificate is installed
..ks = KeyStore.getInstance("Windows-MY","SunMSCAPI"); 
PrivateKey priv = ks.getKey("tsign",password); 
Signature rsa = Signature.getInstance("SHA1withRSA","SunMSCAPI"); 
rsa.initSign(priv);
.. 
rsa.update(buffer, 0, len);
..
byte[] realSig = rsa.sign();

//for writing public key for ms crypto api or exporting it from windows certificate store
Certificate cert = ks.getCertificate("tsign");
byte[] encodedCert = cert.getEncoded();
FileOutputStream certfos = new FileOutputStream("tsigncer.cer");
certfos.write(encodedCert);

//for writing signatures for ms crypto api
FileOutputStream sigfos = new FileOutputStream(targetPath + "/"
                + signatureName);
sigfos.write(realSig);

I believe that SunMSCAPI can resolve my problem, but I don't know when i import public key using MS Crypto API, It never import at at first stage (unless i change big endian to little endian byte order) below is my code for crypto API.

LPCSTR file = "tsigncer.cer";
//LPCSTR file = "omsign.p12";
BOOL crypt_res = FALSE;

HCRYPTPROV crypt_prov_hndl = NULL;
 crypt_res = CryptAcquireContext(&crypt_prov_hndl, NULL, NULL, PROV_RSA_FULL, 0/*CRYPT_NEWKEYSET*/);
//crypt_res = CryptAcquireContext(&crypt_prov_hndl, NULL, NULL, PROV_DSS, CRYPT_VERIFYCONTEXT/*CRYPT_NEWKEYSET*/);

    if (!crypt_res) {
        HRESULT decode_hr = __HRESULT_FROM_WIN32(GetLastError());
        return decode_hr;
    }

    // Load key file
    HANDLE fileHandle = CreateFile(file, // name of the write
                       GENERIC_READ,          // open for writing
                       0,                      // do not share
                       NULL,                   // default security
                       OPEN_EXISTING,             // create new file only
                       FILE_ATTRIBUTE_NORMAL,  // normal file
                       NULL);                  // no attr. template

    if (fileHandle == INVALID_HANDLE_VALUE)
    {
        DWORD d = GetLastError();
        return -1;
    }

    BYTE buffer[2056];
    DWORD fileSize = 0;
    DWORD fileSizeResult = GetFileSize(fileHandle, &fileSize);

    DWORD numBytesRead = 0;
    BOOL fileLoadResult = ReadFile(fileHandle, (PVOID)buffer, fileSizeResult, &numBytesRead, NULL);

    // Import key
    BOOL result = ImportKey(crypt_prov_hndl, (LPBYTE)buffer, numBytesRead);
//result is always false..

If you work with MSCAPI, it is assumed that you've added your key to the Microsoft Certificate store. You can check if the key is present by going to "Internet Properties" > "Content" > "Certificates" which gives you a list of certificates that are available. If your certificate isn't there, you can't use it. If it's there, you need this code:

SunMSCAPI providerMSCAPI = new SunMSCAPI();
Security.addProvider(providerMSCAPI);
KeyStore ks = KeyStore.getInstance("Windows-MY");
ks.load(null, null);

From there on, the code is pretty standard. Please consult my book on digital signatures for more info (the book is free).

IMPORTANT ADDITION: I forgot to mention that SunMSCAPI isn't present in the 64-bit version of Java 6 (I don't know about Java 7). You can fix this by installing the 32-bit version.