How to AES CBC encryption Using cryptoAPI - c++

Question

I want to encrypt a file with AES CBC mode encryption, Using cryptoAPI functions and set my own key from the command-line (It my change in the code)
I imagine that the key (after change) will be 1a1dc91c907325c6 and tried in this form:
HCRYPTPROV hProv = NULL;
HCRYPTKEY hKey = NULL;
DWORD dwBlobLen;
PBYTE pbKeyBlob = NULL;
pbKeyBlob = (PBYTE)"1a1dc91c907325c6";
if(!CryptAcquireContext(&hProv, NULL,NULL, PROV_RSA_AES,CRYPT_VERIFYCONTEXT))
{
printf(" Error in AcquireContext 0x%08x \n",GetLastError());
}
if (!CryptImportKey(hProv,pbKeyBlob,sizeof(pbKeyBlob),0,CRYPT_EXPORTABLE,&hKey ))
{
printf("Error 0x%08x in importing the Des key \n",GetLastError());
}
but CryptImportKey failed
I don't know how to use cryptoAPI functions and It's parameters
I tested some other codes and change the parameters or function's call's order for about 2 weeks but I wasn't able to do this
Please help me [a big help :)]
Thank you

Answer 1

You should do it like this:
if( ::CryptAcquireContext( &m_hCryptoProvider, NULL, NULL/*Default*/, PROV_RSA_AES, CRYPT_VERIFYCONTEXT ) )
{
//Hash Password
// CALG_SHA1 OK
// CALG_AES_128 / CALG_AES_256 => error
if( ::CryptCreateHash( m_hCryptoProvider, CALG_SHA1, 0, 0, &m_hHashPassword ) )
{
// Hash for the password.
if( ::CryptHashData( m_hHashPassword, (BYTE *)password, (DWORD) _tcslen(password) * sizeof(TCHAR), 0 ) )
{
// Session key from the hash
if( ::CryptDeriveKey( m_hCryptoProvider, CALG_AES_256, m_hHashPassword, CRYPT_CREATE_SALT, &m_hCryptKey ) )
{
TRACE( TEXT("Crypto-API OK\n") );
return ERROR_SUCCESS;
}
else
{
TRACE( TEXT("Error in CryptDeriveKey\n") );
}
}
else
{
TRACE( TEXT("Error in CryptHashData\n") );
}
}
else
{
TRACE( TEXT("Error in CryptCreateHash\n") );
}
}
else
{
TRACE( TEXT("Error in CryptAcquireContext\n") );
}
After that you need to use CryptEncrypt/CryptDecrypt to do encode/decode data.