Video Encryption SDK — référence des interfaces¶

using System;
using System.Runtime.InteropServices;

[ComImport]
[Guid("BAA5BD1E-3B30-425e-AB3B-CC20764AC253")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface IVFCryptoConfig
{
    // NOTE : put_Provider / get_Provider sont des stubs dans le wrapper manage —
    // le parametre s'appelle litteralement `passwordProviderNotUsed` car le
    // marshaling .NET pour IVFPasswordProvider n'est pas branche. Depuis C#,
    // appelez put_Password directement avec les octets de cle binaires.
    [PreserveSig]
    int put_Provider([In] IVFPasswordProvider passwordProviderNotUsed);

    [PreserveSig]
    int get_Provider([Out] IVFPasswordProvider passwordProviderNotUsed);

    [PreserveSig]
    int put_Password(IntPtr buffer, [In] int size);

    [PreserveSig]
    int HavePassword();
}

int put_Provider(IVFPasswordProvider passwordProvider);

int get_Provider(IVFPasswordProvider passwordProvider);

int put_Password(IntPtr buffer, int size);

var cryptoConfig = muxerFilter as IVFCryptoConfig;
if (cryptoConfig != null)
{
    // Utiliser la methode utilitaire (recommande)
    cryptoConfig.ApplyString("MySecurePassword123");
    // Ou manuellement avec IntPtr
    string password = "MySecurePassword123";
    IntPtr ptr = Marshal.StringToCoTaskMemUni(password);
    try
    {
        cryptoConfig.put_Password(ptr, password.Length * 2);
    }
    finally
    {
        Marshal.FreeCoTaskMem(ptr);
    }
}

int HavePassword();

var cryptoConfig = muxerFilter as IVFCryptoConfig;
if (cryptoConfig != null)
{
    int hr = cryptoConfig.HavePassword();
    if (hr == 0) // S_OK
    {
        // Mot de passe defini
        Console.WriteLine("Password configured successfully");
    }
    else
    {
        // Aucun mot de passe
        Console.WriteLine("Warning: No password set");
    }
}

[ComImport]
[Guid("6F8162B5-778D-42b5-9242-1BBABB24FFC4")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface IVFPasswordProvider
{
    [PreserveSig]
    int QueryPassword(
        [MarshalAs(UnmanagedType.LPWStr)] string pszFileName,
        [In, Out, MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 2)] byte[] pBuffer,
        [In, Out] ref int plSize
    );
}

int QueryPassword(
    string pszFileName,
    byte[] pBuffer,
    ref int plSize
);

public class CustomPasswordProvider : IVFPasswordProvider
{
    public int QueryPassword(string pszFileName, byte[] pBuffer, ref int plSize)
    {
        // Generer une cle specifique au fichier
        byte[] key = GenerateKeyForFile(pszFileName);
        if (pBuffer == null || plSize < key.Length)
        {
            plSize = key.Length;
            return unchecked((int)0x8007000E); // E_OUTOFMEMORY
        }
        Array.Copy(key, pBuffer, key.Length);
        plSize = key.Length;
        return 0; // S_OK
    }
    private byte[] GenerateKeyForFile(string fileName)
    {
        // Logique personnalisee de generation de cle
        using (var sha256 = SHA256.Create())
        {
            string seed = "MySalt" + fileName;
            return sha256.ComputeHash(Encoding.UTF8.GetBytes(seed));
        }
    }
}

public static int ApplyString(this IVFCryptoConfig cryptoConfig, string key)

var cryptoConfig = muxerFilter as IVFCryptoConfig;
if (cryptoConfig != null)
{
    cryptoConfig.ApplyString("MySecurePassword123");
}

public static int ApplyFile(this IVFCryptoConfig cryptoConfig, string key)

var cryptoConfig = muxerFilter as IVFCryptoConfig;
if (cryptoConfig != null)
{
    cryptoConfig.ApplyFile(@"C:\keys\encryption.key");
}

public static int ApplyBinary(this IVFCryptoConfig cryptoConfig, byte[] key)

var cryptoConfig = muxerFilter as IVFCryptoConfig;
if (cryptoConfig != null)
{
    // Generer une cle aleatoire
    byte[] keyData = new byte[32];
    using (var rng = new RNGCryptoServiceProvider())
    {
        rng.GetBytes(keyData);
    }

    // Appliquer la cle binaire
    cryptoConfig.ApplyBinary(keyData);

    // Stocker keyData de facon securisee pour un dechiffrement ulterieur
    SaveKeyToSecureStorage(keyData);
}

var muxerFilter = (IBaseFilter)Activator.CreateInstance(
    Type.GetTypeFromCLSID(new Guid("F1D3727A-88DE-49ab-A635-280BEFEFF902"))
);

var demuxerFilter = (IBaseFilter)Activator.CreateInstance(
    Type.GetTypeFromCLSID(new Guid("D2C761F0-9988-4f79-9B0E-FB2B79C65851"))
);