5.1 P/Invoke - Integracija DLL-ova

Ova stranica pokazuje kako koristiti OpenSSL putem P/Invoke u .NET-u.

P/Invoke (Platform Invoke) omogućuje pozivanje nativnih DLL funkcija iz .NET-a:

.NET Kod  →  P/Invoke  →  libcrypto-3-x64.dll  →  OpenSSL

cd MojProjekt
copy "D:\Projects\openssl-3.6.0\bin\bin\libcrypto-3-x64.dll" .\
copy "D:\Projects\openssl-3.6.0\bin\bin\libssl-3-x64.dll" .\

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
  </PropertyGroup>
 
  <ItemGroup>
    <!-- OpenSSL Native Libraries -->
    <None Update="libcrypto-3-x64.dll">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="libssl-3-x64.dll">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
  </ItemGroup>
</Project>

using System;
using System.Runtime.InteropServices;
 
namespace MojProjekt;
 
public static class OpenSslInterop
{
    private const string LIBCRYPTO = "libcrypto-3-x64.dll";
 
    // Inicijalizacija
    [DllImport(LIBCRYPTO, CallingConvention = CallingConvention.Cdecl)]
    public static extern int OPENSSL_init_crypto(ulong opts, IntPtr settings);
 
    // Dohvati verziju
    [DllImport(LIBCRYPTO, CallingConvention = CallingConvention.Cdecl)]
    public static extern IntPtr OpenSSL_version(int type);
 
    // Konstante
    public const int OPENSSL_VERSION_STRING = 6;
    public const ulong OPENSSL_INIT_LOAD_CRYPTO_STRINGS = 0x00000002;
    public const ulong OPENSSL_INIT_ADD_ALL_CIPHERS = 0x00000004;
    public const ulong OPENSSL_INIT_ADD_ALL_DIGESTS = 0x00000008;
 
    public static void Initialize()
    {
        OPENSSL_init_crypto(
            OPENSSL_INIT_LOAD_CRYPTO_STRINGS |
            OPENSSL_INIT_ADD_ALL_CIPHERS |
            OPENSSL_INIT_ADD_ALL_DIGESTS,
            IntPtr.Zero);
    }
 
    public static string GetVersion()
    {
        var ptr = OpenSSL_version(OPENSSL_VERSION_STRING);
        return Marshal.PtrToStringAnsi(ptr) ?? "Unknown";
    }
}
 
// Uporaba:
class Program
{
    static void Main()
    {
        OpenSslInterop.Initialize();
        Console.WriteLine($"OpenSSL Verzija: {OpenSslInterop.GetVersion()}");
    }
}

System.DllNotFoundException: Unable to load DLL 'libcrypto-3-x64.dll'

Rješenje:

1. DLL-ovi prisutni u izlaznom direktoriju (bin/Debug/)?
2. .csproj CopyToOutputDirectory ispravan?
3. Platforma ispravna? (x64 vs x86)

System.EntryPointNotFoundException: Unable to find entry point 'XYZ'

Rješenje:

1. Ime funkcije ispravno napisano?
2. CallingConvention.Cdecl postavljen?
3. Verzija OpenSSL-a podržava funkciju?

• Stvaranje NuGet paketa
• 6. Distribucija

Wolfgang van der Stille @ EMSR DATA d.o.o. - Post-Quantum Cryptography Professional