NativeCryptoProvider

Namespace: WvdS.System.Security.Cryptography.Providers

P/Invoke-based crypto provider for server and desktop applications. Communicates directly with OpenSSL 3.6 via Platform Invocation Services.

Overview

The NativeCryptoProvider is the default provider for:

  • Blazor Server
  • ASP.NET Core
  • Desktop applications (Windows, Linux, macOS)
  • Console applications
  • Windows Services / Linux Daemons

Properties

Property Type Description
Name string "Native (P/Invoke)"
IsAvailable bool true if OpenSSL 3.6 is reachable

Initialization

using WvdS.System.Security.Cryptography.Providers;
 
// Create provider
var provider = new NativeCryptoProvider();
 
// Initialize (loads OpenSSL)
await provider.InitializeAsync();
 
// Check if available
if (provider.IsAvailable)
{
    Console.WriteLine($"Provider: {provider.Name}");
    Console.WriteLine($"OpenSSL: {provider.GetOpenSslVersion()}");
}

ML-DSA Operations

GenerateMlDsaKeyPairAsync

Generates an ML-DSA key pair.

var (publicKey, privateKey) = await provider.GenerateMlDsaKeyPairAsync("ML-DSA-65");
 
// Supported algorithms:
// - "ML-DSA-44" (NIST Level 1)
// - "ML-DSA-65" (NIST Level 3, recommended)
// - "ML-DSA-87" (NIST Level 5)

SignMlDsaAsync

Signs data with ML-DSA.

byte[] data = Encoding.UTF8.GetBytes("Important data");
byte[] signature = await provider.SignMlDsaAsync(data, privateKey);

VerifyMlDsaAsync

Verifies an ML-DSA signature.

bool isValid = await provider.VerifyMlDsaAsync(data, signature, publicKey);

ML-KEM Operations

GenerateMlKemKeyPairAsync

Generates an ML-KEM key pair.

var (publicKey, privateKey) = await provider.GenerateMlKemKeyPairAsync("ML-KEM-768");
 
// Supported algorithms:
// - "ML-KEM-512" (NIST Level 1)
// - "ML-KEM-768" (NIST Level 3, recommended)
// - "ML-KEM-1024" (NIST Level 5)

EncapsulateAsync

Encapsulates a shared secret with the public key.

var (sharedSecret, ciphertext) = await provider.EncapsulateAsync(recipientPublicKey);
 
// sharedSecret: 32 bytes symmetric key
// ciphertext: Send to recipient

DecapsulateAsync

Decapsulates the shared secret.

byte[] sharedSecret = await provider.DecapsulateAsync(ciphertext, privateKey);

Certificate Operations

CreateEphemeralCertificateAsync

Creates an ephemeral ML-DSA certificate.

var (pubKey, privKey) = await provider.GenerateMlDsaKeyPairAsync();
 
byte[] certBytes = await provider.CreateEphemeralCertificateAsync(
    "CN=Ephemeral Test",
    TimeSpan.FromHours(24),
    privKey);
 
var cert = new X509Certificate2(certBytes);

SignCertificateAsync

Signs TBS certificate data with ML-DSA.

byte[] tbsCertificate = GetTbsCertificate();
byte[] signedCert = await provider.SignCertificateAsync(tbsCertificate, privateKey);

Method Overview

Method Parameters Return
InitializeAsync() - Task
GetOpenSslVersion() - string
GenerateMlDsaKeyPairAsync string algorithm Task<(byte[], byte[])>
SignMlDsaAsync byte[] data, byte[] privateKey Task<byte[]>
VerifyMlDsaAsync byte[] data, byte[] signature, byte[] publicKey Task<bool>
GenerateMlKemKeyPairAsync string algorithm Task<(byte[], byte[])>
EncapsulateAsync byte[] publicKey Task<(byte[], byte[])>
DecapsulateAsync byte[] ciphertext, byte[] privateKey Task<byte[]>
CreateEphemeralCertificateAsync string subject, TimeSpan validity, byte[] privateKey Task<byte[]>
SignCertificateAsync byte[] tbsCertificate, byte[] privateKey Task<byte[]>

OpenSSL Path Configuration

// Set the path before InitializeAsync()
CryptoConfig.OpenSslPath = @"C:\OpenSSL\bin";
 
var provider = new NativeCryptoProvider();
await provider.InitializeAsync();

Default search paths:

Operating System Paths
Windows .\, C:\OpenSSL\bin, PATH
Linux /usr/local/lib64, /usr/lib/x86_64-linux-gnu
macOS /opt/homebrew/lib, /usr/local/lib

Performance Notes

P/Invoke Performance:
  • Synchronous execution in native code
  • Task wrapper for API consistency with WasmCryptoProvider
  • Minimal overhead through direct memory access
  • Thread-safe through OpenSSL's internal synchronization

Complete Example

using WvdS.System.Security.Cryptography.Providers;
 
// 1. Initialize provider
var provider = new NativeCryptoProvider();
await provider.InitializeAsync();
 
Console.WriteLine($"OpenSSL: {provider.GetOpenSslVersion()}");
 
// 2. ML-KEM Key Exchange
var (alicePublic, alicePrivate) = await provider.GenerateMlKemKeyPairAsync();
var (bobPublic, bobPrivate) = await provider.GenerateMlKemKeyPairAsync();
 
// Alice encapsulates for Bob
var (aliceSecret, ciphertext) = await provider.EncapsulateAsync(bobPublic);
 
// Bob decapsulates
var bobSecret = await provider.DecapsulateAsync(ciphertext, bobPrivate);
 
// Shared secrets are identical
Console.WriteLine($"Keys match: {aliceSecret.SequenceEqual(bobSecret)}");
 
// 3. ML-DSA Signature
var (sigPubKey, sigPrivKey) = await provider.GenerateMlDsaKeyPairAsync();
 
byte[] message = Encoding.UTF8.GetBytes("Important message");
byte[] signature = await provider.SignMlDsaAsync(message, sigPrivKey);
 
bool isValid = await provider.VerifyMlDsaAsync(message, signature, sigPubKey);
Console.WriteLine($"Signature valid: {isValid}");

Security Notes

  • Requires OpenSSL 3.6.0 or higher with PQ algorithms
  • Private keys are held in process memory
  • Keys are not automatically deleted at application end
  • For highest security: explicitly delete keys with CryptographicOperations.ZeroMemory

See Also


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

Zuletzt geändert: on 2026/01/30 at 01:13 AM