OpenMediaID 1.0.1

OpenMediaID

OpenMediaID is an open-source .NET library and container format for signing, verifying, and describing media collections in a secure and portable way.

It allows developers, publishers, and teams to:

• Create signed metadata packages for collections of media files
• Verify the integrity and origin of media using embedded public key signatures
• Embed previews, thumbnails, and structured metadata

✅ Features

• ✍️ Digital signing using RSA private keys
• 🔍 Signature verification using public keys
• 📦 ZIP-based .medid container format
• 📄 Metadata stored as human-readable JSON
• 🖼 Supports thumbnails and preview media
• 🛠 .NET 8+ library and NuGet package

📦 Installation

Install via NuGet:

dotnet add package OpenMediaID

Or via Visual Studio NuGet Manager: OpenMediaID

📂 The .medid Container Format

A .medid file is a ZIP archive containing:

my-collection.medid
├── medid.json         # core metadata file (signed)
├── public.key         # optional: embedded public key
├── info.md            # optional: human-readable info
├── thumbnails/        # optional preview images
└── media/             # optional preview media

🧰 Example Usage

🔐 Signing a media package

var keyPair = KeyPairGenerator.Generate();
var signed = MedidSigner.Sign(medidFile, keyPair.PrivateKey, "Your Name", "pubkey-2025");
MedidPackage.Save(signed, "package.medid", keyPair.PublicKey);

✅ Verifying a signed package

var medid = MedidPackage.Load("package.medid", out var pubkey);
bool isValid = MedidVerifier.Verify(medid, pubkey);

🧾 Creating a metadata file

var entry = new MediaEntry
{
    Filename = "image.jpg",
    Hash = "sha256:...",
    LengthInBytes = 102400,
    MimeType = "image/jpeg",
    Metadata = new MediaMetadata { Width = 800, Height = 600 },
    ThumbnailPath = "thumbnails/image.jpg"
};

var collection = new MediaCollection
{
    Name = "My Images",
    Publisher = "Example Corp",
    Created = DateTime.UtcNow,
    Entries = new() { entry }
};

var medidFile = new MedidFile
{
    Collection = collection
};

🔒 Key Generation

var (priv, pub) = KeyPairGenerator.Generate();
File.WriteAllBytes("private.key", priv);
File.WriteAllBytes("public.key", pub);

To securely store private keys:

var encrypted = EncryptedKeyManager.EncryptPrivateKey(priv, "MyPassword");
var decrypted = EncryptedKeyManager.DecryptPrivateKey(encrypted, "MyPassword");

📄 License

MIT License © 2025 OpenMediaID Project (Idea and Made by: Christof Rakowski)

Copyright Notice

This project utilizes the following open-source libraries:

• Blake3 (https://www.nuget.org/packages/Blake3), licensed under the BSD-2-Clause license.
• SixLabors.ImageSharp (https://www.nuget.org/packages/SixLabors.ImageSharp), licensed under the Six Labors Split License, Version 1.0.

Please refer to the respective license files for detailed terms and conditions.