annotations/Azaion.CommonSecurity/Services/ResourceLoader.cs

using System.Reflection;
using Azaion.CommonSecurity.DTO;

namespace Azaion.CommonSecurity.Services;

public interface IResourceLoader
{
    Task<MemoryStream> Load(string fileName, CancellationToken cancellationToken = default);
    Assembly? LoadAssembly(string asmName);
}

public class ResourceLoader(AzaionApiClient api, ApiCredentials credentials) : IResourceLoader
{
    private static readonly List<string> EncryptedResources =
    [
        "Azaion.Annotator",
        "Azaion.Dataset"
    ];

    public Assembly? LoadAssembly(string resourceName)
    {
        var assemblyName = resourceName.Split(',').First();
        if (EncryptedResources.Contains(assemblyName))
        {
            try
            {
                var stream = Load($"{assemblyName}.dll").GetAwaiter().GetResult();
                return Assembly.Load(stream.ToArray());
            }
            catch (Exception e)
            {
                Console.WriteLine(e);
                var currentLocation = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!;
                var dllPath = Path.Combine(currentLocation, SecurityConstants.DUMMY_DIR, $"{assemblyName}.dll");
                return Assembly.LoadFile(dllPath);
            }
        }

        var loadedAssembly = AppDomain.CurrentDomain.GetAssemblies()
            .FirstOrDefault(a => a.GetName().Name == assemblyName);

        return loadedAssembly;
    }

    public async Task<MemoryStream> Load(string fileName, CancellationToken cancellationToken = default)
    {
        var hardwareService = new HardwareService();
        var hardwareInfo = hardwareService.GetHardware();

        var encryptedStream = Task.Run(() => api.GetResource(fileName, credentials.Password, hardwareInfo), cancellationToken).Result;

        var key = Security.MakeEncryptionKey(credentials.Email, credentials.Password, hardwareInfo.Hash);
        var stream = new MemoryStream();
        await encryptedStream.DecryptTo(stream, key, cancellationToken);
        stream.Seek(0, SeekOrigin.Begin);
        return stream;
    }
}