NdsValidationOptions.cs

namespace NdsForge;

public sealed class NdsValidationOptions
{
    private byte[]? _dsiHmacKey;
    private NdsKey1KeyTable? _secureAreaKeyTable;
    private NdsDsiRsaPublicKey? _dsiRsaPublicKey;

    public static NdsValidationOptions Default => new();

    public NdsValidationOptions SetDsiHmacKey(ReadOnlySpan<byte> key)
    {
        if (key.IsEmpty)
        {
            throw new ArgumentException("A DSi validation HMAC key cannot be empty.", nameof(key));
        }
 
        _dsiHmacKey = key.ToArray();
        return this;
    }

    public NdsValidationOptions SetSecureAreaKeyTable(NdsKey1KeyTable keyTable)
    {
        _secureAreaKeyTable = keyTable ?? throw new ArgumentNullException(nameof(keyTable));
        return this;
    }

    public NdsValidationOptions SetDsiRsaPublicKey(NdsDsiRsaPublicKey publicKey)
    {
        _dsiRsaPublicKey = publicKey ?? throw new ArgumentNullException(nameof(publicKey));
        return this;
    }

    public bool ValidateDsiDevelopmentSignature { get; init; } = true;

    public int MaxDsiDigestTableBytes { get; init; } = 64 * 1024 * 1024;

    public int MaxDsiDigestFailures { get; init; } = 64;

    internal ReadOnlyMemory<byte> DsiHmacKey => _dsiHmacKey;

    internal NdsKey1KeyTable? SecureAreaKeyTable => _secureAreaKeyTable;

    internal NdsDsiRsaPublicKey? DsiRsaPublicKey => _dsiRsaPublicKey;

    internal void Validate()
    {
        if (MaxDsiDigestTableBytes < 20 || MaxDsiDigestFailures < 1)
        {
            throw new ArgumentException("DSi digest validation limits must allow at least one 20-byte entry and one finding.");
        }
    }
}