DigitalData.Core/DigitalData.Core.Security/Config/AsymCryptParams.cs

using DigitalData.Core.Abstractions.Security;

namespace DigitalData.Core.Security.Config
{
    public class AsymCryptParams : RSAFactoryParams
    {
        public string Directory { get; init; } = string.Empty;

        /// <summary>
        /// 0: Issuer - 1: Audience - 2: Type tag - 3: Version
        /// </summary>
        public string FileNameFormat { get; init; } = "{0}_-_{1}_-_{2}_-_{3}.pem";

        public string EncryptorTag { get; init; } = "public";

        public string DecryptorTag { get; init; } = "private";

        public string EncryptedDecryptorTag { get; init; } = "enc-private";

        public IEnumerable<IRSADecryptor> Decryptors { get; init; } = new List<IRSADecryptor>();

        public IEnumerable<IRSAEncryptor> Encryptors { get; init; } = new List<IRSAEncryptor>();
        
        private string TypeTagOf(IRSACryptographer crypt)
        {
            if (crypt is IRSAEncryptor)
                return EncryptorTag;
            else if (crypt is IRSADecryptor decryptor)
                return decryptor.Encrypt ? EncryptedDecryptorTag : DecryptorTag;
            else
                throw new InvalidOperationException(
                    "Unknown cryptographer type. The crypt parameter must be either IRSAEncryptor or IRSADecryptor.");
        }

        public override void OnDeserialized()
        {
            base.OnDeserialized();

            var cryptographers = Encryptors.Cast<IRSACryptographer>().Concat(Decryptors.Cast<IRSACryptographer>());

            foreach (var crypt in cryptographers)
            {
                // set default path
                if (crypt.Pem is null)
                {
                    crypt.Directory ??= Directory;
                    crypt.FileName ??= string.Format(
                            FileNameFormat,
                            crypt.Issuer,
                            crypt.Audience,
                            TypeTagOf(crypt),
                            Secrets.Version);
                }

                crypt.Init();
            }
        }
    }
}