DigitalData.Core/DigitalData.Core.Security/Cryptographer/RSADecryptor.cs

using DigitalData.Core.Abstractions.Security;
using DigitalData.Core.Security.Extensions;
using System.Security.Cryptography;

namespace DigitalData.Core.Security.Cryptographer
{
    public class RSADecryptor : RSACryptographer, IRSADecryptor, IRSACryptographer
    {
        public (string Value, Version Version)? VersionedPassword
        {
            init
            {
                _password = value?.Value;
                PasswordVersion = value?.Version;
            }
        }

        private string? _password;

        public Version? PasswordVersion { get; private init; } = null;

        public bool HasEncryptedPem => _password is not null;

        public bool IsEncrypted => _password is not null;

        private readonly Lazy<IRSAEncryptor> _lazyEncryptor;

        public IRSAEncryptor Encryptor => _lazyEncryptor.Value;

        private readonly Lazy<RSA> lazyRSA;

        protected override RSA RSA => lazyRSA.Value;

        public RSADecryptor()
        {
            _lazyEncryptor = new(() => new RSAEncryptor()
            {
                Pem = RSA.ExportRSAPublicKeyPem(),
                Padding = Padding
            });

            lazyRSA = new(() =>
            {
                var rsa = RSA.Create();
                if (_password is null)
                    RSA.ImportFromPem(Pem);
                else
                    RSA.ImportFromEncryptedPem(Pem, _password.AsSpan());

                return rsa;
            });
        }

        public byte[] Decrypt(byte[] data) => RSA.Decrypt(data, Padding);

        public string Decrypt(string data) => RSA.Decrypt(data.Base64ToByte(), Padding).BytesToString();
    }
}