DigitalData.Core/DigitalData.Core.Security/Cryptographer/RSACryptographer.cs

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

namespace DigitalData.Core.Security.Cryptographer
{
    public class RSACryptographer : IRSACryptographer
    {
        protected string? _pem;

        public string Pem
        {
            get => _pem
                ?? throw PemIsNullException;
            init => _pem = value;
        }

        internal bool IsPemNull => _pem is null;
        
        private InvalidOperationException PemIsNullException => new($"Pem is not initialized. Please ensure that the PEM is set or properly loaded from the file. Issuer: {Issuer}, Audience: {Audience}.");
        
        public RSAEncryptionPadding Padding { get; init; } = RSAEncryptionPadding.OaepSHA256;

        protected virtual RSA RSA { get; } = RSA.Create();

        public string Issuer { get; init; } = string.Empty;

        public string Audience { get; init; } = string.Empty;

        internal RSACryptographer() { }

        internal void SetPem(string pem) => _pem = pem;

        public virtual void Init()
        {
            if (_pem is null)
                throw PemIsNullException;
        }
    }
}