// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System;
using System.Diagnostics;
using System.Security.Cryptography.X509Certificates;
 
namespace System.Security.Cryptography.Pkcs
{
    public sealed class CmsRecipient
    {
        public CmsRecipient(X509Certificate2 certificate)
            : this(SubjectIdentifierType.IssuerAndSerialNumber, certificate)
        {
        }
 
#if NETSTANDARD2_0
        internal
#else
        public
#endif
        CmsRecipient(X509Certificate2 certificate, RSAEncryptionPadding rsaEncryptionPadding)
            : this(certificate)
        {
            if (rsaEncryptionPadding is null)
            {
                throw new ArgumentNullException(nameof(rsaEncryptionPadding));
            }
 
            ValidateRSACertificate(certificate);
            RSAEncryptionPadding = rsaEncryptionPadding;
        }
 
#if NETSTANDARD2_0
        internal
#else
        public
#endif
        CmsRecipient(SubjectIdentifierType recipientIdentifierType, X509Certificate2 certificate, RSAEncryptionPadding rsaEncryptionPadding)
            : this(recipientIdentifierType, certificate)
        {
            if (rsaEncryptionPadding is null)
            {
                throw new ArgumentNullException(nameof(rsaEncryptionPadding));
            }
 
            ValidateRSACertificate(certificate);
            RSAEncryptionPadding = rsaEncryptionPadding;
        }
 
        public CmsRecipient(SubjectIdentifierType recipientIdentifierType, X509Certificate2 certificate)
        {
            if (certificate is null)
            {
                throw new ArgumentNullException(nameof(certificate));
            }
 
            switch (recipientIdentifierType)
            {
                case SubjectIdentifierType.Unknown:
                    recipientIdentifierType = SubjectIdentifierType.IssuerAndSerialNumber;
                    break;
                case SubjectIdentifierType.IssuerAndSerialNumber:
                    break;
                case SubjectIdentifierType.SubjectKeyIdentifier:
                    break;
                default:
                    throw new CryptographicException(SR.Format(SR.Cryptography_Cms_Invalid_Subject_Identifier_Type, recipientIdentifierType));
            }
 
            RecipientIdentifierType = recipientIdentifierType;
            Certificate = certificate;
        }
 
#if NETSTANDARD2_0
        internal
#else
        public
#endif
        RSAEncryptionPadding? RSAEncryptionPadding { get; }
        public SubjectIdentifierType RecipientIdentifierType { get; }
        public X509Certificate2 Certificate { get; }
 
        private static void ValidateRSACertificate(X509Certificate2 certificate)
        {
            switch (certificate.GetKeyAlgorithm())
            {
                case Oids.Rsa:
                case Oids.RsaOaep:
                    break;
                default:
                    throw new CryptographicException(SR.Cryptography_Cms_Recipient_RSARequired_RSAPaddingModeSupplied);
            }
        }
    }
}