One file encryption for multiple public keys and private key decryption C#

Question

I have ASP .NET C# project and I want to encrypt file with multiple public keys from certificates using X509Store and I am using this function to encrypt the file its fine but I need it for group of certificates:

private static void EncryptFile(string inFile, RSACryptoServiceProvider rsaPublicKey)
{

    using (AesManaged aesManaged = new AesManaged())
    {
        // Create instance of AesManaged for
        // symetric encryption of the data.
        aesManaged.KeySize = 256;
        aesManaged.BlockSize = 128;
        aesManaged.Mode = CipherMode.CBC;
        using (ICryptoTransform transform = aesManaged.CreateEncryptor())
        {
            RSAPKCS1KeyExchangeFormatter keyFormatter = new RSAPKCS1KeyExchangeFormatter(rsaPublicKey);
            byte[] keyEncrypted = keyFormatter.CreateKeyExchange(aesManaged.Key, aesManaged.GetType());

            // Create byte arrays to contain
            // the length values of the key and IV.
            byte[] LenK = new byte[4];
            byte[] LenIV = new byte[4];

            int lKey = keyEncrypted.Length;
            LenK = BitConverter.GetBytes(lKey);
            int lIV = aesManaged.IV.Length;
            LenIV = BitConverter.GetBytes(lIV);

            // Write the following to the FileStream
            // for the encrypted file (outFs):
            // - length of the key
            // - length of the IV
            // - ecrypted key
            // - the IV
            // - the encrypted cipher content

            int startFileName = inFile.LastIndexOf("\\") + 1;
            // Change the file's extension to ".enc"
            string outFile = encrFolder + inFile.Substring(startFileName, inFile.LastIndexOf(".") - startFileName) + ".enc";
            Directory.CreateDirectory(encrFolder);

            using (FileStream outFs = new FileStream(outFile, FileMode.Create))
            {

                outFs.Write(LenK, 0, 4);
                outFs.Write(LenIV, 0, 4);
                outFs.Write(keyEncrypted, 0, lKey);
                outFs.Write(aesManaged.IV, 0, lIV);

                // Now write the cipher text using
                // a CryptoStream for encrypting.
                using (CryptoStream outStreamEncrypted = new CryptoStream(outFs, transform, CryptoStreamMode.Write))
                {

                    // By encrypting a chunk at
                    // a time, you can save memory
                    // and accommodate large files.
                    int count = 0;
                    int offset = 0;

                    // blockSizeBytes can be any arbitrary size.
                    int blockSizeBytes = aesManaged.BlockSize / 8;
                    byte[] data = new byte[blockSizeBytes];
                    int bytesRead = 0;

                    using (FileStream inFs = new FileStream(inFile, FileMode.Open))
                    {
                        do
                        {
                            count = inFs.Read(data, 0, blockSizeBytes);
                            offset += count;
                            outStreamEncrypted.Write(data, 0, count);
                            bytesRead += blockSizeBytes;
                        }
                        while (count > 0);
                        inFs.Close();
                    }
                    outStreamEncrypted.FlushFinalBlock();
                    outStreamEncrypted.Close();
                }
                outFs.Close();
            }
        }
    }
}