ImageAttrib
using System;
using System.IO;
namespace Org.BouncyCastle.Bcpg.Attr
{
    public class ImageAttrib : UserAttributeSubpacket
    {
        public enum Format : byte
        {
            Jpeg = 1
        }
        private static readonly byte[] Zeroes = new byte[12];
        private int hdrLength;
        private int _version;
        private int _encoding;
        private byte[] imageData;
        public virtual int Version => _version;
        public virtual int Encoding => _encoding;
        public ImageAttrib(byte[] data)
            : this(false, data)
        {
        }
        public ImageAttrib(bool forceLongLength, byte[] data)
            : base(UserAttributeSubpacketTag.ImageAttribute, forceLongLength, data)
        {
            hdrLength = (((data[1] & 255) << 8) | (data[0] & 255));
            _version = (data[2] & 255);
            _encoding = (data[3] & 255);
            imageData = new byte[data.Length - hdrLength];
            Array.Copy(data, hdrLength, imageData, 0, imageData.Length);
        }
        public ImageAttrib(Format imageType, byte[] imageData)
            : this(ToByteArray(imageType, imageData))
        {
        }
        private static byte[] ToByteArray(Format imageType, byte[] imageData)
        {
            MemoryStream memoryStream = new MemoryStream();
            memoryStream.WriteByte(16);
            memoryStream.WriteByte(0);
            memoryStream.WriteByte(1);
            memoryStream.WriteByte((byte)imageType);
            memoryStream.Write(Zeroes, 0, Zeroes.Length);
            memoryStream.Write(imageData, 0, imageData.Length);
            return memoryStream.ToArray();
        }
        public virtual byte[] GetImageData()
        {
            return imageData;
        }
    }
}