init commit

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Bcpg/Attr/ImageAttrib.cs

@@ -0,0 +1,63 @@
+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(forceLongLength: false, data)
+	{
+	}
+
+	public ImageAttrib(bool forceLongLength, byte[] data)
+		: base(UserAttributeSubpacketTag.ImageAttribute, forceLongLength, data)
+	{
+		hdrLength = ((data[1] & 0xFF) << 8) | (data[0] & 0xFF);
+		_version = data[2] & 0xFF;
+		_encoding = data[3] & 0xFF;
+		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;
+	}
+}