init commit

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Bcpg/UserAttributeSubpacketsParser.cs

@@ -0,0 +1,60 @@
+using System.IO;
+using Org.BouncyCastle.Bcpg.Attr;
+using Org.BouncyCastle.Utilities.IO;
+
+namespace Org.BouncyCastle.Bcpg;
+
+public class UserAttributeSubpacketsParser
+{
+	private readonly Stream input;
+
+	public UserAttributeSubpacketsParser(Stream input)
+	{
+		this.input = input;
+	}
+
+	public virtual UserAttributeSubpacket ReadPacket()
+	{
+		int num = input.ReadByte();
+		if (num < 0)
+		{
+			return null;
+		}
+		int num2 = 0;
+		bool forceLongLength = false;
+		if (num < 192)
+		{
+			num2 = num;
+		}
+		else if (num <= 223)
+		{
+			num2 = (num - 192 << 8) + input.ReadByte() + 192;
+		}
+		else
+		{
+			if (num != 255)
+			{
+				throw new IOException("unrecognised length reading user attribute sub packet");
+			}
+			num2 = (input.ReadByte() << 24) | (input.ReadByte() << 16) | (input.ReadByte() << 8) | input.ReadByte();
+			forceLongLength = true;
+		}
+		int num3 = input.ReadByte();
+		if (num3 < 0)
+		{
+			throw new EndOfStreamException("unexpected EOF reading user attribute sub packet");
+		}
+		byte[] array = new byte[num2 - 1];
+		if (Streams.ReadFully(input, array) < array.Length)
+		{
+			throw new EndOfStreamException();
+		}
+		UserAttributeSubpacketTag userAttributeSubpacketTag = (UserAttributeSubpacketTag)num3;
+		UserAttributeSubpacketTag userAttributeSubpacketTag2 = userAttributeSubpacketTag;
+		if (userAttributeSubpacketTag2 == UserAttributeSubpacketTag.ImageAttribute)
+		{
+			return new ImageAttrib(forceLongLength, array);
+		}
+		return new UserAttributeSubpacket(userAttributeSubpacketTag, forceLongLength, array);
+	}
+}