using System;

namespace Org.BouncyCastle.Bcpg.OpenPgp;

public sealed class PgpPad
{
	private PgpPad()
	{
	}

	public static byte[] PadSessionData(byte[] sessionInfo)
	{
		byte[] array = new byte[40];
		Array.Copy(sessionInfo, 0, array, 0, sessionInfo.Length);
		byte b = (byte)(array.Length - sessionInfo.Length);
		for (int i = sessionInfo.Length; i != array.Length; i++)
		{
			array[i] = b;
		}
		return array;
	}

	public static byte[] UnpadSessionData(byte[] encoded)
	{
		byte b = encoded[^1];
		for (int i = encoded.Length - b; i != encoded.Length; i++)
		{
			if (encoded[i] != b)
			{
				throw new PgpException("bad padding found in session data");
			}
		}
		byte[] array = new byte[encoded.Length - b];
		Array.Copy(encoded, 0, array, 0, array.Length);
		return array;
	}
}