using System; using System.Collections.Generic; namespace Org.BouncyCastle.Tls { internal sealed class DtlsReassembler { private sealed class Range { private int m_start; private int m_end; public int Start { get { return m_start; } set { m_start = value; } } public int End { get { return m_end; } set { m_end = value; } } internal Range(int start, int end) { m_start = start; m_end = end; } } private readonly short m_msg_type; private readonly byte[] m_body; private readonly List<Range> m_missing = new List<Range>(); internal short MsgType => m_msg_type; internal DtlsReassembler(short msg_type, int length) { m_msg_type = msg_type; m_body = new byte[length]; m_missing.Add(new Range(0, length)); } internal byte[] GetBodyIfComplete() { if (m_missing.Count <= 0) return m_body; return null; } internal void ContributeFragment(short msg_type, int length, byte[] buf, int off, int fragment_offset, int fragment_length) { int num = fragment_offset + fragment_length; if (m_msg_type == msg_type && m_body.Length == length && num <= length) { if (fragment_length == 0) { if (fragment_offset == 0 && m_missing.Count > 0 && m_missing[0].End == 0) m_missing.RemoveAt(0); } else { for (int i = 0; i < m_missing.Count; i++) { Range range = m_missing[i]; if (range.Start >= num) break; if (range.End > fragment_offset) { int num2 = System.Math.Max(range.Start, fragment_offset); int num3 = System.Math.Min(range.End, num); int length2 = num3 - num2; Array.Copy(buf, off + num2 - fragment_offset, m_body, num2, length2); if (num2 == range.Start) { if (num3 == range.End) m_missing.RemoveAt(i--); else range.Start = num3; } else { if (num3 != range.End) m_missing.Insert(++i, new Range(num3, range.End)); range.End = num2; } } } } } } internal void Reset() { m_missing.Clear(); m_missing.Add(new Range(0, m_body.Length)); } } }