using Org.BouncyCastle.Crypto.Utilities; using Org.BouncyCastle.Utilities.IO; using System; using System.IO; namespace Org.BouncyCastle.Bcpg { internal static class StreamUtilities { [Flags] internal enum StreamFlags { None = 0, LongLength = 1, Partial = 2, Eof = 4 } internal static uint ReadBodyLen(Stream s, out StreamFlags flags) { flags = StreamFlags.None; int num = s.ReadByte(); if (num < 0) { flags = StreamFlags.Eof; return 0; } if (num < 192) return (uint)num; if (num < 224) { int num2 = RequireByte(s); return (uint)((num - 192 << 8) + num2 + 192); } if (num == 255) { flags |= StreamFlags.LongLength; return RequireUInt32BE(s); } flags |= StreamFlags.Partial; return (uint)(1 << num); } internal static uint RequireBodyLen(Stream s, out StreamFlags streamFlags) { uint result = ReadBodyLen(s, out streamFlags); if (streamFlags.HasFlag(StreamFlags.Eof)) throw new EndOfStreamException(); return result; } internal static byte RequireByte(Stream s) { int num = s.ReadByte(); if (num < 0) throw new EndOfStreamException(); return (byte)num; } internal static byte[] RequireBytes(Stream s, int count) { byte[] array = new byte[count]; RequireBytes(s, array); return array; } internal static void RequireBytes(Stream s, byte[] buffer) { RequireBytes(s, buffer, 0, buffer.Length); } internal static void RequireBytes(Stream s, byte[] buffer, int offset, int count) { if (Streams.ReadFully(s, buffer, offset, count) < count) throw new EndOfStreamException(); } internal static void RequireBytes(Stream s, Span<byte> buffer) { if (Streams.ReadFully(s, buffer) != buffer.Length) throw new EndOfStreamException(); } internal unsafe static ushort RequireUInt16BE(Stream s) { Span<byte> span = new Span<byte>(stackalloc byte[2], 2); RequireBytes(s, span); return Pack.BE_To_UInt16(span); } internal unsafe static uint RequireUInt32BE(Stream s) { Span<byte> span = new Span<byte>(stackalloc byte[4], 4); RequireBytes(s, span); return Pack.BE_To_UInt32(span); } internal unsafe static ulong RequireUInt64BE(Stream s) { Span<byte> span = new Span<byte>(stackalloc byte[8], 8); RequireBytes(s, span); return Pack.BE_To_UInt64(span); } internal unsafe static void WriteNewPacketLength(Stream s, long bodyLen, bool longLength = false) { if (longLength || bodyLen > 8383) { Span<byte> span = new Span<byte>(stackalloc byte[5], 5); span[0] = byte.MaxValue; Pack.UInt32_To_BE((uint)bodyLen, span, 1); s.Write(span); } else if (bodyLen < 192) { s.WriteByte((byte)bodyLen); } else { bodyLen -= 192; Span<byte> span2 = new Span<byte>(stackalloc byte[2], 2); span2[0] = (byte)(((bodyLen >> 8) & 255) + 192); span2[1] = (byte)bodyLen; s.Write(span2); } } internal unsafe static void WriteUInt16BE(Stream s, ushort n) { Span<byte> span = new Span<byte>(stackalloc byte[2], 2); Pack.UInt16_To_BE(n, span); s.Write(span); } internal unsafe static void WriteUInt32BE(Stream s, uint n) { Span<byte> span = new Span<byte>(stackalloc byte[4], 4); Pack.UInt32_To_BE(n, span); s.Write(span); } internal unsafe static void WriteUInt64BE(Stream s, ulong n) { Span<byte> span = new Span<byte>(stackalloc byte[8], 8); Pack.UInt64_To_BE(n, span); s.Write(span); } } }