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 } internal static int ReadBodyLen(Stream s, out StreamFlags flags) { flags = StreamFlags.None; int num = s.ReadByte(); if (num < 0) return -1; if (num < 192) return num; if (num < 224) { int num2 = RequireByte(s); return (num - 192 << 8) + num2 + 192; } if (num == 255) { flags |= StreamFlags.LongLength; return (int)RequireUInt32BE(s); } flags |= StreamFlags.Partial; return 1 << num; } internal static int RequireBodyLen(Stream s, out StreamFlags flags) { int num = ReadBodyLen(s, out flags); if (num < 0) throw new EndOfStreamException(); return num; } internal static byte RequireByte(Stream s) { int num = s.ReadByte(); if (num < 0) throw new EndOfStreamException(); return (byte)num; } 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); } } }