_ Git - BoarSSL/blob - SSLTLS/IO.cs

   1 /*
   2  * Copyright (c) 2017 Thomas Pornin <pornin@bolet.org>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining
   5  * a copy of this software and associated documentation files (the
   6  * "Software"), to deal in the Software without restriction, including
   7  * without limitation the rights to use, copy, modify, merge, publish,
   8  * distribute, sublicense, and/or sell copies of the Software, and to
   9  * permit persons to whom the Software is furnished to do so, subject to
  10  * the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be
  13  * included in all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  */
  24
  25 using System;
  26 using System.IO;
  27
  28 namespace SSLTLS {
  29
  30 internal class IO {
  31
  32         internal static void Enc16be(int x, byte[] buf, int off)
  33         {
  34                 buf[off + 0] = (byte)(x >> 8);
  35                 buf[off + 1] = (byte)x;
  36         }
  37
  38         internal static void Enc24be(int x, byte[] buf, int off)
  39         {
  40                 buf[off + 0] = (byte)(x >> 16);
  41                 buf[off + 1] = (byte)(x >> 8);
  42                 buf[off + 2] = (byte)x;
  43         }
  44
  45         internal static void Enc32be(uint x, byte[] buf, int off)
  46         {
  47                 buf[off + 0] = (byte)(x >> 24);
  48                 buf[off + 1] = (byte)(x >> 16);
  49                 buf[off + 2] = (byte)(x >> 8);
  50                 buf[off + 3] = (byte)x;
  51         }
  52
  53         internal static void Enc64be(ulong x, byte[] buf, int off)
  54         {
  55                 for (int i = 0; i < 8; i ++) {
  56                         buf[off + 7 - i] = (byte)x;
  57                         x >>= 8;
  58                 }
  59         }
  60
  61         internal static int Dec16be(byte[] buf, int off)
  62         {
  63                 return (buf[off + 0] << 8)
  64                         | buf[off + 1];
  65         }
  66
  67         internal static int Dec24be(byte[] buf, int off)
  68         {
  69                 return (buf[off + 0] << 16)
  70                         | (buf[off + 1] << 8)
  71                         | buf[off + 2];
  72         }
  73
  74         internal static uint Dec32be(byte[] buf, int off)
  75         {
  76                 return ((uint)buf[off + 0] << 24)
  77                         | ((uint)buf[off + 1] << 16)
  78                         | ((uint)buf[off + 2] << 8)
  79                         | (uint)buf[off + 3];
  80         }
  81
  82         internal static ulong Dec64be(byte[] buf, int off)
  83         {
  84                 ulong x = 0;
  85                 for (int i = 0; i < 8; i ++) {
  86                         x = (x << 8) | buf[off + i];
  87                 }
  88                 return x;
  89         }
  90
  91         internal static void Write16(Stream s, int x)
  92         {
  93                 s.WriteByte((byte)(x >> 8));
  94                 s.WriteByte((byte)x);
  95         }
  96
  97         internal static void Write24(Stream s, int x)
  98         {
  99                 s.WriteByte((byte)(x >> 16));
 100                 s.WriteByte((byte)(x >> 8));
 101                 s.WriteByte((byte)x);
 102         }
 103
 104         /*
 105          * Write a 5-byte record header at the specified offset.
 106          */
 107         internal static void WriteHeader(int recordType, int version,
 108                 int length, byte[] buf, int off)
 109         {
 110                 buf[off] = (byte)recordType;
 111                 IO.Enc16be(version, buf, off + 1);
 112                 IO.Enc16be(length, buf, off + 3);
 113         }
 114
 115         /*
 116          * Read all requested bytes. Fail on unexpected EOF, unless
 117          * 'eof' is true, in which case an EOF is acceptable at the
 118          * very beginning (i.e. no byte read at all).
 119          *
 120          * Returned value is true, unless there was an EOF at the
 121          * start and 'eof' is true, in which case returned value is
 122          * false.
 123          */
 124         internal static bool ReadAll(Stream s, byte[] buf, bool eof)
 125         {
 126                 return ReadAll(s, buf, 0, buf.Length, eof);
 127         }
 128
 129         /*
 130          * Read all requested bytes. Fail on unexpected EOF, unless
 131          * 'eof' is true, in which case an EOF is acceptable at the
 132          * very beginning (i.e. no byte read at all).
 133          *
 134          * Returned value is true, unless there was an EOF at the
 135          * start and 'eof' is true, in which case returned value is
 136          * false.
 137          */
 138         internal static bool ReadAll(Stream s,
 139                 byte[] buf, int off, int len, bool eof)
 140         {
 141                 int tlen = 0;
 142                 while (tlen < len) {
 143                         int rlen = s.Read(buf, off + tlen, len - tlen);
 144                         if (rlen <= 0) {
 145                                 if (eof && tlen == 0) {
 146                                         return false;
 147                                 }
 148                                 throw new SSLException("Unexpected EOF");
 149                         }
 150                         tlen += rlen;
 151                 }
 152                 return true;
 153         }
 154
 155         /*
 156          * Compare two arrays of bytes for equality.
 157          */
 158         internal static bool Eq(byte[] a, byte[] b)
 159         {
 160                 return EqCT(a, b) != 0;
 161         }
 162
 163         /*
 164          * Compare two arrays of bytes for equality. This is constant-time
 165          * if both arrays have the same length. Returned value is 0xFFFFFFFF
 166          * on equality, 0 otherwise.
 167          */
 168         internal static uint EqCT(byte[] a, byte[] b)
 169         {
 170                 int n = a.Length;
 171                 if (n != b.Length) {
 172                         return 0;
 173                 }
 174                 int z = 0;
 175                 for (int i = 0; i < n; i ++) {
 176                         z |= a[i] ^ b[i];
 177                 }
 178                 return ~(uint)((z | -z) >> 31);
 179         }
 180
 181         /*
 182          * Duplicate an array of bytes. null is duplicated into null.
 183          */
 184         internal static byte[] CopyBlob(byte[] x)
 185         {
 186                 if (x == null) {
 187                         return null;
 188                 }
 189                 byte[] y = new byte[x.Length];
 190                 Array.Copy(x, 0, y, 0, x.Length);
 191                 return y;
 192         }
 193 }
 194
 195 }