ceph/src/boost/boost/beast/websocket/detail/mask.ipp

   1 //
   2 // Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
   3 //
   4 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   5 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // Official repository: https://github.com/boostorg/beast
   8 //
   9
  10 #ifndef BOOST_BEAST_WEBSOCKET_DETAIL_MASK_IPP
  11 #define BOOST_BEAST_WEBSOCKET_DETAIL_MASK_IPP
  12
  13 #include <boost/beast/websocket/detail/mask.hpp>
  14
  15 namespace boost {
  16 namespace beast {
  17 namespace websocket {
  18 namespace detail {
  19
  20 void
  21 prepare_key(prepared_key& prepared, std::uint32_t key)
  22 {
  23     prepared[0] = (key >>  0) & 0xff;
  24     prepared[1] = (key >>  8) & 0xff;
  25     prepared[2] = (key >> 16) & 0xff;
  26     prepared[3] = (key >> 24) & 0xff;
  27 }
  28
  29 inline
  30 void
  31 rol(prepared_key& v, std::size_t n)
  32 {
  33     auto v0 = v;
  34     for(std::size_t i = 0; i < v.size(); ++i )
  35         v[i] = v0[(i + n) % v.size()];
  36 }
  37
  38 // Apply mask in place
  39 //
  40 void
  41 mask_inplace(net::mutable_buffer const& b, prepared_key& key)
  42 {
  43     auto n = b.size();
  44     auto const mask = key; // avoid aliasing
  45     auto p = static_cast<unsigned char*>(b.data());
  46     while(n >= 4)
  47     {
  48         for(int i = 0; i < 4; ++i)
  49             p[i] ^= mask[i];
  50         p += 4;
  51         n -= 4;
  52     }
  53     if(n > 0)
  54     {
  55         for(std::size_t i = 0; i < n; ++i)
  56             p[i] ^= mask[i];
  57         rol(key, n);
  58     }
  59 }
  60
  61 } // detail
  62 } // websocket
  63 } // beast
  64 } // boost
  65
  66 #endif