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xahaud/Subtrees/websocket/src/processors/hybi_util.hpp

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/*
* Copyright (c) 2011, Peter Thorson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the WebSocket++ Project nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL PETER THORSON BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#ifndef WEBSOCKET_HYBI_UTIL_HPP
#define WEBSOCKET_HYBI_UTIL_HPP
#include "../common.hpp"
namespace websocketpp {
namespace processor {
namespace hybi_util {
// type used to store a masking key
union masking_key_type {
int32_t i;
char c[4];
};
// extract a masking key into a value the size of a machine word. Machine word
// size must be 4 or 8
size_t prepare_masking_key(const masking_key_type& key);
// circularly shifts the supplied prepared masking key by offset bytes
// prepared_key must be the output of prepare_masking_key with the associated
// restrictions on the machine word size.
// offset must be 0, 1, 2, or 3
size_t circshift_prepared_key(size_t prepared_key, size_t offset);
// basic byte by byte mask
template <typename iter_type>
void byte_mask(iter_type b, iter_type e, const masking_key_type& key, size_t key_offset = 0) {
size_t key_index = key_offset;
for (iter_type i = b; i != e; i++) {
*i ^= key.c[key_index++];
key_index %= 4;
}
}
// exactly masks the bytes from start to end using key `key`
void word_mask_exact(char* data,size_t length,const masking_key_type& key);
} // namespace hybi_util
} // namespace processor
} // namespace websocketpp
#endif // WEBSOCKET_HYBI_UTIL_HPP