Web Socket rfc6455 握手 (C++)

来源：互联网发布：九九乘法表的vb代码编辑：程序博客网时间：2024/05/14 08:54

std::string data((const char*)buf->data(),bytes_transferred);recycle_buffer(buf);std::string key="Sec-WebSocket-Key:";auto pos = data.find(key);auto posEnd = data.find("\r\n",pos);auto value = data.substr(pos + key.length(),posEnd - (pos + key.length()));std::string sha1Src = trim(value);sha1Src += std::string("258EAFA5-E914-47DA-95CA-C5AB0DC85B11");unsigned char sha1out[20];sha1((const unsigned char *)sha1Src.c_str(),sha1Src.length(),sha1out);std::vector<unsigned char> data64;for( auto c: sha1out) data64.push_back(c);std::ostringstream os_rsp;os_rsp<<"HTTP/1.1 101 Switching Protocols\r\n"      <<"Upgrade: websocket\r\n"      <<"Connection: Upgrade\r\n"      <<"Sec-WebSocket-Accept: "<<base64Encode(data64)<<"=\r\n"  <<"\r\n";std::string rsp = os_rsp.str();

1) data 为连接建立以后，web socket客户端发送的握手协议。

2)查询到字段 Sec-WebSocket_key的值，并且拼接上GUID字符串"258EAFA5-E914-47DA-95CA-C5AB0DC85B11"值。得到 sha1Src

3)对 key拼接后的值计算 sha1值，得到 sha1Out

4)应答，最主要的就是计算 Sec-WebSocket-Accept值，通过函数 base64Encode进行计算；

using namespace std;static const unsigned char bt[64]={'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/'};std::string base64Encode(const std::vector<unsigned char> & data ){std::list< std::bitset<8> > bits;for( auto c : data ){        std::bitset<8> bit(c);        bits.push_back(bit);}while( bits.size() % 3 != 0 ) bits.push_back( bitset<8>() );std::vector<unsigned char> base64;while( !bits.empty() ){std::bitset<6> bit6_1,bit6_2,bit6_3,bit6_4;  std::bitset<8> bit8_1 = *bits.begin(); bits.pop_front();        std::bitset<8> bit8_2 = *bits.begin(); bits.pop_front();        std::bitset<8> bit8_3 = *bits.begin(); bits.pop_front();   bit6_1.set(0, bit8_1[2]);        bit6_1.set(1, bit8_1[3]);        bit6_1.set(2, bit8_1[4]);        bit6_1.set(3, bit8_1[5]);        bit6_1.set(4, bit8_1[6]);        bit6_1.set(5, bit8_1[7]);        bit6_2.set(0, bit8_2[4]);        bit6_2.set(1, bit8_2[5]);        bit6_2.set(2, bit8_2[6]);        bit6_2.set(3, bit8_2[7]);        bit6_2.set(4, bit8_1[0]);        bit6_2.set(5, bit8_1[1]);        bit6_3.set(0, bit8_3[6]);        bit6_3.set(1, bit8_3[7]);        bit6_3.set(2, bit8_2[0]);        bit6_3.set(3, bit8_2[1]);        bit6_3.set(4, bit8_2[2]);        bit6_3.set(5, bit8_2[3]);        bit6_4.set(0, bit8_3[0]);        bit6_4.set(1, bit8_3[1]);        bit6_4.set(2, bit8_3[2]);        bit6_4.set(3, bit8_3[3]);        bit6_4.set(4, bit8_3[4]);        bit6_4.set(5, bit8_3[5]);    base64.push_back( bt[bit6_1.to_ulong() ]);        base64.push_back( bt[bit6_2.to_ulong() ]);        base64.push_back( bt[bit6_3.to_ulong() ]);        base64.push_back( bt[bit6_4.to_ulong() ]);}base64.pop_back();string strdata(base64.begin(),base64.end());return strdata;}

5）计算后把RSP发生出去即可；

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