Github user bgaff commented on a diff in the pull request:

    https://github.com/apache/trafficserver/pull/624#discussion_r62697922
  
    --- Diff: lib/atscppapi/examples/websocket/WebSocket.cc ---
    @@ -0,0 +1,246 @@
    +#include "WebSocket.hh"
    +
    +#include <iostream>
    +#include "ts/ink_base64.h"
    +#include "openssl/evp.h"
    +
    +using namespace atscppapi;
    +
    +#define SAY(a) std::cout << a << std::endl;
    +#define SHOW(a) std::cout << #a << " = " << a << std::endl
    +
    +void TSPluginInit(int argc, const char* argv[])
    +{
    +    RegisterGlobalPlugin("WebSocket", "Apache", "supp...@example.com");
    +    new WebSocketInstaller();
    +}
    +
    +
    +// WebSocketInstaller
    +
    +WebSocketInstaller::WebSocketInstaller()
    +    : GlobalPlugin(true /* ignore internal transactions */)
    +{
    +    
GlobalPlugin::registerHook(Plugin::HOOK_READ_REQUEST_HEADERS_PRE_REMAP);
    +}
    +
    +#define WS_DIGEST_MAX ATS_BASE64_ENCODE_DSTLEN(20)
    +static const std::string magic = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
    +
    +static std::string ws_digest(std::string const& key) {
    +    EVP_MD_CTX digest;
    +    EVP_MD_CTX_init(&digest);
    +
    +    if (!EVP_DigestInit_ex(&digest, EVP_sha1(), NULL)) {
    +        EVP_MD_CTX_cleanup(&digest);
    +        return "init-failed";
    +    }
    +    if (!EVP_DigestUpdate(&digest, key.data(), key.length())) {
    +        EVP_MD_CTX_cleanup(&digest);
    +        return "update1-failed";
    +    }
    +    if (!EVP_DigestUpdate(&digest, magic.data(), magic.length())) {
    +        EVP_MD_CTX_cleanup(&digest);
    +        return "update2-failed";
    +    }
    +
    +    unsigned char hash_buf[EVP_MAX_MD_SIZE];
    +    unsigned int hash_len = 0;
    +    if (!EVP_DigestFinal_ex(&digest, hash_buf, &hash_len)) {
    +        EVP_MD_CTX_cleanup(&digest);
    +        return "final-failed";
    +    }
    +    EVP_MD_CTX_cleanup(&digest);
    +    if (hash_len != 20) {
    +        return "bad-hash-length";
    +    }
    +
    +    char digest_buf[WS_DIGEST_MAX];
    +    size_t digest_len = 0;
    +
    +    ats_base64_encode(hash_buf, hash_len, digest_buf, WS_DIGEST_MAX, 
&digest_len);
    +
    +    return std::string((char*)digest_buf, digest_len);
    +}
    +
    +
    +void WebSocketInstaller::handleReadRequestHeadersPreRemap(Transaction 
&transaction)
    +{
    +    SAY("Incoming request.");
    +    transaction.addPlugin(new WebSocket(transaction));
    +    transaction.resume();
    +}
    +
    +// WebSocket implementation.
    +
    +WebSocket::WebSocket(Transaction& transaction)
    +    : InterceptPlugin(transaction, InterceptPlugin::SERVER_INTERCEPT)
    +    , pos_(0)
    +    , ctrl_(0)
    +    , msg_len_(0)
    +    , ws_handshake_done_(false)
    +{
    +    ws_key_ = 
transaction.getClientRequest().getHeaders().values("sec-websocket-key");
    +    if (ws_key_.size()) {
    +        printf("setting timeouts\n");
    +        transaction.setTimeout(Transaction::TIMEOUT_ACTIVE, 844000000);
    +        transaction.setTimeout(Transaction::TIMEOUT_NO_ACTIVITY, 84400000);
    +    }
    +}
    +
    +WebSocket::~WebSocket()
    +{
    +    SAY("WebSocket finished.");
    +}
    +
    +void WebSocket::ws_send(std::string const& data, int code)
    +{
    +    std::string frame(1, char(code));
    +    size_t len = data.length();
    +    if (len <= 125) {
    +        frame += char(len);
    +    } else {
    +        int len_len;
    +        if (len <= 65535) {
    +            frame += char(126);
    +            len_len = 2;
    +        } else {
    +            frame += char(127);
    +            len_len = 8;
    +        }
    +        while (--len_len >= 0) {
    +            frame += char((len >> (8*len_len)) & 0xFF);
    +        }
    +    }
    +    produce(frame + data);
    +}
    +
    +void WebSocket::consume(const std::string &data, 
InterceptPlugin::RequestDataType type)
    +{
    +    if (isWebsocket()) {
    +        if (!ws_handshake_done_) {
    +            std::string digest = ws_digest(ws_key_);
    +
    +            printf("WS key digest: %s %s\n", ws_key_.c_str(), 
digest.c_str());
    +
    +            std::string headers;
    +            headers +=
    +                "HTTP/1.1 101 Switching Protocols\r\n"
    +                "Upgrade: websocket\r\n"
    +                "Connection: Upgrade\r\n"
    +                "Sec-WebSocket-Accept: " + digest + "\r\n\r\n";
    +            produce(headers);
    +            ws_handshake_done_ = true;
    +        }
    +    }
    +
    +    // auto tid = std::this_thread::get_id();
    +    if (type == InterceptPlugin::REQUEST_HEADER) {
    +        headers_ += data;
    +    } else {
    +        // cout << tid << ": Read request body" << endl << data << endl;
    +        if (isWebsocket()) {
    +
    +       // When we've read as much as we can for any incoming
    +       // data chunk we remove the head of ws_buf_ and reset pos_
    +       // to 0.
    +       //
    +       // If we can't read a complete length + masks, we leave
    +       // pos_ unchanged and just append what we got to ws_buf_.
    +       //
    +       // When we get the length, we update pos_ and length.
    +       // While length is non-zero we wait for ws_buf_ to have
    +       // msg_len_ bytes beyond pos_.
    +
    +            ws_buf_ += data;
    +            while (true) {
    +                if (!msg_len_) {
    +                    size_t avail = ws_buf_.size() - pos_;
    +
    +                    // Read the msg_length if we have enough data.
    +                    if (avail < 6) break; // 2 + 4 mask
    +                    ctrl_ = ws_buf_[pos_] & 0xF;
    +                    size_t msg_len = ws_buf_[pos_ + 1] & 0x7F;
    +                    if (msg_len == 0x7E) {
    +                        if (avail < 8) { // 2 + 2 + length bytes + 4 mask.
    +                            break;
    +                        }
    +                        msg_len = 0;
    +                        pos_ += 2;
    +                        for (int i = 0; i < 2; ++i, ++pos_) {
    +                            msg_len <<= 8;
    +                            msg_len += (unsigned char)(ws_buf_[pos_]);
    +                        }
    +                    } else if (msg_len == 0x7F) {
    +                        if (avail < 14) { // 2 + 8 length bytes + 4 mask.
    +                            break;
    +                        }
    +                        msg_len = 0;
    +                        pos_ += 2;
    +                        for (int i = 0; i < 8; ++i, ++pos_) {
    --- End diff --
    
    Similarly you need to convert the 64bit quantity using network byte order 
conversions:
    
    be64toh((\*((uint64_t\* )(ws_buf_ + pos_))));


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