Be more strict with content-length, transfer-encoding

This commit is contained in:
Alex Hultman
2022-10-22 00:43:58 +02:00
parent 7cdb1f7224
commit d18deb8fe3
+44 -33
View File
@@ -246,6 +246,17 @@ private:
/* We ran out of header space, too large request */
return 0;
}
/* Doing a deep scan to determine in a standards-compliant way whether this request is chunked or not.
* This is going to be the place where obfuscated transfer-encoding shananigans are found. */
bool isChunkedBody(std::string_view transferEncodingString, HttpRequest */*req*/) {
return transferEncodingString.find("chunked") != std::string_view::npos;
/*for (HttpRequest::Header *h = req->headers; (++h)->key.length(); ) {
}*/
}
// the only caller of getHeaders
template <int CONSUME_MINIMALLY>
@@ -289,47 +300,47 @@ private:
return {consumedTotal, returnedUser};
}
/* Highest priority is always transfer-encoding: chunked */
std::string_view transferEncodingString = req->getHeader("transfer-encoding");
if (transferEncodingString.length() && isChunkedBody(transferEncodingString, req)) {
remainingStreamingBytes = STATE_IS_CHUNKED;
/* If consume minimally, we do not want to consume anything but we want to mark this as being chunked */
if (!CONSUME_MINIMALLY) {
/* Go ahead and parse it (todo: better heuristics for emitting FIN to the app level) */
std::string_view dataToConsume(data, length);
for (auto chunk : uWS::ChunkIterator(&dataToConsume, &remainingStreamingBytes)) {
dataHandler(user, chunk, chunk.length() == 0);
}
unsigned int consumed = (length - (unsigned int) dataToConsume.length());
data = (char *) dataToConsume.data();
length = (unsigned int) dataToConsume.length();
consumedTotal += consumed;
}
/* Do not try anything else */
continue;
}
if (req->getMethod() != "get") {
std::string_view contentLengthString = req->getHeader("content-length");
if (contentLengthString.length()) {
remainingStreamingBytes = toUnsignedInteger(contentLengthString);
/* Second priority is content-length */
std::string_view contentLengthString = req->getHeader("content-length");
if (contentLengthString.length()) {
remainingStreamingBytes = toUnsignedInteger(contentLengthString);
if (!CONSUME_MINIMALLY) {
unsigned int emittable = std::min<unsigned int>(remainingStreamingBytes, length);
dataHandler(user, std::string_view(data, emittable), emittable == remainingStreamingBytes);
remainingStreamingBytes -= emittable;
if (!CONSUME_MINIMALLY) {
unsigned int emittable = std::min<unsigned int>(remainingStreamingBytes, length);
dataHandler(user, std::string_view(data, emittable), emittable == remainingStreamingBytes);
remainingStreamingBytes -= emittable;
data += emittable;
length -= emittable;
consumedTotal += emittable;
}
} else {
/* We are not GET and we have no content-length */
if (req->getHeader("transfer-encoding").find("chunked") != std::string_view::npos) {
remainingStreamingBytes = STATE_IS_CHUNKED;
/* If consume minimally, we do not want to consume anything but we want to mark this as being chunked */
if (!CONSUME_MINIMALLY) {
/* Go ahead and parse it (todo: better heuristics for emitting FIN to the app level) */
std::string_view dataToConsume(data, length);
for (auto chunk : uWS::ChunkIterator(&dataToConsume, &remainingStreamingBytes)) {
dataHandler(user, chunk, chunk.length() == 0);
}
unsigned int consumed = (length - (unsigned int) dataToConsume.length());
data = (char *) dataToConsume.data();
length = (unsigned int) dataToConsume.length();
consumedTotal += consumed;
}
} else {
/* We have no content-length and no transfer-encoding: chunked */
dataHandler(user, {}, true);
}
data += emittable;
length -= emittable;
consumedTotal += emittable;
}
} else {
/* Still emit an empty data chunk to signal no data */
/* If we came here without a body; emit an empty data chunk to signal no data */
dataHandler(user, {}, true);
}
/* Consume minimally should break as easrly as possible */
if (CONSUME_MINIMALLY) {
break;
}