From 9e94f22bce16995b84a2e46299b901e6f1d77f29 Mon Sep 17 00:00:00 2001
From: gb-123-git <64229388+gb-123-git@users.noreply.github.com>
Date: Fri, 18 Aug 2023 06:21:13 +0530
Subject: [PATCH] Fix infinite loop when the buffer ends with \r #123 (#2)

* Fix infinite loop when the buffer ends with \r

* Properly check for end of line across buffers

---------

Co-authored-by: vvigilante <info@vvigilante.com>
---
 src/HTTPConnection.cpp | 30 ++++++++++++++----------------
 src/HTTPConnection.hpp |  2 ++
 2 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/src/HTTPConnection.cpp b/src/HTTPConnection.cpp
index 33c928d..17452e0 100644
--- a/src/HTTPConnection.cpp
+++ b/src/HTTPConnection.cpp
@@ -290,26 +290,24 @@ void HTTPConnection::raiseError(uint16_t code, std::string reason) {
 void HTTPConnection::readLine(int lengthLimit) {
   while(_bufferProcessed < _bufferUnusedIdx) {
     char newChar = _receiveBuffer[_bufferProcessed];
-
-    if ( newChar == '\r') {
-      // Look ahead for \n (if not possible, wait for next round
-      if (_bufferProcessed+1 < _bufferUnusedIdx) {
-        if (_receiveBuffer[_bufferProcessed+1] == '\n') {
-          _bufferProcessed += 2;
-          _parserLine.parsingFinished = true;
-          return;
-        } else {
-          // Line has not been terminated by \r\n
-          HTTPS_LOGW("Line without \\r\\n (got only \\r). FID=%d", _socket);
-          raiseError(400, "Bad Request");
-          return;
-        }
+    _bufferProcessed++;
+    if ( partialTerminationParsed ){
+      partialTerminationParsed = false;
+      if (newChar == '\n') {
+        _parserLine.parsingFinished = true;
+      } else {
+        // Line has not been terminated by \r\n
+        HTTPS_LOGW("Line without \\r\\n (got only \\r). FID=%d", _socket);
+        raiseError(400, "Bad Request");
       }
+      return;
+    }
+    if ( newChar == '\r') {
+      partialTerminationParsed = true;
     } else {
       _parserLine.text += newChar;
-      _bufferProcessed += 1;
     }
-
+    
     // Check that the max request string size is not exceeded
     if (_parserLine.text.length() > lengthLimit) {
       HTTPS_LOGW("Header length exceeded. FID=%d", _socket);
diff --git a/src/HTTPConnection.hpp b/src/HTTPConnection.hpp
index 2e9d0cb..d59c082 100644
--- a/src/HTTPConnection.hpp
+++ b/src/HTTPConnection.hpp
@@ -134,6 +134,8 @@ class HTTPConnection : private ConnectionContext {
   int _bufferProcessed;
   // The index on the receive_buffer that is the first one which is empty at the end.
   int _bufferUnusedIdx;
+  // If \r character has been read, in this case we expect \n to terminate the line
+  bool partialTerminationParsed = false;
 
   // Socket address, length etc for the connection
   struct sockaddr _sockAddr;