Use CloudFlare ddos-protected sites from other programs (by going through nginx)

0readme.txt

What you need:
* nginx
* dependencies to build CutyCapt (http://cutycapt.sourceforge.net/)

Steps:
* build CutyCapt with CutyCapt.patch applied and copy the executable somewhere
* install nginx and edit the config as outlined in nginx.conf
* change the paths to nginx, the nginx config and the patched cutycapt in renewcf.sh
* start nginx
* ensure that renewcf.sh runs every 55 minutes

* http://yourdomain.com/some_path/ now points to https://cf-ddos-protected-site.example.com/
* e.g. http://yourdomain.com/some_path/blog/2015/07/14/foobar -> https://cf-ddos-protected-site.example.com/blog/2015/07/14/foobar

CutyCapt.patch

diff -u -r CutyCapt.orig/CutyCapt.cpp CutyCapt/CutyCapt.cpp
--- CutyCapt.orig/CutyCapt.cpp	2015-07-09 19:40:34.311891000 +0200
+++ CutyCapt/CutyCapt.cpp	2015-07-09 21:35:36.077458663 +0200
@@ -27,15 +27,12 @@
 #include <QtWebKit>
 #include <QtGui>
 #include <QSvgGenerator>
-
-#if QT_VERSION < 0x050000
 #include <QPrinter>
-#endif
-
 #include <QTimer>
 #include <QByteArray>
 #include <QNetworkRequest>
 #include <QNetworkProxy>
+#include <iostream>
 #include "CutyCapt.hpp"
 
 #if QT_VERSION >= 0x040600 && 0
@@ -76,6 +73,8 @@
   { CutyCapt::OtherFormat,       "",            ""      }
 };
 
+const char *argUrl = NULL;
+
 QString
 CutyPage::chooseFile(QWebFrame* /*frame*/, const QString& /*suggestedFile*/) {
   return QString::null;
@@ -270,6 +269,18 @@
 
   mPage->setViewportSize( mainFrame->contentsSize() );
 
+  QUrl url = QUrl::fromEncoded(argUrl);
+  QString ua = mPage->userAgentForUrl(url);
+  std::cout << "proxy_set_header User-Agent \"" << ua.toStdString() << "\";" << std::endl;
+  QList<QNetworkCookie> cl = mPage->networkAccessManager()->cookieJar()->cookiesForUrl(url);
+  std::cout << "proxy_set_header Cookie \"";
+  for(QList<QNetworkCookie>::const_iterator ci = cl.cbegin(); ci != cl.cend(); ci++) {
+    std::cout << ci->toRawForm(QNetworkCookie::NameAndValueOnly).constData();
+    if(*ci != cl.last())
+      std::cout << "; ";
+  }
+  std::cout << "\";" << std::endl;
+
   switch (mFormat) {
     case SvgFormat: {
       QSvgGenerator svg;
@@ -408,7 +419,7 @@
   int argVerbosity = 0;
   int argSmooth = 0;
 
-  const char* argUrl = NULL;
+  //const char* argUrl = NULL;
   const char* argUserStyle = NULL;
   const char* argUserStylePath = NULL;
   const char* argUserStyleString = NULL;
@@ -705,6 +716,9 @@
     SLOT(JavaScriptWindowObjectCleared()));
 #endif
 
+  QNetworkCookieJar *jar = new QNetworkCookieJar();
+  page.networkAccessManager()->setCookieJar(jar);
+
   app.connect(page.networkAccessManager(),
     SIGNAL(sslErrors(QNetworkReply*, QList<QSslError>)),
     &main,
diff -u -r CutyCapt.orig/CutyCapt.hpp CutyCapt/CutyCapt.hpp
--- CutyCapt.orig/CutyCapt.hpp	2015-07-09 19:40:34.311891000 +0200
+++ CutyCapt/CutyCapt.hpp	2015-07-09 21:18:40.880361201 +0200
@@ -15,6 +15,7 @@
   void setPrintAlerts(bool printAlerts);
   void setCutyCapt(CutyCapt* cutyCapt);
   QString getAlertString();
+  QString userAgentForUrl(const QUrl& url) const;
 
 protected:
   QString chooseFile(QWebFrame *frame, const QString& suggestedFile);
@@ -22,7 +23,6 @@
   bool javaScriptPrompt(QWebFrame* frame, const QString& msg, const QString& defaultValue, QString* result);
   void javaScriptAlert(QWebFrame* frame, const QString& msg);
   bool javaScriptConfirm(QWebFrame* frame, const QString& msg);
-  QString userAgentForUrl(const QUrl& url) const;
   QString mUserAgent;
   QString mAlertString;
   bool mPrintAlerts;
diff -u -r CutyCapt.orig/CutyCapt.pro CutyCapt/CutyCapt.pro
--- CutyCapt.orig/CutyCapt.pro	2015-07-09 19:40:34.311891000 +0200
+++ CutyCapt/CutyCapt.pro	2015-07-09 20:53:49.227671076 +0200
@@ -4,7 +4,7 @@
 CONFIG   +=  qt console
 
 greaterThan(QT_MAJOR_VERSION, 4): {
-  QT       +=  webkitwidgets
+  QT       +=  webkitwidgets printsupport
 }
 
 contains(CONFIG, static): {

nginx.conf

[...]

http {
	[...]
	server {
		[...]
		location /some_path/ {
			proxy_pass https://cf-ddos-protected-site.example.com/;
			proxy_ssl_server_name on;
			proxy_http_version 1.1;
			include cloudflare.conf;
		}
	}
}

renewcf.sh

#!/bin/bash

# renews cloudflare anti-ddos cookies (they expire every hour)

function renew {
	echo "Renewing CF cookies for $1"
	/path/to/patched/cutycapt \
		"--url=$1" --out=/dev/null \
		--out-format=png --delay=5000 > "/path/to/nginx/conf/$2"
}

renew "https://cf-ddos-protected-site.example.com/" "cloudflare.conf"

/path/to/nginx -s reload

echo "done."