--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Core/HttpServer/HttpServer.cpp	Thu Jan 17 18:29:16 2019 +0100
@@ -0,0 +1,1184 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2019 Osimis S.A., Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * In addition, as a special exception, the copyright holders of this
+ * program give permission to link the code of its release with the
+ * OpenSSL project's "OpenSSL" library (or with modified versions of it
+ * that use the same license as the "OpenSSL" library), and distribute
+ * the linked executables. You must obey the GNU General Public License
+ * in all respects for all of the code used other than "OpenSSL". If you
+ * modify file(s) with this exception, you may extend this exception to
+ * your version of the file(s), but you are not obligated to do so. If
+ * you do not wish to do so, delete this exception statement from your
+ * version. If you delete this exception statement from all source files
+ * in the program, then also delete it here.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+// http://en.highscore.de/cpp/boost/stringhandling.html
+
+#include "../PrecompiledHeaders.h"
+#include "HttpServer.h"
+
+#include "../Logging.h"
+#include "../ChunkedBuffer.h"
+#include "../OrthancException.h"
+#include "HttpToolbox.h"
+
+#if ORTHANC_ENABLE_MONGOOSE == 1
+#  include <mongoose.h>
+
+#elif ORTHANC_ENABLE_CIVETWEB == 1
+#  include <civetweb.h>
+#  define MONGOOSE_USE_CALLBACKS 1
+
+#else
+#  error "Either Mongoose or Civetweb must be enabled to compile this file"
+#endif
+
+#include <algorithm>
+#include <string.h>
+#include <boost/lexical_cast.hpp>
+#include <boost/algorithm/string.hpp>
+#include <iostream>
+#include <string.h>
+#include <stdio.h>
+#include <boost/thread.hpp>
+
+#if !defined(ORTHANC_ENABLE_SSL)
+#  error The macro ORTHANC_ENABLE_SSL must be defined
+#endif
+
+#if ORTHANC_ENABLE_SSL == 1
+#include <openssl/opensslv.h>
+#endif
+
+#define ORTHANC_REALM "Orthanc Secure Area"
+
+
+namespace Orthanc
+{
+  static const char multipart[] = "multipart/form-data; boundary=";
+  static unsigned int multipartLength = sizeof(multipart) / sizeof(char) - 1;
+
+
+  namespace
+  {
+    // Anonymous namespace to avoid clashes between compilation modules
+    class MongooseOutputStream : public IHttpOutputStream
+    {
+    private:
+      struct mg_connection* connection_;
+
+    public:
+      MongooseOutputStream(struct mg_connection* connection) : connection_(connection)
+      {
+      }
+
+      virtual void Send(bool isHeader, const void* buffer, size_t length)
+      {
+        if (length > 0)
+        {
+          int status = mg_write(connection_, buffer, length);
+          if (status != static_cast<int>(length))
+          {
+            // status == 0 when the connection has been closed, -1 on error
+            throw OrthancException(ErrorCode_NetworkProtocol);
+          }
+        }
+      }
+
+      virtual void OnHttpStatusReceived(HttpStatus status)
+      {
+        // Ignore this
+      }
+    };
+
+
+    enum PostDataStatus
+    {
+      PostDataStatus_Success,
+      PostDataStatus_NoLength,
+      PostDataStatus_Pending,
+      PostDataStatus_Failure
+    };
+  }
+
+
+// TODO Move this to external file
+
+
+  class ChunkedFile : public ChunkedBuffer
+  {
+  private:
+    std::string filename_;
+
+  public:
+    ChunkedFile(const std::string& filename) :
+      filename_(filename)
+    {
+    }
+
+    const std::string& GetFilename() const
+    {
+      return filename_;
+    }
+  };
+
+
+
+  class ChunkStore
+  {
+  private:
+    typedef std::list<ChunkedFile*>  Content;
+    Content  content_;
+    unsigned int numPlaces_;
+
+    boost::mutex mutex_;
+    std::set<std::string> discardedFiles_;
+
+    void Clear()
+    {
+      for (Content::iterator it = content_.begin();
+           it != content_.end(); ++it)
+      {
+        delete *it;
+      }
+    }
+
+    Content::iterator Find(const std::string& filename)
+    {
+      for (Content::iterator it = content_.begin();
+           it != content_.end(); ++it)
+      {
+        if ((*it)->GetFilename() == filename)
+        {
+          return it;
+        }
+      }
+
+      return content_.end();
+    }
+
+    void Remove(const std::string& filename)
+    {
+      Content::iterator it = Find(filename);
+      if (it != content_.end())
+      {
+        delete *it;
+        content_.erase(it);
+      }
+    }
+
+  public:
+    ChunkStore()
+    {
+      numPlaces_ = 10;
+    }
+
+    ~ChunkStore()
+    {
+      Clear();
+    }
+
+    PostDataStatus Store(std::string& completed,
+                         const char* chunkData,
+                         size_t chunkSize,
+                         const std::string& filename,
+                         size_t filesize)
+    {
+      boost::mutex::scoped_lock lock(mutex_);
+
+      std::set<std::string>::iterator wasDiscarded = discardedFiles_.find(filename);
+      if (wasDiscarded != discardedFiles_.end())
+      {
+        discardedFiles_.erase(wasDiscarded);
+        return PostDataStatus_Failure;
+      }
+
+      ChunkedFile* f;
+      Content::iterator it = Find(filename);
+      if (it == content_.end())
+      {
+        f = new ChunkedFile(filename);
+
+        // Make some room
+        if (content_.size() >= numPlaces_)
+        {
+          discardedFiles_.insert(content_.front()->GetFilename());
+          delete content_.front();
+          content_.pop_front();
+        }
+
+        content_.push_back(f);
+      }
+      else
+      {
+        f = *it;
+      }
+
+      f->AddChunk(chunkData, chunkSize);
+
+      if (f->GetNumBytes() > filesize)
+      {
+        Remove(filename);
+      }
+      else if (f->GetNumBytes() == filesize)
+      {
+        f->Flatten(completed);
+        Remove(filename);
+        return PostDataStatus_Success;
+      }
+
+      return PostDataStatus_Pending;
+    }
+
+    /*void Print() 
+      {
+      boost::mutex::scoped_lock lock(mutex_);
+
+      printf("ChunkStore status:\n");
+      for (Content::const_iterator i = content_.begin();
+      i != content_.end(); i++)
+      {
+      printf("  [%s]: %d\n", (*i)->GetFilename().c_str(), (*i)->GetNumBytes());
+      }
+      printf("-----\n");
+      }*/
+  };
+
+
+  struct HttpServer::PImpl
+  {
+    struct mg_context *context_;
+    ChunkStore chunkStore_;
+  };
+
+
+  ChunkStore& HttpServer::GetChunkStore()
+  {
+    return pimpl_->chunkStore_;
+  }
+
+
+
+  static PostDataStatus ReadBody(std::string& postData,
+                                 struct mg_connection *connection,
+                                 const IHttpHandler::Arguments& headers)
+  {
+    IHttpHandler::Arguments::const_iterator cs = headers.find("content-length");
+    if (cs == headers.end())
+    {
+      return PostDataStatus_NoLength;
+    }
+
+    int length;      
+    try
+    {
+      length = boost::lexical_cast<int>(cs->second);
+    }
+    catch (boost::bad_lexical_cast&)
+    {
+      return PostDataStatus_NoLength;
+    }
+
+    if (length < 0)
+    {
+      length = 0;
+    }
+
+    postData.resize(length);
+
+    size_t pos = 0;
+    while (length > 0)
+    {
+      int r = mg_read(connection, &postData[pos], length);
+      if (r <= 0)
+      {
+        return PostDataStatus_Failure;
+      }
+
+      assert(r <= length);
+      length -= r;
+      pos += r;
+    }
+
+    return PostDataStatus_Success;
+  }
+
+
+
+  static PostDataStatus ParseMultipartPost(std::string &completedFile,
+                                           struct mg_connection *connection,
+                                           const IHttpHandler::Arguments& headers,
+                                           const std::string& contentType,
+                                           ChunkStore& chunkStore)
+  {
+    std::string boundary = "--" + contentType.substr(multipartLength);
+
+    std::string postData;
+    PostDataStatus status = ReadBody(postData, connection, headers);
+
+    if (status != PostDataStatus_Success)
+    {
+      return status;
+    }
+
+    /*for (IHttpHandler::Arguments::const_iterator i = headers.begin(); i != headers.end(); i++)
+      {
+      std::cout << "Header [" << i->first << "] = " << i->second << "\n";
+      }
+      printf("CHUNK\n");*/
+
+    typedef IHttpHandler::Arguments::const_iterator ArgumentIterator;
+
+    ArgumentIterator requestedWith = headers.find("x-requested-with");
+    ArgumentIterator fileName = headers.find("x-file-name");
+    ArgumentIterator fileSizeStr = headers.find("x-file-size");
+
+    if (requestedWith != headers.end() &&
+        requestedWith->second != "XMLHttpRequest")
+    {
+      return PostDataStatus_Failure; 
+    }
+
+    size_t fileSize = 0;
+    if (fileSizeStr != headers.end())
+    {
+      try
+      {
+        fileSize = boost::lexical_cast<size_t>(fileSizeStr->second);
+      }
+      catch (boost::bad_lexical_cast&)
+      {
+        return PostDataStatus_Failure;
+      }
+    }
+
+    typedef boost::find_iterator<std::string::iterator> FindIterator;
+    typedef boost::iterator_range<char*> Range;
+
+    //chunkStore.Print();
+
+    try
+    {
+      FindIterator last;
+      for (FindIterator it =
+             make_find_iterator(postData, boost::first_finder(boundary));
+           it!=FindIterator();
+           ++it)
+      {
+        if (last != FindIterator())
+        {
+          Range part(&last->back(), &it->front());
+          Range content = boost::find_first(part, "\r\n\r\n");
+          if (/*content != Range()*/!content.empty())
+          {
+            Range c(&content.back() + 1, &it->front() - 2);
+            size_t chunkSize = c.size();
+
+            if (chunkSize > 0)
+            {
+              const char* chunkData = &c.front();
+
+              if (fileName == headers.end())
+              {
+                // This file is stored in a single chunk
+                completedFile.resize(chunkSize);
+                if (chunkSize > 0)
+                {
+                  memcpy(&completedFile[0], chunkData, chunkSize);
+                }
+                return PostDataStatus_Success;
+              }
+              else
+              {
+                return chunkStore.Store(completedFile, chunkData, chunkSize, fileName->second, fileSize);
+              }
+            }
+          }
+        }
+
+        last = it;
+      }
+    }
+    catch (std::length_error&)
+    {
+      return PostDataStatus_Failure;
+    }
+
+    return PostDataStatus_Pending;
+  }
+
+
+  static bool IsAccessGranted(const HttpServer& that,
+                              const IHttpHandler::Arguments& headers)
+  {
+    bool granted = false;
+
+    IHttpHandler::Arguments::const_iterator auth = headers.find("authorization");
+    if (auth != headers.end())
+    {
+      std::string s = auth->second;
+      if (s.size() > 6 &&
+          s.substr(0, 6) == "Basic ")
+      {
+        std::string b64 = s.substr(6);
+        granted = that.IsValidBasicHttpAuthentication(b64);
+      }
+    }
+
+    return granted;
+  }
+
+
+  static std::string GetAuthenticatedUsername(const IHttpHandler::Arguments& headers)
+  {
+    IHttpHandler::Arguments::const_iterator auth = headers.find("authorization");
+
+    if (auth == headers.end())
+    {
+      return "";
+    }
+
+    std::string s = auth->second;
+    if (s.size() <= 6 ||
+        s.substr(0, 6) != "Basic ")
+    {
+      return "";
+    }
+
+    std::string b64 = s.substr(6);
+    std::string decoded;
+    Toolbox::DecodeBase64(decoded, b64);
+    size_t semicolons = decoded.find(':');
+
+    if (semicolons == std::string::npos)
+    {
+      // Bad-formatted request
+      return "";
+    }
+    else
+    {
+      return decoded.substr(0, semicolons);
+    }
+  }
+
+
+  static bool ExtractMethod(HttpMethod& method,
+                            const struct mg_request_info *request,
+                            const IHttpHandler::Arguments& headers,
+                            const IHttpHandler::GetArguments& argumentsGET)
+  {
+    std::string overriden;
+
+    // Check whether some PUT/DELETE faking is done
+
+    // 1. Faking with Google's approach
+    IHttpHandler::Arguments::const_iterator methodOverride =
+      headers.find("x-http-method-override");
+
+    if (methodOverride != headers.end())
+    {
+      overriden = methodOverride->second;
+    }
+    else if (!strcmp(request->request_method, "GET"))
+    {
+      // 2. Faking with Ruby on Rail's approach
+      // GET /my/resource?_method=delete <=> DELETE /my/resource
+      for (size_t i = 0; i < argumentsGET.size(); i++)
+      {
+        if (argumentsGET[i].first == "_method")
+        {
+          overriden = argumentsGET[i].second;
+          break;
+        }
+      }
+    }
+
+    if (overriden.size() > 0)
+    {
+      // A faking has been done within this request
+      Toolbox::ToUpperCase(overriden);
+
+      LOG(INFO) << "HTTP method faking has been detected for " << overriden;
+
+      if (overriden == "PUT")
+      {
+        method = HttpMethod_Put;
+        return true;
+      }
+      else if (overriden == "DELETE")
+      {
+        method = HttpMethod_Delete;
+        return true;
+      }
+      else
+      {
+        return false;
+      }
+    }
+
+    // No PUT/DELETE faking was present
+    if (!strcmp(request->request_method, "GET"))
+    {
+      method = HttpMethod_Get;
+    }
+    else if (!strcmp(request->request_method, "POST"))
+    {
+      method = HttpMethod_Post;
+    }
+    else if (!strcmp(request->request_method, "DELETE"))
+    {
+      method = HttpMethod_Delete;
+    }
+    else if (!strcmp(request->request_method, "PUT"))
+    {
+      method = HttpMethod_Put;
+    }
+    else
+    {
+      return false;
+    }    
+
+    return true;
+  }
+
+
+  static void ConfigureHttpCompression(HttpOutput& output,
+                                       const IHttpHandler::Arguments& headers)
+  {
+    // Look if the client wishes HTTP compression
+    // https://en.wikipedia.org/wiki/HTTP_compression
+    IHttpHandler::Arguments::const_iterator it = headers.find("accept-encoding");
+    if (it != headers.end())
+    {
+      std::vector<std::string> encodings;
+      Toolbox::TokenizeString(encodings, it->second, ',');
+
+      for (size_t i = 0; i < encodings.size(); i++)
+      {
+        std::string s = Toolbox::StripSpaces(encodings[i]);
+
+        if (s == "deflate")
+        {
+          output.SetDeflateAllowed(true);
+        }
+        else if (s == "gzip")
+        {
+          output.SetGzipAllowed(true);
+        }
+      }
+    }
+  }
+
+
+  static void InternalCallback(HttpOutput& output /* out */,
+                               HttpMethod& method /* out */,
+                               HttpServer& server,
+                               struct mg_connection *connection,
+                               const struct mg_request_info *request)
+  {
+    bool localhost;
+
+#if ORTHANC_ENABLE_MONGOOSE == 1
+    static const long LOCALHOST = (127ll << 24) + 1ll;
+    localhost = (request->remote_ip == LOCALHOST);
+#elif ORTHANC_ENABLE_CIVETWEB == 1
+    // The "remote_ip" field of "struct mg_request_info" is tagged as
+    // deprecated in Civetweb, using "remote_addr" instead.
+    localhost = (std::string(request->remote_addr) == "127.0.0.1");
+#else
+#  error
+#endif
+    
+    // Check remote calls
+    if (!server.IsRemoteAccessAllowed() &&
+        !localhost)
+    {
+      output.SendUnauthorized(server.GetRealm());
+      return;
+    }
+
+
+    // Extract the HTTP headers
+    IHttpHandler::Arguments headers;
+    for (int i = 0; i < request->num_headers; i++)
+    {
+      std::string name = request->http_headers[i].name;
+      std::string value = request->http_headers[i].value;
+
+      std::transform(name.begin(), name.end(), name.begin(), ::tolower);
+      headers.insert(std::make_pair(name, value));
+      VLOG(1) << "HTTP header: [" << name << "]: [" << value << "]";
+    }
+
+    if (server.IsHttpCompressionEnabled())
+    {
+      ConfigureHttpCompression(output, headers);
+    }
+
+
+    // Extract the GET arguments
+    IHttpHandler::GetArguments argumentsGET;
+    if (!strcmp(request->request_method, "GET"))
+    {
+      HttpToolbox::ParseGetArguments(argumentsGET, request->query_string);
+    }
+
+
+    // Compute the HTTP method, taking method faking into consideration
+    method = HttpMethod_Get;
+    if (!ExtractMethod(method, request, headers, argumentsGET))
+    {
+      output.SendStatus(HttpStatus_400_BadRequest);
+      return;
+    }
+
+
+    // Authenticate this connection
+    if (server.IsAuthenticationEnabled() && 
+        !IsAccessGranted(server, headers))
+    {
+      output.SendUnauthorized(server.GetRealm());
+      return;
+    }
+
+    
+#if ORTHANC_ENABLE_MONGOOSE == 1
+    // Apply the filter, if it is installed
+    char remoteIp[24];
+    sprintf(remoteIp, "%d.%d.%d.%d", 
+            reinterpret_cast<const uint8_t*>(&request->remote_ip) [3], 
+            reinterpret_cast<const uint8_t*>(&request->remote_ip) [2], 
+            reinterpret_cast<const uint8_t*>(&request->remote_ip) [1], 
+            reinterpret_cast<const uint8_t*>(&request->remote_ip) [0]);
+
+    const char* requestUri = request->uri;
+      
+#elif ORTHANC_ENABLE_CIVETWEB == 1
+    const char* remoteIp = request->remote_addr;
+    const char* requestUri = request->local_uri;
+#else
+#  error
+#endif
+
+    if (requestUri == NULL)
+    {
+      requestUri = "";
+    }
+      
+    std::string username = GetAuthenticatedUsername(headers);
+
+    IIncomingHttpRequestFilter *filter = server.GetIncomingHttpRequestFilter();
+    if (filter != NULL)
+    {
+      if (!filter->IsAllowed(method, requestUri, remoteIp,
+                             username.c_str(), headers, argumentsGET))
+      {
+        //output.SendUnauthorized(server.GetRealm());
+        output.SendStatus(HttpStatus_403_Forbidden);
+        return;
+      }
+    }
+
+
+    // Extract the body of the request for PUT and POST
+
+    // TODO Avoid unneccessary memcopy of the body
+
+    std::string body;
+    if (method == HttpMethod_Post ||
+        method == HttpMethod_Put)
+    {
+      PostDataStatus status;
+
+      IHttpHandler::Arguments::const_iterator ct = headers.find("content-type");
+      if (ct == headers.end())
+      {
+        // No content-type specified. Assume no multi-part content occurs at this point.
+        status = ReadBody(body, connection, headers);          
+      }
+      else
+      {
+        std::string contentType = ct->second;
+        if (contentType.size() >= multipartLength &&
+            !memcmp(contentType.c_str(), multipart, multipartLength))
+        {
+          status = ParseMultipartPost(body, connection, headers, contentType, server.GetChunkStore());
+        }
+        else
+        {
+          status = ReadBody(body, connection, headers);
+        }
+      }
+
+      switch (status)
+      {
+        case PostDataStatus_NoLength:
+          output.SendStatus(HttpStatus_411_LengthRequired);
+          return;
+
+        case PostDataStatus_Failure:
+          output.SendStatus(HttpStatus_400_BadRequest);
+          return;
+
+        case PostDataStatus_Pending:
+          output.AnswerEmpty();
+          return;
+
+        default:
+          break;
+      }
+    }
+
+
+    // Decompose the URI into its components
+    UriComponents uri;
+    try
+    {
+      Toolbox::SplitUriComponents(uri, requestUri);
+    }
+    catch (OrthancException&)
+    {
+      output.SendStatus(HttpStatus_400_BadRequest);
+      return;
+    }
+
+
+    LOG(INFO) << EnumerationToString(method) << " " << Toolbox::FlattenUri(uri);
+
+    bool found = false;
+
+    if (server.HasHandler())
+    {
+      found = server.GetHandler().Handle(output, RequestOrigin_RestApi, remoteIp, username.c_str(), 
+                                         method, uri, headers, argumentsGET, body.c_str(), body.size());
+    }
+
+    if (!found)
+    {
+      throw OrthancException(ErrorCode_UnknownResource);
+    }
+  }
+
+
+  static void ProtectedCallback(struct mg_connection *connection,
+                                const struct mg_request_info *request)
+  {
+    try
+    {
+#if ORTHANC_ENABLE_MONGOOSE == 1
+      void *that = request->user_data;
+      const char* requestUri = request->uri;
+#elif ORTHANC_ENABLE_CIVETWEB == 1
+      // https://github.com/civetweb/civetweb/issues/409
+      void *that = mg_get_user_data(mg_get_context(connection));
+      const char* requestUri = request->local_uri;
+#else
+#  error
+#endif
+
+      if (requestUri == NULL)
+      {
+        requestUri = "";
+      }
+      
+      HttpServer* server = reinterpret_cast<HttpServer*>(that);
+
+      if (server == NULL)
+      {
+        MongooseOutputStream stream(connection);
+        HttpOutput output(stream, false /* assume no keep-alive */);
+        output.SendStatus(HttpStatus_500_InternalServerError);
+        return;
+      }
+
+      MongooseOutputStream stream(connection);
+      HttpOutput output(stream, server->IsKeepAliveEnabled());
+      HttpMethod method = HttpMethod_Get;
+
+      try
+      {
+        try
+        {
+          InternalCallback(output, method, *server, connection, request);
+        }
+        catch (OrthancException&)
+        {
+          throw;  // Pass the exception to the main handler below
+        }
+        // Now convert native exceptions as OrthancException
+        catch (boost::bad_lexical_cast&)
+        {
+          throw OrthancException(ErrorCode_BadParameterType,
+                                 "Syntax error in some user-supplied data");
+        }
+        catch (std::runtime_error&)
+        {
+          // Presumably an error while parsing the JSON body
+          throw OrthancException(ErrorCode_BadRequest);
+        }
+        catch (std::bad_alloc&)
+        {
+          throw OrthancException(ErrorCode_NotEnoughMemory,
+                                 "The server hosting Orthanc is running out of memory");
+        }
+        catch (...)
+        {
+          throw OrthancException(ErrorCode_InternalError,
+                                 "An unhandled exception was generated inside the HTTP server");
+        }
+      }
+      catch (OrthancException& e)
+      {
+        assert(server != NULL);
+
+        // Using this candidate handler results in an exception
+        try
+        {
+          if (server->GetExceptionFormatter() == NULL)
+          {
+            LOG(ERROR) << "Exception in the HTTP handler: " << e.What();
+            output.SendStatus(e.GetHttpStatus());
+          }
+          else
+          {
+            server->GetExceptionFormatter()->Format(output, e, method, requestUri);
+          }
+        }
+        catch (OrthancException&)
+        {
+          // An exception here reflects the fact that the status code
+          // was already set by the HTTP handler.
+        }
+      }
+    }
+    catch (...)
+    {
+      // We should never arrive at this point, where it is even impossible to send an answer
+      LOG(ERROR) << "Catastrophic error inside the HTTP server, giving up";
+    }
+  }
+
+
+#if MONGOOSE_USE_CALLBACKS == 0
+  static void* Callback(enum mg_event event,
+                        struct mg_connection *connection,
+                        const struct mg_request_info *request)
+  {
+    if (event == MG_NEW_REQUEST) 
+    {
+      ProtectedCallback(connection, request);
+
+      // Mark as processed
+      return (void*) "";
+    }
+    else
+    {
+      return NULL;
+    }
+  }
+
+#elif MONGOOSE_USE_CALLBACKS == 1
+  static int Callback(struct mg_connection *connection)
+  {
+    const struct mg_request_info *request = mg_get_request_info(connection);
+
+    ProtectedCallback(connection, request);
+
+    return 1;  // Do not let Mongoose handle the request by itself
+  }
+
+#else
+#  error Please set MONGOOSE_USE_CALLBACKS
+#endif
+
+
+
+
+
+  bool HttpServer::IsRunning() const
+  {
+    return (pimpl_->context_ != NULL);
+  }
+
+
+  HttpServer::HttpServer() : pimpl_(new PImpl)
+  {
+    pimpl_->context_ = NULL;
+    handler_ = NULL;
+    remoteAllowed_ = false;
+    authentication_ = false;
+    ssl_ = false;
+    port_ = 8000;
+    filter_ = NULL;
+    keepAlive_ = false;
+    httpCompression_ = true;
+    exceptionFormatter_ = NULL;
+    realm_ = ORTHANC_REALM;
+    threadsCount_ = 50;  // Default value in mongoose
+    tcpNoDelay_ = true;
+
+#if ORTHANC_ENABLE_SSL == 1
+    // Check for the Heartbleed exploit
+    // https://en.wikipedia.org/wiki/OpenSSL#Heartbleed_bug
+    if (OPENSSL_VERSION_NUMBER <  0x1000107fL  /* openssl-1.0.1g */ &&
+        OPENSSL_VERSION_NUMBER >= 0x1000100fL  /* openssl-1.0.1 */) 
+    {
+      LOG(WARNING) << "This version of OpenSSL is vulnerable to the Heartbleed exploit";
+    }
+#endif
+  }
+
+
+  HttpServer::~HttpServer()
+  {
+    Stop();
+  }
+
+
+  void HttpServer::SetPortNumber(uint16_t port)
+  {
+    Stop();
+    port_ = port;
+  }
+
+  void HttpServer::Start()
+  {
+#if ORTHANC_ENABLE_MONGOOSE == 1
+    LOG(INFO) << "Starting embedded Web server using Mongoose";
+#elif ORTHANC_ENABLE_CIVETWEB == 1
+    LOG(INFO) << "Starting embedded Web server using Civetweb";
+#else
+#  error
+#endif  
+
+    if (!IsRunning())
+    {
+      std::string port = boost::lexical_cast<std::string>(port_);
+      std::string numThreads = boost::lexical_cast<std::string>(threadsCount_);
+
+      if (ssl_)
+      {
+        port += "s";
+      }
+
+      const char *options[] = {
+        // Set the TCP port for the HTTP server
+        "listening_ports", port.c_str(), 
+        
+        // Optimization reported by Chris Hafey
+        // https://groups.google.com/d/msg/orthanc-users/CKueKX0pJ9E/_UCbl8T-VjIJ
+        "enable_keep_alive", (keepAlive_ ? "yes" : "no"),
+
+#if ORTHANC_ENABLE_CIVETWEB == 1
+        // https://github.com/civetweb/civetweb/blob/master/docs/UserManual.md#enable_keep_alive-no
+        "keep_alive_timeout_ms", (keepAlive_ ? "500" : "0"),
+#endif
+
+#if ORTHANC_ENABLE_CIVETWEB == 1
+        // Disable TCP Nagle's algorithm to maximize speed (this
+        // option is not available in Mongoose).
+        // https://groups.google.com/d/topic/civetweb/35HBR9seFjU/discussion
+        // https://eklitzke.org/the-caveats-of-tcp-nodelay
+        "tcp_nodelay", (tcpNoDelay_ ? "1" : "0"),
+#endif
+
+        // Set the number of threads
+        "num_threads", numThreads.c_str(),
+        
+        // Set the SSL certificate, if any. This must be the last option.
+        ssl_ ? "ssl_certificate" : NULL,
+        certificate_.c_str(),
+        NULL
+      };
+
+#if MONGOOSE_USE_CALLBACKS == 0
+      pimpl_->context_ = mg_start(&Callback, this, options);
+
+#elif MONGOOSE_USE_CALLBACKS == 1
+      struct mg_callbacks callbacks;
+      memset(&callbacks, 0, sizeof(callbacks));
+      callbacks.begin_request = Callback;
+      pimpl_->context_ = mg_start(&callbacks, this, options);
+
+#else
+#  error Please set MONGOOSE_USE_CALLBACKS
+#endif
+
+      if (!pimpl_->context_)
+      {
+        throw OrthancException(ErrorCode_HttpPortInUse);
+      }
+
+      LOG(WARNING) << "HTTP server listening on port: " << GetPortNumber()
+                   << " (HTTPS encryption is "
+                   << (IsSslEnabled() ? "enabled" : "disabled")
+                   << ", remote access is "
+                   << (IsRemoteAccessAllowed() ? "" : "not ")
+                   << "allowed)";
+    }
+  }
+
+  void HttpServer::Stop()
+  {
+    if (IsRunning())
+    {
+      mg_stop(pimpl_->context_);
+      pimpl_->context_ = NULL;
+    }
+  }
+
+
+  void HttpServer::ClearUsers()
+  {
+    Stop();
+    registeredUsers_.clear();
+  }
+
+
+  void HttpServer::RegisterUser(const char* username,
+                                const char* password)
+  {
+    Stop();
+
+    std::string tag = std::string(username) + ":" + std::string(password);
+    std::string encoded;
+    Toolbox::EncodeBase64(encoded, tag);
+    registeredUsers_.insert(encoded);
+  }
+
+  void HttpServer::SetSslEnabled(bool enabled)
+  {
+    Stop();
+
+#if ORTHANC_ENABLE_SSL == 0
+    if (enabled)
+    {
+      throw OrthancException(ErrorCode_SslDisabled);
+    }
+    else
+    {
+      ssl_ = false;
+    }
+#else
+    ssl_ = enabled;
+#endif
+  }
+
+
+  void HttpServer::SetKeepAliveEnabled(bool enabled)
+  {
+    Stop();
+    keepAlive_ = enabled;
+    LOG(INFO) << "HTTP keep alive is " << (enabled ? "enabled" : "disabled");
+
+#if ORTHANC_ENABLE_MONGOOSE == 1
+    if (enabled)
+    {
+      LOG(WARNING) << "You should disable HTTP keep alive, as you are using Mongoose";
+    }
+#endif
+  }
+
+
+  void HttpServer::SetAuthenticationEnabled(bool enabled)
+  {
+    Stop();
+    authentication_ = enabled;
+  }
+
+  void HttpServer::SetSslCertificate(const char* path)
+  {
+    Stop();
+    certificate_ = path;
+  }
+
+  void HttpServer::SetRemoteAccessAllowed(bool allowed)
+  {
+    Stop();
+    remoteAllowed_ = allowed;
+  }
+
+  void HttpServer::SetHttpCompressionEnabled(bool enabled)
+  {
+    Stop();
+    httpCompression_ = enabled;
+    LOG(WARNING) << "HTTP compression is " << (enabled ? "enabled" : "disabled");
+  }
+  
+  void HttpServer::SetIncomingHttpRequestFilter(IIncomingHttpRequestFilter& filter)
+  {
+    Stop();
+    filter_ = &filter;
+  }
+
+
+  void HttpServer::SetHttpExceptionFormatter(IHttpExceptionFormatter& formatter)
+  {
+    Stop();
+    exceptionFormatter_ = &formatter;
+  }
+
+
+  bool HttpServer::IsValidBasicHttpAuthentication(const std::string& basic) const
+  {
+    return registeredUsers_.find(basic) != registeredUsers_.end();
+  }
+
+
+  void HttpServer::Register(IHttpHandler& handler)
+  {
+    Stop();
+    handler_ = &handler;
+  }
+
+
+  IHttpHandler& HttpServer::GetHandler() const
+  {
+    if (handler_ == NULL)
+    {
+      throw OrthancException(ErrorCode_InternalError);
+    }
+
+    return *handler_;
+  }
+
+
+  void HttpServer::SetThreadsCount(unsigned int threads)
+  {
+    if (threads <= 0)
+    {
+      throw OrthancException(ErrorCode_ParameterOutOfRange);
+    }
+    
+    Stop();
+    threadsCount_ = threads;
+  }
+
+
+  void HttpServer::SetTcpNoDelay(bool tcpNoDelay)
+  {
+    Stop();
+    tcpNoDelay_ = tcpNoDelay;
+    LOG(INFO) << "TCP_NODELAY for the HTTP sockets is set to "
+              << (tcpNoDelay ? "true" : "false");
+  }
+}