Commit message: Fix a buffer overflow.

This is only the minimum workaround to prevent buffer overflow:
Stop iterating once the (fixed!) size of the output buffers is
reached. In response to
https://www.talosintelligence.com/vulnerability_reports/TALOS-2017-0317

However, this code is a huge mess anyway and is in no way
anything like up-to-date C++ code. Please, anyone, replace it
with something more modern. Thanks.
CVE: CVE-2017-2920
CWE: CWE-119
Vulnerability description: An memory corruption vulnerability exists in the .SVG parsing functionality of Computerinsel Photoline 20.02. A specially crafted .SVG file can cause a vulnerability resulting in memory corruption, which can potentially lead to arbitrary code execution. An attacker can send a specific .SVG file to trigger this vulnerability.

Project: libofx

std::string find_dtd(LibofxContextPtr ctx, const std::string& dtd_filename)
{
  string dtd_path_filename;
  char *env_dtd_path;

  dtd_path_filename = reinterpret_cast<const LibofxContext*>(ctx)->dtdDir();
  if (!dtd_path_filename.empty())
  {
    dtd_path_filename.append(dtd_filename);
    ifstream dtd_file(dtd_path_filename.c_str());
    if (dtd_file)
    {
      message_out(STATUS, "find_dtd():DTD found: " + dtd_path_filename);
      return dtd_path_filename;
    }
  }

#ifdef OS_WIN32
  dtd_path_filename = get_dtd_installation_directory();
  if (!dtd_path_filename.empty())
  {
    dtd_path_filename.append(DIRSEP);
    dtd_path_filename.append(dtd_filename);
    ifstream dtd_file(dtd_path_filename.c_str());
    if (dtd_file)
    {
      message_out(STATUS, "find_dtd():DTD found: " + dtd_path_filename);
      return dtd_path_filename;
    }
  }
#endif
  /* Search in environement variable OFX_DTD_PATH */
  env_dtd_path = getenv("OFX_DTD_PATH");
  if (env_dtd_path)
  {
    dtd_path_filename.append(env_dtd_path);
    dtd_path_filename.append(DIRSEP);
    dtd_path_filename.append(dtd_filename);
    ifstream dtd_file(dtd_path_filename.c_str());
    if (!dtd_file)
    {
      message_out(STATUS, "find_dtd():OFX_DTD_PATH env variable was was present, but unable to open the file " + dtd_path_filename);
    }
    else
    {
      message_out(STATUS, "find_dtd():DTD found: " + dtd_path_filename);
      return dtd_path_filename;
    }
  }

  for (int i = 0; i < DTD_SEARCH_PATH_NUM; i++)
  {
    dtd_path_filename = DTD_SEARCH_PATH[i];
    dtd_path_filename.append(DIRSEP);
    dtd_path_filename.append(dtd_filename);
    ifstream dtd_file(dtd_path_filename.c_str());
    if (!dtd_file)
    {
      message_out(DEBUG, "find_dtd():Unable to open the file " + dtd_path_filename);
    }
    else
    {
      message_out(STATUS, "find_dtd():DTD found: " + dtd_path_filename);
      return dtd_path_filename;
    }
  }

  /* Last resort, look in source tree relative path (useful for development) */
  dtd_path_filename = "";
  dtd_path_filename.append("..");
  dtd_path_filename.append(DIRSEP);
  dtd_path_filename.append("dtd");
  dtd_path_filename.append(DIRSEP);
  dtd_path_filename.append(dtd_filename);
  ifstream dtd_file(dtd_path_filename.c_str());
  if (!dtd_file)
  {
    message_out(DEBUG, "find_dtd(): Unable to open the file " + dtd_path_filename + ", most likely we are not in the source tree.");
  }
  else
  {
    message_out(STATUS, "find_dtd():DTD found: " + dtd_path_filename);
    return dtd_path_filename;
  }


  message_out(ERROR, "find_dtd():Unable to find the DTD named " + dtd_filename);
  return "";
}

Project: libofx

int ofx_proc_file(LibofxContextPtr ctx, const char * p_filename)
{
  LibofxContext *libofx_context;
  bool ofx_start = false;
  bool ofx_end = false;
  bool file_is_xml = false;

  ifstream input_file;
  ofstream tmp_file;
  char buffer[READ_BUFFER_SIZE];
  char *iconv_buffer;
  string s_buffer;
  char *filenames[3];
  char tmp_filename[256];
  int tmp_file_fd;
#ifdef HAVE_ICONV
  iconv_t conversion_descriptor;
#endif
  libofx_context = (LibofxContext*)ctx;

  if (p_filename != NULL && strcmp(p_filename, "") != 0)
  {
    message_out(DEBUG, string("ofx_proc_file():Opening file: ") + p_filename);

    input_file.open(p_filename);
    if (!input_file)
    {
      message_out(ERROR, "ofx_proc_file():Unable to open the input file " + string(p_filename));
    }

    mkTempFileName("libofxtmpXXXXXX", tmp_filename, sizeof(tmp_filename));

    message_out(DEBUG, "ofx_proc_file(): Creating temp file: " + string(tmp_filename));
    tmp_file_fd = mkstemp(tmp_filename);
    if (tmp_file_fd)
    {
      tmp_file.open(tmp_filename);
      if (!tmp_file)
      {
        message_out(ERROR, "ofx_proc_file():Unable to open the created temp file " + string(tmp_filename));
        return -1;
      }
    }
    else
    {
      message_out(ERROR, "ofx_proc_file():Unable to create a temp file at " + string(tmp_filename));
      return -1;
    }

    if (input_file && tmp_file)
    {
      int header_separator_idx;
      string header_name;
      string header_value;
      string ofx_encoding;
      string ofx_charset;
      do
      {
        s_buffer.clear();
        bool end_of_line = false;
        do
        {
          input_file.get(buffer, sizeof(buffer), '\n');
          //cout<< "got: \"" << buffer<<"\"\n";
          s_buffer.append(buffer);

          // Watch out: If input_file is in eof(), any subsequent read or
          // peek() will fail and we must exit this loop.
          if (input_file.eof())
            break;

          //cout<<"input_file.gcount(): "<<input_file.gcount()<< " s_buffer.size=" << s_buffer.size()<<" sizeof(buffer): "<<sizeof(buffer) << " peek=\"" << int(input_file.peek()) << "\"" <<endl;
          if (input_file.fail()) // If no characters were extracted above, the failbit is set.
          {
            // No characters extracted means that we've reached the newline
            // delimiter (because we already checked for EOF). We will check
            // for and remove that newline in the next if-clause, but must
            // remove the failbit so that peek() will work again.
            input_file.clear();
          }

          // Is the next character really the newline?
          if (input_file.peek() == '\n')
          {
            // Yes. Then discard that newline character from the stream and
            // append it manually to the output string.
            input_file.get();
            s_buffer.append("\n");
            end_of_line = true; // We found the end-of-line.
          }
        }
        // Continue reading as long as we're not at EOF *and* we've not yet
        // reached an end-of-line.
        while (!input_file.eof() && !end_of_line);

        if (ofx_start == false && (s_buffer.find("<?xml") != string::npos))
        {
          message_out(DEBUG, "ofx_proc_file(): File is an actual XML file, iconv conversion will be skipped.");
          file_is_xml = true;
        }

        int ofx_start_idx;
        if (ofx_start == false &&
            (
              (libofx_context->currentFileType() == OFX &&
               ((ofx_start_idx = s_buffer.find("<OFX>")) !=
                string::npos || (ofx_start_idx = s_buffer.find("<ofx>")) != string::npos))
              || (libofx_context->currentFileType() == OFC &&
                  ((ofx_start_idx = s_buffer.find("<OFC>")) != string::npos ||
                   (ofx_start_idx = s_buffer.find("<ofc>")) != string::npos))
            )
           )
        {
          ofx_start = true;
          if (file_is_xml == false)
          {
            s_buffer.erase(0, ofx_start_idx); //Fix for really broken files that don't have a newline after the header.
          }
          message_out(DEBUG, "ofx_proc_file():<OFX> or <OFC> has been found");

          if (file_is_xml == true)
          {
            static char sp_charset_fixed[] = "SP_CHARSET_FIXED=1";
            if (putenv(sp_charset_fixed) != 0)
            {
              message_out(ERROR, "ofx_proc_file(): putenv failed");
            }
            /* Normally the following would be "xml".
             * Unfortunately, opensp's generic api will garble UTF-8 if this is
             * set to xml.  So we set any single byte encoding to avoid messing
             * up UTF-8.  Unfortunately this means that non-UTF-8 files will not
             * get properly translated.  We'd need to manually detect the
             * encoding in the XML header and convert the xml with iconv like we
             * do for SGML to work around the problem.  Most unfortunate. */
            static char sp_encoding[] = "SP_ENCODING=ms-dos";
            if (putenv(sp_encoding) != 0)
            {
              message_out(ERROR, "ofx_proc_file(): putenv failed");
            }
          }
          else
          {
            static char sp_charset_fixed[] = "SP_CHARSET_FIXED=1";
            if (putenv(sp_charset_fixed) != 0)
            {
              message_out(ERROR, "ofx_proc_file(): putenv failed");
            }
            static char sp_encoding[] = "SP_ENCODING=ms-dos"; //Any single byte encoding will do, we don't want opensp messing up UTF-8;
            if (putenv(sp_encoding) != 0)
            {
              message_out(ERROR, "ofx_proc_file(): putenv failed");
            }
#ifdef HAVE_ICONV
            string fromcode;
            string tocode;
            if (ofx_encoding.compare("USASCII") == 0)
            {
              if (ofx_charset.compare("ISO-8859-1") == 0 || ofx_charset.compare("8859-1") == 0)
              {
                //Only "ISO-8859-1" is actually a legal value, but since the banks follows the spec SO well...
                fromcode = "ISO-8859-1";
              }
              else if (ofx_charset.compare("1252") == 0 || ofx_charset.compare("CP1252") == 0)
              {
                //Only "1252" is actually a legal value, but since the banks follows the spec SO well...
                fromcode = "CP1252";
              }
              else if (ofx_charset.compare("NONE") == 0)
              {
                fromcode = LIBOFX_DEFAULT_INPUT_ENCODING;
              }
              else
              {
                fromcode = LIBOFX_DEFAULT_INPUT_ENCODING;
              }
            }
            else if (ofx_encoding.compare("UTF-8") == 0 || ofx_encoding.compare("UNICODE") == 0)
            {
              //While "UNICODE" isn't a legal value, some cyrilic files do specify it as such...
              fromcode = "UTF-8";
            }
            else
            {
              fromcode = LIBOFX_DEFAULT_INPUT_ENCODING;
            }
            tocode = LIBOFX_DEFAULT_OUTPUT_ENCODING;
            message_out(DEBUG, "ofx_proc_file(): Setting up iconv for fromcode: " + fromcode + ", tocode: " + tocode);
            conversion_descriptor = iconv_open (tocode.c_str(), fromcode.c_str());
#endif
          }
        }
        else
        {
          //We are still in the headers
          if ((header_separator_idx = s_buffer.find(':')) != string::npos)
          {
            //Header processing
            header_name.assign(s_buffer.substr(0, header_separator_idx));
            header_value.assign(s_buffer.substr(header_separator_idx + 1));
            while ( header_value[header_value.length() -1 ] == '\n' ||
                    header_value[header_value.length() -1 ] == '\r' )
              header_value.erase(header_value.length() - 1);
            message_out(DEBUG, "ofx_proc_file():Header: " + header_name + " with value: " + header_value + " has been found");
            if (header_name.compare("ENCODING") == 0)
            {
              ofx_encoding.assign(header_value);
            }
            if (header_name.compare("CHARSET") == 0)
            {
              ofx_charset.assign(header_value);
            }
          }
        }

        if (file_is_xml == true || (ofx_start == true && ofx_end == false))
        {
          if (ofx_start == true)
          {
            /* The above test won't help us if the <OFX> tag is on the same line
             * as the xml header, but as opensp can't be used to parse it anyway
             * this isn't a great loss for now.
             */
            s_buffer = sanitize_proprietary_tags(s_buffer);
          }
          //cout<< s_buffer<<"\n";
          if (file_is_xml == false)
          {
#ifdef HAVE_ICONV
            size_t inbytesleft = strlen(s_buffer.c_str());
            size_t outbytesleft = inbytesleft * 2 - 1;
            iconv_buffer = (char*) malloc (inbytesleft * 2);
            memset(iconv_buffer, 0, inbytesleft * 2);
#if defined(OS_WIN32) || defined(__sun) || defined(__NetBSD__)
            const char * inchar = (const char *)s_buffer.c_str();
#else
            char * inchar = (char *)s_buffer.c_str();
#endif
            char * outchar = iconv_buffer;
            int iconv_retval = iconv (conversion_descriptor,
                                      &inchar, &inbytesleft,
                                      &outchar, &outbytesleft);
            if (iconv_retval == -1)
            {
              message_out(ERROR, "ofx_proc_file(): Conversion error");
            }
            s_buffer = iconv_buffer;
            free (iconv_buffer);
#endif
          }
          //cout << s_buffer << "\n";
          tmp_file.write(s_buffer.c_str(), s_buffer.length());
        }

        if (ofx_start == true &&
            (
              (libofx_context->currentFileType() == OFX &&
               ((ofx_start_idx = s_buffer.find("</OFX>")) != string::npos ||
                (ofx_start_idx = s_buffer.find("</ofx>")) != string::npos))
              || (libofx_context->currentFileType() == OFC &&
                  ((ofx_start_idx = s_buffer.find("</OFC>")) != string::npos ||
                   (ofx_start_idx = s_buffer.find("</ofc>")) != string::npos))
            )
           )
        {
          ofx_end = true;
          message_out(DEBUG, "ofx_proc_file():</OFX> or </OFC>  has been found");
        }

      }
      while (!input_file.eof() && !input_file.bad());
    }
    input_file.close();
    tmp_file.close();
#ifdef HAVE_ICONV
    if (file_is_xml == false)
    {
      iconv_close(conversion_descriptor);
    }
#endif
    char filename_openspdtd[255];
    char filename_dtd[255];
    char filename_ofx[255];
    strncpy(filename_openspdtd, find_dtd(ctx, OPENSPDCL_FILENAME).c_str(), 255); //The opensp sgml dtd file
    if (libofx_context->currentFileType() == OFX)
    {
      strncpy(filename_dtd, find_dtd(ctx, OFX160DTD_FILENAME).c_str(), 255); //The ofx dtd file
    }
    else if (libofx_context->currentFileType() == OFC)
    {
      strncpy(filename_dtd, find_dtd(ctx, OFCDTD_FILENAME).c_str(), 255); //The ofc dtd file
    }
    else
    {
      message_out(ERROR, string("ofx_proc_file(): Error unknown file format for the OFX parser"));
    }

    if ((string)filename_dtd != "" && (string)filename_openspdtd != "")
    {
      strncpy(filename_ofx, tmp_filename, 255); //The processed ofx file
      filenames[0] = filename_openspdtd;
      filenames[1] = filename_dtd;
      filenames[2] = filename_ofx;
      if (libofx_context->currentFileType() == OFX)
      {
        ofx_proc_sgml(libofx_context, 3, filenames);
      }
      else if (libofx_context->currentFileType() == OFC)
      {
        ofc_proc_sgml(libofx_context, 3, filenames);
      }
      else
      {
        message_out(ERROR, string("ofx_proc_file(): Error unknown file format for the OFX parser"));
      }
      if (remove(tmp_filename) != 0)
      {
        message_out(ERROR, "ofx_proc_file(): Error deleting temporary file " + string(tmp_filename));
      }
    }
    else
    {
      message_out(ERROR, "ofx_proc_file(): FATAL: Missing DTD, aborting");
    }
  }
  else
  {
    message_out(ERROR, "ofx_proc_file():No input file specified");
  }
  return 0;
}

Project: libofx

string sanitize_proprietary_tags(string input_string)
{
  unsigned int i;
  bool strip = false;
  bool tag_open = false;
  int tag_open_idx = 0; //Are we within < > ?
  bool closing_tag_open = false; //Are we within </ > ?
  int orig_tag_open_idx = 0;
  bool proprietary_tag = false; //Are we within a proprietary element?
  bool proprietary_closing_tag = false;
  int crop_end_idx = 0;
  char buffer[READ_BUFFER_SIZE] = "";
  char tagname[READ_BUFFER_SIZE] = "";
  int tagname_idx = 0;
  char close_tagname[READ_BUFFER_SIZE] = "";

  for (i = 0; i < READ_BUFFER_SIZE; i++)
  {
    buffer[i] = 0;
    tagname[i] = 0;
    close_tagname[i] = 0;
  }

  size_t input_string_size = input_string.size();

  // Minimum workaround to prevent buffer overflow: Stop iterating
  // once the (fixed!) size of the output buffers is reached. In
  // response to
  // https://www.talosintelligence.com/vulnerability_reports/TALOS-2017-0317
  //
  // However, this code is a huge mess anyway and is in no way
  // anything like up-to-date C++ code. Please, anyone, replace it
  // with something more modern. Thanks. - cstim, 2017-09-17.
  for (i = 0; i < std::min(input_string_size, size_t(READ_BUFFER_SIZE)); i++)
  {
    if (input_string.c_str()[i] == '<')
    {
      tag_open = true;
      tag_open_idx = i;
      if (proprietary_tag == true && input_string.c_str()[i+1] == '/')
      {
        //We are now in a closing tag
        closing_tag_open = true;
        //cout<<"Comparaison: "<<tagname<<"|"<<&(input_string.c_str()[i+2])<<"|"<<strlen(tagname)<<endl;
        if (strncmp(tagname, &(input_string.c_str()[i+2]), strlen(tagname)) != 0)
        {
          //If it is the begining of an other tag
          //cout<<"DIFFERENT!"<<endl;
          crop_end_idx = i - 1;
          strip = true;
        }
        else
        {
          //Otherwise, it is the start of the closing tag of the proprietary tag
          proprietary_closing_tag = true;
        }
      }
      else if (proprietary_tag == true)
      {
        //It is the start of a new tag, following a proprietary tag
        crop_end_idx = i - 1;
        strip = true;
      }
    }
    else if (input_string.c_str()[i] == '>')
    {
      tag_open = false;
      closing_tag_open = false;
      tagname[tagname_idx] = 0;
      tagname_idx = 0;
      if (proprietary_closing_tag == true)
      {
        crop_end_idx = i;
        strip = true;
      }
    }
    else if (tag_open == true && closing_tag_open == false)
    {
      if (input_string.c_str()[i] == '.')
      {
        if (proprietary_tag != true)
        {
          orig_tag_open_idx = tag_open_idx;
          proprietary_tag = true;
        }
      }
      tagname[tagname_idx] = input_string.c_str()[i];
      tagname_idx++;
    }
    //cerr <<i<<endl;
    if (strip == true && orig_tag_open_idx < input_string.size())
    {
      input_string.copy(buffer, (crop_end_idx - orig_tag_open_idx) + 1, orig_tag_open_idx);
      message_out(INFO, "sanitize_proprietary_tags() (end tag or new tag) removed: " + string(buffer));
      input_string.erase(orig_tag_open_idx, (crop_end_idx - orig_tag_open_idx) + 1);
      i = orig_tag_open_idx - 1;
      proprietary_tag = false;
      proprietary_closing_tag = false;
      closing_tag_open = false;
      tag_open = false;
      strip = false;

      input_string_size = input_string.size();
    }

  }//end for
  if (proprietary_tag == true && orig_tag_open_idx < input_string.size())
  {
    if (crop_end_idx == 0)   //no closing tag
    {
      crop_end_idx = input_string.size() - 1;
    }
    input_string.copy(buffer, (crop_end_idx - orig_tag_open_idx) + 1, orig_tag_open_idx);
    message_out(INFO, "sanitize_proprietary_tags() (end of line) removed: " + string(buffer));
    input_string.erase(orig_tag_open_idx, (crop_end_idx - orig_tag_open_idx) + 1);
    input_string_size = input_string.size();
  }
  return input_string;
}

Project: libofx

static std::string get_dtd_installation_directory()
{
  // Partial implementation of
  // http://developer.gnome.org/doc/API/2.0/glib/glib-Windows-Compatibility-Functions.html#g-win32-get-package-installation-directory
  char ch_fn[MAX_PATH], *p;
  std::string str_fn;

  if (!GetModuleFileName(NULL, ch_fn, MAX_PATH)) return "";

  if ((p = strrchr(ch_fn, '\\')) != NULL)
    * p = '\0';

  p = strrchr(ch_fn, '\\');
  if (p && (_stricmp(p + 1, "bin") == 0 ||
            _stricmp(p + 1, "lib") == 0))
    *p = '\0';

  str_fn = ch_fn;
  str_fn += "\\share\\libofx\\dtd";

  return str_fn;
}