cacert-codedocs/source/directories.rst

Directory structure

root Directory

The root directory contains

• a .gitignore file with a list of excluded files
• a LICENSE file the GPL license text
• a README file with very rudimentary documentation stating the license and a list of system requirements

cgi-bin

Directory cgi-bin

The cgi-bin directory contains

PHP

• siteseal.cgi a PHP CGI script that generates some JavaScript code to invoke sealgen.php <www-sealgen-php>. The configuration on www.cacert.org does not seem to support this script https://www.cacert.org/cgi-bin/siteseal.cgi returns a 403 response.

commModule

Perl

bash

Directory CommModule

This directory contains the CommModule that is implemented in Perl:

• client.pl the signer protocol <signer> client, running on the webserver and talking to the server via a serial link.

  The style of the Perl code seems a bit inconsistent (mix of uppercase and lowercase function names, usage of brackets). The code uses database polling in a loop. It might be a better idea to use some kind of queueing (Redis, AMQP, ...) to not waste resources when there is nothing to do). Function parameters are not named which makes the code hard to read.

  The script calls several system binaries that need to be present in compatible versions:

  • openssl
  • xdelta

  The script uses several Perl standard library modules as well as the following third party modules:

  Perl, thirdparty

  • DBD::mysql
  • DBI
  • Device::SerialPort
  • File::CounterFile

  The script references several openssl configuration files in the HandleCerts function that are not included in the code repository. There are some openssl configuration files with similar names in https://svn.cacert.org/CAcert/SystemAdministration/signer/

  The database password is parsed from includes/mysql.php <includes-mysql-php> and relies on the exact code that is defined there. Database name, user and host are hardcoded in the DBI->connect call.

  The script implements the client side of the signer protocol which is specified in signer.

  The script performs the following operations:

  • parse password from includes/mysql.php
  • read a list of CRL files and logs their SHA-1 hashes
  • read serial.conf, create a Device::SerialPort instance $portObj, sets serial parameters and saves serial.conf
  • run a main loop as long as a file ./client.pl-active is present. The main loop performs the following tasks
    • handle pending OpenPGP key signing request via HandleGPG()
    • handle pending certificate signing requests:
      • personal client certificates via HandleCerts(0, 0)
      • personal server certificates via HandleCerts(0, 1)
      • organization client certificates via HandleCerts(1, 0)
      • organization server certificates via HandleCerts(1, 1)
    • handle pending certificate revocation requests
      • personal client certificates via RevokeCerts(0, 0)
      • personal server certificates via RevokeCerts(0, 1)
      • organization client certificates via RevokeCerts(1, 0)
      • organization server certificates via RevokeCerts(1, 1)
    • refresh CRLs <CRL> via RefreshCRLs() in every 100st iteration
    • send a NUL request <signer-nul-request-format> to keep the signer connection alive
    • sleep for 2.7 seconds

  There is potential for optimization in the main loop. The CRL update could be performed if a certificate has been revoked. The NUL request needs only to be sent if no other request has been sent.

  The script uses a lot of temporary files instead of piping input and output to and from external commands.

  describe more in-depth what each of the main loop steps does

• commdaemon a script to run client.pl <commmodule-client-pl> or server.pl <commmodule-server-pl>

  This bash script is automatically restarting the {script} given as the first parameter as long as a file {script}-active exists. Informational messages and errors are logged to syslog via logger.

  The script is most probably used to recover from crashed scripts. This could be implemented via supervisor or systemd instead of a custom script.

• commmodule a System V style init script for startup/shutdown of CommModule

  On test.cacert.org two slightly different versions are deployed in /etc/init.d the first version starts client.pl <commmodule-client-pl> in /home/cacert/www/CommModule/ and the second variant starts server.pl <commmodule-server-pl> in /home/signer/cacert-devel/CommModule/.

• logclean.sh maintenance script for logfiles generated by CommModule

  The logclean.sh script performs log rotation of signer logfiles.

  discuss replacement of this script with logrotate and a custom logrotate.conf for the signer

• serial.conf serial port configuration file

  This file is read and written by both client.pl <commmodule-client-pl> and server.pl <commmodule-server-pl> therefore both cannot be run from the same directory without interfering with each other.

  add a serial.conf template and move the actual serial.conf into configuration management

• server.pl the real server, running on the signing server

  This script implements the signer (server) side of the signer protocol <signer> and performs the actual signing operations.

  The script contains a some code that is duplicated by client.pl <commmodule-client-pl>.

  Note

  The server.pl used on test.cacert.org is different from the version in the cacert-devel repository. The git origin is recorded as git://git-cacert.it-sls.de/cacert-devel.git and there are some small uncommitted changes too.

  get the versions of server.pl on git.cacert.org, the real production signer and the cacert-devel repository synchronized

• usbclient.pl obsoleted USB version of client.pl <commmodule-client-pl> above

  remove unused file (usbclient.pl)

includes

PHP

Directory includes

• .cvsignore includes the parameters for CVS, which files to ignore by versioning

• .gitignore includes the parameters for GIT, which files to ignore by versioning

• about_menu.php is a part (<div>) of a PHP-Page, containing most of the CAcert-related links.

• account_stuff.php

• account.php

• general_stuff.php

• general.php

• keygen.php

• loggedin.php

• mysql.php.sample is a template for the database connection handling code that is meant to be copied to mysql.php.

  The template defines the MySQL connection as a session variable mconn and tries to connect to that database. It also defines the session variables normalhostname, securehostname and tverify.

  The template defines a function :phpsendmail for sending mails.

  Configuration and actual code are mixed. It would be better to have a separate file that just includes configuration.

  This file is parsed by CommModule/client.pl <commmodule-client-pl> format changes might break the CommModule code.

• notary.inc.php

• shutdown.php

• sponsorinfo.php

• tverify_stuff.php

includes/lib

PHP

Directory includes/lib

• account.php

• check_weak_key.php

• general.php

• l10n.php

locale

Directory locale

C

• cv.c

PHP

• escape_special_chars.php

bash

• makefile

pages

Directory pages

This directory only contains other (sub-) directorys, structured according to specific topics.

scripts

PHP

txt

Directory scripts

WWW

PHP

Directory www

This contains the PHP code that is the entry point to the application:

• sealgen.php generates a small site seal image from www/images/secured.png <www-images-secured-png>. This could be replaced with a static image if it is used at all. This is referenced by cgi-bin/siteseal.cgi <cgi-bin-siteseal-cgi>

Directory www/images

• secured.png is a small image used by www/sealgen.php <www-sealgen-php>