Resources and Further Reading

http://www.linuxworld.com/linuxworld/lw-1999-05/lw-05-ramparts.html

http://www.linuxgazette.com/issue34/vertes.html

http://www.redhat.com/docs/manuals/linux/RHL-7.1-Manual/ref-guide/ch-security.html

http://linuxdoc.org/LDP/solrhe/Securing-Optimizing-Linux-RH-Edition-v1.3/index.html

http://www.ssh.fi/ – The home of the original ssh project

http://www.openssl.org/ – The home of the openssl project

http://www.fressh.org/ – The home of the fressh project

http://www.redhat.com/docs/manuals/linux/RHL-7.1-Manual/custom-guide/openssh-servers.html – A guide to setting up an openssh server on Linux

http://www.kleber.net/ssh/ssh-faq.html – The secure shell FAQ

http://www.redhat.com/docs/manuals/linux/RHL-7.1-Manual/ref-guide/ch-tripwire.html – A guide to setting up Tripwire for Linux

http://www.allaire.com/DocumentCenter/Partners/ASZ_ASWPS_Securing_Apache.pdf – An Allaire document on securing Apache: clear and concise

http://www.php.net/manual/en/features.safe-mode.php – Safe mode manual section

http://www.php.net/manual/en/configuration.php – Configuration manual section

http://www.faqts.com/knowledge_base/index.phtml/fid/35 – various FAQs about securing PHP

http://mcrypt.hellug.gr/ – The home of the mcrypt library

http://www.openssl.org/ – The home of the openssl library

http://www.pgpi.com/ – The home of Pretty Good Privacy International

http://www.gnupg.org/ – The home of the GNU Privacy Guard project.
The Code Book from Anchor Books

http://www.thawte.com/certs/server/Apachepaper.html – A good document on mod_ssl, Apache and thawte certificates

http://www.linuxdoc.org/HOWTO/Secure-Programs-HOWTO/ – A howto on secure programming (not just PHP)

http://www.cert.org/advisories/CA-2000-02.html – The CERT advisory on cross-site scripting

http://www.securityfocus.org – The home of BugTraq

http://packetstorm.decepticons.org/ – The home of Packetstorm

http://www.atstake.com/research/index.html – @stake research (previously l0pht)

http://www.phrack.org/ – A hacker's ezine explaining various exploits

http://directory.google.com/Top/Computers/Security/Internet/ – Google directory of security sites