Difference between revisions of "Short Notes on Security"

Revision as of 16:22, 3 July 2011

Apache

Note - serving of local files

Note: Often the initial installation of Apache has <Directory /> directive (directive for the root of the filesystem) set to "Allow from All", in [Apache config dir]/sites-available/default! This means that server can server any file from the file system, not just the files in the htdocs document folder, which you typically want!

To avoid this, simply change this to "Deny from All".

Enable SSL/HTTPS in Apache

HowTo: Use the following virtual host definition:

<VirtualHost *:443>
ServerName ssl-name
DocumentRoot /var/www/ssl/root
SSLEngine on
SSLCertificateFile /etc/apache2/server.crt
SSLCertificateKeyFile /etc/apache2/server.key
SetEnvIf User-Agent ".*MSIE.*" nokeepalive ssl-unclean-shutdown
</VirtualHost>

where certificate file and the certificate key file are either authority-signed or self-signed certificate files (see below), and add

NameVirtualHost *:443
Listen 443

to /etc/apache2/ports.conf and restart Apache.

Other

Password Generators

• PHP - replace the '16' with length of the generated password (28 is most you can get):

$password = substr(str_replace(array('$1$', '$2$', '$2a$', '$', '.', '/'), '', crypt(php_uname() . microtime())), 0, 16);

or, terminal version:

$ php -r "echo substr(str_replace(array('$1$', '$2$', '$2a$', '$', '.', '/'), '', crypt(php_uname() . microtime())), 0, 16);"; echo
1hlNxRwBr4mCZWQF

• Bash - replace the '64' with length of the generated password (no real limit here), and change the characters class in tr -d as you please, to control what characters can be contained in the password; the characters class presented here are all characters that are treated as a part of the word in terminal (i.e. you can double-click the word and it gets selected as a whole):

$ cat /dev/urandom | tr -d -c "a-zA-Z0-9@#%&\-\_+=:,.?/" | head -c 64; echo
uQ,XGSG4qPtE4.&UQT,jPA#=a8j-mhy+qjQUg:m#s7g1@c2-#J8D-,3zQFd+o_-W

External Links

Apache

• .htaccess files in Apache2
• htpasswd utility in Apache2
• Authentication, Authorization and Access Control in Apache2
• How to create your own (aka self-signed) SSL Certificate

Other

• How To scp, ssh and rsync without prompting for password