Apache

Intro

Source: vogella.com

Basics

• List the available modules of the Apache HTTP server

apache2 -l

• Main configuration file for the Apache Http server

/etc/apache2/apache2.conf

• The error log of Apache is located in the

/var/log/apache2/error.log
grep MaxClients /var/log/apache2/error.log

Multi-Processing-Module

Apache HTTP can run in different modes. MPM modes determine how the web requests of users are answered.

• The selected mode is compiled into the server and can be checked with:

sudo apachectl -V | grep -i mpm

• Configuration for the event mpm is stored in below file:

Configure only the module which your server is using.

/etc/apache2/mods-available/mpm_event.conf

htaccess

One major application of this file is to redirect an URL to other URL’s.

• The following .htacess file reroutes http://vogella.com to http://www.vogella.com.
• It also redirect access to a certain webpage (/articles/SpringFramework/article.html) to another webpage via a 301 redirect.
• The 301 redirect will tell search engines that this side has moved and is the recommended way to move webpages.

RewriteEngine on
RewriteCond %{HTTP_HOST} !^www\.vogella\.de$
RewriteRule ^(.*)$ http://www.vogella.com/$1 [L,R=301]
redirect 301 /articles/SpringFramework/article.html http://www.vogella.com/tutorials/SpringDependencyInjection/article.html

Using modules

Apache Http supports the usage of modules. To enable modules use the a2enmod command

a2enmod rewrite

Gzip compression

To optimize the download time of your webpages you can turn on gzip compression. This requires the Apache module "mod_deflate":

a2enmod deflate
/etc/init.d/apache2 restart

The compression can be activated in the default configuration file for this module located in /etc/apache2/mods-available/deflate.conf or via the ".htaccess" file.

# compress all text & html:
AddOutputFilterByType DEFLATE text/plain
AddOutputFilterByType DEFLATE text/html
AddOutputFilterByType DEFLATE text/xml
AddOutputFilterByType DEFLATE text/css
AddOutputFilterByType DEFLATE application/xml
AddOutputFilterByType DEFLATE application/xhtml+xml
AddOutputFilterByType DEFLATE application/rss+xml
AddOutputFilterByType DEFLATE application/javascript
AddOutputFilterByType DEFLATE application/x-javascript

Other modules Supporting php and wordpress

sudo apt-get install libapache2-mod-fcgid
sudo apt-get install php5-cgi

Afterwards activate the corresponding modules:

sudo a2enmod fastcgi
sudo a2enmod proxy
# required for wordpress blog
sudo a2enmod rewrite

This section is under construction.

Certificates

Source: sslshopper.com

General OpenSSL Commands

• Generate a new private key and Certificate Signing Request

openssl req -out CSR.csr -new -newkey rsa:2048 -nodes -keyout privateKey.key

• Generate a self-signed certificate (see How to Create and Install an Apache Self Signed Certificate for more info)

openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -keyout privateKey.key -out certificate.crt

• Generate a certificate signing request (CSR) for an existing private key

openssl req -out CSR.csr -key privateKey.key -new

• Generate a certificate signing request based on an existing certificate

 openssl x509 -x509toreq -in certificate.crt -out CSR.csr -signkey privateKey.key

• Remove a passphrase from a private key

openssl rsa -in privateKey.pem -out newPrivateKey.pem

Checking Using OpenSSL

• Check a Certificate Signing Request (CSR)

openssl req -text -noout -verify -in CSR.csr

• Check a private key

openssl rsa -in privateKey.key -check

• Check a certificate

openssl x509 -in certificate.crt -text -noout

• Check a PKCS#12 file (.pfx or .p12)

openssl pkcs12 -info -in keyStore.p12

Debugging Using OpenSSL

• Check an MD5 hash of the public key to ensure that it matches with what is in a CSR or private key

openssl x509 -noout -modulus -in certificate.crt | openssl md5
openssl rsa -noout -modulus -in privateKey.key | openssl md5
openssl req -noout -modulus -in CSR.csr | openssl md5

• Check an SSL connection. All the certificates (including Intermediates) should be displayed

openssl s_client -connect www.paypal.com:443

Converting Using OpenSSL

• Convert a DER file (.crt .cer .der) to PEM

openssl x509 -inform der -in certificate.cer -out certificate.pem

• Convert a PEM file to DER

openssl x509 -outform der -in certificate.pem -out certificate.der

• Convert a PKCS#12 file (.pfx .p12) containing a private key and certificates to PEM

openssl pkcs12 -in keyStore.pfx -out keyStore.pem -nodes

You can add -nocerts to only output the private key or add -nokeys to only output the certificates.

• Convert a PEM certificate file and a private key to PKCS#12 (.pfx .p12)

openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt

References

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