Difference between revisions of "Configuring multiple SSL sites"

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RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
</pre>
</pre>
then it will not work.  The reason being the values would have gone by HTTP before server could redirect client to HTTPS and hence they would get leaked anyway.  The issue is described http://stackoverflow.com/questions/4083221/how-to-redirect-all-http-requests-to-https and http://stackoverflow.com/questions/4070262/how-in-htaccess-can-i-redirect-the-user-to-https-from-http-and-back-again/4071655#4071655  Best is to write application to support HTTPS or to redirect HTTP base to HTTPS base and hope application does not breaks the security through various links.  Another way using configuration has been used in [[Forcing HTTPS for redmine]]
then it will not work for the first request, which is typically displaying of login page.  But if the website supports cookies and remembers login through non-secure cookies then those cookies would end-up being transmitted in plain-text before redirection to HTTPS takes effect.   


The issue is described http://stackoverflow.com/questions/4083221/how-to-redirect-all-http-requests-to-https and http://stackoverflow.com/questions/4070262/how-in-htaccess-can-i-redirect-the-user-to-https-from-http-and-back-again/4071655#4071655  Another way using configuration has been used in [[Forcing HTTPS for redmine]]
==Forcing HTTPS redirection while supporting mod_proxy==
Note that this configuration would also break any ProxyPass configurations done to Proxy requests to above server.  For example consider two server public-http and issues.  If issues server is configured as explained here to redirect all non-https requests as https and public-http server is configured to ProxyPass all requests coming for issues to issues server then this configuration wont work.  This is because when public-http passes requests to issues server, issues server will redirect even public-http servers requests to HTTPS.  But mod_proxy does not supports HTTPS so it would use HTTP again which would result into infinite loop of redirections.
To solve this one can use following configuration:
<pre>
RewriteEngine On
RewriteCond %{HTTPS} !on
RewriteCond %{REMOTE_HOST} !&lt;ip&gt;
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}  [R,L]
</pre>
where, &lt;ip&gt; can be replaced with IP of public-http server as seen by issues server.  In this case the redirection to HTTPS wont apply when requests are coming from public-http server.  For HTTPS security the redirection to HTTPS configuration can be done on public-http server so that it receives requests meant for issues server through HTTPS.


<yambe:breadcrumb self="Configuring mod gnutls">Apache web server configuration</yambe:breadcrumb>
<yambe:breadcrumb self="Configuring mod gnutls">Apache web server configuration</yambe:breadcrumb>

Revision as of 03:00, 4 March 2013

<yambe:breadcrumb self="Configuring mod gnutls">Apache web server configuration</yambe:breadcrumb>

Configuring mod gnutls so that we can have HTTPS virtual hosts in apache

mod_gnutls allows us to have multiple HTTPS virtual hosts on same physical server with single IP address and multiple domain names. The certificate should be wildcard certificate like for *.iiit.ac.in, so that we can host any hostname with suffix iiit.ac.in with same certificate.

Installing and configuring mod_gnutls on Cent-OS

  1. Install libgpg-error from ftp://ftp.gnupg.org/gcrypt/libgpg-error
  2. Compile and install libgcrypt from source. Take libgcrypt from ftp://ftp.gnupg.org/gcrypt/libgcrypt
  3. rm /usr/lib64/httpd/modules/*tls*
  4. cp /usr/lib64/libgnutls* /usr/lib64/httpd/modules/
  5. Configure and make mod_gnutls from http://linux.wareseeker.com/download/mod-gnutls-0.2.0.rar/319193. Do not make install
  6. cp src/.libs/libmod_gnutls.so /usr/lib64/httpd/modules/
  7. cp data/{rsa,dh}file /etc/httpd/conf (Very important step. Do not miss)
  8. cd /usr/lib64/httpd/modules/
  9. mv libmod_gnutls.so mod_gnutls.so
  10. Put LoadModule gnutls_module modules/mod_gnutls.so in /etc/httpd/conf/httpd.conf
  11. Put 
    AddType application/x-x509-ca-cert .crt
    

    AddType application/x-pkcs7-crl    .crl
    in /etc/httpd/conf/httpd.conf
  12. mkdir -m 0700 /var/cache/mod_gnutls_cache
  13. chown apache:apache /var/cache/mod_gnutls_cache
  14. Put 
    GnuTLSCache dbm "/var/cache/mod_gnutls_cache"
    

    GnuTLSCacheTimeout 300
    in /etc/httpd/conf/httpd.conf
  15. Do configuration in /etc/httpd/conf/httpd.conf for 443 virtualhosts like 
    NameVirtualHost *:443
    

    <VirtualHost *:443>
    

    ServerAdmin a@b.com
    

    DocumentRoot /home/test1/html
    

    ServerName test1.barjatiya.com
    

    ErrorLog logs/test1.barjatiya.com-error_log
    

    CustomLog logs/test1.barjatiya.com-access_log common
    

    SSLEngine on
    

    SSLProtocol all -SSLv2
    

    SSLCipherSuite ALL:!ADH:!EXPORT:!SSLv2:RC4+RSA:+HIGH:+MEDIUM:+LOW
    

    SSLCertificateFile /etc/httpd/conf/test1.pem
    

    </VirtualHost>
    where Certificate can be generated using openssl req -new -x509 -days 999 -nodes -out apache.pem -keyout apache.pem
    Do chown root:apache /etc/httpd/conf/httpd.conf and chmod 640 /etc/httpd/conf/httpd.conf so that normal users cannot read httpd.conf file when using virtual hosting
  16. Comment VirtualHost setting in /etc/httpd/conf.d/ssl.conf


Configuring apache for SSL virtual-hosting using httpd.conf and ssl.conf modification

To configure SSL virtual-hosting without mod_gnutls one can use following steps:

  1. Install mod_ssl using 'yum -y install mod_ssl'
  2. Rename '/etc/httpd/conf.d/ssl.conf' to '/etc/httpd/conf.d/ssl_backup' to effectively disable the configuration
  3. Edit '/etc/httpd/conf/httpd.conf' file and append following configuration 
    LoadModule ssl_module modules/mod_ssl.so
    

    Listen 443
    

    SSLPassPhraseDialog  builtin
    

    SSLSessionCache         shmcb:/var/cache/mod_ssl/scache(512000)
    

    SSLSessionCacheTimeout  300
    

    SSLMutex default
    

    SSLRandomSeed startup file:/dev/urandom  256
    

    SSLRandomSeed connect builtin
    

    SSLCryptoDevice builtin
    

    NameVirtualHost *:443
    

    

    <VirtualHost *:443>
    

    

    <Appropriate virtual-host configuration>
    

    

    SSLEngine on
    

    SSLProtocol all -SSLv2
    

    SSLCipherSuite ALL:!ADH:!EXPORT:!SSLv2:RC4+RSA:+HIGH:+MEDIUM:+LOW
    

    SSLCertificateFile <full-path-of-certificate-file>
    

    SSLCertificateKeyFile <full-path-of-key-file>
    

    </VirtualHost>


Working of HTTPS

During a HTTPS communication first a secure channel is established which required exchange of certificates. Since the client has not sent any request yet, server has no idea for which virtual host is the request going to come. Hence only one generic wildcard certificate is returned. After secure channel is established using the wildcard certificate, the client send HTTPS request and server sends HTTPS response. Now based on the domain name present in request appropriate virtual host is contacted and response is sent. Hence we cannot have HTTPS virtual hosts of two different domains on same apache server.


Forcing redirect of all HTTP requests to HTTPS

One can attempt trying to redirect all HTTP requests to HTTPS automatically using: 

RewriteEngine On
RewriteCond %{HTTPS} !on
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}

then it will not work for the first request, which is typically displaying of login page. But if the website supports cookies and remembers login through non-secure cookies then those cookies would end-up being transmitted in plain-text before redirection to HTTPS takes effect.

The issue is described http://stackoverflow.com/questions/4083221/how-to-redirect-all-http-requests-to-https and http://stackoverflow.com/questions/4070262/how-in-htaccess-can-i-redirect-the-user-to-https-from-http-and-back-again/4071655#4071655 Another way using configuration has been used in Forcing HTTPS for redmine


Forcing HTTPS redirection while supporting mod_proxy

Note that this configuration would also break any ProxyPass configurations done to Proxy requests to above server. For example consider two server public-http and issues. If issues server is configured as explained here to redirect all non-https requests as https and public-http server is configured to ProxyPass all requests coming for issues to issues server then this configuration wont work. This is because when public-http passes requests to issues server, issues server will redirect even public-http servers requests to HTTPS. But mod_proxy does not supports HTTPS so it would use HTTP again which would result into infinite loop of redirections.

To solve this one can use following configuration: 

RewriteEngine On
RewriteCond %{HTTPS} !on
RewriteCond %{REMOTE_HOST} !<ip>
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}  [R,L]

where, <ip> can be replaced with IP of public-http server as seen by issues server. In this case the redirection to HTTPS wont apply when requests are coming from public-http server. For HTTPS security the redirection to HTTPS configuration can be done on public-http server so that it receives requests meant for issues server through HTTPS.


<yambe:breadcrumb self="Configuring mod gnutls">Apache web server configuration</yambe:breadcrumb>

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