Monday, August 01, 2011

SSL in Tomcat under Eclipse (part 1 - self signed certificate)

  • installed Java (description here)
  • installed and configured Eclipse (description here)
  • installed and configured Tomcat for the Eclipse (description here)
You will learn:
  • how to set up Tomcat for SSL connection using self signed certificate under Eclipse
When You want to secure Your application SSL is the most natural choice. In order to make Your application be recognized as trusted by browser, You can by a buy a certificate from well known certificate authority (CA), which will be generated for the domain Your application uses. If You do not care about being recognized as trusted service, but instead You just want to encrypt the data exchanged between server and client's browser, You can use Your own self signed SSL certificate. In this post I will show how to generate such SSL certificate and how to set up Tomcat (from the Eclipse level) to use generated certificate.

Note: let's assume that You created an application which is going to be visible under the following URL:

Step 1: generating self signed certificate for domain

Go into Your Java bin directory (i.e C:\Development\Java\bin). Then open Windows console (under Windows Vista/7 open the console with Administrator right) and type in command:

keytool -genkey -alias myappcert -keyalg RSA -keystore myapp.keystore

where myappcert is the name of the certificate being generated and myapp.keystore is a file where certificate will be stored. You will be asked about the password for created the myapp.keystore file. Type in "mypass", press Enter and type it again and press Enter again. Then You will be asked for some details about You:

Please note that for the first question about first and last name I gave answer This is very important - this name (known as CN - Common Name) will be used for the checking if certificate on the page we visit was generated for the same URL which we typed in in the browser.
At the end You will be asked for the password for the newly created certificate. The password must be the same as one used for myapp.keystore file ("mypass"). Do not type antyhing, just press Enter to use the same password. Your myapp.keystore file containing myappcert certificate is ready.

Step 2: copy Your myapp.keystore file into Tomcat's /conf directory

Step 3:  modify Tomcat configuration to use SSL certificate.

Make sure that Your Tomcat is configured with Eclipse and works OK without SSL (start Tomcat from Eclipse and type in http://localhost:8080 in the browser). Stop Tomcat if it is running. Then open server.xml file form the "Servers" view:

and locate default element for standard HTTP connections (marked red). Then add additional element for the SSL connection (next to existing one):

Please note that next to some specific SSL settings, we set the location of the keystore file, the password for that file and certificate name to be use. SSL connection uses port 8081, where normal HTTP connection
uses port 8080.

Note 1: all modification of server.xml file were done from Eclipse level, using "Servers" view. If You want to use Eclipse WTP for starting Tomcat (like I do so far) You can't edit this file from elsewhere. Eclipse WTP overrides original Tomcat configuration files by files visible under "Servers" - changes done outside Eclipse will not be visible for WTP.

Note 2: I added element specific for SSL next to existing element for standard non encrypted HTTPS connections. This is second issue directly connected with Eclipse WTP - when You remove standard connector for HTTP, Eclipse will close Tomcat after a time set in "Timeouts" section in the Tomcat settings:

Some people try to extend the timeout time into long period, but still after this period Eclipse kills Tomcat process, as if Tomcat was not properly started in the required time. Unfortunately there is no way to set timeout into ifinite time - the only way to fix this under WTP is to leave standard HTTP element in Tomcat's server.xml file.

Step 4: that's all. Tomcat is configured to work with SSL. 

Try to enter the URL: https://localhost:8081. If You see Tomcat's page, everything works OK (You can see certificate warning - You Need to add security exception for that certificate). Of course You can still open the same Tomcat page by standard HTTP (You have two elements), just enter http://localhost:8080 URL.


Anonymous said...

very nice tutorial, thanks a lot

Alex Petrik said...

if anyone has issues loading the keystore cert. try the below: