Configuring Transport Level Security

Given below are the various transport-level security configurations that are required for WSO2 EI. See the following topics for instructions.

Enabling TLS and disabling SSL support

The transport-level security protocol of the Tomcat server is configured in the /conf/tomcat/catalina-server.xml file. By default, "TLS" is configured as the SSL protocol for HTTPS communication by setting the sslProtocol="TLS" attribute in the catalina-server.xml file. Specifying TLS as the SSL protocol ensures that all TLS versions, as well as SSL protocol versions, are supported. However, due to the Poodle Attack, it is necessary to make sure that only TLS protocol versions are enabled.

Note that in some WSO2 products, such as WSO2 Enterprise Integrator's ESB profile, the pass-thru transport is enabled. Therefore, to disable SSL in such products, the axis2.xml file stored in the /conf/axis2/ directory should also be configured.

Disabling SSL support for products with JDK 1.8

Follow the steps given below to disable SSL support for the Tomcat layer.

1. Open the /conf/tomcat/catalina-server.xml file. 
2. Make a backup of the catalina-server.xml file and stop the product server.

3. Find the Connector configuration corresponding to TLS (usually, this connector has the port set to 9443 and the sslProtocol as TLS). Remove the sslProtocol="TLS" attribute and replace it with sslEnabledProtocols="TLSv1,TLSv1.1,TLSv1.2" as shown below.

   <Connector protocol="org.apache.coyote.http11.Http11NioProtocol"
                   port="9443"
                   bindOnInit="false"
                   sslEnabledProtocols="TLSv1,TLSv1.1,TLSv1.2" 

4. Start the server.

5. To verify that the configurations are all set correctly, download and run the TestSSLServer.jar.

   java -jar TestSSLServer.jar localhost 9443

   The output of the command after disabling SSL is shown below.

   Supported versions: TLSv1.0
   Deflate compression: no
   Supported cipher suites (ORDER IS NOT SIGNIFICANT):
     TLSv1.0
        RSA_EXPORT_WITH_RC4_40_MD5
        RSA_WITH_RC4_128_MD5
        RSA_WITH_RC4_128_SHA
        RSA_EXPORT_WITH_DES40_CBC_SHA
        RSA_WITH_DES_CBC_SHA
        RSA_WITH_3DES_EDE_CBC_SHA
        DHE_RSA_EXPORT_WITH_DES40_CBC_SHA
        DHE_RSA_WITH_DES_CBC_SHA
        DHE_RSA_WITH_3DES_EDE_CBC_SHA
        RSA_WITH_AES_128_CBC_SHA
        DHE_RSA_WITH_AES_128_CBC_SHA
        RSA_WITH_AES_256_CBC_SHA
        DHE_RSA_WITH_AES_256_CBC_SHA

If you have enabled the PassThrough transport, do the following:

1. Stop the server.

2. Open the <PRODUCT_HOME>/conf/axis2/axis2.xml file and add the specified parameter under the <transportReceiver name="https" class="org.apache.synapse.transport.passthru.PassThroughHttpSSLListener"> element as well as under the <transportSender name="https" class="org.apache.synapse.transport.passthru.PassThroughHttpSSLSender"> element. If you are using JDK 1.8, you can add the following parameter:

   <parameter name="HttpsProtocols">TLSv1,TLSv1.1,TLSv1.2</parameter> 

   • If you are using JDK 1.6, add the following parameter:

     <parameter name="HttpsProtocols">TLSv1</parameter> 

   • If you are using JDK 1.7, add the following parameter:

     <parameter name="HttpsProtocols">TLSv1,TLSv1.1,TLSv1.2</parameter> 

   • If you are using JDK 1.8, add the following parameter:

     <parameter name="HttpsProtocols">TLSv1,TLSv1.1,TLSv1.2</parameter> 

3. Start the server.

4. Test the pass-through transport using the following command with the corresponding port:

   java -jar TestSSLServer.jar localhost 8243

Enabling SSL protocols and ciphers in ThriftAuthenticationService

Do the following to enable SSL protocols and ciphers in the ThriftAuthenticationService.

1. Add the following configurations in the /conf/identity/thrift-authentication.xml file as sub-elements of the root <Server> element.

   <SSLEnabledProtocols>TLSv1,TLSv1.1,TLSv1.2</SSLEnabledProtocols
   <Ciphers>TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_DHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_DHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_DHE_RSA_WITH_AES_128_GCM_SHA256</Ciphers>

   Tip: You can also add the following additional cipher suites to the <Ciphers> property if JCE Unlimited Strength Jurisdiction Policy is enabled in Java.

   TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,TLS_DHE_RSA_WIT

   If you wish to remove TLSv1 or TLSv1.1, you can do so by removing them as values from the <SSLEnabledProtocols> property.

2. Restart the server. 

Enabling TLSv1.1/TLSv1.2 for products with JDK 1.7

The TLS protocol is set to TLSv1.0 (by default) in WSO2 products running on JDK 1.7. You cannot configure this using the catalina-server.xml file or the axis2.xml file as we do with products based on JDK 1.7. Therefore, you need to enable TLSv1.1 and TLSv1.2 globally by setting a system property.

1. Download the following artifacts:
   • wso2-ssl-socket-factory-provider-1.0.0.jar
     
   • wso2-ssl-security
2. Copy the wso2-ssl-socket-factory-provider-1.0.0.jar file to the <PRODUCT_HOME>/lib/endorsed directory.
3. Copy the wso2-ssl-security file to the <PRODUCT_HOME>/repository/conf/ directory.

4. Open the product startup script (wso2server.sh for Linux, or wso2server.bat for Windows), which is stored in the <PRODUCT_HOME>/bin directory.

5. Add the following system properties to the script:

   -Djdk.tls.client.protocols="TLSv1.1,TLSv1.2" \
   -Djava.security.properties="$CARBON_HOME/repository/conf/wso2-ssl-security" \

6. Start the server.

Disabling weak ciphers

A cipher is an algorithm for performing encryption or decryption. When you set the sslprotocol of your server to TLS, the TLS and the default ciphers get enabled without considering the strength of the ciphers. This is a security risk as weak ciphers, also known as EXPORT ciphers, can make your system vulnerable to attacks such as the Logjam attack on Diffie-Hellman key exchange. The Logjam attack is also called the Man-in-the-Middle attack. It downgrades your connection's encryption to a less-secured level (e.g., 512 bit) that can be decrypted with sufficient processing power.

To prevent these types of security attacks, it is encouraged to disable the weak ciphers. You can enable only the ciphers that you want the server to support in a comma-separated list in the ciphers  attribute. Also, if you do not add this cipher attribute or keep it blank, the browser will support all the SSL ciphers by JSSE. This will enable the weak ciphers.

Disabling weak ciphers for the Tomcat transport

1. Open the /conf/tomcat/catalina-server.xml file.
2. Make a backup of the catalina-server.xml  file and stop the server.

3. Add the cipher  attribute to the existing configuration in the catalina-server.xml file by adding the list of ciphers that you want your server to support as follows: ciphers="<cipher-name>,<cipher-name>". See the example given below.

   For Tomcat version 7.0.59 and JDK version 1.7:
   ciphers="TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_DHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_DHE_RSA_WITH_AES_128_CBC_SHA"  
   
   For Tomcat version 7.0.59 and JDK version 1.8:
   ciphers="TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_DHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_DHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_DHE_RSA_WITH_AES_128_GCM_SHA256"

   See the list of supported cipher suites.

4. Start the server.

5. To verify that the configurations are all set correctly, download and run the TestSSLServer.jar.

   $ java -jar TestSSLServer.jar localhost 9443

   Note the following when you run TestSSLServer.jar:

   • The "Supported cipher suites" section in the output does not contain any EXPORT ciphers.

   • When you use the supported cipher suites listed here, the BEAST attack status will be shown as vulnerable. Note that this is a client-side vulnerability caused by the TLSv1 protocol. You can make the BEAST status protected by removing TLSv1, which will make clients with TLSv1 unusable. Therefore, it is recommended to fix this from the client side.

Disables weak ciphers for the PassThrough transport

Remove any weak ciphers from the PassThrough transport and ensure that the server does not accept connections using those weak ciphers. The PassThrough transport is configured using the axis2.xml file (stored in the /conf/axis2/  directory). 

1. Open the /conf/axis2/axis2.xml  file.
2. Make a backup of the axis2.xml  file and stop the WSO2 product server.

3. You need to add the PreferredCiphers parameter under the "Transport Ins (Listeners)" section along with the list of relevant cipher suites.

   <parameter name="PreferredCiphers">TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_DHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_DHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_DHE_RSA_WITH_AES_128_GCM_SHA256</parameter>

4. Start the server.

5. Test the pass-through transport using the following command with the corresponding port:

   $ java -jar TestSSLServer.jar localhost 8243

Changing the server name in HTTP response headers

By default, all WSO2 products pass "WSO2 Carbon Server" as the server value in HTTP headers when sending HTTP responses. This means that information about the WSO2 product stack will be exposed through HTTP responses. It is recommended to change this by configuring the server name in the catalina-server.xml file.

1. Open the /conf/tomcat/catalina-server.xml file.

2. Add a new server name using the server property (under the relevant Tomcat connector configuration):

   server="WSO2 Carbon Server"