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The transport level security protocol of the Tomcat server is configured in the <PRODUCT_HOME>/conf/tomcat/catalina-server.xml file. Note that the ssLprotocol attribute is set to "TLS" by default. 
See the following topics for detailed configuration options:

Table of Contents
maxLevel3
minLevel3

...

Disabling SSL 

Info

It is necessary to disable SSL version 3 in Carbon servers because of a bug ( Poodle Attack) in the SSL version 3 protocol that could expose critical data encrypted between clients and servers. The Poodle Attack makes the system vulnerable by telling the client that the server does not support the more secure TLS (Transport Layer Security) protocol, and thereby forces it to connect via SSL 3.0. The effect of this bug can be mitigated by disabling SSL version 3 protocol for your server.

Follow the steps given below to disable SSL 3.0 support on WSO2 Carbon 4.3.0 based servers.

  1. Open the <PRODUCT_HOME>/repository/conf/tomcat/catalina-server.xml file. 
  2. Make a backup of the catalina-server.xml file and stop the Carbon server.
  3. Find the Connector configuration corresponding to TLS (usually, this connector has the port set to 9443 and the sslProtocol as TLS).

    If you are using JDK 1.6, remove

    Remove the sslProtocol="TLS" attribute

    from the configuration

    and replace it with sslEnabledProtocols="TLSv1

    " as shown below.
    Code Block
    <Connector protocol="org.apache.coyote.http11.Http11NioProtocol"
                    port="9443"
                    bindOnInit="false"
                    sslEnabledProtocols="TLSv1"
     If you are using JDK 1.7

    ,

    remove the sslProtocol="TLS" attribute from the above configuration and replace it with sslEnabledProtocols="TLSv1,

    TLSv1.1,TLSv1.2" as shown below.

    Code Block
    <Connector protocol="org.apache.coyote.http11.Http11NioProtocol"
                    port="9443"
                    bindOnInit="false"
                    sslEnabledProtocols="TLSv1,TLSv1.1,TLSv1.2" 
  4. Start the server.

    Note

    In some Carbon products, such as WSO2 ESB and WSO2 API Manager, pass-thru transports are enabled. Therefore, to disable SSL version 3 in such products, the axis2.xml file stored in the <PRODUCT_HOME>/repository/conf/axis2/ directory should also be configured.

To test if SSL version 3 is disabled:

  1. Download TestSSLServer.jar from here.
  2. Execute the following command to test the transport:

    Code Block
    java -jar TestSSLServer.jar localhost 9443 
  3. The output of the command before and after disabling SSL version 3 is shown below.
    Before SSL version 3 is disabled:

    Code Block
    Supported versions: SSLv3 TLSv1.0
    Deflate compression: no
    Supported cipher suites (ORDER IS NOT SIGNIFICANT):
      SSLv3
         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
      (TLSv1.0: idem)

    After SSL version 3 is disabled:

    Code Block
    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

...

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.

...

  1. Open the <PRODUCT_HOME>/repository/conf/tomcat/catalina-server.xml file.
  2. Make a backup of the catalina-server.xml  file and stop the WSO2 product 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>". For example,

    Code Block
    For Tomcat version 7.0.59 and JDK version 1.7:
    ciphers="SSLTLS_RSAECDHE_WITH_RC4_128_MD5,SSL_RSA_ECDSA_WITH_RC4AES_128_SHA,SSL_DHE_RSA_WITH_DES_CBC_SHA,
             SSL_DHESHA256,TLS_ECDHE_RSA_WITH_3DESAES_EDE128_CBC_SHASHA256,TLS_DHE_RSA_WITH_AES_128_CBC_SHASHA256,TLS_DHEECDHE_RSAECDSA_WITH_AES_128_CBC_SHA,
             TLS_ECDHE_RSA_WITH_AES_256128_CBC_SHA,TLS_DHE_RSA_WITH_AES_256128_CBC_SHA"  
    
    For Tomcat version 7.0.59 and JDK version 1.8:
    ciphers="SSLTLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_RC4AES_128_MD5,SSL_RSACBC_SHA256,TLS_DHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_ECDSA_WITH_RC4AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_DHE_RSA_WITH_AES_256128_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"
  4. Start the server.
  5. To verify that the configurations are all set correctly, download and run the TestSSLServer.jar.

    Code Block
    $ java -jar TestSSLServer.jar localhost 9443
  6. Note that in the output that you get, the section "Supported cipher suites" does not contain any export ciphers.

Firefox 39.0 onwards does not allow to access Web sites that support DHE with keys less than 1023 bits (not just DHE_EXPORT). 768/1024 bits are considered to be too small and vulnerable to attacks if the hacker has enough computing resources. 

Tip

Tip: To use AES-256, the Java JCE Unlimited Strength Jurisdiction Policy files need to be installed. Downloaded them from http://www.oracle.com/technetwork/java/javase/downloads/index.html.

Tip

Tip: From Java 7, you must set the jdk.certpath.disabledAlgorithms property in the <JAVA_HOME>/jre/lib/security/java.security file to jdk.certpath.disabledAlgorithms=MD2, DSA, RSA keySize < 2048. It rejects all algorithms that have key sizes less than 2048 for MD2, DSA and RSA.

Note

Note that is tip is not applicable when you are disabling weak ciphers in WSO2 Identity Server.