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 | ||||
---|---|---|---|---|
|
...
Disabling SSL
Info |
---|
It is necessary to disable SSL in Carbon servers because of a bug ( Poodle Attack) in the SSL 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. The effect of this bug can be mitigated by disabling SSL protocol for your server. |
...
- Download
TestSSLServer.jar
from here. Execute the following command to test the transport:
Code Block java -jar TestSSLServer.jar localhost 9443
The output of the command before and after disabling SSL is shown below.
Before SSL 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 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.
...
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 |