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Disable SSL version 3 on Carbon server

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.

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  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

Disable weak ciphers in Carbon server

A cipher is an algorithm for performing encryption or decryption. When the sslprotocol is set to "TLS", only the TLS and default ciphers are enabled by default. However, note that the strength of the ciphers will not be considered when they are enabled. Therefore, to disable the weak ciphers, you must ensure that only the ciphers you want your server to support are entered for the ciphers attribute in a comma-separated list. Also, if you do not add this cipher attribute or keep it blank, all SSL ciphers by JSSE will be supported by your server, thereby enabling the weak ciphers.

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