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Thiyagu's avatar
Thiyagu
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Jun 10, 2019

Need help in disabling the weak ciphers in Client SSL profile

Hello All,

I'm working to disable exporting of weak cipher suties from LTM using Client SSL profile. For example I want to disable the below cipher sutite:

TLS_RSA_WITH_AES_256_GCM_SHA384 (0x9d) then what could be be the ciphers to use in client SSL profile to not export this sipher suites.

 

Could you also share any article which will help to learn on this?

 

Regards,

Thiyagu

2 Replies

  • ​Hello

    Configure cipher strength in your profile

    https://support.f5.com/csp/article/K13171

    Cipher List base on your release

    https://support.f5.com/csp/article/K13156

    Recopilation of KB about ciphers

    https://support.f5.com/csp/article/K8802

    KR,

    Dario.

    • Dario_Garrido's avatar
      Dario_Garrido
      Icon for MVP rankMVP

      BTW, "TLS_RSA_WITH_AES_256_GCM_SHA384 (0x9d)" is weak because of the key exchange (it's not ephemeral).

      You can configure your ciphersuite as "DEFAULT:!RSA" to avoid using not ephemeral key exchanges.

      # tmm --clientciphers DEFAULT:\!RSA
             ID  SUITE                            BITS PROT    METHOD  CIPHER    MAC     KEYX
       0:   159  DHE-RSA-AES256-GCM-SHA384        256  TLS1.2  Native  AES-GCM   SHA384  EDH/RSA   
       1:   158  DHE-RSA-AES128-GCM-SHA256        128  TLS1.2  Native  AES-GCM   SHA256  EDH/RSA   
       2:   107  DHE-RSA-AES256-SHA256            256  TLS1.2  Native  AES       SHA256  EDH/RSA   
       3:    57  DHE-RSA-AES256-SHA               256  TLS1    Native  AES       SHA     EDH/RSA   
       4:    57  DHE-RSA-AES256-SHA               256  TLS1.1  Native  AES       SHA     EDH/RSA   
       5:    57  DHE-RSA-AES256-SHA               256  TLS1.2  Native  AES       SHA     EDH/RSA   
       6:    57  DHE-RSA-AES256-SHA               256  DTLS1   Native  AES       SHA     EDH/RSA   
       7:   103  DHE-RSA-AES128-SHA256            128  TLS1.2  Native  AES       SHA256  EDH/RSA   
       8:    51  DHE-RSA-AES128-SHA               128  TLS1    Native  AES       SHA     EDH/RSA   
       9:    51  DHE-RSA-AES128-SHA               128  TLS1.1  Native  AES       SHA     EDH/RSA   
      10:    51  DHE-RSA-AES128-SHA               128  TLS1.2  Native  AES       SHA     EDH/RSA   
      11:    51  DHE-RSA-AES128-SHA               128  DTLS1   Native  AES       SHA     EDH/RSA   
      12:    22  DHE-RSA-DES-CBC3-SHA             168  TLS1    Native  DES       SHA     EDH/RSA   
      13:    22  DHE-RSA-DES-CBC3-SHA             168  TLS1.1  Native  DES       SHA     EDH/RSA   
      14:    22  DHE-RSA-DES-CBC3-SHA             168  TLS1.2  Native  DES       SHA     EDH/RSA   
      15:    22  DHE-RSA-DES-CBC3-SHA             168  DTLS1   Native  DES       SHA     EDH/RSA   
      16: 49200  ECDHE-RSA-AES256-GCM-SHA384      256  TLS1.2  Native  AES-GCM   SHA384  ECDHE_RSA 
      17: 49199  ECDHE-RSA-AES128-GCM-SHA256      128  TLS1.2  Native  AES-GCM   SHA256  ECDHE_RSA 
      18: 49192  ECDHE-RSA-AES256-SHA384          256  TLS1.2  Native  AES       SHA384  ECDHE_RSA 
      19: 49172  ECDHE-RSA-AES256-CBC-SHA         256  TLS1    Native  AES       SHA     ECDHE_RSA 
      20: 49172  ECDHE-RSA-AES256-CBC-SHA         256  TLS1.1  Native  AES       SHA     ECDHE_RSA 
      21: 49172  ECDHE-RSA-AES256-CBC-SHA         256  TLS1.2  Native  AES       SHA     ECDHE_RSA 
      22: 49191  ECDHE-RSA-AES128-SHA256          128  TLS1.2  Native  AES       SHA256  ECDHE_RSA 
      23: 49171  ECDHE-RSA-AES128-CBC-SHA         128  TLS1    Native  AES       SHA     ECDHE_RSA 
      24: 49171  ECDHE-RSA-AES128-CBC-SHA         128  TLS1.1  Native  AES       SHA     ECDHE_RSA 
      25: 49171  ECDHE-RSA-AES128-CBC-SHA         128  TLS1.2  Native  AES       SHA     ECDHE_RSA 
      26: 49170  ECDHE-RSA-DES-CBC3-SHA           168  TLS1    Native  DES       SHA     ECDHE_RSA 
      27: 49170  ECDHE-RSA-DES-CBC3-SHA           168  TLS1.1  Native  DES       SHA     ECDHE_RSA 
      28: 49170  ECDHE-RSA-DES-CBC3-SHA           168  TLS1.2  Native  DES       SHA     ECDHE_RSA 

      KR,

      Dario.