ADC

Cipher redirection

During the SSL handshake, the SSL client (usually a web browser) announces the suite of ciphers that it supports, in the configured order of cipher preference. From that list, the SSL server then selects a cipher that matches its own list of configured ciphers.

If the ciphers announced by the client does not match the ciphers configured on the SSL server, the SSL handshake fails. The failure is announced by a cryptic error message displayed in the browser. These messages rarely mention the exact cause of the error.

With cipher redirection, you can configure an SSL virtual server to deliver accurate, meaningful error messages when an SSL handshake fails. When an SSL handshake fails, the ADC appliance redirects the user to a previously configured URL or, if no URL is configured, displays an internally generated error page.

Configure cipher redirection by using the CLI

At the command prompt, type the following commands to configure cipher redirection and verify the configuration:

-  set ssl vserver <vServerName> -cipherRedirect < ENABLED | DISABLED> -cipherURL < URL>  
-  show ssl vserver <vServerName>
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Example:

set ssl vserver vs-ssl -cipherRedirect ENABLED -cipherURL http://redirectURl

Done

show ssl vserver vs-ssl

Advanced SSL configuration for VServer vs-ssl:
DH: DISABLED
Ephemeral RSA: ENABLED          Refresh Count: 1000
Session Reuse: ENABLED          Timeout: 600 seconds
Cipher Redirect: ENABLED        Redirect URL: http://redirectURl
SSLv2 Redirect: DISABLED
ClearText Port: 0
Client Auth: DISABLED
SSL Redirect: DISABLED
Non FIPS Ciphers: DISABLED
SNI: DISABLED
OCSP Stapling: DISABLED
HSTS: DISABLED
HSTS IncludeSubDomains: NO
HSTS Max-Age: 0
SSLv2: DISABLED SSLv3: ENABLED  TLSv1.0: ENABLED TLSv1.2: ENABLED  TLSv1.2: ENABLED
    1)      CertKey Name: Auth-Cert-1       Server Certificate
    1)      Cipher Name: DEFAULT
            Description: Predefined Cipher Alias
Done
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Configure cipher redirection by using the GUI

  1. Navigate to Traffic Management > Load Balancing > Virtual Servers, and open a virtual server.
  2. In the SSL Parameters section, select Enable Cipher Redirect, and specify a redirect URL.
Cipher redirection