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MDPF52_180608's avatar
MDPF52_180608
Icon for Nimbostratus rankNimbostratus
Feb 26, 2015

iRule hashing + trim

Hello Devcentral community,

 

Please can you tell me how to a hash a variable like the sha 512 (i store a certain parameter value by the uri ) and after that i want to keep only the last 10 characters of the sha.

 

Variable Variablehash--> hashed sha512 of $variable

 

Than, only the last 10 characters of the $Variablehash

 

One more question: how i can inspect the response page that returns to the client ( passing from the big ip ) and if a certain string in the HTML body is present than i ll generate a message ( hsl)?

 

Thanks in advance,

 

Best Regards,

 

Matteo

 

application delivery
design
devops
iRules
LTM
TMOS

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  • Brad_Parker's avatar
    Brad_Parker
    Icon for Cirrus rankCirrus
    Feb 26, 2015

    Try this for your hash variable:

    set variableHash [sha512 $variable]
set lastTenHash [string range $variableHash [expr [string length $variableHash] - 10] end]

    For your response you would need to do a 

    HTTP::collect [HTTP::header Content-Length]
    in your when HTTP_RESPONSE event and then in the HTTP_RESPONSE_DATA event you would need to inspect the HTTP::payload for your string probably using scan. Be weary, that this will collect the whole payload of every response which could be a performance hit to the application.

    https://devcentral.f5.com/wiki/iRules.HTTP_RESPONSE_DATA.ashx