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Forum Discussion

dubdub's avatar
dubdub
Icon for Nimbostratus rankNimbostratus
Oct 26, 2011

HTTP::payload replace length

Hi all, I used Colin's excellent example of replacing outbound payload content at http://devcentral.f5.com/Tutorials/...Rules.aspx - but was curious, that last line where it says: HTTP::payloa...
application delivery
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devops
iRules
Michael_Yates's avatar
Michael_Yates
Icon for Nimbostratus rankNimbostratus
Oct 26, 2011
If you edit the payload and do not correct the length then you can get mismatch errors which would tell the client that the data has been tampered with. Some systems like the ASM will flag or even block this.

 

 

Colin followed the formula: HTTP::payload replace

 

http://devcentral.f5.com/wiki/iRules.HTTP__payload.ashx

 

 

HTTP::payload replace 0 [string length $newPayload] $newPayload

 

 

HTTP::payload

 

replace - Offset 0

 

string length $newPayload - Returns a decimal string giving the number of characters in string

 

$newPayload - Payload

 

 

Hope this helps.