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Louis27's avatar
Louis27
Icon for Nimbostratus rankNimbostratus
Jun 09, 2022

Remove values in the payload

Hello, I am new to the F5 iRules. I need to remove all the values of '<pan>' in the 'HTTP::payload', either remove all the tags '<pan>' too. The structure is as below.  This '<pan>' can exsit o...
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JRahm's avatar
JRahm
Icon for Admin rankAdmin
Jun 09, 2022

I'm not sure I follow exactly, are you trying to do this:

 

<card>
   <expDate>[string]</expDate>
        <plainPan>[string?]</plainPan>
</card>
<card>
    <expDate>[string]</expDate>
         <plainPan>[string?]</plainPan>
</card>

 

or this:

 

<card>
   <expDate>[string]</expDate>
</card>
<card>
    <expDate>[string]</expDate>
</card>

 

If the first, you can do that with a simple stream profile:

ltm profile stream pan_test_stream {
    app-service none
    defaults-from stream
    target "@<pan>@@ @</pan>@@"
}

If the latter, an html content profile should work, but I haven't done that before. Something to look into before thinking about regex.

 

  • Louis27's avatar
    Louis27
    Icon for Nimbostratus rankNimbostratus
    Jun 13, 2022

    Hello JRahm,  Thanks for your response. 

    What I want to do is the second one as you mentioned. 
    I have tried 'html content' with this article https://support.f5.com/csp/article/K99872325, it doesn't work. It seems that 'html content profile' is only for modify HTML content sent in responses from the back-end servers. 

    What I want is to modify the request . Do you have any suggestion about  that?

    By the way， the request is in the format xml SOAP as below:

     

    <Envelope xmlns="http://schemas.xmlsoap.org/soap/envelope/">
    <Body>
            <cardsData>
                <card>
                    <expDate>[string]</expDate>
                    <pan>
                        <plainPan>[string?]</plainPan>
                    </pan>
                </card>
                <card>
                    <expDate>[string]</expDate>
                    <pan>
                        <plainPan>[string?]</plainPan>
                    </pan>
                </card>
               can exist serveral cards
    </Body>
</Envelope>

     

    Thank you in advance.

    • JRahm's avatar
      JRahm
      Icon for Admin rankAdmin
      Jun 13, 2022

      Yeah, I found that out myself on the HTML profile, couldn't get it to work on request traffic. What's your virtual server setup look like regarding profiles? Might need to do some payload manipulation in iRules.

    • JRahm's avatar
      JRahm
      Icon for Admin rankAdmin
      Jun 13, 2022

      Try this stream profile on your virtual server:

      ltm profile stream pantest_stream {
    app-service none
    chunking enabled
    defaults-from stream
    target @<pan>(.*\?)<\\/pan>@@
}

      My test request on the clientside of BIG-IP:

      And on the server-side:

      Ignore the card(n) and string(n)...I added those while troubleshooting my failed attempts! 🙂

      • Louis27's avatar
        Louis27
        Icon for Nimbostratus rankNimbostratus
        Jun 14, 2022

        Hello, JRahm Thanks again for your reponse, you are so warm hearted.

        I didn't find the way your created stream.

         

        ltm profile stream pantest_stream {
    app-service none
    chunking enabled
    defaults-from stream
    target @<pan>(.*\?)<\\/pan>@@
}

         

        I've tried my side with graphic configuration stream as below:

        source I put '<pan>(.*\?)<\\/pan>', and nothing for target. chunk deactivated.

        and then activate this stream profile dans virtuel server like this:

        After that I checked the data receieved on the server side, it doesn't change anything. There is still 'pan'. Do I miss anything?

        PS: 'plainPanRemoved' is done by our app to remove sensitive data.

        I also tried with iRules,  the back-end throws directly 'Error reading XMLStreamReader'.

         

        when HTTP_REQUEST {
	# Verify Content-length, POST, URI
    if { [HTTP::header exists Content-length] and [HTTP::method] equals "POST" and [string tolower [HTTP::uri]] contains "/endPointName"}{
	
		# Verify if the request is CreateWalletReq 
		if { [HTTP::payload] contains "<CreateWalletReq"} {        
		
	   # Remove PAN
            STREAM::expression {@<pan>(.*\?)<\\/pan>@@}
	    STREAM::enable

		}
	}
}


when HTTP_RESPONSE {
    STREAM::disable
}

         


        Thanks again.