Rewrite JSON value.

[Muhannad]

Dear Experts,

I need to ask if is it possible to inject a value "deviceName": "ESSApp" in the JSON content below if i got the following value in the "formName": "P59MBLVR_W59MBLVRE" value, in mean rerwite the http request when it is forwarded to the real application server (node).

POST /xxx/formservice HTTP/1.1

Content-Type: application/json; charset=utf-8

Content-Length: 1127

Expect: 100-continue

Host: xxx:7003

{"token":"044kNJzsQNJJnQ86kw3bkBeWcNRoA8MdJ6wczvYhBbQ77Q=MDE5MDA2MjU3MjM2MDc5NDk0ODQ0MTEwNkVTU0FwcDE1OTgyNTA3ODAwNDU=","formActions": [        {      "command": "SetControlValue",      "value": "ESS",      "controlID": "15"    },        {      "command": "SetControlValue",      "value": "",      "controlID": "19"    },     {      "command": "SetControlValue",      "value": "90013234",      "controlID": "29"    },    {      "command": "SetControlValue",      "value": "24/08/2020",      "controlID": "21"    },    {      "command": "SetControlValue",      "value": "120000",      "controlID": "25"    },    {      "command": "SetControlValue",      "value": "30",      "controlID": "35"    },        {      "command": "SetControlValue",      "value": "01",      "controlID": "33"    },    {"command": "DoAction",      "controlID": "11"}   ],   "formName": "P59MBLVR_W59MBLVRE",   "returnControlIDs":"39|31|37"  }

[Simon_Blakely]

You can do this in an irule with the STREAM profile, or collect the payload parse it and rewrite it.

The question is how much parsing of the content is required to make the insertion safe.

Please provide an example of the incoming and outgoing content.

[Muhannad]

Any update Simon?

[Muhannad]

Hi Simon,

Thanks for your kind help.

I have collected some captures to show you how is the flow:

The client request a token:

POST /xxx/v2/tokenrequest/ HTTP/1.1

Authorization: Basic Q1NTUE9SVEFMOnBydHVzcl81MzE=

Content-Type: application/json

Content-Length: 23

Host: xxx:7003

{"deviceName":"ESSApp"}

HTTP/1.1 200 OK

Date: Tue, 25 Aug 2020 07:46:27 GMT

Content-Length: 680

Content-Type: application/json; charset=UTF-8

Access-Control-Allow-Methods: GET, POST, OPTIONS

Set-Cookie: JSESSIONID=12UklSL6A3BL2RYaOwxuAb0E35FhInJQPDhX13PQgrej7jYI2T40!-976037407; path=/jderest; HttpOnly

Access-Control-Allow-Origin: *

{"username":"CSSPORTAL","environment":"JPD920","role":"*ALL","jasserver":"http://HQOWL2:8005","userInfo":{"token":"0445GZVPRIhb9rtxHtxl9HfKVaikQpPgw2BdIQ5BEGz8tQ=MDE5MDA2MTk4OTM5NzkwMjk4NzA4MjkwNEVTU0FwcDE1OTgzNDE1ODc3MDU=","langPref":" ","locale":"en","dateFormat":"DME","dateSeperator":"/","simpleDateFormat":"dd/MM/yyyy","decimalFormat":".","addressNumber":0,"alphaName":"CSSPORTAL","appsRelease":"E920","country":" ","username":"CSSPORTAL"},"userAuthorized":false,"version":null,"poStringJSON":null,"altPoStringJSON":null,"aisSessionCookie":"12UklSL6A3BL2RYaOwxuAb0E35FhInJQPDhX13PQgrej7jYI2T40!-976037407!1598341587706","adminAuthorized":false,"passwordAboutToExpire":false}

The client is requesting the formservices:

POST /xxx/formservice HTTP/1.1

Content-Type: application/json; charset=utf-8

Content-Length: 1133

Host: xxxx:7003

{"token":"044VZAliLSXEo2l4Xcv9DFPNLQKbX7p8E3i/Zt+ksskQ+E=MDE5MDA2MjgwOTQzNzQwNjUwMjI4NzM5OUVTU0FwcDE1OTgzNDA4NzQ3NDM=","formActions": [        {      "command": "SetControlValue",      "value": "ESS",      "controlID": "15"    },        {      "command": "SetControlValue",      "value": "Ggtest",      "controlID": "19"    },     {      "command": "SetControlValue",      "value": "90013234",      "controlID": "29"    },    {      "command": "SetControlValue",      "value": "29/08/2020",      "controlID": "21"    },    {      "command": "SetControlValue",      "value": "120000",      "controlID": "25"    },    {      "command": "SetControlValue",      "value": "55",      "controlID": "35"    },        {      "command": "SetControlValue",      "value": "03",      "controlID": "33"    },    {"command": "DoAction",      "controlID": "11"}   ],   "formName": "P59MBLVR_W59MBLVRE",   "returnControlIDs":"39|31|37"  }

The Response from the server is 444 cause i am missing the "deviceName":"ESSApp" in the body:

HTTP/1.1 444 

Date: Tue, 25 Aug 2020 07:46:27 GMT

Content-Length: 162

Content-Type: application/json; charset=UTF-8

Access-Control-Allow-Methods: GET, POST, OPTIONS

Access-Control-Allow-Origin: *

{

 "message" : "Invalid Token: Please Request a New Token",

 "exception" : "java.lang.Exception",

 "timeStamp" : "2020-08-25:10.46.27"

,"deprecated":true }

What i need is to make the F5 inserting the {"deviceName":"ESSApp"} before the   "formName": "P59MBLVR_W59MBLVRE",   "returnControlIDs":"39|31|37" in the JSON body.

Many thanks in advance for your help.

Regards,

Muhannad

[Muhannad]

This should be done from f5 side to the server.

[Simon_Blakely]

when HTTP_REQUEST {
  log local0. "starting collect"
      HTTP::collect [HTTP::header Content-Length]
      set clen [HTTP::header Content-Length]
}
when HTTP_REQUEST_DATA {
  binary scan [HTTP::payload] c* throwaway
  set incoming [HTTP::payload]
  log local0. "before: $incoming"
  regsub -all {,   "formName} $incoming {,  {"deviceName":"ESSApp"},  } newdata
  log local0. "new data is $newdata"
  HTTP::payload replace 0 $clen $newdata
  log local0. "after: [HTTP::payload]" 
}

$ curl -kv https://172.16.0.220/xxx/formservice -d '{"token":"044VZAliLSXEo2l4Xcv9DFPNLQKbX7p8E3i/Zt+ksskQ+E=MDE5MDA2MjgwOTQzNzQwNjUwMjI4NzM5OUVTU0FwcDE1OTgzNDA4NzQ3NDM=",",   "formName": "P59MBLVR_W59MBLVRE",   "returnControlIDs":"39|31|37"  }' -H 'Content-Type: application/json; charset=utf-8'
 
Aug 30 16:07:03 bigip1 info tmm[12235]: Rule /Common/json_modify <HTTP_REQUEST>: starting collect
Aug 30 16:07:03 bigip1 info tmm[12235]: Rule /Common/json_modify <HTTP_REQUEST_DATA>: before: {"token":"044VZAliLSXEo2l4Xcv9DFPNLQKbX7p8E3i/Zt+ksskQ+E=MDE5MDA2MjgwOTQzNzQwNjUwMjI4NzM5OUVTU0FwcDE1OTgzNDA4NzQ3NDM=",",   "formName": "P59MBLVR_W59MBLVRE",   "returnControlIDs":"39|31|37"  }
Aug 30 16:07:03 bigip1 info tmm[12235]: Rule /Common/json_modify <HTTP_REQUEST_DATA>: new data is {"token":"044VZAliLSXEo2l4Xcv9DFPNLQKbX7p8E3i/Zt+ksskQ+E=MDE5MDA2MjgwOTQzNzQwNjUwMjI4NzM5OUVTU0FwcDE1OTgzNDA4NzQ3NDM=",",  {"deviceName":"ESSApp"},  ": "P59MBLVR_W59MBLVRE",   "returnControlIDs":"39|31|37"  }
Aug 30 16:07:03 bigip1 info tmm[12235]: Rule /Common/json_modify <HTTP_REQUEST_DATA>: after: {"token":"044VZAliLSXEo2l4Xcv9DFPNLQKbX7p8E3i/Zt+ksskQ+E=MDE5MDA2MjgwOTQzNzQwNjUwMjI4NzM5OUVTU0FwcDE1OTgzNDA4NzQ3NDM=",",  {"deviceName":"ESSApp"},  ": "P59MBLVR_W59MBLVRE",   "returnControlIDs":"39|31|37"  }

[Muhannad]

Dear Simon,

Thanks for your help.

It is working perfectly except one issue, it is inserting the "deviceName":"ESSApp" in every request thus it is causing issues to other requests, it seems we need to match exactly the "formName": "P59MBLVR_W59MBLVRE" toinsert the {"deviceName":"ESSApp"}

Regards,

Muhannad

[Muhannad]

How can i matach the "formName": "P59MBLVR_W59MBLVRE" in this IRULE:

when HTTP_REQUEST {

log local0. "starting collect"

HTTP::collect [HTTP::header Content-Length]

set clen [HTTP::header Content-Length]

when HTTP_REQUEST_DATA {

binary scan [HTTP::payload] c* throwaway

set incoming [HTTP::payload]

log local0. "before: $incoming"

regsub -all {, "formName} $incoming {, {"deviceName":"ESSApp"}, } newdata

log local0. "new data is $newdata"

HTTP::payload replace 0 $clen $newdata

log local0. "after: [HTTP::payload]"

}

Regards,

Muhannad