Hi I have the same problem as this issue <https github com k kotlinlang #ktor

Hi, I have the same problem as this issue https://github.com/ktorio/ktor/issues/1058 - I have an endpoint for receiving form data but I can easily receive data above 65kb, how can I increase this limit? Only solution I've found involves using internal APIs

11/26/2019, 10:01 AM

Why do you send so much data through a text field? Shouldn't a file be uploaded instead?

Lauritz Hilsøe

11/26/2019, 10:01 AM

We are using a service that's pushing their data, I can't control it unfortunately

11/26/2019, 10:06 AM

Well, for now, the only you can do is to use

CIOMultipartDataBase

that is marked as internal API so it is not guaranteed to be stable . However, I see no reason for any change in this place in the near future

The only copy-paste will be

multiPartData()

that is not that big

Lauritz Hilsøe

11/26/2019, 10:07 AM

I ended up with this, taking inspiration from https://git.io/Je6Ys

val xmlFormData = CIOMultipartDataBase(
  coroutineContext + Dispatchers.Unconfined,
  call.receiveChannel(),
  contentType,
  null,
  99999999
)

11/26/2019, 10:08 AM

Specifying so big limit may cause OOM

the other question is why content length is always

null

Lauritz Hilsøe

11/26/2019, 10:10 AM

Does it allocate that much memory? I can try and figure out a more sane limit based on file sizes

Not sure, I didn't actually notice the line

val contentLength = call.request.header(HttpHeaders.ContentLength)?.toLong()

but I can update to use that

11/26/2019, 10:10 AM

I recommend you to specify content length if available

Of course it doesn't allocate all this size, only if a request has such big field

this limit is just a guard to avoid OOM and potential DoS caused by big requests

So specifying too big limit makes you vulnerable

Lauritz Hilsøe

11/26/2019, 10:12 AM

Makes sense, I think one of the biggest is around 100kb so I'll limit it to that + a little more and be sure to specify content length if available

Is there any plans to make this configurable somehow or open the API instead of using internal?

11/26/2019, 10:30 AM

Need to think of how do we provide it

Lauritz Hilsøe

11/27/2019, 9:21 AM

Would be a nice option, but thanks for your help, appreciate it

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