Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Handle messages containing only end boundary, fixes #38 #142

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Handle messages containing only end boundary, fixes #38 #142

wants to merge 1 commit into from

Conversation

jhnstrk
Copy link
Contributor

@jhnstrk jhnstrk commented Apr 23, 2024 •
edited
Loading

Some browsers create empty messages when forms are posted - see #38 for examples.

The fix here adds a new state in the parser which is entered when the first hyphen after the first boundary is encountered. This is only the case for the very first boundary. Anything but a second hyphen after the first is considered an error.
@tomchristie
Copy link
Collaborator

tomchristie commented Apr 24, 2024 •
edited
Loading

Sounds feasible, let's get some clarity on it...

  • Is that spec compliant?
  • ~~Can you provide an example (which browser and how to test)?~

Edit:

Apologies for the noise, I've not confirmed this but can see the following linked...

Firefox and Chrome produce empty messages like this, e.g. when POSTing a HTML form with only a unchecked checkbox.

(And... probably not relevant if it's spec compliant or not if that's the actual behavior.)
@jhnstrk
Copy link
Contributor Author

jhnstrk commented Apr 24, 2024

To me the spec isn't 100% clear. rfc2046 appears to assume that there is always at least one body part, so this would not be valid. But it doesn't make it clear how a form with no parts should be communicated either.

Anyway, it's what Chrome (and probably Firefox, but I haven't tested myself) does now. Take the following text, adapted from the examples in #38

  • save as a test.html
  • open the file in Chrome
  • open Chrome dev tools
  • click the button on the form
  • inspect the payload sent to example.com (Network tab,--> Payload --> View Source)
<!DOCTYPE html>
<html>
  <head><meta charset="UTF-8"></head>
  <body>
        <form action="http://example.com/" enctype="multipart/form-data" method="post">
            <input type="checkbox" id="check" name="check">
            <label for="check">Breaks unless you check it</label>
			<input type="submit" value="Submit">
        </form>  
  </body>
</html>

I got the following payload: (Chrome Version 124.0.6367.61 (Official Build) (64-bit))

------WebKitFormBoundaryBBDliyOmePSMlFiJ--

Clicking (enabling) the check box in the form gives valid content with 1 part.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
2 participants
@jhnstrk @tomchristie