From 10d70bfe77b0bd1a140ee3334e6a997d18f960f7 Mon Sep 17 00:00:00 2001
From: Athanasius <github@miggy.org>
Date: Fri, 7 Jan 2022 16:45:37 +0000
Subject: [PATCH] Gateway: Properly report 'not compressed, badly form-encoded'
 to uploaders

* This code worked if the request was *properly* form-encoded, with a
'data' key whose value was a valid message.

* It failed to detect where the request was form-encoded, with without a
'data' key.  It would just assume 'not form-encoded' in that case, then
fail later on JSON parsing.

Thus, re-use the `urlparse.parse_qs()` check for form-encoded format.
This passes:

  1. Properly, `data` key, form-encoded with valid value is fully JSON
  parsed, schema checked and accepted.
  2. *NOT* compressed *or* form-encoded valid message is properly parsed
  and accepted.
  2. Uncompressed, form-encoded, but no `data` key correctly returns the
  same error status and body as the compressed+form-encoded+no data key
  path.
---
 src/eddn/Gateway.py | 27 +++++++++++++++++++++------
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/src/eddn/Gateway.py b/src/eddn/Gateway.py
index 90e8ac1..091088c 100644
--- a/src/eddn/Gateway.py
+++ b/src/eddn/Gateway.py
@@ -164,13 +164,28 @@ def get_decompressed_message():
             logger.debug('Request is *NOT* form-encoded')
 
     else:
-        # Uncompressed request. Bottle handles all of the parsing of the
-        # POST key/vals, or un-encoded body.
-        data_key = request.forms.get('data')
-        if data_key:
-            # This is a form-encoded POST. Support the silly people.
-            message_body = data_key
+        logger.debug('Content-Encoding indicates *not* compressed...')
+
+        form_enc_parsed = urlparse.parse_qs(request.body.read())
+        if form_enc_parsed:
+            logger.debug('Request is form-encoded')
+
+            # Uncompressed request. Bottle handles all of the parsing of the
+            # POST key/vals, or un-encoded body.
+            data_key = request.forms.get('data')
+            if data_key:
+                logger.debug('form-encoded POST request detected...')
+                # This is a form-encoded POST. Support the silly people.
+                message_body = data_key
+    
+            else:
+                raise MalformedUploadError(
+                    "No 'data' POST key/value found. Check your POST key "
+                    "name for spelling, and make sure you're passing a value."
+                )
+
         else:
+            logger.debug('Plain POST request detected...')
             # This is a non form-encoded POST body.
             message_body = request.body.read()