POST /upload HTTP/1.1
Host: assets.drop.io
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.10) Gecko/2
009042316 Firefox/3.0.10
Accept: text/html,ap
The schematic syntax of a multipart/form-data message is as follows:
Content-Type: multipart/form-data; boundary=boundary
--boundary
Content-Disposition: form-data; name="field 1"
data 1
--boundary
Content-Disposition: form-data; name="field 2"
data 2
⋮
--boundary
Content-Disposition: form-data; name="field N"
data N
--boundary--
So the inner part boundaries are --boundary
(--
followed by the boundary value) and the last is --boundary--
(--
followed by the boundary value followed by --
).
In your case you are just missing the leading --
.