Conversion problem in parse_multipart

[Michele Belloli]

Hi folks...

I have a problem uploading a file to a web server.

I created an html page with a multipart/form-data form and used
cgi.parse_multi part function to obtain form data (and obviuosly
uploaded file).
I noticed that if I upload an excutable file, I obtain a file where
0x0a 0x0a, are converted in 0x0a and 0x2e.
Obviously this file is corrupted.

When I save the file, I use 'wb' flags to create a binary file...

Analyzing the file before cgi.parse_multi part, it's possible to
verify that it's correct but when this function tries to extract its
value, 0x0a 0x0a are converted in 0x0a and 02e.

Any suggestion?

Thanks a lot...

[Tim Roberts]

Re: Conversion problem in parse_multipart

Michele Belloli <mkbelloli@libe ro.it> wrote:[color=blue]
>
>I have a problem uploading a file to a web server.
>
>I created an html page with a multipart/form-data form and used
>cgi.parse_mult ipart function to obtain form data (and obviuosly
>uploaded file).
>I noticed that if I upload an excutable file, I obtain a file where
>0x0a 0x0a, are converted in 0x0a and 0x2e.
>Obviously this file is corrupted.[/color]

Are you sure? We had something similar reported just a few weeks ago where
the bug turned out to be in the program displaying the hex results; the
binary file was just fine.

I have used cgi.py to handle large file uploads literally tens of thousands
of times, and never had one go bad.
[color=blue]
>Analyzing the file before cgi.parse_multi part, it's possible to
>verify that it's correct but when this function tries to extract its
>value, 0x0a 0x0a are converted in 0x0a and 02e.[/color]

How are you determining this? That is, how are you accessing the final
data?

What operating system and what web server?
--
- Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.

[Michele Belloli]

Re: Conversion problem in parse_multipart

On Wed, 01 Oct 2003 20:23:56 -0700, Tim Roberts <timr@probo.com >
wrote:
[color=blue]
>Michele Belloli <mkbelloli@libe ro.it> wrote:[color=green]
>>
>>I have a problem uploading a file to a web server.
>>
>>I created an html page with a multipart/form-data form and used
>>cgi.parse_mul tipart function to obtain form data (and obviuosly
>>uploaded file).
>>I noticed that if I upload an excutable file, I obtain a file where
>>0x0a 0x0a, are converted in 0x0a and 0x2e.
>>Obviously this file is corrupted.[/color]
>
>Are you sure? We had something similar reported just a few weeks ago where
>the bug turned out to be in the program displaying the hex results; the
>binary file was just fine
>
>I have used cgi.py to handle large file uploads literally tens of thousands
>of times, and never had one go bad.
>[/color]

I read cgi.py, in particular 'parse_multipar t'; and I repeated each
command in a python shell.
It works fine.
I use the same version (2.2.3) in Python shell and web server but I
obtain two different behaviuors.
[color=blue][color=green]
>>Analyzing the file before cgi.parse_multi part, it's possible to
>>verify that it's correct but when this function tries to extract its
>>value, 0x0a 0x0a are converted in 0x0a and 02e.[/color]
>
>How are you determining this? That is, how are you accessing the final
>data?
>[/color]

I noticed a bug displaying the hex results using 'print' statement
too, so I created a binary file (using 'wb' flags) and write down
results. Then, I read it using an hex-editor.
Reading file, I tought 'write' method could modify result like 'print'
statement do.
So I used a simple conditional statement.
if result =='\x2e':
file.write(.... .)

Both test in cgi.parse_mulit part shows the problem.
[color=blue]
>What operating system and what web server?[/color]

W2K and python web server using SimpleHTTPServe r classes


Thanks