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Re: Problem downloading files greater than 32Mb after upgrading from 7.14 to 7.20.1

From: Daniel Stenberg <>
Date: Tue, 22 Nov 2011 22:41:30 +0100 (CET)

On Mon, 21 Nov 2011, David Tong wrote:

> I have a legacy project that recently upgraded libcurl from 7.14 to 7.20
> (and yes I know that's not the latest)

Still you switched to an almost 5 years newer version!

> The project uses libcurl to download binary objects via SSL. I'm finding
> that objects over 32Mb in size fail to download. Looking in detail it seems
> that the first block (less than, but close to 32Mb) downloads successfully.
> The code then attempts to connect again to download more data, but the
> connection fails.

So what's the exact error in the first fail? And when you say "The code"
attempts to connect again, is this code your application you mean?

> The issue appears to be related to re-using the connection

If the connection previously ended with an error it should never be reused.

> and may also be related to the fact that the SSL certificate is self-signed.

I don't think it matters.

> And here's what I see with the same code using 7.20:
> < HTTP/1.0 200 Connection established^M
> < ^M
> * Proxy replied OK to CONNECT request
> * Unknown SSL protocol error in connection to [SERVER]
> * Closing connection #0
> Any suggestions would be appreciated

Could I ask you to try the latest libcurl version first just an experiment to
see if the problem remains? It seems pointless to chase for something that
might already work...

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Received on 2011-11-22