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Re: Strange redirection to Cloudflare server with Captcha?

From: Petr Pisar via curl-users <curl-users_at_cool.haxx.se>
Date: Sun, 16 May 2021 15:43:23 +0200

V Sun, May 16, 2021 at 03:16:13PM +0200, Mac-Fly via curl-users napsal(a):
> So it looks like either my version is too new or something has changes that
> requires a certain flag to be set. Whatever was changed is different between
> version 7.76.1 and 7.64.0 on Windows an Linux. This could (of course) be the
> SSL layer. But how to find out now whats happening?
>
> Here is the difference in the logs of CURL 7.76.1 on Windows versus Linux (note that the IP is different!):
>
> ------------------- <WINDOWS> -------------------
> % Total % Received % Xferd Average Speed Time Time Time Current
> Dload Upload Total Spent Left Speed
>
> 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0* Trying 172.67.74.133:443...
> * Connected to www.audacityteam.org (172.67.74.133) port 443 (#0)
> * ALPN, offering h2
> * ALPN, offering http/1.1
> * successfully set certificate verify locations:
> * CAfile: D:\Users\Martin\Documents\Code\CodeBlocks_Projects\WebChangeMonitor\curl\bin\curl-ca-bundle.crt
> * CApath: none
> ------------------- </WINDOWS> -------------------
>
You need to compare the whole output (as I showed). Especially debugging of
the TLS version, HTTP version, and HTTP headers.

> What does TCP_NODELAY mean??? The same is set for Windows built-in curl 7.55.1.
>
It instructs a TCP layer not to buffer data to be sent into larger chunks.
I.e. it sends every byte as soon as possible.

-- Petr


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Received on 2021-05-16