[R] download.file strict certificate revocation check

[John Neset]

Ivan,
SSL connect error & we definitely have MITM doing certificate interference.
No change with True or False with R_LIBCURL_SSL_REVOKE_BEST_EFFORT
Environment variable results should be attached.

-----Original Message-----
From: Ivan Krylov <krylov.r00t using gmail.com>
Sent: Wednesday, October 4, 2023 8:52 AM
To: John Neset <John.Neset using noridian.com>
Cc: r-help using R-project.org
Subject: Re: [R] download.file strict certificate revocation check

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В Wed, 4 Oct 2023 13:09:47 +0000
John Neset <John.Neset using noridian.com> пишет:

> Trying to do this, reference FAQ-
> 2.18 The Internet download functions fail.
> (c) A MITM proxy (typically in enterprise environments) makes it
> impossible to validate that certificates haven't been revoked. One can
> switch to only best effort revocation checks via an environment
> variable: see ?download.file.

Here's what help(download.file) has to say:

>>     On Windows with ‘method = "libcurl"’, when R was linked with
>>     ‘libcurl’ with ‘Schannel’ enabled, the connection fails if it
>>     cannot be established that the certificate has not been revoked.
>>     Some MITM proxies present particularly in corporate environments
>>     do not work with this behavior. It can be changed by setting
>>     environment variable ‘R_LIBCURL_SSL_REVOKE_BEST_EFFORT’ to
>>     ‘TRUE’, with the consequence of reducing security.

Does it help to Sys.setenv(...) this environment variable before downloading? If not, please provide your sessionInfo() and the full error message.

--
Best regards,
Ivan
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