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schannel error for validating hosts with AltNames #3711
Trying to upgrade the R bindings on Windows from 7.59.1 to 7.64.1. The curl configuration is dual-ssl (openssl + schannel) with the latter being the default.
The bindings set
Anyway, with the new version, trying to connect to e.g.
The line below wasn't there in 7.59.1, I guess it is now using the bundle instead of windows certificate store for validating certs with schannel which was probably already added in 7.60.0.
However it doesn't seem to support AltName certs, which is why connecting to
The problem does not appear when using the openssl backend (so the bundle file is not the problem), or when using the schannel without setting
CERT_NAME_SEARCH_ALL_NAMES_FLAG isn't available earlier than Windows 8 as discussed here.
curl tool doesn't set CAINFO for schannel, it does it like this:
Likely you specified CAINFO and the CERT_NAME_SEARCH_ALL_NAMES_FLAG was not available at build time because you targeted < Windows 8. It's fixable but I've focused on other issues. It should be possible to fix by iterating through CERT_ALT_NAME_INFO instead of using that flag.
Right this is the case. I will make sure to not set CAINFO icw/ CURLSSLBACKEND_SCHANNEL then.
Perhaps there should be a warning of some sort in the
Yeah that's a fair point we'll try to fix it for the next release.
- Support hostname verification via alternative names (SAN) in the peer certificate when CURLOPT_CAINFO is used in Windows 7 and earlier. CERT_NAME_SEARCH_ALL_NAMES_FLAG doesn't exist before Windows 8. As a result CertGetNameString doesn't quite work on those versions of Windows. This change provides an alternative solution for CertGetNameString by iterating through CERT_ALT_NAME_INFO for earlier versions of Windows. Prior to this change many certificates failed the hostname validation when CURLOPT_CAINFO was used in Windows 7 and earlier. Most certificates now represent multiple hostnames and rely on the alternative names field exclusively to represent their hostnames. Reported-by: Jeroen Ooms Fixes #3711 Closes #4761