[ldns-users] Hostname verification in certificate chain?

Jeffrey Walton noloader at gmail.com
Wed Feb 5 17:12:35 UTC 2020


Hi Everyone,

I may be parsing use of X509_verify_cert incorrectly... but it does
not appear hostname matching and verification is occurring in dane.c.

If I recall correctly... For OpenSSL 1.0.2, you had to manually match
the server name in the request with hostname in the end entity
certificate. It made using OpenSSL 1.0.2 a drag. Also see
https://wiki.openssl.org/index.php/SSL/TLS_Client on the OpenSSL wiki.

For OpenSSL 1.1.x, you use X509_VERIFY_PARAM_set_hostflags and
X509_check_host to have the library do it. But I don't see a call to
X509_VERIFY_PARAM_set_hostflags. Also see
https://wiki.openssl.org/index.php/Hostname_validation on the OpenSSL
wiki.

Can someone familiar with the OpenSSL code in dane.c please take a look at it.

Lack of hostname verification is a CVE item. If hostname verification
is not occurring, then that should be listed in the README so folks
are aware of the risk.

Sorry to bring this up.

Jeff


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