Re: [PATCH] send-email: If the ca path is not specified, use the defaults

Jonathan Nieder <jrnieder@gmail.com> writes:

Hmph, is that the same issue, though? That page seems to suggest using an empty ca file that does not have any useful information as a workaround. The issue Fedora folks saw is that we see a directory /etc/ssl/certs exist on the system, and blindly attempt to use it as SSL_ca_path when the directory is not suitable to be used as such.

In any case, I tried to summarize the discussion in the updated log message. I wanted to say "does not" but stopped at "should not" in the last paragraph for now. Maybe Ram can say something before we merge it to 'next'.

The patch in the meantime will be queued on 'pu'.

-- >8 --
From: Ruben Kerkhof <ruben@rubenkerkhof.com>
Date: Wed, 15 Jan 2014 21:31:11 +0400
Subject: [PATCH] send-email: /etc/ssl/certs/ directory may not be usable as ca_path

When sending patches on Fedora rawhide with git-1.8.5.2-1.fc21.x86_64 and perl-IO-Socket-SSL-1.962-1.fc21.noarch, with the following

    [sendemail]
	    smtpencryption = tls
	    smtpserver = smtp.gmail.com
	    smtpuser = ruben@rubenkerkhof.com
	    smtpserverport = 587

git-send-email fails with:

    STARTTLS failed! SSL connect attempt failed with unknown error
    error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate
    verify failed at /usr/libexec/git-core/git-send-email line 1236.

The current code detects the presence of /etc/ssl/certs directory (it actually is a symlink to another directory, but that does not matter) and uses SSL_ca_path to point at it when initializing the connection with IO::Socket::SSL or Net::SMTP::SSL. However, on the said platform, it seems that this directory is not designed to be used as SSL_ca_path. Using a single file inside that directory (cert.pem, which is a Mozilla CA bundle) with SSL_ca_file does work, and also not specifying any SSL_ca_file/SSL_ca_path (and letting the library use its own default) and asking for peer verification does work.

By removing the code that blindly defaults $smtp_ssl_cert_path to "/etc/ssl/certs", we can prevent the codepath that treats any directory specified with that variable as usable for SSL_ca_path from incorrectly triggering.

This change could introduce a regression for people on a platform whose certificate directory is /etc/ssl/certs but its IO::Socket:SSL somehow fails to use it as SSL_ca_path without being told. Using /etc/ssl/certs directory as SSL_ca_path by default like the current code does would have been hiding such a broken installation without its user needing to do anything. These users can still work around such a platform bug by setting the configuration variable explicitly to point at /etc/ssl/certs.

This change should not negate what 35035bbf (send-email: be explicit with SSL certificate verification, 2013-07-18), which was the original change that introduced the defaulting to /etc/ssl/certs/, attempted to do, which is to make sure we do not communicate over insecure connection by default, triggering warning from the library.

Cf. https://bugzilla.redhat.com/show_bug.cgi?id=1043194

Tested-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>
Signed-off-by: Ruben Kerkhof <ruben@rubenkerkhof.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-send-email.perl | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)