Thursday 15 October 2015

Building git 2.6 and enabling TLS 1.2 on CentOS 7

There are scenarios where TLS 1.2 is not just enabled, but the only one accepted.
In these cases many clients fail to connect over HTTPS.
I needed to be able to use 'git clone https://...' on CentOS 7, and since it was failing and I spent some time on a work around, I'm sharing it here.

The system is a CentOS 7 host on DigitalOcean, with kernel

Linux 3.10.0-123.8.1.el7.x86_64

git is 1.8.3, the stock version
nss is 3.19.1-5.el7_1

If I do something like

curl  --tlsv1.2

the connection is successful, but a command like

GIT_CURL_VERBOSE=1 git clone

was giving a connection error with this code:

( only accepts TLSv1.2).

Long story short, I read somewhere that git 2.6 had support for configuring TLSv1.2, and I downloaded the source code of git 2.6.0 from

Built, installed, added to my .gitconfig this:

sslVersion = tlsv1.2

but no cigar.

So I dug in the code and commented out a dependency for a version of libcurl in http.c (I'm commenting out the #if - #endif):

  //GV#if LIBCURL_VERSION_NUM >= 0x072200           { "tlsv1.0", CURL_SSLVERSION_TLSv1_0 },           { "tlsv1.1", CURL_SSLVERSION_TLSv1_1 },           { "tlsv1.2", CURL_SSLVERSION_TLSv1_2 }, 

Rebuilt and reinstalled, and this time it worked fine.


  1. great, it works for my redhatel-6.5

  2. Thanks for the tip, it lead me to "yum update curl" which worked for me on Rhel 6.

  3. Thanks Jan for taking the time to confirm.


About ICE negotiation

Disclaimer: I wrote this article on March 2022 while working with Subspace, and the original link is here: