git clone: CONNECT_CR_SRVR_HELLO:wrong version number

Question

I'm trying to proxy through a jumphost, for access to github, using a VM that's outside the firewall.

git clone https://github.com/<user>/<repo> works on the VM.

I setup the jumphost on my Mac laptop's .ssh/config as:

Host vm-proxy
    HostName <vm-ip_address>
    User centos
    IdentityFile ~/.ssh/id.pem

Host githubproxy
    Hostname github.com
    ProxyJump vm-proxy

But the clone fails from the laptop:

$ git clone https://githubproxy/<user>/<repo>
Cloning into '<repo>'...
fatal: unable to access 'https://githubproxy/<user>/<repo>/': error:1400410B:SSL routines:CONNECT_CR_SRVR_HELLO:wrong version number

Versions:

MacOs: Catalina 10.15.6
git on laptop: 2.24.3 (Apple Git-128)
git on VM: 1.8.3.1

Answer 1

:SSL routines:CONNECT_CR_SRVR_HELLO:wrong version number

That means you are sending TCP content (HTTPS) to an HTTP port or an SSH one, but not 443

And your proxyjump is for jumping to an SSH session on your VM, so it might not be a good fit for an HTTPS URL.