Cannot communicate securely with peer: no common encryption algorithm(s)

algorithm, encryption, fedora20, git

Solution

The simplest solution is just to use `http` instead of `https`:

$ git clone http://openhatch.org/git-mission-data/git/hithard/
Cloning into 'hithard'...
remote: Counting objects: 3, done.
remote: Total 3 (delta 0), reused 0 (delta 0)
Unpacking objects: 100% (3/3), done.
Checking connectivity... done.

I think the error itself ("no common encryption algorithms") is accurate; it appears that the server wants to use some sort of elliptic curve cipher (TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256) that is not supported by git's underlying SSL library. You can use something like `wireshark` to capture the SSL handshake between git and the server and see the options being passed back and forth.

At least on my system, `curl` does not seem to support this cipher, and `git` uses `libcurl` for handling https/http connections.

Update

So, based on my last comment to @mattdm, in which I discovered that `curl` on my system is using the NSS crypto library, the following works:

curl --ciphers ecdhe_ecdsa_aes_128_gcm_sha_256 https://openhatch.org/

Unfortunately, there isn't any way to pass a cipher list to `git`. The patch to make it do so is trivial -- here is one version I just made -- but I don't know what the odds are of getting this accepted upstream.

Problem

Original source