Multiple SSH keys for different github accounts

multiple_ssh_setting.md

Multiple SSH Keys settings for different github account

create different public key

create different ssh key according the article Mac Set-Up Git

$ ssh-keygen -t rsa -C "your_email@youremail.com"

Please refer to github ssh issues for common problems.

for example, 2 keys created at:

~/.ssh/id_rsa_activehacker
~/.ssh/id_rsa_jexchan

then, add these two keys as following

$ ssh-add ~/.ssh/id_rsa_activehacker
$ ssh-add ~/.ssh/id_rsa_jexchan

you can delete all cached keys before

$ ssh-add -D

finally, you can check your saved keys

$ ssh-add -l

Modify the ssh config

$ cd ~/.ssh/
$ touch config
$ subl -a config

Then added

#activehacker account
Host github.com-activehacker
	HostName github.com
	User git
	IdentityFile ~/.ssh/id_rsa_activehacker

#jexchan account
Host github.com-jexchan
	HostName github.com
	User git
	IdentityFile ~/.ssh/id_rsa_jexchan

Clone you repo and modify your Git config

clone your repo git clone git@github.com:activehacker/gfs.git gfs_jexchan

cd gfs_jexchan and modify git config

$ git config user.name "jexchan"
$ git config user.email "jexchan@gmail.com" 

$ git config user.name "activehacker"
$ git config user.email "jexlab@gmail.com" 

or you can have global git config $ git config --global user.name "jexchan" $ git config --global user.email "jexchan@gmail.com"

then use normal flow to push your code

$ git add .
$ git commit -m "your comments"
$ git push

Another related article in Chinese

1. http://4simple.github.com/docs/multipleSSHkeys/

GIT_SSH_COMMAND='ssh -i ~/.ssh/my_gitlab_key_rsa -o IdentitiesOnly=yes' git clone <your clone git url here>

I got the following error on MacBook
"could not resolve hostname i: nodename nor servname provided"

Thanks worked a treat. The following worked for me:
git clone git@github.com-sshID:myGitHubAccount/myRepo.git

Perfect solution

I had to change the [remote "origin"] / url field in my local .git/config to use the Host defined in .ssh/config in order for this to work, i.e.,

[remote "origin"]
        url = git@github.com-activehacker:activehacker/gfs.git

Without that modification, git would just try to use my default ssh key.

Thanks @oleweidner

Thanks worked a treat. The following worked for me:
git clone git@github.com-sshID:myGitHubAccount/myRepo.git

Perfect solution

Yep, this worked for me too!

The simplest way to clone a repo is git clone git@github.com-sshID:myGitHubAccount/myRepo.git(thanks to @wmyers).

ssh-add ~/.ssh/key is unnecessary, this method still works if you execute ssh-add -D.

This looks like it would work great with Git profiles!

@serg06 Very nice!! I'll try this and see how it works. Seems like a much better way to organize things.

I had to change the [remote "origin"] / url field in my local .git/config to use the Host defined in .ssh/config in order for this to work, i.e.,

[remote "origin"]
        url = git@github.com-activehacker:activehacker/gfs.git

Without that modification, git would just try to use my default ssh key.

Thanks @oleweidner!! from the year 2021...your comment/answer back in 2012 helped me in 2021 !!! Was struggling to fix my stuff for 2 days...luckily I hit your answer...

e.g.

git clone git@github.com-activehacker:activehacker/gfs.git gfs_jexchan
________________________^

as oppose to:

git clone git@github.com:activehacker/gfs.git gfs_jexchan

that's the ticket!

Thanks man you saved my day

I am still having issues, with this. In my ~/.ssh/config I have a catch-all block at the end with default options and fallback keys

Host github.com-Anonymous5726221
  HostName github.com
  User git
  IdentityFile ~/.ssh/id_ed25519_Anonymous_5726221

Host * 
  IdentityFile ~/.ssh/id_ed25519
  IdentityFile ~/.ssh/id_ed25519_Anonymous_5726221
  IdentitiesOnly=yes
  PreferredAuthentications=publickey,gssapi-keyex,gssapi-with-mic,password
  AddressFamily inet
  Protocol 2
  Compression yes

I ran git push and I can see in ssh debug it's matching the Host rule correctly but it still tried the Host * first with my personnal key first. If I comment out the 2 IdentityFile in Host * when it works as intended.

Any idea?

Does anyone know how to make git+ssh://git@github.com/myorganisation/myrepo.git work with this configuration?

I create a CLI command to handle this!
Checkout my repo~~
This repo uses ssh-agent to switch your ssh account.

Git_SSH-Account_Switch

A CLI tool can switch an ssh account to your current shell. You will easily switch to your git account & ssh key when using the server, and using your account to manipulate the project on the server.

Installation

$ bash ./setup.sh

it will add some code in your profile & $logout_profile, and setup git-acc & .gitacc on the $HOME.
file:

git-acc.sh -> $HOME/.git-acc, git-acc function.
.gitacc -> $HOME/.gitacc, save info. that regist on git-acc.

Control

        +---------------+
        |    git-acc    |
        +---------------+

SYNOPSIS

  git-acc [account]|[option]

OPTIONS

  [account]               use which accounts on this shell, type the account name that you register.
  -h, --help              print help information.
  -add, --add_account     build git_account info. & ssh-key.
      -t, --type          ssh-key types, follow `ssh-keygen` rule, 
                          types: dsa | ecdsa | ecdsa-sk | ed25519 | ed25519-sk | rsa(default)
  -rm, --remove_account   remove git_account info. & ssh-key from this device
  -out, --logout          logout your current ssh-acc.


EXAMPLES

  $ git-acc tw-yshuang

It only works with this https://gist.github.com/jexchan/2351996#gistcomment-522294

just use the includeif rule of your gitconfig ... messing with hostnames or cli switcher malarky just leads to complication and non portable setups.

For everyone in here who doesn't want to use unique identifiers, just use the Hostname as the Host:

Host github.com
    HostName github.com
    User git
    IdentityFile ...

Now you don't have to remember to change your SSH identifier and you can just copy the "git@github.com..." address from your clone instructions.

@arcsector will below work for multiple accounts?

Host github.com
    HostName github.com
    User git
    IdentityFile ~/.ssh/id_rsa_id1

Host github.com
    HostName github.com
    User git
    IdentityFile ~/.ssh/id_rsa_id2

@gamesover i tried that config too. what happens is, ssh will be able to identify both configuration but only uses the first matching one. so if one of your git command requires id_rsa_id2, the operation will be unsuccessful.

@jaanhio thanks very much for your updates.
True. I found the same issue.
So far, I did not find a perfect solution yet.

Each time, I have to check ssh-add -l to delete unneeded keys and reserve the key needed.

For example, if I need id_rsa_id2, then I will do the below

ssh-add -d ~/.ssh/id_rsa_id1
ssh-add ~/.ssh/id_rsa_id2

To be frank, I guess when initially ssh was designed, they never thought there are a senario that diff acount needs diff keys for the same site.

Previously, github allows the same key was added to diff accounts, so no such issue.
Now, one key can only be used once in the whole github for diff accounts.
So we have such troubles now.

Thanks @jexchan and @mixua. The combination of your answers worked great for me.

I'm sharing mine .ssh/config file, hope it helps someone(working fine on MacOS BigSur)

Then you have to add your private key ssh agent as below:
ssh-add -K ~/.ssh/work

ssh-add -K ~/.ssh/altif
In final step, you can confirm the connection using below command and get below output if everything setup correctly.

MAltif1M-BNG1:~ Mohammad.Altif$ ssh -T work

Hi <github_username>! You've successfully authenticated, but GitHub does not provide shell access.

MAltif1M-BNG1:~ Mohammad.Altif$ ssh -T altif

Hi <github_username>! You've successfully authenticated, but GitHub does not provide shell access.

If your ssh keys don't all show up with
ssh-add -l
you have to run
ssh-add ~/.ssh/yourkey.rsa

7 years later, your reply is still saving lives. My Salute！

+1

From OP's, modified according to @oleweidner @jmpnot you two's, and now it works. Thank y'all!

Anyone who is having a problem like in which I followed the instruction on mac, for some reason when I was attempting to push into the repo from my second account, git was using my first account and I was getting permission denied error, after spending few hours this answer finally helped me https://stackoverflow.com/a/12438179/12702093.

You can add this to an existing repo by doing the following:
git config --get remote.origin.url

Which will give you something like:

git@github.com:HughAJWood/repo

Copy and modify the resulting url as so:

git@github.com-<sshId>:HughAJWood/repo
ie
git@github.com-hugh:HughAJWood/repo

This should match the id in the .ssh/config file

# Personal account - the default config
Host github.com-hugh
   HostName github.com
   User git
   IdentityFile ~/.ssh/personal_private_key

I had to change the [remote "origin"] / url field in my local .git/config to use the Host defined in .ssh/config in order for this to work, i.e.,

[remote "origin"]
        url = git@github.com-activehacker:activehacker/gfs.git

Without that modification, git would just try to use my default ssh key.

Thanks @oleweidner

Yeah, Even I had to make this change to get it working.

every time I want to interact with a second git account I need to explicitly provide a path to keys: like GIT_SSH_COMMAND="ssh -i ~/.ssh/personal" git push origin master

I had to remove the wildcard Host * section from the .ssh/config file

Below are the ~/.gitconfig aliases which could clone with specific github.com replacement and change remote origin URL of existing repo

[alias]
  clc = "!f(){ git clone `sed 's/github.com/github.com-work/g' <<< \"$1\"`;};f"
  Cld = "!f(){ git clone `sed 's/github.com/github.com-default/g' <<< \"$1\"`;};f"
  urlc = "!f(){ git config remote.origin.url `git config remote.origin.url | sed 's/github.com/github.com-work/g'`;};f"
  urld = "!f(){ git config remote.origin.url `git config remote.origin.url | sed 's/github.com/github.com-default/g'`;};f"

use it like git cld github.com/repo to clone repo and replace github.com host to github.com-default automatically

I had to change the [remote "origin"] / url field in my local .git/config to use the Host defined in .ssh/config in order for this to work, i.e.,

[remote "origin"]
        url = git@github.com-activehacker:activehacker/gfs.git

Without that modification, git would just try to use my default ssh key.

Thanks!!! working perfectly.