Win7 Git bash 出現Permission denied (publickey)錯誤

Windows使用者的多數程式員喜歡安裝Git bash，用指令行控制。最近發現如果要操作多個git repos，需要生成多個MD5密鑰。在執行git操作時需要指定使用哪個密碼，通過以下設定可以實作。

Check that you are connecting to the correct server

使用下面的指令檢查是否連接配接到正确的domain：

$ ssh -vT ssh -vT [email protected]
OpenSSH_7.p2, OpenSSL .h   May 
debug1: Reading configuration data /c/Users/Amy Zhao/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Connecting to github.com [.] port .
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file /c/Users/Amy Zhao/.ssh/id_rsa type -
debug1: key_load_public: No such file or directory
...
           

Always use the “git” user

All connections must be made as the “git” user. If you try to connect with your GitHub username, it will fail:

$ ssh -T [email protected]
Permission denied (publickey)
           

Instead, you should verify your connection by typing:

$ ssh -T [email protected]
Hi your_username! You've successfully authenticated, but GitHub does not provide shell access.
           

Make sure you have a key that is being used

First, you should turn on ssh-agent:

# start the ssh-agent in the background
$ eval "$(ssh-agent -s)"
Agent pid 
           

Verify that you have a private key generated and loaded into SSH. If you’re using OpenSSH 6.7 or older, typing:

$ ssh-add -l
 a0:dd::c:a:d:e4:a:::e:::e:c8:d /Users/you/.ssh/id_rsa (RSA)
           

Or if you’re using OpenSSH 6.8 or newer:

$ ssh-add -l -E md5
 MD5:a0:dd::c:a:d:e4:a:::e:::e:c8:d /Users/you/.ssh/id_rsa (RSA)
           

The

ssh-add

command should print out a long string of numbers and letters. If it doesn’t print anything, you’ll need to [generate a new SSH key][generate SSH keys] and associate it the GitHub.

Tip: On most systems the default private keys (~/.ssh/id_rsa, ~/.ssh/id_dsa and ~/.ssh/identity) are automatically added to the SSH authentication agent. You shouldn’t need to run ssh-add path/to/key unless you override the file name when you generate a key.

Auto-launching ssh-agent on Git for Windows

If you want to auto-start ssh-agent and add the private key you wanted, you can config your

~/.bashrc

file like below:

env=~/.ssh/agent.env

agent_load_env () { test -f "$env" && . "$env" >| /dev/null ; }

agent_start () {
    (umask ; ssh-agent >| "$env")
    . "$env" >| /dev/null ; }

agent_load_env

# agent_run_state: 0=agent running w/ key; 1=agent w/o key; 2= agent not running
agent_run_state=$(ssh-add -l >| /dev/null >&; echo $?)

if [ ! "$SSH_AUTH_SOCK" ] || [ $agent_run_state =  ]; then
    agent_start
    ssh-add ~/.ssh/github-amy
    ssh-add ~/.ssh/github_rsa
elif [ "$SSH_AUTH_SOCK" ] && [ $agent_run_state =  ]; then
    ssh-add ~/.ssh/github-amy
    ssh-add ~/.ssh/github_rsa
fi

unset env
           

Tip: If your private keys are not stored in ~/.ssh/id_rsa or ~/.ssh/id_dsa, you must add their paths with the ssh-add command so that your SSH authentication agent knows where to find them. For example:

ssh-add ~/.my_other_ssh/id_rsa

Now, when you first run Git Bash, your ssh-agent and identities was started automatically.

The

ssh-agent

process will continue to run until you log out, shut down your computer or kill the process.

If you want

ssh-agent

to forget your key after some time, you can configure it to do so by running

ssh-add -t <seconds>

.

參考

GitHub Help

Working with SSH key passphrases

Error: Permission denied (publickey)

Amy’s Blog