Record a solution about 'Permission denied' in Git


Record a solution about 'Permission denied' in Git


     Usually when we use the git clone code, we install the git tool, then generate the ssh private key pair, and add the public key to the SSH keys of github or gitlib. But I sometimes encounter this situation, Prompt Permission denied. Then I will record here, how I solved this problem, and provide you with more ideas to solve this problem.

Problem

     Isn’t this a command we usually use? Why does it fail all of a sudden. From this phenomenon, it should be that the public key does not exist.

$ git clone git@github.com:graalvm/mx.git
Cloning into 'mx'...
git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.

Solutions

General idea

Generate private key pair

$ ssh-keygen -o -t rsa -b 4096 -C "xxx@xxx.com"
Generating public/private rsa key pair.
Enter file in which to save the key (/Users/xxx/.ssh/id_rsa): /Users/xxx/.ssh/id_rsa_xxx #Support custom file names
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /Users/xxx/.ssh/id_rsa_xxx.
Your public key has been saved in /Users/xxx/.ssh/id_rsa_xxx.pub.
The key fingerprint is:
SHA256:QBo6c0OT2g+SmTIElhDCvuQVxwqK4Wp7JOnmwm5U1/A xxx@xxx.com
The key's randomart image is:
+---[RSA 4096]----+
|Oo. =..          |
|+= +.O           |
|*.=*B =          |
|=+*Boo E         |
|+o=..o  S        |
|.B .  .          |
|= +              |
|.* .             |
|*o.              |
+----[SHA256]-----+

Copy public key

     Copy the public key to the SSH keys page of gitlab.

$ cat  ~/.ssh/id_rsa_xxx.pub

Add private key

$ ssh-add -K ~/.ssh/id_rsa_xxx

Special cases

View key

     First use ssh-add -l to view the private key. Under normal circumstances, the RSA line should appear, if not, add it, but the Agent does not exist.

$ ssh-add -l
Could not open a connection to your authentication agent.

View proxy

     So what does ssh-agent do, I will only briefly talk about the role of this ssh-agent, but there are actually two functions.

# Does not exist
$ ps -ef | grep ssh-agent 
root      499761  498856  0 03:56 pts/6    00:00:00 grep --color=auto ssh-agent 

# Start Agent
$ eval `ssh-agent -s`
Agent pid 497890

# View Agent
$ ssh-agent
SSH_AUTH_SOCK=/var/folders/7g/j8kn3xy50mgdb1c7jz_vp6_c0000gn/T//ssh-wTB99grIdHS9/agent.49789; export SSH_AUTH_SOCK;
SSH_AGENT_PID=497890; export SSH_AGENT_PID;
echo Agent pid 497890;

Add private key

#Add default private key
$ ssh-add 
Identity added: /Users/xxx/.ssh/id_rsa (xxx@xxx.local)

# Delete default private key
$ ssh-add -d                     
Identity removed: /Users/xxx/.ssh/id_rsa RSA (xxx@xxx.local)

     Add the specified private key, there is a place to pay attention. That is, if it is a Mac system, use uppercase K . If it is a Linux system, use lowercase k.

# Add the specified private key
$ ssh-add -K ~/.ssh/id_rsa_xxx      
Identity added: /Users/xxx/.ssh/id_rsa_xxx (xxx@xxx.com)

# Delete the specified private key
➜  ssh-add -d  ~/.ssh/id_rsa_xxx                   
Identity removed: /Users/xxx/.ssh/id_rsa_github RSA (xxx@xxx.com)

Check the private key again

     If there is, it means normal, otherwise it means that it has not been added successfully or has expired (the expiration time is not clear).

$ ssh-add -l
4096 SHA256:bTbs6kx7yG96kNd1fGO1lgaCNIZAcZzS8OtQzKDcai8 xx@xx.com (RSA)

Verification status

     It’s ok if it returns the following.

# Gitlab
ssh -T git@gitlab.company.com
Welcome to GitLab, @xxx!

# Github
ssh -T  git@github.com
Hi xxx! You've successfully authenticated, but GitHub does not provide shell access.


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