Load key error in libcrypto

If your screen looks like this 

jovyan@jupyter-rachitgupta:~$ git clone git@github.com:ucsb-cs5b-s26/lab01-rachit182.git
Cloning into 'lab01-rachit182'...
Load key "/home/jovyan/.ssh/id_ed25519": error in libcrypto
git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

What this usually means

Your SSH private key file exists, but it is empty or corrupted.

For example, you may see something like this:

jovyan@jupyter-rachitgupta:~$ ls -l ~/.ssh
total 8
-rwx------. 1 jovyan users   0 Apr  1 19:38 id_ed25519
-rwx------. 1 jovyan users 108 Apr  1 18:22 id_ed25519.pub
-rwx------. 1 jovyan users 142 Apr  6 17:41 known_hosts

In ls -l output, the file size is the number just before the date.

So in this line:

-rwx------. 1 jovyan users   0 Apr  1 19:38 id_ed25519

the 0 is the size of id_ed25519, measured in bytes.

If id_ed25519 is 0 bytes, the private key is not usable. That is why SSH reports error in libcrypto and GitHub rejects the login.

How to fix it

  1. Run:
ssh-keygen
  1. When you see:
Enter file in which to save the key (/home/jovyan/.ssh/id_ed25519):
/home/jovyan/.ssh/id_ed25519 already exists.
Overwrite (y/n)?

Type:

y

You must type y or the broken key will not be replaced.

  1. Press Enter to accept the default file location.
  2. You can leave the passphrase empty if your course instructions say that is okay.

Check that the new key is valid

Run:

ls -l ~/.ssh

Your id_ed25519 file should now be much larger than 0 bytes.

You can also test it with:

ssh-keygen -y -f ~/.ssh/id_ed25519

If the key is valid, this should print a public key and should not show a libcrypto error.

Final steps

  1. Show your public key:
cat ~/.ssh/id_ed25519.pub
  1. Copy that output and add it on GitHub under Settings -> SSH and GPG keys.
  2. Test the connection:
ssh -T git@github.com
  1. Retry your original command:
git clone git@github.com:ucsb-cs5b-s26/lab01-rachit182.git

Summary

The root cause is usually an empty private SSH key file, often shown as 0 bytes in ~/.ssh/id_ed25519.

The fix is to regenerate the key and make sure you confirm overwrite with y.