Profiles

System profiles change server configuration outside the LetXDP traffic path.

Current system profile:

Profile	What it does
Disable SSH Password & Generate key	Turns off SSH password login, creates a private SSH key, and installs the matching public key for root access.

Disable SSH Password & Generate key

Use this profile when you want root SSH access to use a private key instead of a password.

When enabled, LetCore:

• Generates a private key on the server.
• Adds the matching public key to /root/.ssh/authorized_keys.
• Updates SSH server settings to disable password login.
• Restarts or reloads SSH so the change takes effect.
• Shows a Download key action in the profile table.

Caution

Download the key and test a new SSH login before closing your current SSH session. If the key is missing or saved incorrectly, password login may no longer work.

How to enable it

1. Open System configuration.
2. Click Add profile.
3. Add Disable SSH Password & Generate key.
4. Enable the profile.
5. Click Download key and save the file as letcore_ssh_access.
6. Test a new SSH connection with the downloaded key.

Connect from macOS or Linux

Open Terminal in the folder where you saved the key.

Set private permissions:

chmod 600 letcore_ssh_access

Connect to the server:

ssh -i ./letcore_ssh_access root@YOUR_SERVER_IP

Replace YOUR_SERVER_IP with your server IP address or hostname.

If SSH uses a custom port, add -p:

ssh -i ./letcore_ssh_access -p 2222 root@YOUR_SERVER_IP

Connect from Windows PowerShell

Save the downloaded key somewhere stable, for example:

C:\Users\YourName\.ssh\letcore_ssh_access

Open PowerShell and connect:

ssh -i $env:USERPROFILE\.ssh\letcore_ssh_access root@YOUR_SERVER_IP

If SSH uses a custom port:

ssh -i $env:USERPROFILE\.ssh\letcore_ssh_access -p 2222 root@YOUR_SERVER_IP

Fix Windows “bad permissions” errors

Windows OpenSSH may reject the key if the file inherited permissions from Downloads or another user/group can read it.

If you see WARNING: UNPROTECTED PRIVATE KEY FILE! or Bad permissions, open Command Prompt in the folder where the key is saved and run:

takeown /f .\letcore_ssh_access
icacls .\letcore_ssh_access /reset
icacls .\letcore_ssh_access /inheritance:r
icacls .\letcore_ssh_access /remove:g "Users"
icacls .\letcore_ssh_access /remove:g "Authenticated Users"
icacls .\letcore_ssh_access /grant:r "%USERDOMAIN%\%USERNAME%:R"

Check the remaining permissions:

icacls .\letcore_ssh_access

Then connect again:

ssh -i .\letcore_ssh_access root@YOUR_SERVER_IP

If OpenSSH names a specific SID in the error, remove that SID too. For example:

icacls .\letcore_ssh_access /remove:g *S-1-5-21-EXAMPLE

You can also restrict the file permissions from File Explorer:

1. Right-click the key file.
2. Open Properties > Security > Advanced.
3. Disable inheritance.
4. Keep access only for your Windows user.

Connect from PuTTY on Windows

PuTTY uses its own key format.

1. Open PuTTYgen.
2. Click Load.
3. Select the downloaded letcore_ssh_access file.
4. Click Save private key and save a .ppk file.
5. Open PuTTY.
6. Enter your server IP or hostname.
7. Go to Connection > SSH > Auth > Credentials.
8. Select the saved .ppk private key.
9. Connect as user root.

Disable or remove the profile

Disabling or removing the profile deletes the LetCore-generated key and turns SSH password login back on.

After disabling, test SSH again before ending your current session.