# SSH

## Create key

```bash
ssh-keygen -t ecdsa -b 521

# specif an file
ssh-keygen -t ecdsa -b 521 -f ~/.ssh/key-ecdsa
```

## Copy public key

```bash
ssh-add ~/.ssh/id_ed25519
ssh-copy-id -i ~/.ssh/y-ecdsa.pub example_user@192.0.2.4
```

## Add existing Key

```bash
ssh-add ~/.ssh/key-ecdsa
```

## Alias

```bash
Host srv01
    HostName srv01.lan
    User john
    RemoteCommand cd ~/; exec bash --login
    RequestTTY yes
```

## Port Binding

Bind local port 8001 to target-server port 80 using jump-machine.local.  
_(local machine without direct access to target-server)_

```bash
ssh -f -N -L localhost:8001:target-server:80 usr@jump-machine.local
```