Setup SSH Login With Keygen In OSX

I’m quite tired with copy-pasting passwords from my Evernote every time I login to my company’s remote server. Especially my company uses a proxy server, which means I have to type two passwords to eventually login.

（;≧皿≦）。゜°。

Then I found Keygen tool, which can help us login without typing password.

＼（○＾ω＾○）／

SSH Keygen is to generate a pair of key, putting the public key in your remote server, secret key in your local machine.
If you are also using a Mac, ~/.ssh/id_ras is the default option of storing secret key, ~/.ssh/id_ras for public key. You can create many key pairs, and specify which pair to use by adding IdentityFile option in your ~/.ssh/config file.

Configurations With Single SSH Connection

1. generate keys in your local machine

~ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/Users/user/.ssh/id_rsa): [press Enter]
Enter passphrase (empty for no passphrase): [press Enter]
Enter same passphrase again: [press Enter]
Your identification has been saved in /Users/user/.ssh/id_rsa.
Your public key has been saved in /Users/user/.ssh/id_rsa.pub.
The key fingerprint is:
**fingerprint**
The key's randomart image is:
+---[RSA 2048]----+
|    ...          |
|     o . .       |
|    o o + o      |
|     + B B +     |
| .   .= S B o    |
|=o...o.o * o     |
|Bo+oE ... +      |
|=.++ ..  .       |
|o++oooo.         |
+----[SHA256]-----+

2. copy public key to your server

If you haven’t installed ssh-copy-id yet, use homebrew or Macports to install it.
Then, copy your public key to your remote server, this step needs you type password.

~ ssh-copy-id -i ~/.ssh/id_rsa.pub username@servername

Finally, make sure you can now login without password, and it’s done.

ヘ(・、ヘ)ホイホイ(ノ、・)ノホイホイ

~ ssh username@servername
Last login: Sat Sep 17 15:00:45 2016 from XXX.XXX.XXX.XXX

Configurations for Multiple SSH connections

1. change ssh configuration

If you use a proxy server like my company does, edit .ssh/config file to change your ssh configuration (If there is no file named config in OSX, create a new one).

Host [servername]
ServerAliveInterval 90
ServerAliveCountMax 8
Hostname [username@servername]
User [username]
ProxyCommand ssh [username@proxyname] nc %h %p

2. generate key pairs

Same as Step 1 in Single SSH connection do.

3. copy your public key to both your proxy server and your real server

Same as Step 2 in Single SSH connection do.

Make sure you can login your real server password, and it’s done.