SSH

Setup ssh keys on mac

  • Step 1 - Create ssh key pairs and add passphase to the private key

  • Step 2 - Store the key in the keychain

    Just do this once:

    ssh-add -K ~/.ssh/[your-private-key]

  • Step 3 - Configure SSH to always use the keychain

.ssg/config

Host *
  UseKeychain yes
  AddKeysToAgent yes
  IdentityFile ~/.ssh/[your-private-key]

list ssh fingerprint of public key

ssh -l -f <path_to_public_key>

if you need MD5 output specify -E md5 as

ssh -l -E md5 -f <path_to_public_key>

The fingerprint is the MD5 of the Base64-encoded public key.

$ ssh-keygen -f foo
Generating public/private rsa key pair.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in foo.
Your public key has been saved in foo.pub.
The key fingerprint is:
65:30:38:96:35:56:4f:64:64:e8:e3:a4:7d:59:3e:19 andrew@localhost
The key's randomart image is:
+--[ RSA 2048]----+
|       +*..+*    |
|      =. +.=     |
|     . . .o .    |
|         o+   E  |
|        S= . + o |
|        . o o +  |
|           .   . |
|                 |
|                 |
+-----------------+
$ cat foo.pub
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDEbKq5U57fhzQ3SBbs3NVmgY2ouYZfPhc6cXBNEFpRT3T100fnbkYw+EHi76nwsp+uGxk08kh4GG881DrgotptrJj2dJxXpWp/SFdVu5S9fFU6l6dCTC9IBYYCCV8PvXbBZ3oDZyyyJT7/vXSaUdbk3x9MeNlYrgItm2KY6MdHYEg8R994Sspn1sE4Ydey5DfG/WNWVrzFCI0sWI3yj4zuCcUXFz9sEG8fIYikD9rNuohiMenWjkj6oLTwZGVW2q4wRL0051XBkmfnPD/H6gqOML9MbZQ8D6/+az0yF9oD61SkifhBNBRRNaIab/Np7XD61siR8zNMG/vCKjFGICnp andrew@localhost
$ echo 'AAAAB3NzaC1yc2EAAAADAQABAAABAQDEbKq5U57fhzQ3SBbs3NVmgY2ouYZfPhc6cXBNEFpRT3T100fnbkYw+EHi76nwsp+uGxk08kh4GG881DrgotptrJj2dJxXpWp/SFdVu5S9fFU6l6dCTC9IBYYCCV8PvXbBZ3oDZyyyJT7/vXSaUdbk3x9MeNlYrgItm2KY6MdHYEg8R994Sspn1sE4Ydey5DfG/WNWVrzFCI0sWI3yj4zuCcUXFz9sEG8fIYikD9rNuohiMenWjkj6oLTwZGVW2q4wRL0051XBkmfnPD/H6gqOML9MbZQ8D6/+az0yF9oD61SkifhBNBRRNaIab/Np7XD61siR8zNMG/vCKjFGICnp' \
    | base64 -d | md5sum
6530389635564f6464e8e3a47d593e19

The md5sum 6530389635564f6464e8e3a47d593e19 is the fingerprint displayed when the key is generated, only without the separating colons.

convert openssh to rsa

ssh-keygen -p -N "" -m PEM -f <OPENSSH_PRIVATE> -t rsa

ssh config for multple github accounts

Host github.com-work
  User git
  Hostname github.com
  PreferredAuthentications publickey
  IdentityFile ~/.ssh/id_rsa_work
  IdentitiesOnly yes

Host github.com-personal
  User git
  Hostname github.com
  IdentityFile ~/.ssh/id_rsa_personal
  IdentitiesOnly yes
 
Host *
  AddKeysToAgent yes
  #IdentityFile ~/.ssh/id_rsa
  StrictHostKeyChecking no
  UserKnownHostsFile=/dev/null
  ServerAliveInterval 300
  ServerAliveCountMax 2

Other

export ssh_auth_sock which will be used later for backup (so root can use your ssh keys for connecting to the remote box)

server$ sudo su -l -c "export SSH_AUTH_SOCK=$SSH_AUTH_SOCK; bash"

Getting the ssh-keyscan via your Jenkins installation

> ssh-keyscan github.com
# github.com:22 SSH-2.0-babeld-f1c576c9
github.com ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBEmKSENjQEezOmxkZMy7opKgwFB9nkt5YRrYMjNuG5N87uRgg6CLrbo5wAdT/y6v0mKV0U2w0WZ2YB/++Tpockg=
# github.com:22 SSH-2.0-babeld-f1c576c9
github.com ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ==
# github.com:22 SSH-2.0-babeld-f1c576c9
github.com ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOMqqnkVzrm0SdG6UOoqKLsabgH5C9okWi0dh2l9GKJl
# github.com:22 SSH-2.0-babeld-f1c576c9
# github.com:22 SSH-2.0-babeld-f1c576c9