Macで公開鍵生成する
- Motivation
- クラウド、オンプレ問わずネットワークを経由してサーバーへアクセスする際にまず最低限求められることは公開鍵、秘密鍵による認証である。
- またソースIP制限などもよく見かけるが、組み合わせて使用されることが多い（インターネットから誰でもアクセスできるところにパスワード認証のみのサーバーを置いてある人は今すぐ設定を再考すべし。）
Pre-requirements
- Macbook Pro
- Teminal
0. Steps
-
.sshディレクトリ作成 - 公開鍵/秘密鍵作成
1. .sshディレクトリの作成
すでに.sshディレクトリがすでにある場合はスキップ
1-1. ディレクトリ移動
# Usersのホームディレクトリへ移動
$ cd ~/
# 移動できたことを確認
$ pwd
/Users/[Username]
# .sshディレクトリがあるか確認する
$ ls -la
total 32
drwxr-xr-x+ 16 [Username] staff 512 5 1 22:59 .
drwxr-xr-x 5 root admin 160 4 7 04:45 ..
-r-------- 1 [Username] staff 7 5 1 20:52 .CFUserTextEncoding
-rw-r--r--@ 1 [Username] staff 8196 5 1 20:43 .DS_Store
drwx------ 2 [Username] staff 64 5 1 22:59 .Trash
-rw------- 1 [Username] staff 0 5 1 21:33 .bash_history
drwx------ 4 [Username] staff 128 5 1 22:59 .bash_sessions
drwx------@ 3 [Username] staff 96 5 1 20:36 Applications
drwx------@ 4 [Username] staff 128 5 1 23:00 Desktop
drwx------@ 3 [Username] staff 96 5 1 19:52 Documents
drwx------+ 4 [Username] staff 128 5 1 21:02 Downloads
drwx------@ 64 [Username] staff 2048 5 1 22:58 Library
drwx------+ 3 [Username] staff 96 5 1 19:47 Movies
drwx------+ 3 [Username] staff 96 5 1 19:47 Music
drwx------+ 3 [Username] staff 96 5 1 19:47 Pictures
drwxr-xr-x+ 4 [Username] staff 128 5 1 19:47 Public
ない！！から作る！！
1-2. ディレクトリ作成
# 作る
$ mkdir .ssh
# できたか確認する
$ ls -al
total 32
drwxr-xr-x+ 17 [Username] staff 544 5 1 23:36 .
drwxr-xr-x 5 root admin 160 4 7 04:45 ..
-r-------- 1 [Username] staff 7 5 1 20:52 .CFUserTextEncoding
-rw-r--r--@ 1 [Username] staff 8196 5 1 23:33 .DS_Store
drwx------ 4 [Username] staff 128 5 1 23:33 .Trash
-rw------- 1 [Username] staff 0 5 1 21:33 .bash_history
drwx------ 4 [Username] staff 128 5 1 22:59 .bash_sessions
drwxr-xr-x 2 [Username] staff 64 5 1 23:36 .ssh
drwx------@ 3 [Username] staff 96 5 1 20:36 Applications
drwx------@ 4 [Username] staff 128 5 1 23:00 Desktop
drwx------@ 3 [Username] staff 96 5 1 19:52 Documents
drwx------+ 4 [Username] staff 128 5 1 23:33 Downloads
drwx------@ 64 [Username] staff 2048 5 1 22:58 Library
drwx------+ 3 [Username] staff 96 5 1 19:47 Movies
drwx------+ 3 [Username] staff 96 5 1 19:47 Music
drwx------+ 3 [Username] staff 96 5 1 19:47 Pictures
drwxr-xr-x+ 4 [Username] staff 128 5 1 19:47 Public
2. 公開鍵/秘密鍵作成
2-1. ディレクトリ移動
# ディレクトリの移動
$ cd ~/.ssh
# 自分の居場所確認
$ pwd
/Users/[Username]/.ssh
2-2. 鍵作成
$ ssh-keygen -t rsa -b 4096
Generating public/private rsa key pair.
Enter file in which to save the key (/Users/[Username]/.ssh/id_rsa): <-- Enter
Enter passphrase (empty for no passphrase): <-- Enter
Enter same passphrase again: <-- Enter
Your identification has been saved in /Users/[Username]/.ssh/id_rsa.
Your public key has been saved in /Users/[Username]/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:******************************************
The key's randomart image is:
+---[RSA 4096]----+
|Eoo.=++...o.o |
|o*.o =o= + o |
|+++ = Boo o |
|oo.. =.+ . |
|.o = S . |
|+ o B . |
|.. . * . |
|. o . |
| |
+----[SHA256]-----+
2-3. できた
$ ls -la
total 16
drwxr-xr-x 4 [Username] staff 128 5 1 23:53 .
drwxr-xr-x+ 17 [Username] staff 544 5 1 23:36 ..
-rw------- 1 [Username] staff 3414 5 1 23:53 id_rsa
-rw-r--r-- 1 [Username] staff 761 5 1 23:53 id_rsa.pub
id_rsa : 秘密鍵
id_rsa.pub : 公開鍵
絶対にid_rsa(秘密鍵は漏らさない)/つまり共有するのはいつもid_rsa.pub)
おまけ： ssh-keygenのその他のオプション
usage: ssh-keygen [-q] [-b bits] [-C comment] [-f output_keyfile] [-m format]
[-N new_passphrase] [-t dsa | ecdsa | ed25519 | rsa]
ssh-keygen -p [-f keyfile] [-m format] [-N new_passphrase]
[-P old_passphrase]
ssh-keygen -i [-f input_keyfile] [-m key_format]
ssh-keygen -e [-f input_keyfile] [-m key_format]
ssh-keygen -y [-f input_keyfile]
ssh-keygen -c [-C comment] [-f keyfile] [-P passphrase]
ssh-keygen -l [-v] [-E fingerprint_hash] [-f input_keyfile]
ssh-keygen -B [-f input_keyfile]
ssh-keygen -D pkcs11
ssh-keygen -F hostname [-lv] [-f known_hosts_file]
ssh-keygen -H [-f known_hosts_file]
ssh-keygen -R hostname [-f known_hosts_file]
ssh-keygen -r hostname [-g] [-f input_keyfile]
ssh-keygen -G output_file [-v] [-b bits] [-M memory] [-S start_point]
ssh-keygen -f input_file -T output_file [-v] [-a rounds] [-J num_lines]
[-j start_line] [-K checkpt] [-W generator]
ssh-keygen -I certificate_identity -s ca_key [-hU] [-D pkcs11_provider]
[-n principals] [-O option] [-V validity_interval]
[-z serial_number] file ...
ssh-keygen -L [-f input_keyfile]
ssh-keygen -A [-f prefix_path]
ssh-keygen -k -f krl_file [-u] [-s ca_public] [-z version_number]
file ...
ssh-keygen -Q -f krl_file file ...
ssh-keygen -Y check-novalidate -n namespace -s signature_file
ssh-keygen -Y sign -f key_file -n namespace file ...
ssh-keygen -Y verify -f allowed_signers_file -I signer_identity
-n namespace -s signature_file [-r revocation_file]