什么是ssh查看ssh公钥是否存在创建ssh公钥
什么是ssh
使用 SSH 协议可以连接远程服务器和服务并向它们验证。 利用 SSH 密钥可以连接 GitHub，而无需在每次访问时提供用户名或密码。
查看ssh公钥是否存在 cat ~/.ssh/id_rsa.pub如果显示 cat: /Users/********/.ssh/id_rsa.pub: No such file or directory ，表示没有创建公钥，则需要自己创建公钥。
创建ssh公钥（1）用 ssh-keygen 创建公钥：
xinna@sionas-MacBook-Air ~ % ssh-keygen Generating public/private rsa key pair.Enter file in which to save the key (/Users/xinna/.ssh/id_rsa): /Users/xinna/.ssh/id_rsa already exists.Overwrite (y/n)? yEnter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /Users/xinna/.ssh/id_rsa.Your public key has been saved in /Users/xinna/.ssh/id_rsa.pub.The key fingerprint is:SHA256:UmEi7XKNfPMu1ZkNPtJsGGkCyTrfOjTrF+IQAn7sqwE xinna@sionas-MacBook-Air.localThe key's randomart image is:+---[RSA 2048]----+| .o..o ||. .=o . ||... + +. . || ..o= =.= + . ||E o. *.oS= B = ||. .. =.o = X . || . .+ = + o . || .. = o . || .. ..o . |+----[SHA256]-----+它先要求你确认保存公钥的位置（.ssh/id_rsa），然后它会让你重复一个密码两次，如果不想在使用公钥的时候输入密码，可以留空。
（2）使用cat ~/.ssh/id_rsa.pub 查看公钥：
xinna@sionas-MacBook-Air ~ % cat ~/.ssh/id_rsa.pubssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDkL0lFa+JqVPDiFeE2BvaMwWH496wkc7e+IVOZoJ+UzooK7B6/IBZ7HcBoHs8ckF3DdFpdJonwGkNFlCnpVDs+wxamdUgPqARJq7nEe5DeG5UQ4LCyZSwRA1OUOl/3gpAK+oYm/v11EgdGoajYJDUCTTp5fsSxaCl4s/Ym8uqUWR+Ba4Aoz117ka4i6yX1EiFfkv2ztbES+Lq9wNs57vK/ktoQmBLslGq2HqTt//WrJJkK2C0HlVSV9lkLZgH1qd5K7dxP1rY7IOrdwvhtwVUGE5V3fmBWGqnlZWJ2tkYczlnPWb0uX0FqP1qod8GZGBoJfgVhGShQBFMXdgqY+V9h xinna@sionas-MacBook-Air.local