$ ssh-keygen -p终端提示
Enter file in which the key is (/Users/wengf/.ssh/id_rsa): # 这里直接回车
Enter old passphrase: // 输入密码
Enter new passphrase (empty for no passphrase): // 新密码直接回车
Enter same passphrase again:
Your identification has been saved with the new passphrase. // Ok