关于.ssh出错，无法从远程git仓库拉代码

背景：从windows开发环境改到ubuntu，将windows下生成的.ssh文件拷贝到ubuntu下，以clone远程git仓库代码

错误：sign_and_send_pubkey: signing failed: agent refused operation

解决方法：

ssh-agent -s
ssh-add

错误：Permissions 0664 for '/home/root/.ssh/id_rsa' are too open

解决方法：

sudo chmod 600 id_rsa
sudo chmod 600 id_rsa.pub 
sudo chmod 600 known_hosts