no matching host key type found. Their offer: ssh-dss
使用SSH登录时报错如下：
代码语言：javascript复制Unable to negotiate with 20.1.1.174 port 22: no matching host key type found. Their offer: ssh-dss
报错原因是OpenSSH7.0之后不再支持ssh-dss算法，可以通过添加参数-oHostKeyAlgorithms= ssh-dss来支持该算法：
sftp -oHostKeyAlgorithms= ssh-dss -i id_rsa test@20.1.1.174
Permissions 0644 for ‘id_rsa’ are too open
使用SSH登录时报错如下：
代码语言：javascript复制Permissions 0644 for 'id_rsa' are too open.
It is required that your private key files are NOT accessible by others.
This private key will be ignored.
这个报错是因为id_rsa是私钥文件，属于敏感文件，不能开放权限给其他用户组，哪怕是只读也不行，在缩小权限之前该私钥文件将一直被忽略。
通过赋予该文件400或600的权限即可成功登陆SSH：
代码语言：javascript复制chmod 400 id_rsa
chmod 600 id_rsa
参考链接
- no matching host key type found. Their offer: ssh-dss,ssh-rsa
- 【web渗透】私钥ssh远程登录报错：permission 0644 for ‘id_rsa‘ are too open
