无法通过VS Code连接Azure Ubuntu VM：公钥权限拒绝问题求助

使用.ppk文件可通过Putty正常连接Azure虚拟机，但通过VS Code的SSH配置文件使用.ppk或.pem文件连接时，均出现错误：Permission denied(Public key)。

SSH日志 #

root@VMWDEPOCEUS001:/var/log# tail -30 auth.log  
Oct 27 10:19:12 VMWDEPOCEUS001 sshd[3087]: Failed password for invalid user ssh user from 156.163.33.75 port 56425 ssh2 
Oct 27 10:19:14 VMWDEPOCEUS001 sshd[3087]: Failed password for invalid user ssh user from 156.163.33.75 port 56425 ssh2 
Oct 27 10:19:15 VMWDEPOCEUS001 sshd[3087]: Connection reset by invalid user ssh user 156.163.33.75 port 56425 [preauth] 
Oct 27 10:23:52 VMWDEPOCEUS001 sshd[3095]: Invalid user ssh user1 from 156.163.33.75 port 56590 
Oct 27 10:23:57 VMWDEPOCEUS001 sshd[3095]: Failed none for invalid user ssh user1 from 156.163.33.75 port 56590 ssh2 
Oct 27 10:24:00 VMWDEPOCEUS001 sshd[3095]: Failed password for invalid user ssh user1 from 156.163.33.75 port 56590 ssh2 
Oct 27 10:24:04 VMWDEPOCEUS001 sshd[3095]: Failed password for invalid user ssh user1 from 156.163.33.75 port 56590 ssh2 
Oct 27 10:24:05 VMWDEPOCEUS001 sshd[3095]: Connection reset by invalid user ssh user1 156.163.33.75 port 56590 [preauth] 
Oct 27 10:25:26 VMWDEPOCEUS001 sshd[3099]: Accepted password for user1 from 156.163.33.75 port 56649 ssh2 
Oct 27 10:25:26 VMWDEPOCEUS001 sshd[3099]: pam_unix(sshd:session): session opened for user user1 by (uid=0) 
Oct 27 10:25:26 VMWDEPOCEUS001 systemd-logind[1238]: New session 6 of user user1. 
Oct 27 10:25:28 VMWDEPOCEUS001 sshd[3167]: Accepted password for user1 from 156.163.33.75 port 56651 ssh2 
Oct 27 10:25:28 VMWDEPOCEUS001 sshd[3167]: pam_unix(sshd:session): session opened for user user1 by (uid=0) 
Oct 27 10:25:28 VMWDEPOCEUS001 systemd-logind[1238]: New session 7 of user user1. 
Oct 27 10:27:00 VMWDEPOCEUS001 sshd[3258]: Invalid user ssh user1 from 156.163.33.75 port 26689 
Oct 27 10:27:14 VMWDEPOCEUS001 sshd[3258]: pam_unix(sshd:auth): check pass; user unknown 
Oct 27 10:27:14 VMWDEPOCEUS001 sshd[3258]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=156.163.33.75 
Oct 27 10:27:16 VMWDEPOCEUS001 sshd[3258]: Failed password for invalid user ssh user1 from 156.163.33.75 port 26689 ssh2 
Oct 27 10:27:30 VMWDEPOCEUS001 sshd[3258]: pam_unix(sshd:auth): check pass; user unknown 
Oct 27 10:27:33 VMWDEPOCEUS001 sshd[3258]: Failed password for invalid user ssh user1 from 156.163.33.75 port 26689 ssh2 
Oct 27 10:27:47 VMWDEPOCEUS001 sshd[3258]: pam_unix(sshd:auth): check pass; user unknown 
Oct 27 10:27:49 VMWDEPOCEUS001 sshd[3258]: Failed password for invalid user ssh user1 from 156.163.33.75 port 26689 ssh2 
Oct 27 10:27:49 VMWDEPOCEUS001 sshd[3258]: Connection reset by invalid user ssh user1 156.163.33.75 port 26689 [preauth] 
Oct 27 10:27:49 VMWDEPOCEUS001 sshd[3258]: PAM 2 more authentication failures; logname= uid=0 euid=0 tty=ssh ruser= rhost=156.163.33.75 
Oct 27 10:31:22 VMWDEPOCEUS001 sshd[3279]: Invalid user ssh user1 from 156.163.33.75 port 56826 
Oct 27 10:31:34 VMWDEPOCEUS001 sshd[3279]: pam_unix(sshd:auth): check pass; user unknown 
Oct 27 10:31:34 VMWDEPOCEUS001 sshd[3279]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=156.163.33.75 
Oct 27 10:31:35 VMWDEPOCEUS001 sshd[3279]: Failed password for invalid user ssh user1 from 156.163.33.75 port 56826 ssh2 
Oct 27 10:32:09 VMWDEPOCEUS001 sshd[3279]: pam_unix(sshd:auth): check pass; user unknown 
Oct 27 10:32:10 VMWDEPOCEUS001 sshd[3279]: Failed password for invalid user ssh user1 from 156.163.33.75 port 56826 ssh2

问题分析 #

从日志可以看到，VS Code发起的连接尝试中，使用的用户名是ssh user1，但系统中实际存在的有效用户名是user1（日志10:25:26处有Accepted password for user1的成功记录），这说明SSH配置文件里的用户名配置错误，多了"ssh "前缀。另外，VS Code的SSH客户端不直接支持.ppk格式密钥，需要转换成OpenSSH兼容的.pem格式。

解决方案 #

1. 修正SSH配置文件中的用户名

   • 打开VS Code的SSH配置文件（可通过Remote-SSH插件的"Open SSH Configuration File"选项打开，或直接编辑本地~/.ssh/config文件）
   • 找到对应Azure虚拟机的Host配置块，确保User字段为正确的用户名user1，而非带前缀的"ssh user1"

2. 将.ppk密钥转换为OpenSSH兼容格式

   • 用Puttygen打开你的.ppk文件
   • 点击菜单栏Conversions -> Export OpenSSH key，将密钥保存为.pem格式文件
   • 修改.pem文件的权限（必须设置为600，否则SSH会拒绝使用）：

     chmod 600 /path/to/your/converted-key.pem
     

3. 更新SSH配置的密钥路径
   在Host配置块中指定转换后的.pem文件路径，示例配置：

   Host azure-ubuntu-vm
       HostName <你的虚拟机IP或域名>
       User user1
       IdentityFile /path/to/your/converted-key.pem
   

4. 重新尝试连接
   在VS Code的Remote-SSH插件中选择配置好的Host，发起连接即可。

内容的提问来源于stack exchange，提问作者Pradeep