Permission denied error while using scp command between two remote machine

Question

I have 3 machines in my local network. These are

Machine1 : 192.168.1.1 (root user: user1)
Machine2 : 192.168.1.2 (root user: user2) 
Machine3 : 192.168.1.3 (root user: user3)

I am working on Machine1. Other machines (2 and 3) my remote machines. I reach my remote machines using ssh command from Machine1. I have not any direct access to Machine2 and Machine3 other than network-ssh connection.

I want to copy some files that are located on /usr/local/lib path in Machine2 to /usr/local/lib path of machine 3.

For this purpose from my main machine Machine1 when I used the command:

scp [email protected]:/usr/local/lib/my_file [email protected]:/usr/local/lib/my_file

I get the error :

Permission denied, please try again.

Permission denied, please try again.

Permission denied (publickey,password).

After encountering this error I used another method. From my main machine Machine1, I connect Machine2 with ssh connection. From ssh connected Machine2 I used the command:

scp /usr/local/lib/my_file [email protected]:/usr/local/lib/my_file

I get the error:

scp: /usr/local/lib/my_file: Permission denied

From ssh connected Machine3 I used the command:

scp [email protected]:/usr/local/lib/my_file /usr/local/lib/my_file

I get the same error:

scp: /usr/local/lib/my_file: Permission denied

I have tried 3 different method to copy some file in /usr/local/lib path. However I couldn't achieve copy.
How can I copy files, which are located in /usr directory, between 2 remote machines?

Answer 1

I believe the reason you are getting the error is that the regular users do not have the correct permissions set in order to read, write or execute the files you are trying to copy.

I created 2 files, /root/FileByRoot and /home/admin/FileByAdmin.

$ ll /root/FileByRoot
-rw-r--r-- 1 root root 13 Oct 10 00:43 /root/FileByRoot

$ ll /home/admin/FileByAdmin
-rw-rw-r-- 1 admin admin 19 Oct 10 00:43 /home/admin/FileByAdmin

Now, here is what I get when I try to copy them using the admin user to another machine.

$ scp -P 2220 [email protected]:/root/FileByRoot /home/heysus/
[email protected]'s password:
scp: /root/FileByRoot: Permission denied

$ scp -P 2220 [email protected]:/home/admin/FileByAdmin /home/heysus/
[email protected]'s password:
FileByAdmin                                                                           100%   19     0.5KB/s   00:00

$ ll /home/heysus/FileByAdmin
-rw-rw-r-- 1 heysus heysus 19 Oct 10 00:56 /home/heysus/FileByAdmin

Now let's move the file to a directory where admin has full control.

$ mv FileByRoot /home/admin/FileByRoot

Since admin has permissions to the folder, I now can copy it.

$ scp -P 2220 [email protected]:/home/admin/FileByRoot /home/heysus/
[email protected]'s password:
FileByRoot                                                                            
100%   13     0.3KB/s   00:00

In conclusion, enable the root user on your /etc/ssh/sshd_config file and copy the necessary files via the root user. Once you are done, disable root login in the /etc/ssh/sshd_config.