How Can I Use SFTP to Transfer Files Between a Local Linux Computer and a Linux ECS?

Scenarios

You want to use SFTP to transfer files between a local Linux computer and a Linux ECS. The following uses CentOS as an example.

Procedure

Log in to the ECS as user root.
Run the following command to check the OpenSSH version, which is expected to be 4.8p1 or later:
ssh -V

Information similar to the following is displayed:
```
# OpenSSH_7.4p1, OpenSSL 1.0.2k-fips 26 Jan 2017
```
Create a user group and a user (for example, user1).
groupadd sftp

useradd -g sftp -s /sbin/nologin user1
Set a password for the user.
passwd user1

Figure 1 Setting a password
Assign permissions to directories.
chown root:sftp /home/user1

chmod 755 -R /home/user1

mkdir /home/user1/upload

chown -R user1:sftp /home/user1/upload

chmod -R 755 /home/user1/upload
Run the following command to edit the sshd_config configuration file:
vim /etc/ssh/sshd_config
Comment out the following information:
```
#Subsystem sftp /usr/libexec/openssh/sftp-server
```
Add the following information:
```
Subsystem sftp internal-sftp
Match Group sftp
ChrootDirectory /home/%u 
ForceCommand internal-sftp
AllowTcpForwarding no
X11Forwarding no
```
Figure 2 sshd_config file with the added information
Run the following command to restart the ECS:
service sshd restart

Alternatively, run the following command to restart sshd:

systemctl restart sshd
Run the following command on the local computer to set up the connection:
sftp root@IP address
Run the sftp command to check the connection.
Transfer files or folders.
To upload files or folders, run the put -r command.

To download files or folders, run the get -r command.