SSH to the Remote AWS Instance and Security Copy Files

1. SSH to the instance

The AWS console always ask us to login to the instance by using a key pair file (*.pem file, Privacy Enchanced Mail). Make sure you have downloaded the key file on the last step of launching an instance.

1.1 SSH on Mac

Open a terminal, and execute:

ssh -i /path/of/you/key/file/key_file_name.pem username@dns-of-the-instance

In this case,
if we have a key file named: 15619.pem, and we put it under: /Users/15619/Demo/; and we have an instance on ec2-1-5-6-19.compute-1.amazonaws.com within username: ec2-user,
then, we will run the command like this:

ssh -i /Users/15619/Demo/15619.pem ec2-user@ec2-1-5-6-19.compute-1.amazonaws.com

Sometimes it will return a warning message that:

bad permissions: ignore key: /Users/15619/Demo/15619.pem
Permission denied (publickey).

In this case, you need to check and change the access permissions to the key pair file:

chmod 600 /Users/15619/Demo/15619.pem

Now re-run the ssh command and you can login to the instance successfully.

1.2 SSH on Windows

On Windows I use PuTTY to ssh to the remote instance. Once you install it on you PC you need to generate a ppk file (PuTTY Private Key) using PuTTYgen and the pem file.
First, lauch PuTTYgen:
Then, load the pem file to PuTTYgen:
Click the button Save private key, then save it to you PC:
Now you are ready to ssh to the instance.
Launch PuTTY, fill the Host Name using the username and instance dns:

ec2-user@ec2-1-5-6-19.compute-1.amazonaws.com

On the left side-panel, choose: Connection->SSH->Auth, click Browse… and select your ppk file,

Then click Open and you can login to the instance successfully.

2. Secure copy

Similarly, we use key file (pem/ppk file) as the identifying flag when we want to transfer file between the remote AWS instance and the local machine, especially, if we want to transfer a folder we need to add a recusive flag -r.

2.1 scp on Mac

If you are under Mac environment, the command is:

scp -i /path/of/you/key/file/key_file_name.pem path/of/the/source/directory/file_name path/of/the/destination/directory/file_name

Now you want to copy a file named Hello.java under /Users/15619/Demo/ from your local device to the remote instance under /Java/Demo/, the command is:

scp -i /Users/15619/Demo/15619.pem /Users/15619/Demo/Hello.java ec2-user@ec2-1-5-6-19.compute-1.amazonaws.com:/Java/Demo/Hello.java

Conversely, if you want to copy a file named Demo.java under /Java/Demo/ from the remote instance to you local device under /Users/15619/Demo/, the command is:

scp -i /Users/15619/Demo/15619.pem ec2-user@ec2-1-5-6-19.compute-1.amazonaws.com:/Java/Demo/Demo.java /Users/15619/Demo/Demo.java

2.2 scp on Windows

If you are under Windows environment, notice here you CANNOT use scp, alternatively, we use pscp instead, the command is:

pscp -i /path/of/you/key/file/key_file_name.ppk path/of/the/source/directory/file_name path/of/the/destination/directory/file_name

Now you want to copy a file named Hello.java under C:\Users\15619\Demo\ from your local device to the remote instance under /Java/Demo/, the command is:

pscp -i C:\Users\15619\Demo\15619.ppk C:\Users\15619\Demo\Hello.java ec2-user@ec2-1-5-6-19.compute-1.amazonaws.com:/Java/Demo/Hello.java

Conversely, if you want to copy a file named Demo.java under /Java/Demo/ on the remote instance to you local device under C:\Users\15619\Demo\, the command is:

pscp -i C:\Users\15619\Demo\15619.ppk ec2-user@ec2-1-5-6-19.compute-1.amazonaws.com:/Java/Demo/Demo.java C:\Users\15619\Demo\Demo.java

2.3 scp recursively

If we need to copy a folder including all the files in it, then we should add -r:
On Mac:

scp -r -i /Users/15619/Demo/15619.pem ec2-user@ec2-1-5-6-19.compute-1.amazonaws.com:/Java/TestFiles/ /Users/15619/Demo/TestFiles/

On Windows:

pscp -r -i C:\Users\15619\Demo\15619.ppk ec2-user@ec2-1-5-6-19.compute-1.amazonaws.com:/Java/Demo/TestFiles/ C:\Users\15619\Demo\TestFiles\