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SCP with a Key

SCP is a secure copy utility in Linux. You’ll need access to your system. In this example, a pem key is used to authenticate to a host. SCP copies filename.ext to the home directory of ec2-user. It’s important to add the target directory, otherwise it will not work.

Here’s how to use SCP with a key from local to server.

scp -i key.pem filename.ext user@server:/home/user

From server to local. Run the command from local machine.

scp user@server:/home/user/file.txt /local/directory

OpenSSL Upgrade

Here’s how to upgrade to OpenSSL 1.1 on Redhat/Centos.

# check
openssl version
yum info openssl
# download and install
cd /usr/local/src
wget https://www.openssl.org/source/openssl-1.0.2-latest.tar.gz
tar -zxf openssl-1.0.2-latest.tar.gz
# compile
cd openssl-1.0.2a
./config
make
make test
make install
# update softlink
mv /usr/bin/openssl /root/
ln -s /usr/local/ssl/bin/openssl /usr/bin/openssl
# verify new version
openssl version

SSH Script

Here’s my custom ssh script named login.sh using multiple arguments. 

#!/bin/bash
if [ $# -eq 0 ]
  then
    echo 'no server supplied'
        exit 1
fi
INPUT=$2
case "$INPUT" in
  abc)
    ssh user1@$1
    ;;
  def)
    ssh user2@$1
    ;;
  *)
    ssh user3@$1
    ;;
esac

How to use with expected outputs.

./login.sh
no server supplied
./login.sh server3 abc
ssh user1@server3
./login.sh server2 def
ssh user2@server2
./login.sh server1
ssh user3@server1