OpenSSL commands

Convert .p12 to .pem using Openssl
openssl pkcs12 -in filename.p12 -out filename.pem

Convert .key to .pem
openssl rsa -in server.key -text > my-key.pem

Convert .crt to .pem
openssl x509 -inform PEM -in server.crt > my-cert.pem

Create .p12 from .crt and .key
1) openssl rsa -in server.key -text > my-key.pem
2) openssl x509 -inform PEM -in server.crt > my-cert.pem
3) openssl pkcs12 -inkey my-key.pem -in my-cert.pem -export -name mycertname -out myp12file.p12
Enter Export Password:
Verifying - Enter Export Password:

Export private key from password protected .p12 file 

openssl pkcs12 -in filename.p12 -password stdin -out key.pem -nocerts

Export cert from password protected .p12 file 

openssl pkcs12 -in filename.p12 -password stdin -out key.pem -nokeys -clcerts

option -clcerts extract only client certificate without ca certs

Create request (CSR) for submission to Certificate Authority

openssl req -out /opt/apacheconf/ssl/mywebsite.csr -new -newkey rsa:2048 -nodes -keyout /opt/apacheconf/ssl/mywebsite-privkey.key

View CSR file content
openssl req -in myfile.csr -noout -text

Error

C:\OpenSSL-Win64\bin>openssl
WARNING: can't open config file: /usr/local/ssl/openssl.cnf

Solution
set OPENSSL_CONF=C:\OpenSSL-Win64\bin\openssl.cfg
Set openssl conf path in command line and rerun openssl

SSH authorization between hosts with no password

This script will allow to login to remote servers with no password after first time execution.

ssh_script.sh
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#!/bin/sh
source ~/.bash_profile

# Uncomment and execute this line only one for generation of keys on local server running the script
#ssh-keygen -t rsa

user=myuser
servers="server1-ip server2-ip"

for server in $servers
do
  #Make sure .ssh directory has permissions 700 (Higher privileges cause authorization issues)
  ssh $user@$server 'mkdir ~/.ssh; chmod -R 700 ~/.ssh'
  echo "Copying to server $server"

  # the line copies the authorized keys to the remote server
  #scp ~/.ssh/id_rsa.pub $user@$server:~/.ssh/authorized_keys

  #-------- Append local server id_rsa.pub content into remote server authorized_keys file
  cat ~/.ssh/id_rsa.pub | ssh $user@$server "cat >> ~/.ssh/authorized_keys"
done
exit 0
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