Generate Free SSL HTTPS Certificates with 90 days validity using letsencrypt

 Hi all,

As discussed in my earlier blog, Generate Free SSL Certificate using ZeroSSL where the limitation of one free certificate on ZeroSSL can be eliminated using Get HTTPS for free!

This process includes the following prerequisites and procedures.

Note: This process is not for beginners or production usage scenarios. Use this process if you are knowledgeable about certificate generation.

Prerequisites

• OpenSSL command line
• [Li]nix / Mac OS

Procedure

• Open the URL https://gethttpsforfree.com
• It has 5 steps
• Account Info
• Certificate Signing Request
• Sign API Requests
• Verify Ownership
• Install Certificate
• In each step, some commands or processes need to be followed to get the free SSL certificate.

1. Account Info
1. In this step, we will be providing the email and public key.
2. Keep the generated private key security in your system.

• Note: If you are unsure about the public key generation commands, click on the "how do I generate this?" link, which is available over the public key input textbox.

2. Certificate Signing Request (CSR)
1. Generate the CSR for the required domains

• Note: You can generate the CSR for wildcard certificates and www subdomain with the same command

2. Try to follow the same format, including the line feeds mentioned below.

#change "/etc/ssl/openssl.cnf" as needed:
    #  Debian: /etc/ssl/openssl.cnf
    #  RHEL and CentOS: /etc/pki/tls/openssl.cnf
    #  Mac OSX: /System/Library/OpenSSL/openssl.cnf

    openssl req -new -sha256 -key domain.key -subj "/" \
      -reqexts SAN -config <(cat /etc/ssl/openssl.cnf \
      <(printf "\n[SAN]\nsubjectAltName=DNS:foo.com,DNS:www.foo.com")) 

3.  Sign API Requests
1. Sign all the requests with the private key

• Note: You need to copy the command and execute it on your PC/Mac terminal, and the result needs to be pasted on the web page.

4. Verify Ownership
1. In this step, you need to prove your domain ownership
2. You will be given 3 options
1. Python server
2. file-based
3. DNS record (I've used this option)
1. Update the DNS records with new TXT entries, and use the online dig tool to make sure the records are visible.
2. After we verify the availability of the records, you need to click on the respective buttons on the web page.
3. Repeat the same steps for each domain on CSR (www and any sub-domains).
5. Install Certificate
1. You will be able to receive your certificate in "chained.pem" format
2. Copy and paste the first certificate section (e.g. the first "-----BEGIN CERTIFICATE-----" section) into a text file named "domain.crt".
3. Copy and paste the second certificate section (e.g. the second "-----BEGIN CERTIFICATE-----" section) into a text file named "intermediate.pem".

• Note: Expand the "how do I install this?" link for quick help.

Hope this will help you to generate free SSL for your websites.

Request you to send your valuable feedback and comments to psrdotcom@gmail.com

Finding IP address to MAC and vice versa on same network (subnet) or different subnet which is reachable by ping

Hi all,

After long time I got a chance to write the blog.

 

This time it is related to networking.

 

Finding out which all the system up on the network

Syntax

cmd> nmap –sP < regex IP >

Example

cmd> nmap –sP 192.168.1.*

 

Finding MAC address of a device which is connected in same network

Syntax

cmd> ping <broadcast address>

cmd> arp –a [ <IP address> ]

 

Example

cmd> ping 192.168.1.255

cmd> arp –a –> Gives all the IP address and MAC address in the same subnet network

cmd> arp –a 192.168.1.25 –> Give the MAC of the specified IP address

 

arp –a : Lists all the IP addresses which are recently got into network with its MAC addresses

 

Finding MAC address of a device which is connected in same network but different subnet

Syntax

nbtstat –A <IP address>

Example

nbtstat –A 192.168.2.45

 

Please send your comments and feedback to psrdotcom@gmail.com

Changing MAC address of a system in Linux with root privileges

Hi Friends,

Have you ever tried to change the MAC address? It is so easy to do. Just follow the below steps.

1. Login as root


2. Write the MAC addresses of the system which u r going to change on a file or paper if you want the previous MAC addresses.


3. Open terminal


4. ifconfig eth0 down


5. ifconfig eth0 hw ether XX:XX:XX:XX:XX:XX


6. ifconfig up


7. ifconfig

Now your system MAC address will be changed to the specified MAC address. If any packet comes into the network to the specified MAC it will get confused where to go. If u specified the MAC address of the other system. i.e. if two system's MAC addresses are same.