AWS IoT allows you to create and manage X.509 certificates for securing communication between IoT devices and the AWS IoT platform.
In the context of SSL/TLS certificates;
A CSR file (Certificate Signing Request) is a block of encoded text generated by a server or software application to apply for a digital certificate. When you want to obtain an SSL/TLS certificate for your website, web server, or any other secure service, you typically generate a CSR file. The CSR contains information about the entity requesting the certificate (such as the domain name) and a public key that will be included in the certificate. In this case, AWS IoT, makes this available for you.
Here's a brief overview of how to use a CSR file with a PFX file (Personal Information Exchange), which is a file format used to store the private key, certificate, and any intermediate certificates as a single encrypted archive.
Obtaining the SSL/TLS certificate: Once you have generated the CSR file, you can submit it to a Certificate Authority (CA) of your choice to obtain an SSL/TLS certificate. The CA will use the information in the CSR to create the certificate. After the certificate is issued, the CA will provide you with the certificate in a file format like PEM or DER.
Combining the certificate and private key into a PFX file: In some cases, you might receive the SSL/TLS certificate as separate PEM files for the certificate itself and the private key. To use them together in a PFX file, you'll need to combine them. This can be done using various tools or commands depending on your operating system or software.
For example, if you have the certificate file named "certificate.pem" and the private key file named "privatekey.pem," you can use the OpenSSL command-line tool to create a PFX file:
A .pem file can contain the certificate (public key) itself, the private key, and sometimes even the entire certificate chain (including intermediate and root certificates).
.crt (certificate)file contains both certificate and public key, they usually do not include private key
PFX
PFX contains both the certificate and private key and is protected by a password. See it as a zip folder that contains all your certs and you need a password to open it
To combine the certificate and private key into a PFX file, use the following OpenSSL command:
openssl pkcs12 -export -out yourdomain.pfx -inkey yourdomain.key -in yourdomain.crt
- Using the PFX file: Once you have the PFX file containing the certificate and private key, you can typically use it to configure your web server for SSL/TLS encryption. The process for using the PFX file will vary depending on the web server software you are using.
Remember to keep the PFX file secure since it contains both the private key and the certificate. It's essential to protect this file to prevent unauthorized access to your SSL/TLS encryption.
Here's a simple illustration for a 5-year-old on how certificates work;
Imagine you have a secret code that only you and your best friend understand. This code helps you keep your messages safe and private. But, before you can start using this code, you need to ask someone (let's call them the "Secret Code Maker") to create it for you.
So, you tell the Secret Code Maker what secret messages you want to send, like "I love ice cream!" The Secret Code Maker then takes this message and makes a special code for it. This special code is like a secret password that only you and your best friend can understand.
But, here's the trick: the Secret Code Maker needs a special request from you first. This request is like saying, "Hey, I want a secret code for my message, please!" This special request is called a "Certificate Signing Request," which we can call a "Code Request" for now.
Once the Secret Code Maker gets your Code Request, they create the secret code, and you get it back as a "Certificate" (another fancy word). This Certificate is like a magical paper that shows your secret code is real and safe.
Now, you have your secret code (the Certificate) and the secret message you want to send (like "I love ice cream!"). To put them together, you create a special package called a "PFX file." Think of it like wrapping a gift. The PFX file keeps your secret code (the Certificate) and the secret message (like "I love ice cream!") together and protected.
Finally, you give this special package (the PFX file) to your best friend or a computer (like a web server) so they can understand your secret messages safely. Your best friend or the computer can use the secret code (the Certificate in the PFX file) to read and understand the secret messages you send.
That's it! Now you and your best friend can share secret messages using your special code and keep them safe from others. 😊