Understanding HTTPS, SSL/TLS & Certificate Generation | Learn How SSL Works

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In today’s digital landscape, ensuring the security and privacy of web communications is paramount. HTTPS, SSL, and TLS are critical technologies that safeguard data transmission over the internet. In this comprehensive guide, we will explore how these technologies work together to secure web communications, delve into the intricacies of SSL, and discuss the essential features of HTTPS. Additionally, we will explain the concepts of self-signed certificates, Certificate Signing Requests (CSR), and Certificate Authorities (CA).

Table of Contents

  1. What is HTTPS?
  2. Understanding SSL and TLS
  3. How SSL/TLS Works
  4. Features of HTTPS
  5. Types Of SSL Certificates
  6. Self-Signed Certificates
  7. Generating CSR and Certificates
  8. Where and why Self-Signed Certificate Are Used
  9. Conclusion
  10. FAQ Section

What is HTTPS?

HTTPS (Hypertext Transfer Protocol Secure) is the secure version of HTTP, the protocol used for transferring data over the web. HTTPS ensures that all communication between your browser and the website is encrypted, providing confidentiality, integrity, and authentication. This not only protects sensitive information but also enhances user trust and SEO performance.
Diagram showing HTTP as not secure and HTTPS as secure, highlighting the importance of HTTPS and SSL/TLS for secure web communications.
Http Vs Https

Understanding SSL and TLS

SSL (Secure Sockets Layer) and TLS (Transport Layer Security) are cryptographic protocols designed to provide secure communication over a computer network. While SSL is the predecessor of TLS, TLS is now the standard protocol due to its enhanced security features.

Key Differences:

SSL: Older and less secure, now largely deprecated.
TLS: Modern and more secure, with multiple versions (e.g., TLS 1.2, TLS 1.3) offering stronger encryption and better performance.

How SSL/TLS Works

The SSL/TLS handshake is a crucial process that establishes a secure connection between a browser and a server. Here’s how it works:

  1. Client Hello: The browser initiates a connection by sending a “hello” message to the server, including supported cipher suites and the TLS version.
  2. Server Hello and Certificate: The server responds with its own “hello” message, selecting a cipher suite and sending its SSL certificate along with the public key.
  3. Certificate Verification: The browser verifies the server’s certificate against trusted Certificate Authorities (CAs). If valid, the browser generates a symmetric key, encrypts it with the server’s public key, and sends it to the server.
  4. Key Exchange: The server decrypts the symmetric key using its private key. Both parties now share the symmetric key, which is used for encrypting data during the session.

This process ensures that the connection is secure and that data cannot be intercepted or tampered.

Features of HTTPS

1. Confidentiality/Privacy

How It’s Achieved:
HTTPS ensures confidentiality by encrypting data using the symmetric key established during the SSL/TLS handshake. This encryption makes it extremely difficult for unauthorized parties to intercept and read the data.
 

2. Integrity

How It’s Achieved:
Integrity is maintained through cryptographic hashing (e.g., SHA-256). Hash functions generate a unique digest for each message, ensuring that any alteration in the data during transmission can be detected.
 

3. Authentication

How It’s Achieved:
Authentication is provided through SSL certificates. These certificates, issued by trusted Certificate Authorities (CAs), verify the identity of the server, ensuring users are communicating with the legitimate server and not an imposter.

What are the different types of SSL certificates available?

When it comes to SSL certificates, there are several options available, but three types stand out as the most popular and widely used: Single, Wildcard, and Multi-Domain SSL certificates.

  1. Single Domain SSL Certificates.
  2. Wildcard SSL Certificates.
  3. Multi-Domain SSL Certificates (MDC).

Single Domain SSL Certificates

Single Domain SSL Certificates are designed to secure a single domain name. It cannot be used to authenticate any other domain, not even subdomains of the domain it is issued for.

Single Domain SSL Certificate
Single Domain SSL Certificate

Wildcard SSL Certificates

Wildcard SSL Certificates offer more flexibility by allowing you to secure a primary domain and all its subdomains with a single certificate.

For example, if you have a website with multiple subdomains (such as blog.yourdomain.com, shop.yourdomain.com, etc.), a Wildcard SSL Certificate will cover them all.

Wildcard SSL Certificate - Protect your primary domain and all its subdomains.

Multi-Domain SSL Certificates (MDC)

Multi-Domain SSL Certificates, also known as Subject Alternative Name (SAN) certificates, enable you to secure multiple domains and subdomains with one certificate.

Multi-Domain SSL Certificate icon securing multiple domains
Multi-Domain SSL Certificate icon securing multiple domains

What is Self-Signed Certificates

A self-signed certificate is an SSL certificate that is not signed by a trusted CA. Instead, it is signed by the entity that creates it. While self-signed certificates provide encryption, they do not offer the same level of trust as CA-signed certificates since they are not verified by a third party.

Generating CSR and Certificates

A Certificate Signing Request (CSR) is a block of encoded text submitted to a CA to apply for an SSL certificate. It contains the public key and information about the organization.

Command to Generate a CSR:

Create a folder and run below commands in its terminal. 
openssl req -new -newkey rsa:2048 -nodes -keyout yourdomain.key -out yourdomain.csr

You will be asked some question

Country Name (2 letter code) [AU]: IN
State or Province Name (full name) [Some-State]: MH
Locality Name (eg, city) []: Mumbai
Organization Name (eg, company) [Internet Widgits Pty Ltd]: CodeOps Trek
Organizational Unit Name (eg, section) []:
Common Name (e.g. server FQDN or YOUR name) []: www.codeopstrek.com
Email Address []: contact@codeopstrek.com
OpenSSL CSR Generation
Input fields for generating a CSR using OpenSSL, including Country, State, City, Organization, Common Name (FQDN), and Email.

CSR & Key will generated in the folder.

OpenSSL CSR form : includes fields for Country Code, State, City, Organization, Common Name, and Email.
Form for OpenSSL CSR Generation
OpenSSL key generation interface
OpenSSL key generation interface

Self-Sign the CSR

Run below command in the terminal of same folder where  csr & key available.

openssl x509 -req -days 365 -in yourdomain.csr -signkey yourdomain.key -out yourdomain.crt
Self-signed SSL certificate generated using OpenSSL
Details of a self-signed SSL certificate generated with OpenSSL

Where and Why Self-Signed Certificates Are Used

Self-signed certificates are used primarily for testing, development, and internal purposes. They are ideal for securing communications within private networks, development environments, and internal applications where trust from a public Certificate Authority (CA) is not required. Unlike certificates issued by a CA, self-signed certificates are signed by the entity’s own private key, making them cost-effective and immediately available. They are commonly used for:

  • Testing and Development: To simulate SSL/TLS encryption in a development environment.
  • Internal Networks: To secure internal communications without the need for a publicly trusted certificate.
  • Learning and Training: To practice and understand certificate management without incurring costs.

Learn how to integrate self-signed SSL into Nginx web server easily.

Despite their benefits, self-signed certificates should not be used for public-facing websites or applications because they won’t be trusted by web browsers and can expose users to security risks.

Conclusion

Securing web communications through HTTPS, SSL, and TLS is essential for protecting sensitive data and ensuring user trust. By understanding how these technologies work together, you can implement robust security measures for your website. Remember to use SSL certificates from trusted CAs for authentication, employ cryptographic hashing for data integrity, and ensure all data transmissions are encrypted to maintain confidentiality.

 

For more detailed information on SSL/TLS protocols and best practices, visit Mozilla’s SSL Configuration Generator and SSL Labs.

Other Resources

SSL Checker Tool
Enhance your SSL/TLS management with the SSL Checker Tool by WebsitePlanet.
Features:
  • SSL Certificate Details
  • Server Details
  • Certificate Chain Validation
  • Report Download

FAQ Section

SSL (Secure Sockets Layer) and TLS (Transport Layer Security) are cryptographic protocols for secure communication over networks. TLS is the successor to SSL, offering improved security and modern encryption algorithms.

SSL (Secure Sockets Layer) can be used to secure websites (HTTPS), emails, VPNs, file transfers, APIs, IoT communications, database connections, and online payments.

openssl req -x509 -newkey rsa:2048 -keyout server.key -out server.crt -days 365

The validity of a self-signed certificate is determined by the issuer and can typically range from a few months to several years. Commonly, self-signed certificates are set to expire in 1 year (365 days), but the validity period can be customized during creation

Self-signed certificates cannot be verified through traditional Certificate Authorities (CAs), but can be verified using their own public key.

CA stands for Certificate Authority. It is a trusted entity that issues digital certificates used to verify the identities of organizations, websites, and individuals on the internet.

Yes, a self-signed certificate can encrypt data, enabling secure communication between the server and client using its own public key infrastructure, though it lacks validation by a third-party Certificate Authority (CA).

At CodeOps Trek, we are dedicated to providing solutions and building robust code architectures. Integrating NGINX into your web stack is a vital step toward achieving these goals. Stay tuned for more in-depth guides on software development, and happy coding! 

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