What is a TLS/SSL handshake, and how does it work?
Visiting websites on the Internet that require a user to input their personal information may raise a sense of security. Users may fear for the safety and intactness of their data in various online interactions. A breach of the security of a user's personal details or credential information could lead to identity theft and fraud, which could result in the loss of money or personal information.
Therefore, one must protect their interests, ensuring that they are not compromised in any way. A TLS/SSL handshake creates a safe encrypted communication channel over a computer network. This happens between the user's browser and the website's browser.
A user can visit Vodien's website to get a free SSL certificate. Overall, an SSL certificate process helps safeguard data from an attacker and ensures its safety and intactness.
What is a TLS/SSL handshake?
A TLS/SSL handshake is a series of steps for a user and the website they attempt to access. This includes authenticating each other, agreeing on encryption standards, and establishing a safe channel for data transfer. The TLS/SSL handshake encrypts a user's data and transfers it over a computer network safely, ensuring its intactness.
Now, you may wonder about the difference between TLS and SSL.
Secure socket layers, or SSL, is a cryptographic protocol that transmits data over two servers safely. It establishes an encrypted connection between the user's browser and the server, protecting the confidentiality and integrity of the user's data.
SSL was developed in 1994, but its first version was never made public due to flaws regarding the protection of a user's data. The second version of SSL was made public and released in 1995. SSL 3.0 was released a year later.
With the internet proliferating, SSL was still not secure enough. Therefore, in 1999, TLS was created as the next upgrade to SSL 3.0. TLS is the upgraded and more secure version of SSL. All modern web browsers and servers use TLS for secure communication.
Other versions that later came out include:
TLS 1.1 was created in 2006, followed by TLS 1.2, which came out in 2008, and TLS 1.3, which was released in September 2018. Both the TLS handshake and the SSL handshake work together to protect a user's data from any malpractice that may occur otherwise. While similar to SSL, the TLS handshake process is more complex and offers more flexibility for negotiation between client and server.
The primary goal of a TLS/SSL handshake is to encrypt the data transmission for authentication and security. This ability enables us to safely connect online communication and commerce.
Why Is the TLS/SSL Handshake Important?
A TLS/SSL handshake secures the connection between the user's browser and the website's server. The sensitive data that a user may input into the website remains secure and intact.
It also protects a user's data from 'man in the middle' attacks that are responsible for data theft. Harmful attackers may try to manipulate the data being shared over the Internet. This is only possible because the SSL or TLS handshake makes the data being shared tough to decipher.
This protects the data from being intercepted by any attacker and restricts it from being stolen. Upon getting such services after visiting a website, the user's trust and confidence are established in terms of online transactions.
Google prioritizes websites in its search results. This means that using a TLS/SSL certificate boosts a website's SEO performance, ensuring more traffic.
Thus, the website owner must use a TLS/SSL certificate to boost its rankings and traffic.
The Steps Involved in a TLS/SSL Handshake
Step 1: Client Hello
Upon visiting a website, a 'Client Hello' is sent to its server. The message encapsulates information that includes the TLS/SSL certificate versions it supports and the cipher suites it uses. This initiates the handshake between the user's browser and the website server.
Step 2: Server Hello
The server then replies with a' Server Hello' message upon receiving the 'Client Hello' message. This message includes the highest version of SSL/TLS and the cipher suite supported by both parties.
Step 3: Server Certificate
After this initial exchange of information occurs, the server provides its digital certificate. The digital website is supposed to be verified by a certificate authority. This certificate is like an identity card that validates the server's certificate and ensures its reliability.
Verifying the source of the server's validity is a must, as it can otherwise breach the information that we are trying to protect through the use of these SSL and TLS certificates.
Step 4: Server Key Exchange
After the user's browser validates the server's certificate, the browser uses the public key to encrypt a 'premaster secret.'The premaster secret is a random sequence extracted from the public key. It is a unique session key used for an SSL/TLS handshake.
Step 5: Client Key Exchange
The key sent to the web server uses its private key to decrypt the premaster secret key. After this, both the user's browser and the website create a 'shared secret key' using a premaster secret key. For all communication that occurs, the shared secret key is the session key used for its symmetric encryption.
Step 6: Client and Server-Finished Messages
The session key created is used by both the user's browser and the web server. Using the shared key, the user sends an encrypted message that says 'finished,' which indicates that the user's part of the handshake is complete.
The process is followed by an encrypted message that says 'finished' from the server's side, which uses the shared secret key again. The server's side of the handshake is now complete as well. Once the negotiation for the TLS/SSL handshake between the browser and server is done, the communication between the user and server continues.
This means that they start sharing messages and files using the session key, which is based on the symmetric encryption we discussed.
Common Issues and Troubleshooting TLS/SSL Handshake Failures
If your TLS/SSL handshake fails to establish the connection between the browser and that website, it can lead to stress for users, as they might not be able to figure out the cause. Below are methods that solve this issue and make it simple for users.
Common issues that can occur on the user's side are:
- The date and time on the user's computer are wrong.
- An attacker intercepts the connection.
- The browser's configuration is wrong.
Common issues that can occur on the server's side are:
- The cipher suite may not match.
- The user's browser uses a protocol not used by the server.
- The server is not valid for some reason or has expired.
A user can troubleshoot the issue via tips and solutions to determine what caused the TLS/SSL handshake to fail. A few methods that can be used to fix this issue are given as follows:
- Correcting your date and time:
Sometimes, due to a glitch or human error, the date and time of the computer are set wrong. This can cause the SSL/TLS certificate to fail. If that is the case, it is a must to fix the date and time.
- Incorrect TLS/SSL certificate:
With the validity of the server lasting from 6 months to 2 years, it might be the case that your SSL certificate has expired. This might cause the SSL/TLS handshake to fail, so it is better to check the validity of your TLS/SSL certificate.
A user can use the SSL certificate checker tool to make sure that their certificate is valid.
It can also happen that the server's hostname fails to match the given CN in the certificate. Intermediate may be missing in the service chain, or the represented server is revoked or untrusted.
- Browser's misconfiguration:
Another culprit for causing the failure could be that your browser's configuration is not correct. A user can confirm this by switching to another browser and then accessing the same website on that browser.
Disabling the plugins and restoring the browser to its default settings might also help fix this error.
A browser's protocol also might not match with the server's version of TLS/SSL. This could be a case, for instance, when the server supports TLS 1.2 or above, and your browser is configured to support TLS 1.1.
This is bound to cause the TLS/SSL handshake to fail. One can refer to Vodien's SSL certificate services for guidance on how to fix this error.
- Improper Server Name Indication Configuration (SNI):
SNI enables a web server to successfully host TLS certificates for an IP address. If the server is not SNI-enabled, it may not be able to identify which server to present at the time of the handshake.
A user can identify this by using a server test or the OpenSSL s_client tool to correct the SNI configuration. Properly enabling the SNI may fix the TLS/SSL handshake failure.
- Matching the cipher suites:
Cipher suites are a set of algorithms that include the algorithms for bulk encryption, key exchange, and message exchange code. These are used to make sure TLS and SSL connections are secure.
If the cipher suite used by the user's server and the website's server do not match, a TLS/SSL handshake failure could occur. A user can again use an SSL server checker by going to the server suites section and looking for the mismatch.
You can benefit from www.vodien.com services to get help and guidance for fixing this TLS handshake failure issue.
- Incorrect hostname:
The incorrect hostname of the web server may also lead to this handshake failure. To fix this error, one can just get their certificate reissued or use a wildcard certificate.
Enhancing Security with Advanced TLS/SSL Configurations
TLS/SSL configurations can be altered to enhance the security of the certificate we rely on.
1—The first method we use to do so is Perfect Forward Secrecy (PFS) or Forward Secrecy (FS). FS is an encryption system that keeps changing the keys used during the TLS/SSL handshake. The keys that encrypt and decrypt the information during a headache are changed frequently. This means that even if the most recent one is hacked, the data lost will be large.
2—For the second method, a user can configure stronger ciphers. This can help enhance the security of the TLS/SSL certificate. The earlier versions of TLS (TLS 1, 1.1, and 1.2) and SSL (2.0, 3.0) possess a weaker set of cipher suites used as the algorithms to protect a website's interface.
Given that the cipher suites can be hardened by disabling these older versions, it is recommended that users primarily use the TLS 1.3 version to surf their web browsers.
To easily enable the above, one can rely on Vodien's services to access the most advanced TLS and SSL certificates.
Conclusion
A TLS/SSL handshake is a protocol that two servers undergo when a user visits a website over a computer network. It involves sharing information to establish an encrypted and safe set of algorithms that protect a user's device from external attacks (3rd party attacks).
One must use SSL certificates for the communication process, as they make sure that the connection between the user's browser and the server being visited is safe. This keeps the sensitive data inputted into the website's server safe and intact. It protects the user from attacks like 'man in the middle,' which involves attackers trying to manipulate the data shared over the internet. Thus, the data that may otherwise be stolen or manipulated remains secure and intact when one uses a TLS/SSL certificate.
Consequently, a user's trust and confidence are established in terms of online transactions. Google promotes secure websites in its search results. Thus, using a TLS/SSL certificate is supposed to boost a website's SEO performance, which will bring more traffic to the website's server.
A user can explore Vodien's SSL certificate, which offers enhanced security to the user's browser and establishes a secure connection between the servers over a computer network.
Skip to section
Other Stuff
