TLS (Transport Layer Security) certificates serve as digital credentials that facilitate secure online connections between two parties. When a user accesses a website, the server hosting the website transmits its TLS certificate to the user’s web browser. This certificate plays a pivotal role in confirming the website’s legitimacy and enabling the establishment of an encrypted connection.
These TLS certificates are officially issued by trusted third-party entities known as Certificate Authorities (CAs) such as Let’s Encrypt and DigiCert. Before granting a TLS certificate, CAs meticulously validate the identity of the website’s owner. This rigorous verification process entails confirming domain ownership and ascertaining the identity of the organization or individual associated with the website.
Now, let’s delve into the intricacies of this process:
Step 1: TLS Certificate Verification
Upon receiving a TLS certificate, the user’s web browser initiates a crucial verification process. It first checks the certificate’s validity, ensuring that it hasn’t expired and has been issued by a recognized and trusted Certificate Authority (CA). Additionally, the browser may verify the certificate’s revocation status by contacting the issuing CA’s revocation server. This diligence is instrumental in preventing potential man-in-the-middle attacks, wherein an adversary might attempt to impersonate the server and intercept sensitive data.
Step 2: Cryptographic Key Exchange
With the certificate’s authenticity verified, the browser and the server engage in a cryptographic key exchange. This involves asymmetric encryption, where the browser generates a random session key and employs the server’s public key to securely encrypt and transmit this key to the server. Subsequently, the server utilizes its private key to decrypt the received session key.
Step 3: Secure Data Exchange
Having completed the key exchange, the browser and the server can now conduct data exchanges confidently over the encrypted connection. Any data transmitted by the browser undergoes encryption using the session key, and the server decrypts it using the same key, and vice versa. This ironclad encryption ensures that data remains safeguarded from potential interception or tampering by unauthorized entities, upholding the integrity and security of the online interaction.
Cert-manager adds certificates and certificate issuers as resource types in Kubernetes clusters, and simplifies the process of obtaining, renewing and using those certificates.
It can issue certificates from a variety of supported sources, including Let’s Encrypt, HashiCorp Vault, and Venafi as well as private PKI.
It will ensure certificates are valid and up to date, and attempt to renew certificates at a configured time before expiry.