SSL Certificate Related Terms and Concepts
Digital Certificate
A digital certificate is a digital authentication that marks the identity information of all communicating parties in Internet communications. People can use it online to identify the counterparty's identity. Therefore, digital certificates are also called digital IDs. Digital certificates ensure the integrity and security of information and data exchanged by network users over computer networks through encryption and decryption.
CA
CA is the abbreviation of Certificate Authority, also known as "certificate authorization". It is a third-party institution responsible for managing and issuing certificates. Its role is to verify the legitimacy of the certificate holder's identity and issue certificates to prevent certificates from being forged or tampered with.
Certificate Validity Period
This refers to the time period from the date a certificate is issued to the date it expires. CAs have shortened the maximum validity period of SSL/TLS certificates to 13 months; after August 31, 2020, the maximum validity period of SSL certificates is set to 398 days.
SSL
SSL is the abbreviation of Secure Socket Layer, also known as "Secure Sockets Layer". It is a network security protocol first adopted by Netscape Communications. It is a security protocol implemented on top of transport communication protocols (TCP/IP) that uses public key technology. SSL establishes a session between the client and server through a handshake, completing the verification of the identities of both communicating parties and the negotiation of keys and cipher suites, thereby ensuring that communication between the client and server is not eavesdropped on and guaranteeing the security of data transmission over the network.
SSL Certificate
An SSL certificate is a type of digital certificate, similar to an electronic copy of a driver's license, passport, or business license. Because it is configured on a server, it is also called an SSL server certificate. An SSL certificate complies with the SSL protocol and is issued by a trusted digital Certificate Authority (CA) after verifying the server's identity. It has the functions of server identity verification and data transmission encryption. It is used to ensure the security of communication between services within a device, as well as between the device and external parties, preventing communication data from being tampered with during transmission to avoid security risks and improving system security.
Root Certificate
A root certificate is an unsigned public key certificate or a self-signed certificate. It is a certificate issued by a CA to itself and is the starting point of the trust chain. Installing a root certificate means trusting that CA, and root certificates are usually pre-installed in browsers. Trusted root certificates belong to Certificate Authorities (CAs), which are organizations that verify and issue SSL certificates.
Intermediate Certificate
Intermediate Certificates, full name Intermediate Certificates, are located between the root certificate and the server certificate, serving as a bridge connecting the protected root certificate and the server certificates issued to the public. The certificate chain is a hierarchical trust chain composed of the server certificate, intermediate certificates, and the root certificate, which ensures that browsers trust the security of a website.
HTTPS
HTTPS (full name: Hypertext Transfer Protocol Secure) is an HTTP channel with security as its goal. On the basis of HTTP, it ensures the security of the transmission process through transport encryption and identity authentication. HTTPS adds SSL on top of HTTP; the security foundation of HTTPS is SSL, so SSL is required for the detailed encryption process.
Domain Name
A domain name, also known as a network domain, is a name for a computer or group of computers on the Internet composed of a string of dot-separated names, used to locate and identify computers during data transmission (sometimes it also refers to geographic location).
Wildcard Certificate
A wildcard certificate is a type of SSL certificate, a public key certificate that can be used for multiple subdomains to protect multiple subdomains. Wildcard certificates can also be called: wildcard SSL certificate, wildcard domain certificate, pan-domain certificate, Wildcard certificate.
Nginx
Nginx (engine x) is a high-performance HTTP and reverse proxy web server, and also provides IMAP/POP3/SMTP services. Nginx is a lightweight web server/reverse proxy server and email (IMAP/POP3) proxy server, released under a BSD-like license. It is characterized by low memory usage and strong concurrency capability.
Tengine
Tengine is a web server project initiated by Taobao. Based on Nginx, it adds many advanced functions and features to meet the needs of high-traffic websites. Its purpose is to build an efficient and secure web platform.
PuTTY
is an open-source software for remote connections, supporting multiple protocols including Telnet, SSH, rlogin, raw TCP, and serial port connections.
Xshell
Is a terminal emulator that supports multiple protocols, allowing you to remotely connect to Linux servers on Windows.
CentOS
CentOS, short for Community Enterprise Operating System, is an open-source, free Linux distribution built from the source code of Red Hat Enterprise Linux (RHEL). It is designed to provide a stable, predictable, manageable, and reproducible platform that is functionally compatible with RHEL.
CSR
CSR, or Certificate Signing Request, is a critical component for protecting any website with an SSL/TLS certificate. A CSR is essential for securing users' sensitive information via encrypted data transmission. Essentially, it is a block of encrypted text that contains important details such as the domain name, organization, and public key.