Openssl

An SSL certificate is a digital certificate issued by a trusted third-party authority known as a Certificate Authority (CA). It verifies the identity of a website or server and enables secure, encrypted communication. Components of an SSL Certificate Public Key: Used for encryption and verifying the certificate’s authenticity. Certificate Holder Information: Details like the domain name, organization, and location. Issuer Information: The CA that issued the certificate. Validity Period: Specifies the time frame during which the certificate is valid. Digital Signature: Ensures the certificate was issued by a trusted CA and has not been tampered with. Self-Signed Certificates Examples and Differences Type Usage Example Difference Self-Signed Internal servers, testing Generated via OpenSSL Not trusted by default in browsers or OS. CA-Signed Public-facing servers Issued by DigiCert, Let’s Encrypt Trusted by browsers and OS. Wildcard Certificate Secures a domain and its subdomains *.example.com Can’t be self-signed, requires a CA. Multi-Domain Certificate Covers multiple domains example.com, test.com Self-signed possible but not widely used. Self-Signed Certificates A self-signed certificate is a digital certificate that is not issued by a trusted Certificate Authority (CA) but is signed by the entity it is certifying (e.g., your own server). These certificates are primarily used for internal testing, development environments, or scenarios where external trust is not required. ...

Its purpose is to ensure that all data transmitted between the server and the client remains private and secure from eavesdropping, tampering, or forgery. While SSL itself has been deprecated in favor of its successor, TLS (Transport Layer Security), the term “SSL” is still commonly used to refer to the broader concept of secure network communication.

RSA (Rivest–Shamir–Adleman) is an asymmetric cryptographic algorithm, widely used for secure data transmission, especially for signing and encrypting data. In the RSA signing process, a private key is used to sign the message, while a public key is used to verify the signature. Here’s how the signing and verification process works: 1. Public and Private Keys Private Key: This key is kept secret and is used to sign data. Only the entity that owns the private key should be able to generate the signature. Public Key: This key is shared with others. It is used to verify that the data was indeed signed by the corresponding private key holder. Key Pair: RSA works on a pair of keys(one private and one public). A unique public/private key pair is generated together. There cannot be multiple private keys for a given public key. For embedded systems, where resources (CPU, memory) are limited, RSA’s asymmetric nature means that only the private key holder can sign, while anyone with the public key can verify. This is useful in secure boot processes or authenticating firmware updates, as the system can verify code signed by the vendor. ...