OpenSSL

Cryptographic toolkit providing SSL/TLS implementations and cryptographic primitives.

openssl

Command-line interface for the OpenSSL cryptographic toolkit.

X.509

Standard defining the structure and semantics of digital certificates.

PEM

Text-based encoding wrapper for cryptographic objects.

DER

Binary encoding format for ASN.1 data structures.

CSR

A signed request containing a public key and subject identity.

CA

Trusted entity that signs and issues certificates.

PFX / P12

Encrypted container bundling private key, certificate, and chain.

DN

Structured identity block describing the certificate subject.

CN

Human-readable name within a Distinguished Name.

O

Organization name within a Distinguished Name.

OU

Department or team name within a Distinguished Name.

C

ISO country code within a Distinguished Name.

ST

Region or state within a Distinguished Name.

L

City or locality within a Distinguished Name.

SAN

X.509 extension listing all identities a certificate is valid for.

DNS

Hierarchical naming system used to resolve hostnames to IP addresses.

IP

Numerical addressing scheme used to identify hosts on IP networks.

URI

Structured identifier for naming or locating resources.

DNS

Hostname identity entry within a SAN extension.