---
type: entity
title: OpenSSL
tags: [tool, cryptography, pki, security]
related: [serverzertifikate, certificate-signing-request]
created: 2026-06-30
updated: 2026-06-30
sources: ["output/rz_uni_greifswald_de_dienste_allgemein_dfn_pki_zertifikate_serverzertifikate.md", "output/rz_uni_greifswald_de_dienste_allgemein_dfn_pki_zertifikate_serverzertifikate_ope.md"]
---

# OpenSSL

**OpenSSL** is a robust, full-featured toolkit for the Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols. 

Depending on the source:
- One version describes it as "commercial-grade".
- Another version describes it as "open-source" and notes that it is available on nearly all modern operating systems.

## Use Case: Server Certificates
At the Universität Greifswald, OpenSSL is specifically utilized as a tool for creating private keys and certificate requests (CSRs) / [[certificate-signing-request]] files when applying for [[serverzertifikate]].

### Implementation Commands
- **For EC Keys (Recommended):**
  `openssl req -new -key <(openssl ecparam -name secp384r1 -genkey | tee hostname_key.pem) -out hostname_request.pem`
- **For RSA Keys (Required for Key Encipherment/Shibboleth):**
  `openssl req -newkey rsa:4096 -keyout hostname_key.pem -out hostname_request.pem -nodes`