From 6353c8a8c904effaedbfbd3489884008fc5af5f6 Mon Sep 17 00:00:00 2001
From: arne <arne@br0tkasten.de>
Date: Sun, 16 Feb 2025 13:41:39 +0100
Subject: [PATCH] feat: add notes for openssl s_client

---
 content/nerdstuff/certificates.md | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 content/nerdstuff/certificates.md

diff --git a/content/nerdstuff/certificates.md b/content/nerdstuff/certificates.md
new file mode 100644
index 0000000..63bd8c2
--- /dev/null
+++ b/content/nerdstuff/certificates.md
@@ -0,0 +1,24 @@
+---
+title: Certificates 
+menu:
+  main:
+    parent: Nerdstuff
+---
+
+## Retrieve certificate information from server
+
+### HTTPS
+
+```
+openssl s_client -connect mail.br0tkasten.de:443 -servername mail.br0tkasten.de </dev/null 2>/dev/null | openssl x509 -noout -text
+```
+
+### IMAP with STARTTLS
+```
+openssl s_client -starttls imap -connect mail.br0tkasten.de:143 </dev/null 2>/dev/null | openssl x509 -noout -text
+```
+
+### SMTP with STARTTLS
+```
+openssl s_client -starttls smtp -connect mail.br0tkasten.de:587 </dev/null 2>/dev/null | openssl x509 -noout -text
+```