docs: create Information

Information.md

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+---
+title: SSL/TLS
+description: 
+published: true
+date: 2025-09-28T14:42:56.701Z
+tags: 
+editor: markdown
+dateCreated: 2025-09-28T14:42:56.701Z
+---
+
+# SSL/TLS
+
+## CA 
+A provider which can sign certificates. 
+
+
+## Certificate 
+
+The CA provides a certificate and signs it with a digital signature using the private key of the CA. 
+
+```
+f(certificate, CA Private Key) = signature
+```
+
+An SSL/TLS certificate (X.509 cert) contains 
+
+* The server’s public key
+* The domain name(s) it’s valid for
+* Validity period (start/end dates)
+* Extensions (like usage constraints)
+* A digital signature made by the issuer (CA)
+
+The client request a certificate from a server and checks that the resulting hashes match. The CA public key is knwon to the browser prior. 
+
+```
+f(signature, CA public key) = result hash
+```
+
+```
+hash(certificate) = result hash
+```
+
+The the client uses the Servers public key taken from the CA certificate and sends a messages which can only be correctly decoded if the server has the correct private key