Basics of SSL working

1. Tuesday Talk
SSL

2. Session Layer Purpose
Layer 5 of OSI M
● layer 5 of OSI
● Manages Session
● Handles things like authentication
and authorization
● Recovering a session in case it is
abruptly terminated
● In case of TCP/IP it is in Application
layer

3. SSL
● Secure Socket Layer
● Primarily doing encryption
● Identification
● OpenSSL> s_client -connect
www.google.com:443

4. SSL

5. ● Want to hide
● What?
● Two systems agree on how to encrypt (Key, Cipher,
Hash, Version, Random No) example- RSA, AES, MD5
etc)
○ Key is piece of information
○ Cipher is an algorithm or defined steps
● Post agreement identification is established
Encryption

6. SSL
● Server sends a copy of its SSL Certificate, including the server’s public key
○ Note- Public and Private Key Pair of server
● Client uses this public key of the server to create a session key and sends
that back to server
○ Session key of client
● Server decrypts this using it’s own private key and then sends an
acknowledgement (this is encrypted with session key)
● Henceforth all communication is encrypted using session key