ISR Computing -

How SSL works?

1. Client sends "CLIENT HELLO" message with the following information:
   • Key exhange method: RSA, Diffie-Hellman, DSA
   • Cipher (way to encrypt): RC4, 3DES, AES
   • Hash (way to calculate hash for Message Authentication Code): hmac-md5, hmac-sha
   • Version of SSL
   • Random number: integer - 239248329478923
2. Server responds with "SERVER HELLO", which contains:
   • Key exhange method: RSA, Diffie-Hellman, DSA
   • Cipher (way to encrypt): RC4, 3DES, AES
   • Hash (way to calculate hash for Message Authentication Code): hmac-md5, hmac-sha
3. Server send "Server certificate" to the Client. Following information is included:
   • Serial number
   • Issuer
   • Valid: From-To
   • Public Key
   • Subject:
   • Site
   • Company
   • Address
4. Client recieves "Server certificate" and then send several messages back:
   • Client Key Exchange - client and server compute master secret code, that they will use to encrypt communications
   • Change Cipher Spec
   • Finished
5. Server responds with:
   • Change Cipher Spec
   • Finished  (This is the first message that gets encrypted by master code)

Finally, web traffic will continue to flow encrypted using master secret.