Secure Socket Layer.pptx
- 1. 1 Date: 2079/01/9 Submitted By: Arun Prajapati Babin Datheputhe Jenish Prajapati Manish Hyongoju Shreejan Shilpakar
- 2. Introduction ● It is an Internet Protocol for secure exchange of information between a web browser and a web server ● Ensuring that all data passed between them remain private and free from attack. ● This is done with the use of Certificates and keys ● Security services are: ○ Authentication ○ Confidentiality ○ Message integrity ● Developed By Netscape Corporation in 1994. ● Currently comes in three versions: 2,3 and 3.1 2
- 3. Example of SSL with Amazon 3 - Secured Website like Amazon uses SSL. - padlock icon. Or (in status bar) or https - This indicates website’s server uses SSL to secure your personal information. - This type of SSL between a client and a website server is known as Server Authentication. Fig. Example of Secure connection
- 4. Server Authentication 4 Fig. Example of Certificate
- 5. Steps for SSL Communication 1) Client connects to a web server (website) secured with SSL (https). Client requests that the server identify itself. 2) Server sends a copy of its SSL Certificate, including the server’s public key. 3) Client checks that the certificate is trusted: unexpired, unrevoked, and valid for the website that it is connecting to. If the client trusts the certificate, it creates, encrypts, and sends back a session key using the server’s public key. 4) Server decrypts the symmetric session key using its private key and begins an encrypted session with the client. The server and client now encrypt all transmitted data with the session key. 5 Fig. General view of SSL communication
- 6. SSL Communication diagram/ Handshake diagram 6 Fig. SSL handshake diagram
- 7. Position of SSL in TCP/IP 7 Fig. TCP/IP or OSI layer
- 8. SSL ARCHITECTURE 8 Fig. Architecture of SSL with respect to OSI layer
- 9. SSL Protocol Stack ● Handshake phase Handshake Protocol is used to establish sessions. This protocol allows the client and server to authenticate each other by sending a series of messages to each other. Handshake protocol uses four phases to complete its cycle. ● Change-cipher Protocol This protocol uses the SSL record protocol. Unless Handshake Protocol is completed, the SSL record Output will be in a pending state. After handshake protocol, the Pending state is converted into the current state. Change-cipher protocol consists of a single message which is 1 byte in length and can have only one value. This protocol’s purpose is to cause the pending state to be copied into the current state. 9
- 10. ● Alert Protocol This protocol is used to convey SSL-related alerts to the peer entity. Each message in this protocol contains 2 bytes. This Alert has no impact on the connection between sender and receiver. But, alert level indicates : Level -1 : Bad certificate, no certificate or certificate expired etc. Level-2 : Handshake failure, Decompression failure, Bad record MAC etc. 10
- 11. SSL Record Protocol 11 ● Divided into fragments ● Block compressed ● Compression encrypted with MAC(Message Authentication Code) ● Encryption of data is done ● SSL header is added
- 12. Silent Features • The advantage of this approach is that the service can be tailored to the specific needs of the given application. • Secure Socket Layer was originated by Netscape. • SSL is designed to make use of TCP to provide reliable end-to-end secure service. • This is a two-layered protocol. 12
- 13. SSL Services ●Receive data from any application layer protocol but receives typically from HTTP ●Data received from application are optionally compressed, signed and encrypted. ●The data is then passed to TCP layer ●SSL provides services on data received from application layer such as:- 13
- 14. SSL Services 1.Fragmentation At first SSL provides the data block into blocks of sizes 2^14 bytes or less 2.Compression Each fragment of data is compressed using lossless compression negotiated between the transmitter and receiver. This service is optional 3. Message Integrity to preserve the integrity of data, SSL uses keyed between hash function to create a MAC 4. Confidentiality the original data and MAC are encrypted using symmetric key cryptography 5. Framing A header is added to encrypted payload which is then passed to a reliable transport layer protocol such as TCP 14
- 15. Thank you!!! 15