FEUP-SSIN

Repository for the Segurança em Sistemas Informáticos course.

Group Elements

• Pedro Galvão
• Eduardo Macedo
• Ana Rita Santos
• Raul Viana

Tools

Pyhton, Javascript, openssl, sqlite3

Scenario

An organization intends to design and implement a system with a trusted server supplying services to client applications, used by their collaborators. The services are REST endpoints that can be called by the client applications. These services have an associated security level (an integer value). Also, collaborators can send messages to each other using the client application. The client applications should be mobile, but, for a proof of concept, they can run on a PC with a CLI (command line interface) or GUI (graphic user interface) interface...(Full Text)

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Install

$ npm install

Create Database

$ cd database
$ cat create.sql | sqlite3 Database.db
or (testing)
$ cd server
$ python create_table.py

Create two clients

To send messages between two clients run them from different folders
Pre-registration needed on both

$ cp -r client ./client2

Pre-registration & Start Server "face-to-face"

$ cd server
$ python register_app.py
$ node index

First Registration &/or Authentication (New Session)

$ cd client
$ python client.py

• Main Menu
  1. Request service
     1. Calculation of square root (security level: 1)
     2. Calculation of cubic root (security level: 2)
     3. Paramaterized n-root (security level: 3)
  2. Send message
  3. Check received messages

Encrypt Process

Registration

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Client asks for server public key.

Server Response:

• not encrypted: public_key

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Client:

• not encrypted: username
• encrypted (rsa): one_time_id, new_iv, symmetric_key, time

Server Response:

• encrypted(symmetric): token

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Authentication

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Client Challenge Request:

• not encrypted: username, new_iv
• encrypted(symmetric): token, msg, time

Server Response:

• not encrypted: challenge, new_iv
• encrypted(symmetric): succ_msg

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Client Challenge Solved Request:

• not encrypted: username, new_iv
• encrypted(symmetric): "challenge", time

Server Response:

• not encrypted: new_iv
• encrypted(symmetric): new_token, succ_msg

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Services

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Client set ip Request:

• not encrypted: username, new_iv
• encrypted(symmetric): token, ip_port, time

Server Response:

• not encrypted: new_iv
• encrypted(symmetric): succ_msg

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Client get ip Request:

• not encrypted: username, new_iv
• encrypted(symmetric): token, username_2, time

Server Response:

• not encrypted: new_iv, ip_port
• encrypted(symmetric): ip_port, succ_msg

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Client service Request:

• not encrypted: username, new_iv
• encrypted(symmetric): token, service_data, time

Server Response:

• not encrypted: new_iv
• encrypted(symmetric): succ_msg with the value

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Client set public_key Request:

• not encrypted: username, new_iv
• encrypted(symmetric): token, public_key, time

Server Response:

• not encrypted: new_iv
• encrypted(symmetric): succ_msg

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Client get public_key Request:

• not encrypted: username, new_iv
• encrypted(symmetric): token, username_2, time

Server Response:

• not encrypted: new_iv, ip_port
• encrypted(symmetric): public_key, succ_msg

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