khabib97 / self-destructing-message

Secrect message sharing application

Self Destructing Message

Database Set Up

1. Install a PostgreSQL
2. Create user and set password for it.
3. Create Database and table using follwing script.

CREATE DATABSE self-destructing-message-db;


CREATE OR REPLACE FUNCTION generate_uid(size INT) RETURNS TEXT AS $$
DECLARE
  characters TEXT := 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
  bytes BYTEA := gen_random_bytes(size);
  l INT := length(characters);
  i INT := 0;
  output TEXT := '';
BEGIN
  WHILE i < size LOOP
    output := output || substr(characters, get_byte(bytes, i) % l + 1, 1);
    i := i + 1;
  END LOOP;
  RETURN output;
END;
$$ LANGUAGE plpgsql VOLATILE;

CREATE TABLE notes (
    id TEXT PRIMARY KEY DEFAULT generate_uid(16),
    name VARCHAR(50),
    message TEXT,
    password VARCHAR(64),-- SHA256 256/4=64
    email VARCHAR(50),
    generation_time TIMESTAMP,
    destruction_time TIMESTAMP,
    is_active BOOLEAN
);

CREATE TABLE users (
    id SERIAL PRIMARY KEY,
    username VARCHAR(50),
    password VARCHAR(64) -- SHA256 256/4=64
);

If you get error something like this:

org.postgresql.util.PSQLException: ERROR: function gen_random_bytes(integer) does not exist

Then check if gen_random_bytes(integer) exists or not.

select pg_get_functiondef(to_regproc('gen_random_bytes'));

If it does not exist then create it:

CREATE EXTENSION pgcrypto;