added login

app/scripts/connection.php

@@ -0,0 +1,15 @@
+<?php
+
+$dbhost = "mysql";
+$dbuser = "grisu";
+$dbpass = "secret";
+$dbname = "ksp";
+
+try {
+    $con = new PDO("mysql:host=$dbhost;dbname=$dbname", $dbuser, $dbpass);
+    $con->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
+    $con->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+} catch(PDOExeption $e) {
+    print "Error!: " . $e->getMessage() . "<br/>";
+    die();
+}

app/scripts/database_queries.php

@@ -1,5 +1,10 @@
 <?php
 
+function handle_pdo_exception($e) {
+    print "Error!: " . $e->getMessage() . "<br/>";
+    die();
+}
+
 function get_Station() {
     try {
         $dbh = new PDO('mysql:host=mysql;dbname=ksp', 'grisu', 'secret');
@@ -8,9 +13,53 @@ function get_Station() {
         }
         $dbh = null;
     } catch(PDOException $e) {
-        print "Error!: " . $e->getMessage() . "<br/>";
-        die();
+        handle_pdo_exception($e);
     }
 }
 
-?>
+function check_user_id($con, $user_id) {
+    try {
+        $stmt = $con->prepare('SELECT user_id FROM users WHERE user_id = :user_id limit 1');
+        $stmt->execute(['user_id' => $user_id]);
+
+        if($stmt) {
+            return true;
+        } else {
+            return false;
+        }
+    } catch(PDOException $e) {
+        handle_pdo_exception($e);
+    }
+}
+
+function get_user_data_name($con, $user_name) {
+    try {
+        $stmt = $con->prepare('SELECT * FROM users WHERE user_name = :user_name limit 1');
+        $stmt->execute(['user_name' => $user_name]);
+        $stmt->setFetchMode(PDO::FETCH_ASSOC);
+        return $stmt->fetch();
+    } catch(PDOException $e) {
+        handle_pdo_exception($e);
+    }
+}
+
+function get_user_data_id($con, $user_id) {
+    try {
+        $stmt = $con->prepare('SELECT * FROM users WHERE user_id = :user_id limit 1');
+        $stmt->execute(['user_id' => $user_id]);
+        $stmt->setFetchMode(PDO::FETCH_ASSOC);
+        return $stmt->fetch();
+    } catch(PDOException $e) {
+        handle_pdo_exception($e);
+    }
+}
+
+function add_user($con, $username, $user_id, $user_group, $password, $salt) {
+    try {
+        $stmt = $con->prepare("INSERT INTO users (user_id, password, user_name, salt, user_group) VALUES (?, ?, ?, ?, ?)");
+        $stmt->bind_param("sssss", $user_id, $password, $username, $salt, $user_group);
+        $stmt->execute();        
+    } catch(PDOExeption $e) {
+        handle_pdo_exception($e);
+    }   
+}

app/scripts/functions.php

@@ -0,0 +1,34 @@
+<?php
+
+include("database_queries.php");
+
+function check_login($con) {
+    
+    if(isset($_SESSION['user_id'])) {
+        
+        $id = $_SESSION['user_id'];
+        if(check_user_id($con, $id)) {
+            return get_user_data_id($con, $id);
+        } else {
+            header("Location: login.php");
+            die;
+        }
+    } else {
+        header("Location: login.php");
+        die;
+    }
+}
+
+function generate_salt() {
+    return substr(bin2hex(random_bytes(128)), 0, 128);
+}
+
+function generate_user_id($username, $salt) {
+    $uname = $username . $salt;
+    return hash('sha3-512', $uname);
+}
+
+function generate_password_hash($password, $salt) {
+    $pword = $password . $salt;
+    return hash('sha3-512', $pword);
+}