check if value exist in json file using php - php

Question

i make a login system using php with json file data. i tried to login with JavaScript file and it works fine. but it is not secure well. then i change some code with php login.
this is my php code
if(isset($_POST['submit'])){
$json_string = file_get_contents('login.json');
$parsed_json = json_decode($json_string, true);
foreach($parsed_json as $key => $value){
$jsonemail = $value['email'];
$jsonpass = $value['pass'];
}
if($email == $jsonemail && $pass == $jsonpass){
header('location: view.php');
}
else{
echo "please check your email or password";
}
}
but this not working. i want to fix this code. i want to check email and password is correct with json file data.
this is my login.json file data like
"1": {
"email": "test123#gmail.com",
"pass": "123"
},
and this is my html login form
<div class="container">
<div class="row">
<div class="col-md-4"></div>
<div class="col-md-4">
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
<div class="form-group">
<label for="email">Email address</label>
<input type="email" class="form-control" name="email" id="email" aria-describedby="emailHelp" required="require" placeholder="Enter email">
</div>
<div class="form-group">
<label for="pass">Password</label>
<input type="password" class="form-control" id="pass" required="require" placeholder="Password">
</div>
<button type="submit" class="btn btn-primary" name="submit" >Submit</button>
</form>
</div>
<div class="col-md-4"></div>
</div>
</div>

Answer 1

I think your email and pass variable are not defined. Have a look at it.
if (isset($_POST['submit'])) {
$json_string = file_get_contents('login.json');
$parsed_json = json_decode($json_string, true);
$email = $_POST['email']; // I think you miss this
$pass = $_POST['pass']; // and this lines as in your code its missing
$flag = false;
foreach ($parsed_json as $key => $value) {
if ($value['email'] == $email && $value['pass'] == $pass) {
$flag = true;
break;
}
}
if ($flag) {
header('location: view.php');
} else {
echo "Please check your email and password."
}
}
And one more thing
while posting any form you must name element which you want in $_POST.
<input type="password" class="form-control" id="pass" required="require" placeholder="Password">
In above line you are missing name as pass. Replace above line with
<input type="password" class="form-control" id="pass" required="require" placeholder="Password" name="pass">
This should solve your problem.

Answer 2

Your foreach is just overwriting the values of $jsonemail and $jsonpass each time, so when you reach the if() part to check the user details, these will always be the last values in the file.
if(isset($_POST['submit'])){
$json_string = file_get_contents('login.json');
$parsed_json = json_decode($json_string, true);
foreach($parsed_json as $key => $value){
if($email == $value['email'] && $pass == $value['pass']){
header('location: view.php');
exit();
}
}
echo "please check your email or password";
}
This code redirects if the user is found and if it gets to the end of the loop, then the user doesn't exist in the file.