PHP password_verify always returns false - php

Question

I´ve been working on an Android app which registers and logins users to a remote MySQL database. I have double-double checked my Android code and the information sent from the app to PHP.
Apparently, the problem is somewhere in the login.php file. Users are registered successfully, but I am unable to login after that.
My DB has 3 fields:
id / int(11)
email / varchar(255)
password /char(60)
Registering a user is giving me 60 characters hashes for the password field. So far, so good. But then when I try to login, I always get a failure response.
I'm using https://github.com/ircmaxell/password_compat since I'm limited to PHP 5.4
Here is my login PHP code:
<?php
if($_SERVER['REQUEST_METHOD']=='POST'){
$email = $_POST['email'];
$passwordFromPost = $_POST['password'];
require_once('dbconnect.php');
$sql = "SELECT password FROM users WHERE email = '$email'";
$hash = mysqli_query($con, $sql);
require_once('lib/password.php');
if (password_verify($passwordFromPost, $hash)) {
echo 'success';
} else {
echo 'failure';
}
}
?>
And just in case, here is my registration PHP code:
<?php
if($_SERVER['REQUEST_METHOD']=='POST'){
$email = $_POST['email'];
$passwordFromPost = $_POST['password'];
require_once('lib/password.php');
$hash = password_hash($passwordFromPost, PASSWORD_BCRYPT);
if($hash) {
require_once('dbconnect.php');
$sql = "INSERT INTO users (email, password) VALUES ('$email','$hash')";
if(mysqli_query($con, $sql)){
echo "Registered succesfully";
} else {
echo "Unable to register the account";
}
} else {
echo 'error';
}
} else {
echo 'error';
}
?>
Any help will be much appreciated. Thank you.

Answer 1

You forgot to fetch your row. As such you were not verifying against a string.
<?php
$result = mysqli_query($con, $sql);
$row = mysqli_fetch_array($result);
password_verify($passwordFromPost, $row['password']);

Answer 2

You need to fetch the row:
<?php
if($_SERVER['REQUEST_METHOD']=='POST'){
$email = $_POST['email'];
$passwordFromPost = $_POST['password'];
require_once('dbconnect.php');
$sql = "SELECT password FROM users WHERE email = '$email'";
$hash = mysqli_query($con, $sql);
while ($row = mysqli_fetch_row($hash)) {
require_once('lib/password.php');
if (password_verify($passwordFromPost, $row["password"])) {
echo 'success';
} else {
echo 'failure';
}
}
}
?>
Reference: http://php.net/manual/en/mysqli-result.fetch-row.php

Answer 3

Your login php file should be
<?php
if($_SERVER['REQUEST_METHOD']=='POST'){
$email = $_POST['email'];
$passwordFromPost = $_POST['password'];
require_once('dbconnect.php');
$sql = "SELECT password FROM users WHERE email = '$email'";
$rst = mysqli_query($con, $sql);
$hash = mysqli_fetch_row($rst);
require_once('lib/password.php');
if (password_verify($passwordFromPost, $hash['password'])) {
echo 'success';
} else {
echo 'failure';
}
}
?>