password_verify

(PHP 5 >= 5.5.0, PHP 7)

password_verify — Verifies that a password matches a hash

Description

boolean password_verify ( string $password , string $hash )

Verifies that the given hash matches the given password.

Note that password_hash() returns the algorithm, cost and salt as part of the returned hash. Therefore, all information that's needed to verify the hash is included in it. This allows the verify function to verify the hash without needing separate storage for the salt or algorithm information.

This function is safe against timing attacks.

Parameters

password: The user's password.
hash: A hash created by password_hash().

Return Values

Returns TRUE if the password and hash match, or FALSE otherwise.

Examples

Example #1 password_verify() example


<?php
// See the password_hash() example to see where this came from.
$hash = '$2y$07$BCryptRequires22Chrcte/VlQH0piJtjXl.0t1XkA8pw9dMXTpOq';

if (password_verify('rasmuslerdorf', $hash)) {
    echo 'Password is valid!';
} else {
    echo 'Invalid password.';
}
?>

The above example will output:

Password is valid!

User Contributed Notes

Anonymous

1 year ago


If you get incorrect false responses from password_verify when manually including the hash variable (eg. for testing) and you know it should be correct, make sure you are enclosing the hash variable in single quotes (') and not double quotes (").



PHP parses anything that starts with a $ inside double quotes as a variable:



<?php

// this will result in 'Invalid Password' as the hash is parsed into 3 variables of

// $2y, $07 and $BCryptRequires22Chrcte/VlQH0piJtjXl.0t1XkA8pw9dMXTpOq

// due to it being enclosed inside double quotes

$hash = "$2y$07$BCryptRequires22Chrcte/VlQH0piJtjXl.0t1XkA8pw9dMXTpOq";



// this will result in 'Password is valid' as variables are not parsed inside single quotes

$hash = '$2y$07$BCryptRequires22Chrcte/VlQH0piJtjXl.0t1XkA8pw9dMXTpOq';



if (password_verify('rasmuslerdorf', $hash)) {

    echo 'Password is valid!';

} else {

    echo 'Invalid password.';

}

?>

chris at weeone dot de

3 months ago


The function password_verify() uses constant time. This makes it safe against timing attacks. Don't use crypt($password_database) === crypt($password_given_by_login), since there is no protection against timing attacks!

If you don't want to use password_verify(), then have a look at hash_equals(), which also runs a timing attack safe string comparison.

Vasil Toshkov

2 years ago


This function can be used to verify hashes created with other functions like crypt(). For example:

<?php

$hash = '$1$toHVx1uW$KIvW9yGZZSU/1YOidHeqJ/';

if (password_verify('rasmuslerdorf', $hash)) {
    echo 'Password is valid!';
} else {
    echo 'Invalid password.';
}

// Output: Password is valid!

?>

suit at rebell dot at