password_verify()

(PHP 5 >= 5.5.0, PHP 7)

验证密码是否和散列值匹配

说明

password_verify(string $password,string $hash): bool

验证密码是否和指定的散列值匹配。

注意password_hash()返回的散列包含了算法、 cost 和盐值。因此，所有需要的信息都包含内。使得验证函数不需要储存额外盐值等信息即可验证哈希。

时序攻击（timing attacks）对此函数不起作用。

参数

$password: 用户的密码。
$hash: 一个由password_hash()创建的散列值。

返回值

如果密码和散列值匹配则返回TRUE，否则返回FALSE。

范例

Example #1password_verify()例子

<?php
// 想知道以下字符从哪里来，可参见 password_hash() 的例子
$hash = '$2y$07$BCryptRequires22Chrcte/VlQH0piJtjXl.0t1XkA8pw9dMXTpOq';
if (password_verify('rasmuslerdorf', $hash)) {
    echo 'Password is valid!';
} else {
    echo 'Invalid password.';
}
?>

以上例程会输出：

Password is valid!

参见

password_hash() 创建密码的散列（hash）
»用户使用

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.';
}
?>

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.

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!
?>

This Is The Most Secure Way To Keep Your Password Safe With PHP 7 , 
Even When Your DataBase Has Been Hacked ,
It Will Be Almost Impossible To Retrieve Your Password .
--------------------------------------------------------
--- When A User Wants To Sign Up ---
1 ---> Get Input From User Which Is The User`s Password
1 ---> Hash The Password
2 ---> Store The Hashed Password In Your DataBase
--------------------------------------------------------
<?php
$hashed_password = password_hash($_POST["password"],PASSWORD_DEFAULT);
// $_POST["password"] ---> Is The User`s Input
// $hashed_password ---> Is The Hashed Password You Can Store In Your DataBase
?>
--------------------------------------------------------
--- When A User Wants To Sign In ---
1 ---> Get Input From User Which Is The User`s Password
2 ---> Fetch The Hashed Password From Your Database
3 ---> Compare The User`s Input And The Hashed Password 
--------------------------------------------------------
<?php
  if(password_verify($_POST["password"],$hashed_password))
  echo "Welcome"; 
  else
  echo "Wrong Password";
// $_POST["password"] ---> Is The User`s Input
// $hashed_password ---> Is The Hashed Password You Have Fetched From DataBase
?>

As Vasil Toshkov stated, password_verify() can be used to verify a password created by crypt() or password_hash()
That is because passwords created by password_hash() also use the C crypt sheme
If you want to verify older plain MD5-Hashes you just need to prefix them with $1$
See https://en.wikipedia.org/wiki/Crypt_(C) for more information.