PHP password_verify 似乎适用于一个字符串，但不适用于另一个被认为相等的字符串

Question

我将用户名和加密密码存储在 mysql 数据库中。仅用于测试，我还将密码以未加密的形式存储在数据库中。

在下面的代码中，我从数据库中获取散列密码和未加密密码。然后我加密未加密的密码。

给定的密码没有通过存储哈希或新哈希的密码验证测试。

存储的密码确实通过了存储哈希和新哈希的密码验证测试。

对 strcmp 的调用表明存储的密码和给定的密码是相等的。

这怎么可能？

[edit] : 我从网页上的用户输入中传入 $password。

// get hashed password from database
$sql = "SELECT member_password FROM member WHERE member_username=:username;";
$stmt = $db->prepare($sql);
$stmt->bindParam("username", $username);
$stmt->execute();
$hash = $stmt->fetch(PDO::FETCH_ASSOC);
$hash = $hash["member_password"];

// get unencrypated password from database
$sql = "SELECT member_unencrypted FROM member WHERE member_username=:username;";
$db = getConnection();
$stmt = $db->prepare($sql);
$stmt->bindParam("username", $username);
$stmt->execute();
$unencrypted = $stmt->fetch(PDO::FETCH_ASSOC);
$unencrypted = $unencrypted["member_unencrypted"];

// encrypt the unencrypted password that was retrieved from the database
$encrypted = password_hash($unencrypted, PASSWORD_DEFAULT);

// given password does not pass the new hash per this test
if(password_verify($password, $encrypted))
  echo '<br>given password passed new hash';
else 
  echo '<br>given password did not pass new hash';

// stored password does pass the new hash per this test
if(password_verify($unencrypted, $encrypted))
  echo '<br>stored password passed new hash';
else
  echo '<br>stored password did not pass new hash';

// given password does not pass the stored hash per this test.
if(password_verify($password, $hash)){
  echo '<br>given password passed stored hash';
else
  echo '<br>given password did not pass stored hash';

// stored password does pass the stored hash per this test.
if(password_verify($unencrypted, $hash))
  echo '<br>stored password passed stored hash';
else
  echo '<br>stored password did not pass stored hash';

// stored and given passwords are equal per this test.
if(strcmp($unencrypted, $password)) 
  echo '<br>stored and given passwords are equal';
else
  echo '<br>stored and given passwords are not equal';

输出：

given password did not pass new hash
stored password passed new hash
given password did not pass stored hash
stored password passed stored hash
stored and given passwords are equal

Answer 1

从您的问题中不清楚变量$password 的来源，以及它是否包含与数据库中存储的文本相同的文本。

如果您进行此类测试，您必须知道函数password_hash() 将生成唯一的盐并将其包含在生成的哈希中。为了验证，您需要此盐（和其他参数）来获得可比较的哈希值。这意味着哈希每次都会不同，如果您调用 password_hash() 两次，您最终会得到不同的盐和不可比较的哈希。

我试图在另一个answer 中解释哈希格式。

[来自布鲁斯的编辑：答案见 cmets]