详谈PHP中的密码安全性Password Hashing

//require 'password.php';

/**

 * 正确的密码是secret-password

 * $passwordHash 是hash 后存储的密码

 * password_verify()用于将用户输入的密码和数据库存储的密码比对。成功返回true，否则false

 */

$passwordHash= password_hash('secret-password', PASSWORD_DEFAULT);

echo$passwordHash;

if(password_verify('bad-password',$passwordHash)) {

  // Correct Password

  echo'Correct Password';

}else{

  echo'Wrong password';

  // Wrong password

}

classUser

{

  // Store password options so that rehash & hash can share them:

  constHASH = PASSWORD_DEFAULT;

  constCOST = 14;//可以确定该算法应多复杂，进而确定生成哈希值将花费多长时间。（将此值视为更改算法本身重新运行的次数，以减缓计算。）

  // Internal data storage about the user:

  public$data;

  // Mock constructor:

  publicfunction__construct() {

    // Read data from the database, storing it into $data such as:

    // $data->passwordHash and $data->username

    $this->data =newstdClass();

    $this->data->passwordHash ='dbd014125a4bad51db85f27279f1040a';

  }

  // Mock save functionality

  publicfunctionsave() {

    // Store the data from $data back into the database

  }

  // Allow for changing a new password:

  publicfunctionsetPassword($password) {

    $this->data->passwordHash = password_hash($password, self::HASH, ['cost'=> self::COST]);

  }

  // Logic for logging a user in:

  publicfunctionlogin($password) {

    // First see if they gave the right password:

    echo"Login: ",$this->data->passwordHash,"n";

    if(password_verify($password,$this->data->passwordHash)) {

      // Success - Now see if their password needs rehashed

      if(password_needs_rehash($this->data->passwordHash, self::HASH, ['cost'=> self::COST])) {

        // We need to rehash the password, and save it. Just call setPassword

        $this->setPassword($password);

        $this->save();

      }

      returntrue;// Or do what you need to mark the user as logged in.

    }

    returnfalse;

  }

}