
- PHP - Home
- PHP - Roadmap
- PHP - Introduction
- PHP - Installation
- PHP - History
- PHP - Features
- PHP - Syntax
- PHP - Hello World
- PHP - Comments
- PHP - Variables
- PHP - Echo/Print
- PHP - var_dump
- PHP - $ and $$ Variables
- PHP - Constants
- PHP - Magic Constants
- PHP - Data Types
- PHP - Type Casting
- PHP - Type Juggling
- PHP - Strings
- PHP - Boolean
- PHP - Integers
- PHP - Files & I/O
- PHP - Maths Functions
- PHP - Heredoc & Nowdoc
- PHP - Compound Types
- PHP - File Include
- PHP - Date & Time
- PHP - Scalar Type Declarations
- PHP - Return Type Declarations
- PHP - Operators
- PHP - Arithmetic Operators
- PHP - Comparison Operators
- PHP - Logical Operators
- PHP - Assignment Operators
- PHP - String Operators
- PHP - Array Operators
- PHP - Conditional Operators
- PHP - Spread Operator
- PHP - Null Coalescing Operator
- PHP - Spaceship Operator
- PHP Control Statements
- PHP - Decision Making
- PHP - If…Else Statement
- PHP - Switch Statement
- PHP - Loop Types
- PHP - For Loop
- PHP - Foreach Loop
- PHP - While Loop
- PHP - Do…While Loop
- PHP - Break Statement
- PHP - Continue Statement
- PHP Arrays
- PHP - Arrays
- PHP - Indexed Array
- PHP - Associative Array
- PHP - Multidimensional Array
- PHP - Array Functions
- PHP - Constant Arrays
- PHP Functions
- PHP - Functions
- PHP - Function Parameters
- PHP - Call by value
- PHP - Call by Reference
- PHP - Default Arguments
- PHP - Named Arguments
- PHP - Variable Arguments
- PHP - Returning Values
- PHP - Passing Functions
- PHP - Recursive Functions
- PHP - Type Hints
- PHP - Variable Scope
- PHP - Strict Typing
- PHP - Anonymous Functions
- PHP - Arrow Functions
- PHP - Variable Functions
- PHP - Local Variables
- PHP - Global Variables
- PHP Superglobals
- PHP - Superglobals
- PHP - $GLOBALS
- PHP - $_SERVER
- PHP - $_REQUEST
- PHP - $_POST
- PHP - $_GET
- PHP - $_FILES
- PHP - $_ENV
- PHP - $_COOKIE
- PHP - $_SESSION
- PHP File Handling
- PHP - File Handling
- PHP - Open File
- PHP - Read File
- PHP - Write File
- PHP - File Existence
- PHP - Download File
- PHP - Copy File
- PHP - Append File
- PHP - Delete File
- PHP - Handle CSV File
- PHP - File Permissions
- PHP - Create Directory
- PHP - Listing Files
- Object Oriented PHP
- PHP - Object Oriented Programming
- PHP - Classes and Objects
- PHP - Constructor and Destructor
- PHP - Access Modifiers
- PHP - Inheritance
- PHP - Class Constants
- PHP - Abstract Classes
- PHP - Interfaces
- PHP - Traits
- PHP - Static Methods
- PHP - Static Properties
- PHP - Namespaces
- PHP - Object Iteration
- PHP - Encapsulation
- PHP - Final Keyword
- PHP - Overloading
- PHP - Cloning Objects
- PHP - Anonymous Classes
- PHP Web Development
- PHP - Web Concepts
- PHP - Form Handling
- PHP - Form Validation
- PHP - Form Email/URL
- PHP - Complete Form
- PHP - File Inclusion
- PHP - GET & POST
- PHP - File Uploading
- PHP - Cookies
- PHP - Sessions
- PHP - Session Options
- PHP - Sending Emails
- PHP - Sanitize Input
- PHP - Post-Redirect-Get (PRG)
- PHP - Flash Messages
- PHP AJAX
- PHP - AJAX Introduction
- PHP - AJAX Search
- PHP - AJAX XML Parser
- PHP - AJAX Auto Complete Search
- PHP - AJAX RSS Feed Example
- PHP XML
- PHP - XML Introduction
- PHP - Simple XML Parser
- PHP - SAX Parser Example
- PHP - DOM Parser Example
- PHP Login Example
- PHP - Login Example
- PHP - Facebook Login
- PHP - Paypal Integration
- PHP - MySQL Login
- PHP Advanced
- PHP - MySQL
- PHP.INI File Configuration
- PHP - Array Destructuring
- PHP - Coding Standard
- PHP - Regular Expression
- PHP - Error Handling
- PHP - Try…Catch
- PHP - Bugs Debugging
- PHP - For C Developers
- PHP - For PERL Developers
- PHP - Frameworks
- PHP - Core PHP vs Frame Works
- PHP - Design Patterns
- PHP - Filters
- PHP - JSON
- PHP - Exceptions
- PHP - Special Types
- PHP - Hashing
- PHP - Encryption
- PHP - is_null() Function
- PHP - System Calls
- PHP - HTTP Authentication
- PHP - Swapping Variables
- PHP - Closure::call()
- PHP - Filtered unserialize()
- PHP - IntlChar
- PHP - CSPRNG
- PHP - Expectations
- PHP - Use Statement
- PHP - Integer Division
- PHP - Deprecated Features
- PHP - Removed Extensions & SAPIs
- PHP - PEAR
- PHP - CSRF
- PHP - FastCGI Process
- PHP - PDO Extension
- PHP - Built-In Functions
PHP - password_needs_rehash() Function
The PHP Hashing password_needs_rehash() function is used to determine whether a given hash matches the given option and check whether the hash needs to be rehashed. In PHP, a "hash" refers to a fixed-size string of characters produced by a hashing algorithm. The input data can be of any size, and the algorithm generates a unique output based on that input.
The options generally include the algorithm used and various parameters, such as cost, which can affect the security and performance of the hashing process.
This function returns a boolean value "true" if the hash can be rehashed to match the given algo and options; otherwise, it returns "false".
Syntax
Following is the syntax of the PHP Hashing password_needs_rehash() function −
password_needs_rehash(string $hash, string $algo, array $options = []): bool
Parameters
This function accepts the following parameters −
- hash − A hash created bypassword_hash() function.
- algo − Apassword algorithm constantrepresents the algorithm to use when hashing the password.
- options − An associative array containing options.
Return value
This function returnstrue, if the hash should be rehashed to match the givenalgoandoptions, orfalseotherwise.
Example 1
The following program demonstrates the usage of the PHP Hashing password_needs_rehash() function −
<?php $passw = "53nh46u74m3nt3"; $hashp = '$argon2i$v=19$m=65536,t=4,p=1$dmJMWlhFUEFvaTFSeFhFNQ$Cpgdj1rHw21Y7WqnMpUAFFp7uLubGoU7Zxc09Pn8t9k'; $algo = PASSWORD_ARGON2I; $options = ['cost' => 12]; $conf = password_needs_rehash($hashp, $algo); echo "The given password: $passw"; echo "\nThe given password hash: $hashp"; echo "\nThe given algo: $algo"; $result = password_needs_rehash($hashp, $algo, $options); if($result){ $newhas = password_hash($passw, $algo); echo "\nThe function result: "; var_dump($result); echo "Hash need to rehashed, Suggested for the new hash: \n"; echo $newhas; } else { echo "\nThe function result: "; var_dump($result); echo "Matched, no need to be rehashed: "; } ?>
Output
The above program produces the following output −
The given password: 53nh46u74m3nt3 The given password hash: $argon2i$v=19$m=65536,t=4,p=1$dmJMWlhFUEFvaTFSeFhFNQ$Cpgdj1rHw21Y7WqnMpUAFFp7uLubGoU7Zxc09Pn8t9k The given algo: argon2i The function result: bool(false) Matched, no need to be rehashed:
Example 2
If the given hash does not match the given options, this function returns "true".
Following is another example of the PHP Hashing password_needs_rehash() function. We use this function to check whether the given hash matches the given options −
<?php $passw = "53nh46u74m3nt3"; $hashp = '$argon2i$v=19$m=1024,t=2,p=2$d1JJWnNHMkVEekZwcTFUdA$zeSi7c/Adh/1KCTHddoF39Xxwo9ystxRzHEnRa0lQeM'; $algo = PASSWORD_ARGON2I; $options = ['cost' => 12]; $conf = password_needs_rehash($hashp, $algo); echo "The given password: $passw"; echo "\nThe given password hash: $hashp"; echo "\nThe given algo: $algo"; $result = password_needs_rehash($hashp, $algo, $options); if($result){ $newhas = password_hash($passw, $algo); echo "\nThe function result: "; var_dump($result); echo "Hash need to rehashed, suggested for the new hash: \n"; echo $newhas; } else { echo "\nThe function result: "; var_dump($result); echo "\nMatched, no need to be rehashed: "; } ?>
Output
After executing the above program, the following output will be displayed −
The given password: 53nh46u74m3nt3 The given password hash: $argon2i$v=19$m=1024,t=2,p=2$d1JJWnNHMkVEekZwcTFUdA$zeSi7c/Adh/1KCTHddoF39Xxwo9ystxRzHEnRa0lQeM The given algo: argon2i The function result: bool(true) Hash need to rehashed, suggested for the new hash: $argon2i$v=19$m=65536,t=4,p=1$amw3ZHM3bEpYN3lWYlp6eg$wNWs5nkT2/Yx7NXkOJ4TZ4EqUmc58Xhb6N3IX5shNc8