wp_check_password( string $password, string $hash, string|int $user_id = '' ): bool
- Since
- 2.5.0
- Source
wp-includes/pluggable.php:2648
Description
Maintains compatibility between old version and the new cookie authentication protocol using PHPass library. The $hash parameter is the encrypted password and the function compares the plain text password when encrypted similarly against the already encrypted password to see if they match.
For integration with other applications, this function can be overwritten to instead use the other package password hashing algorithm.
Compatibility
- WordPress
- since 2.5.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$passwordstring- Plaintext user's password.
$hashstring- Hash of the user's password to check against.
$user_idstring|intoptional- User ID.Default:
''
Return value
bool- False, if the $password does not match the hashed password.
Performance profile
How much work a call to wp_check_password() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Trivial
- Scaling
- Constant
- Instructions
- 22–33
- Plugin surface
- 1 hook
- Called by
- 3
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 58.
Third-party callbacks on 'check_password' run inside this call, and their cost is not bounded by anything here.
3 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- hookthird-party callbacks
apply_filters()called directly
Further down the call graph this can also reach query and cache. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 3 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost wp_check_password() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 22–32 | ->CheckPassword(), apply_filters() |
| always | 24–25 | md5(), hash_equals(), apply_filters() |
| always | 33 | md5(), hash_equals(), wp_set_password(), wp_hash_password(), apply_filters() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 58 instructions, 22–33 executed per call, 4 branches. The work does not change between versions.
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Hooks and filters fired · 2
2 hooks fire while wp_check_password() runs, in this order:
- apply_filters( check_password )filterline 2670 (+22 into the body)
Filters whether the plaintext password matches the encrypted password.
- apply_filters( check_password )filterline 2686 (+38 into the body)
Filters whether the plaintext password matches the encrypted password.
Uses · 5
- hash_equals()Timing attack safe string comparison.
- wp_set_password()Updates the user's password with a new hashed one.
- wp_hash_password()Creates a hash of a plain text password.
- apply_filters()Calls the callback functions that have been added to a filter hook.
- PasswordHash::__construct()
Used by · 3
- wp_authenticate_application_password()Authenticates the user using an application password.
- wp_authenticate_email_password()Authenticates a user using the email and password.
- wp_authenticate_username_password()Authenticates a user, confirming the username and password are valid.
Source code
function wp_check_password( $password, $hash, $user_id = '' ) { global $wp_hasher; // If the hash is still md5... if ( strlen( $hash ) <= 32 ) { $check = hash_equals( $hash, md5( $password ) ); if ( $check && $user_id ) { // Rehash using new hash. wp_set_password( $password, $user_id ); $hash = wp_hash_password( $password ); } /** * Filters whether the plaintext password matches the encrypted password. * * @since 2.5.0 * * @param bool $check Whether the passwords match. * @param string $password The plaintext password. * @param string $hash The hashed password. * @param string|int $user_id User ID. Can be empty. */ return apply_filters( 'check_password', $check, $password, $hash, $user_id ); } /* * If the stored hash is longer than an MD5, * presume the new style phpass portable hash. */ if ( empty( $wp_hasher ) ) { require_once ABSPATH . WPINC . '/class-phpass.php'; // By default, use the portable hash from phpass. $wp_hasher = new PasswordHash( 8, true ); } $check = $wp_hasher->CheckPassword( $password, $hash ); /** This filter is documented in wp-includes/pluggable.php */ return apply_filters( 'check_password', $check, $password, $hash, $user_id ); }Changelog
Introduced in 2.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 6.7.7 tag, from
src/wp-includes/pluggable.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.