wp_generate_auth_cookie( int $user_id, int $expiration, string $scheme = 'auth', string $token = '' ): string

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$user_idint

User ID.

$expirationint

The time the cookie expires as a UNIX timestamp.

$schemestringoptional

The cookie scheme to use: 'auth', 'secure_auth', or 'logged_in'.
Default 'auth'.Default: 'auth'

$tokenstringoptional

User's session token to use for this cookie.Default: ''

Return value

string

Authentication cookie contents. Empty string if user does not exist.

Performance profile

How much work a call to wp_generate_auth_cookie() 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

Heavy

Reaches the database via get_user_by().

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

10–60

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 61.

Plugin surface

1 hook

Third-party callbacks on 'auth_cookie' run inside this call, and their cost is not bounded by anything here.

Called by

1

1 place in core call this, so the cost is paid more often than your own code shows.

What it touches

• hookthird-party callbacksapply_filters()called directly
• querycontent queryget_user_by()one call below wp_generate_auth_cookie()

Further down the call graph this can also reach option, cache, serialize and transient. 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_generate_auth_cookie() can have, taken from its control-flow graph on PHP 8.5.

Hooks and filters fired · 1

One hook fires while wp_generate_auth_cookie() runs, in this order:

1. 1
   apply_filters( auth_cookie )filterline 890 (+33 into the body)

   Filters the authentication cookie.

Uses · 5

• get_userdata()Retrieves user info by user ID.
• wp_hash()Gets hash of given string.
• hash_hmac()Compat function to mimic hash_hmac().
• apply_filters()Calls the callback functions that have been added to a filter hook.
• WP_Session_Tokens::get_instance()Retrieves a session manager instance for a user.

Used by · 1

• wp_set_auth_cookie()Sets the authentication cookies based on user ID.

Source code

View on Trac ↗View on GitHub ↗

857	function wp_generate_auth_cookie( $user_id, $expiration, $scheme = 'auth', $token = '' ) {858		$user = get_userdata( $user_id );859		if ( ! $user ) {860			return '';861		}862 863		if ( ! $token ) {864			$manager = WP_Session_Tokens::get_instance( $user_id );865			$token   = $manager->create( $expiration );866		}867 868		$pass_frag = substr( $user->user_pass, 8, 4 );869 870		$key = wp_hash( $user->user_login . '|' . $pass_frag . '|' . $expiration . '|' . $token, $scheme );871 872		// If ext/hash is not present, compat.php's hash_hmac() does not support sha256.873		$algo = function_exists( 'hash' ) ? 'sha256' : 'sha1';874		$hash = hash_hmac( $algo, $user->user_login . '|' . $expiration . '|' . $token, $key );875 876		$cookie = $user->user_login . '|' . $expiration . '|' . $token . '|' . $hash;877 878		/**879		 * Filters the authentication cookie.880		 *881		 * @since 2.5.0882		 * @since 4.0.0 The `$token` parameter was added.883		 *884		 * @param string $cookie     Authentication cookie.885		 * @param int    $user_id    User ID.886		 * @param int    $expiration The time the cookie expires as a UNIX timestamp.887		 * @param string $scheme     Cookie scheme used. Accepts 'auth', 'secure_auth', or 'logged_in'.888		 * @param string $token      User's session token used.889		 */890		return apply_filters( 'auth_cookie', $cookie, $user_id, $expiration, $scheme, $token );891	}

Changelog

Introduced in 2.5.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 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

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