wppaste
WordPress

wp_fast_hash( string $message ): string

Since
6.8.0
Source
wp-includes/functions.php:9363
Returns a cryptographically secure hash of a message using a fast generic hash function.

Description

Use the wp_verify_fast_hash() function to verify the hash.

This function does not salt the value prior to being hashed, therefore input to this function must originate from a random generator with sufficiently high entropy, preferably greater than 128 bits. This function is used internally in WordPress to hash security keys and application passwords which are generated with high entropy.

Important:

  • This function must not be used for hashing user-generated passwords. Use wp_hash_password() for that.
  • This function must not be used for hashing other low-entropy input. Use wp_hash() for that.

The BLAKE2b algorithm is used by Sodium to hash the message.

Compatibility

WordPress
since 6.8.0
PHP
7.4–8.6-dev
  • 6.7.7
  • 6.8.8
  • 6.9.7
  • 7.0.4
  • 7.1.0

Present in 4 of the 5 tracked releases, added in 6.8.0, and compiles on PHP 7.4 through 8.6-dev.

Parameters

$messagestring
The message to hash.

Return value

string
The hash of the message.

Performance profile

How much work a call to wp_fast_hash() 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

Touches nothing outside its own arguments.

Scaling
Constant

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

Instructions
13

Executed per call on PHP 8.5. The body compiles to 13.

Plugin surface
None

Nothing here hands control to plugin code.

Called by
5

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

What one call costs · 1 distinct outcome

One number would be a lie: the work depends on which branch runs. These are every distinct cost wp_fast_hash() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
always13sodium_crypto_generichash(), sodium_bin2base64()

Across PHP versions

Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 13 instructions, 13 executed per call, 0 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.

Uses · 2

Used by · 5

Source code

function wp_fast_hash(	#[\SensitiveParameter]	string $message): string {	$hashed = sodium_crypto_generichash( $message, 'wp_fast_hash_6.8+', 30 );	return '$generic$' . sodium_bin2base64( $hashed, SODIUM_BASE64_VARIANT_URLSAFE_NO_PADDING );}

Changelog

Introduced in 6.8.0. Unchanged from 6.8.8 through 7.1.0.

  1. 6.8.8
  2. 6.9.7
  3. 7.0.4
  4. 7.1.0

Signature, return type and hooks compared across 4 parsed releases.

About this page

Parsed data
Generated from the wordpress-develop 7.1.0 tag, from src/wp-includes/functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
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