wppaste
WordPress

PasswordHash::gensalt_blowfish( $input )

Source
wp-includes/class-phpass.php:173

Compatibility

WordPress
core
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

$input

Performance profile

How much work a call to PasswordHash::gensalt_blowfish() 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
Light

Touches nothing outside its own arguments.

Scaling
Scales with input

The body loops, so the work grows with what you pass in.

Instructions
34

Executed per call on PHP 8.5. The body compiles to 58.

Plugin surface
None

Nothing here hands control to plugin code.

Called by
1

1 place 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 PasswordHash::gensalt_blowfish() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
$i34chr(), chr(), ord()

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, 34 executed per call, 1 branch. 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.

Used by · 1

Source code

	function gensalt_blowfish($input)	{		# This one needs to use a different order of characters and a		# different encoding scheme from the one in encode64() above.		# We care because the last character in our encoded string will		# only represent 2 bits.  While two known implementations of		# bcrypt will happily accept and correct a salt string which		# has the 4 unused bits set to non-zero, we do not want to take		# chances and we also do not want to waste an additional byte		# of entropy.		$itoa64 = './ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'; 		$output = '$2a$';		$output .= chr((int)(ord('0') + $this->iteration_count_log2 / 10));		$output .= chr(ord('0') + $this->iteration_count_log2 % 10);		$output .= '$'; 		$i = 0;		do {			$c1 = ord($input[$i++]);			$output .= $itoa64[$c1 >> 2];			$c1 = ($c1 & 0x03) << 4;			if ($i >= 16) {				$output .= $itoa64[$c1];				break;			} 			$c2 = ord($input[$i++]);			$c1 |= $c2 >> 4;			$output .= $itoa64[$c1];			$c1 = ($c2 & 0x0f) << 2; 			$c2 = ord($input[$i++]);			$c1 |= $c2 >> 6;			$output .= $itoa64[$c1];			$output .= $itoa64[$c2 & 0x3f];		} while (1); 		return $output;	}

Changelog

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 7.1.0 tag, from src/wp-includes/class-phpass.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
Corrections
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