PHP Class Dcrypt\Str

The functions in this class were inspired by the symfony's StringUtils class.

Author: Michael Meyer (mmeyer2k) ([email protected])

Public Methods

Method	Description
equal ( string $known, string $given ) : boolean	Compares two strings in constant time. Strings are hashed before comparison so information is not leaked when strings are not of equal length.
hashSize ( string $algo ) : integer	Determine the length of the output of a given hash algorithm in bytes.
strlen ( string $string ) : integer	Returns the number of bytes in a string.
substr ( string $string, integer $start, integer $length = null ) : string	Returns part of a string.

Method	Description
strcmp ( string $knownHash, string $givenHash ) : boolean	Private constant-time strcmp method to use when hash_equals is unavailable.

Compares two strings in constant time. Strings are hashed before comparison so information is not leaked when strings are not of equal length.

public static equal ( string $known, string $given ) : boolean
$known	string	The string of known length to compare against
$given	string	The string that the user can control
return	boolean

Determine the length of the output of a given hash algorithm in bytes.

public static hashSize ( string $algo ) : integer
$algo	string	Name of algorithm to look up
return	integer

Returns the number of bytes in a string.

public static strlen ( string $string ) : integer
$string	string	The string whose length we wish to obtain
return	integer

Returns part of a string.

public static substr ( string $string, integer $start, integer $length = null ) : string
$string	string	The string whose length we wish to obtain
$start	integer
$length	integer
return	string	the extracted part of string; or FALSE on failure, or an empty string.