openssl_pbkdf2
  Generates a PKCS5 v2 PBKDF2 string, defaults to SHA-1
  
 
  Description
  
   string openssl_pbkdf2
    ( string $password
   , string $salt
   , int $key_length
   , int $iterations
   [, string $digest_algorithm
  ] )
  
  WarningThis function is
currently not documented; only its argument list is available.
 
  
 
  Parameters
  
   
    - 
password
- 
     
      
      
- 
salt
- 
     
      
      
- 
key_length
- 
     
      
      
- 
iterations
- 
     
      
      
- 
digest_algorithm
- 
     
      
      
 
 
  Return Values
  
   Returns string or FALSE on failure.