text: #!/usr/bin/env python
  
  """
  Copyright (c) 2006-2019 sqlmap developers (http://sqlmap.org/)
  See the file 'LICENSE' for copying permission
  """
  
  import random
  import re
  
  from lib.core.data import kb
  from lib.core.enums import PRIORITY
  
  __priority__ = PRIORITY.NORMAL
  
  def dependencies():
      pass
  
  def tamper(payload, **kwargs):
      """
      Adds multiple spaces (' ') around SQL keywords
  
      Notes:
          * Useful to bypass very weak and bespoke web application firewalls
            that has poorly written permissive regular expressions
  
      Reference: https://www.owasp.org/images/7/74/Advanced_SQL_Injection.ppt
  
      >>> random.seed(0)
      >>> tamper('1 UNION SELECT foobar')
      '1    UNION     SELECT   foobar'
      """
  
      retVal = payload
  
      if payload:
          words = set()
  
          for match in re.finditer(r"\b[A-Za-z_]+\b", payload):
              word = match.group()
  
              if word.upper() in kb.keywords:
                  words.add(word)
  
          for word in words:
              retVal = re.sub(r"(?<=\W)%s(?=[^A-Za-z_(]|\Z)" % word, "%s%s%s" % (' ' * random.randrange(1, 4), word, ' ' * random.randrange(1, 4)), retVal)
              retVal = re.sub(r"(?<=\W)%s(?=[(])" % word, "%s%s" % (' ' * random.randrange(1, 4), word), retVal)
  
      return retVal
  