parameters: (pem_cert_string)
return_statement: return base64.decodestring(d)
docstring: Takes a certificate in ASCII PEM format and returns the
      DER-encoded version of it as a byte sequence
docstring_summary: Takes a certificate in ASCII PEM format and returns the
      DER-encoded version of it as a byte sequence
docstring_tokens: Takes a certificate in ASCII PEM format and returns the DER - encoded version of it as a byte sequence
function: def PEM_cert_to_DER_cert(pem_cert_string):
  
      """Takes a certificate in ASCII PEM format and returns the
      DER-encoded version of it as a byte sequence"""
  
      if not pem_cert_string.startswith(PEM_HEADER):
          raise ValueError("Invalid PEM encoding; must start with %s"
                           % PEM_HEADER)
      if not pem_cert_string.strip().endswith(PEM_FOOTER):
          raise ValueError("Invalid PEM encoding; must end with %s"
                           % PEM_FOOTER)
      d = pem_cert_string.strip()[len(PEM_HEADER):-len(PEM_FOOTER)]
      return base64.decodestring(d)
function_tokens: def PEM_cert_to_DER_cert ( pem_cert_string ) : if not pem_cert_string . startswith ( PEM_HEADER ) : raise ValueError ( "Invalid PEM encoding; must start with %s" % PEM_HEADER ) if not pem_cert_string . strip ( ) . endswith ( PEM_FOOTER ) : raise ValueError ( "Invalid PEM encoding; must end with %s" % PEM_FOOTER ) d = pem_cert_string . strip ( ) [ len ( PEM_HEADER ) : - len ( PEM_FOOTER ) ] return base64 . decodestring ( d )