css_grammar.py

import string
import tinycss
import fuzzingbook
from fuzzingbook import GrammarFuzzer

import string
CSS_GRAMMAR = {
    '<start>': ['<stylesheet>'],

    '<stylesheet>': ['<[CHARSET_SYM_STRING_SEMI]>? <[S_OR_CDO_OR_CDC]>* <[import_CDO_S_OR_CDC_S]>* <[stylesheet_closing_GROUPING]>*'],
    '<[CHARSET_SYM_STRING_SEMI]>': ['<CHARSET_SYM> <STRING> ;'],
    '<[S_OR_CDO_OR_CDC]>': ['<Sp>', '<CDO>', '<CDC>'],
    '<[import_CDO_S_OR_CDC_S]>': ['<import> <[CDO_S_OR_CDC_S]>*'],
    '<[CDO_S_OR_CDC_S]>': ['<CDO> <Ss>', '<CDC> <Ss>'],
    '<[ruleset_OR_media_OR_page]>': ['<ruleset>', '<media>', '<page>'],
    '<[stylesheet_closing_GROUPING]>': ['<[ruleset_OR_media_OR_page]> <[CDO_S_OR_CDC_S]>*'],

    '<import>': ['<IMPORT_SYM> <Ss> <[STRING_OR_URI]> <Ss> <media_list>? ; <Ss>'],
    '<[STRING_OR_URI]>': ['<STRING>', '<URI>'],

    '<media>': ['<MEDIA_SYM> <Ss> <media_list> { <Ss> <ruleset>* } <Ss>'],

    '<media_list>': ['<medium> <[COMMA_S_medium]>*'],
    '<[COMMA_S_medium]>': [', <Ss> <medium>'],

    '<medium>': ['<IDENT> <Ss>'],

    '<page>': ['<PAGE_SYM> <Ss> <pseudo_page>? { <Ss> <declaration>? <[SEMI_S_declaration]>* } <Ss>'],
    '<[SEMI_S_declaration]>': ['; <Ss> <declaration>?'],

    '<pseudo_page>': [': <IDENT> <Ss>'],

    '<operator>': ['/ <Ss>', ', <Ss>'],

    '<combinator>': ['+ <Ss>', '> <Ss>'],

    '<unary_operator>': ['-', '+'],

    '<property>': ['<IDENT> <Ss>'],

    '<ruleset>': ['<selector> <COMMA_S_selector>* { <Ss> <declaration>? <[SEMI_S_declaration]>* } <Ss>'],
    '<COMMA_S_selector>': [', <Ss> selector'],

    '<selector>': ['<simple_selector> <[combinator_selector_OR_S]>?'],
    '<[combinator_selector]>': ['<combinator>? <selector>'],
    '<[combinator_selector_OR_S]>': ['<combinator> <selector>',
                                     '<Sp> <[combinator_selector]>?'],
    
    '<simple_selector>': ['<element_name> <[HASH_OR_class_OR_attrib_OR_pseudo]>*',
                          '<[HASH_OR_class_OR_attrib_OR_pseudo]>+'],
    '<[HASH_OR_class_OR_attrib_OR_pseudo]>': ['<HASH>', '<class>',
                                              '<attrib>', '<pseudo>'],

    '<class>': ['.<IDENT>'],

    '<element_name>': ['<IDENT>', '*'],

    '<attrib>': ['[ <Ss> <IDENT> <Ss> <[attrib_GROUPING]>? ]'],
    '<[EQUAL_OR_INCLUDES_OR_DASHMATCH]>': ['=', '<INCLUDES>', '<DASHMATCH>'],
    '<[IDENT_OR_STRING]>': ['<IDENT>', '<STRING>'],
    '<[attrib_GROUPING]>': ['<[EQUAL_OR_INCLUDES_OR_DASHMATCH]> <Ss> <[IDENT_OR_STRING]> <Ss>'],

    '<pseudo>': [': <[IDENT_OR_FUNCTION]>'],
    '<[IDENT_OR_FUNCTION]>': ['<IDENT>',
                              '<FUNCTION> <Ss> <[IDENT_S]>? )'],
    '<[IDENT_S]>': ['<IDENT> <Ss>'],

    '<declaration>': ['<property> : <Ss> <expr> <prio>?'],

    '<prio>': ['<IMPORT_SYM> <Ss>'],

    '<expr>': ['<term> <[operator_term]>*'],
    '<[operator_term]>': ['<operator>? <term>'],

    '<term>': ['<unary_operator>? <[term_GROUPING]>',
               '<STRING> <Ss>', '<IDENT> <Ss>', '<URI> <Ss>',
               '<hexcolor>', '<function>'],
    '<[term_GROUPING]>': ['<NUMBER> <Ss>', '<PERCENTAGE> <Ss>',
                          '<LENGTH> <Ss>', '<EMS> <Ss>',
                          '<EXS> <Ss>', '<ANGLE> <Ss>',
                          '<TIME> <Ss>', '<FREQ> <Ss>'],

    '<function>': ['<FUNCTION> <Ss> <expr> ) <Ss>'],

    '<hexcolor>': ['#<[three_char_HEX]> <Ss>', '#<[six_char_HEX]> <Ss>'],
    '<[three_char_HEX]>': ['<HEX_CHAR><HEX_CHAR><HEX_CHAR>'],
    '<[six_char_HEX]>': ['<HEX_CHAR><HEX_CHAR><HEX_CHAR><HEX_CHAR><HEX_CHAR><HEX_CHAR>'],
    '<HEX_CHAR>': ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                   'a', 'b', 'c', 'd', 'e', 'f'],

    '<Sp>': ['<WHITESPACE>+'],
    '<Ss>': ['<WHITESPACE>*'],
    '<So>': ['', '<WHITESPACE>'],
    '<CDO>': ['<!--'],
    '<CDC>': ['-->'],
    '<INCLUDES>': ['~='],
    '<DASHMATCH>': ['|='],
    '<STRING>': ['<string1>', '<string2>'],
    '<IDENT>': ['<{ident}>'],
    '<HASH>': ['#<{name}>'],
    
    '<IMPORT_SYM>': ['@import'],
    '<PAGE_SYM>': ['@page'],
    '<MEDIA_SYM>': ['@media'],
    '<CHARSET_SYM>': ['@charset'],

    '<EMS>': ['<{num}>em'],
    '<EXS>': ['<{num}>ex'],
    '<LENGTH>': ['<{num}>px', '<{num}>cm', '<{num}>mm', 
                 '<{num}>in', '<{num}>pt', '<{num}>pc'],
    '<ANGLE>': ['<{num}>deg', '<{num}>rad', '<{num}>grad'],
    '<TIME>': ['<{num}>ms', '<{num}>s'],
    '<FREQ>': ['<{num}>hz', '<{num}>khz'],

    '<PERCENTAGE>': ['<{num}>%'],
    '<NUMBER>': ['<{num}>'],

    '<URI>': [
            'url("<So><url><So>")',
            'url("<So><STRING><So>")',
            ],
    '<url>': ['<url_>*'],
    '<url_>': list("!#$%&*-~") + ['<escape>'],
    '<FUNCTION>': ['<{ident}>('],

    '<string1>': ['"<qmychars1>*"'],
    '<string2>': ["'<qmychars2>*'"],
    '<qnonl1>': list(set(string.printable) - set('\n\r\f"')),
    '<qnonl2>': list(set(string.printable) - set('\n\r\f\'')),
    '<qmychars1>': ['<qnonl1>','\<nl>','<escape>'],
    '<qmychars2>': ['<qnonl2>','\<nl>','<escape>'],
    '<nl>': ['\r', '\n', '\f', '\r\n'],
    '<escape>': [
            #'<unicode>', # TODO
            '\<echar>'],
    '<echar>': list(set(string.printable) - set('\r\n\f0123456789abcdef')),
    '<{ident}>': ['<minus>?<nmstart><nmchar>*'],
    '<nmstart>': list(string.ascii_lowercase) + ['<escape>', '_'],
    '<nmchar>': list(string.ascii_lowercase + string.digits) + ['<escape>', '_', '-'],
    '<minus>': ['-'],
    '<{name}>': ['<nmchar>+'],
    '<{num}>': ['<INTEGER>'],
    '<WHITESPACE>': [' ', '\t'], #list(string.whitespace),
    '<INTEGER>': ['<DIGIT><INTEGER>', '<DIGIT>'],
    '<DIGIT>': ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
}


GrammarFuzzer.is_valid_grammar(CSS_GRAMMAR)

from io import StringIO
parser = tinycss.make_parser('page3')
gf = GrammarFuzzer.GrammarFuzzer(GrammarFuzzer.convert_ebnf_grammar(CSS_GRAMMAR), min_nonterminals=100)
Max = 1000
count = 0
for i in range(Max):
    p = gf.fuzz()
    with open('_.css', 'w+') as f:
        print(p, file=f)
    try:
        print(parser.parse_stylesheet(p))
        print('+', repr(p))
        print(p)
        count += 1
    except:
        print('-', repr(p))

print(count, Max)