shell bypass 403
"""JSON token scanner
"""
import re
def _import_c_make_scanner():
try:
from simplejson._speedups import make_scanner
return make_scanner
except ImportError:
return None
c_make_scanner = _import_c_make_scanner()
__all__ = ['make_scanner', 'JSONDecodeError']
NUMBER_RE = re.compile(
r'(-?(?:0|[1-9]\d*))(\.\d+)?([eE][-+]?\d+)?',
(re.VERBOSE | re.MULTILINE | re.DOTALL))
class JSONDecodeError(ValueError):
"""Subclass of ValueError with the following additional properties:
msg: The unformatted error message
doc: The JSON document being parsed
pos: The start index of doc where parsing failed
end: The end index of doc where parsing failed (may be None)
lineno: The line corresponding to pos
colno: The column corresponding to pos
endlineno: The line corresponding to end (may be None)
endcolno: The column corresponding to end (may be None)
"""
# Note that this exception is used from _speedups
def __init__(self, msg, doc, pos, end=None):
ValueError.__init__(self, errmsg(msg, doc, pos, end=end))
self.msg = msg
self.doc = doc
self.pos = pos
self.end = end
self.lineno, self.colno = linecol(doc, pos)
if end is not None:
self.endlineno, self.endcolno = linecol(doc, end)
else:
self.endlineno, self.endcolno = None, None
def __reduce__(self):
return self.__class__, (self.msg, self.doc, self.pos, self.end)
def linecol(doc, pos):
lineno = doc.count('\n', 0, pos) + 1
if lineno == 1:
colno = pos + 1
else:
colno = pos - doc.rindex('\n', 0, pos)
return lineno, colno
def errmsg(msg, doc, pos, end=None):
lineno, colno = linecol(doc, pos)
msg = msg.replace('%r', repr(doc[pos:pos + 1]))
if end is None:
fmt = '%s: line %d column %d (char %d)'
return fmt % (msg, lineno, colno, pos)
endlineno, endcolno = linecol(doc, end)
fmt = '%s: line %d column %d - line %d column %d (char %d - %d)'
return fmt % (msg, lineno, colno, endlineno, endcolno, pos, end)
def py_make_scanner(context):
parse_object = context.parse_object
parse_array = context.parse_array
parse_string = context.parse_string
match_number = NUMBER_RE.match
encoding = context.encoding
strict = context.strict
parse_float = context.parse_float
parse_int = context.parse_int
parse_constant = context.parse_constant
object_hook = context.object_hook
object_pairs_hook = context.object_pairs_hook
memo = context.memo
def _scan_once(string, idx):
errmsg = 'Expecting value'
try:
nextchar = string[idx]
except IndexError:
raise JSONDecodeError(errmsg, string, idx)
if nextchar == '"':
return parse_string(string, idx + 1, encoding, strict)
elif nextchar == '{':
return parse_object((string, idx + 1), encoding, strict,
_scan_once, object_hook, object_pairs_hook, memo)
elif nextchar == '[':
return parse_array((string, idx + 1), _scan_once)
elif nextchar == 'n' and string[idx:idx + 4] == 'null':
return None, idx + 4
elif nextchar == 't' and string[idx:idx + 4] == 'true':
return True, idx + 4
elif nextchar == 'f' and string[idx:idx + 5] == 'false':
return False, idx + 5
m = match_number(string, idx)
if m is not None:
integer, frac, exp = m.groups()
if frac or exp:
res = parse_float(integer + (frac or '') + (exp or ''))
else:
res = parse_int(integer)
return res, m.end()
elif nextchar == 'N' and string[idx:idx + 3] == 'NaN':
return parse_constant('NaN'), idx + 3
elif nextchar == 'I' and string[idx:idx + 8] == 'Infinity':
return parse_constant('Infinity'), idx + 8
elif nextchar == '-' and string[idx:idx + 9] == '-Infinity':
return parse_constant('-Infinity'), idx + 9
else:
raise JSONDecodeError(errmsg, string, idx)
def scan_once(string, idx):
if idx < 0:
# Ensure the same behavior as the C speedup, otherwise
# this would work for *some* negative string indices due
# to the behavior of __getitem__ for strings. #98
raise JSONDecodeError('Expecting value', string, idx)
try:
return _scan_once(string, idx)
finally:
memo.clear()
return scan_once
make_scanner = c_make_scanner or py_make_scanner