import logging
from abc import ABC
from typing import List, Optional, Tuple
from credsweeper.common.constants import MIN_DATA_LEN
from credsweeper.credentials.candidate import Candidate
from credsweeper.deep_scanner.abstract_scanner import AbstractScanner
from credsweeper.file_handler.data_content_provider import DataContentProvider
from credsweeper.file_handler.string_content_provider import StringContentProvider
logger = logging.getLogger(__name__)
[docs]
class StringsScanner(AbstractScanner, ABC):
"""Implements known binary file scanning with ASCII strings representations"""
[docs]
@staticmethod
def get_enumerated_lines(data: bytes) -> List[Tuple[int, str]]:
"""Processes binary to found ASCII strings. Use offset instead line number."""
enumerated_lines = []
offset = -1
line_items = []
for n, x in enumerate(data):
if 0x09 == x or 0x20 <= x <= 0x7E:
# TAB, SPACE and visible ASCII symbols
if 0 > offset:
# use start of string as line number
offset = n
line_items.append(chr(x))
continue
if MIN_DATA_LEN <= len(line_items):
# add valuable lines only
enumerated_lines.append((offset, ''.join(line_items)))
offset = -1
line_items.clear()
if MIN_DATA_LEN <= len(line_items):
enumerated_lines.append((offset, ''.join(line_items)))
return enumerated_lines
[docs]
def data_scan(
self, #
data_provider: DataContentProvider, #
depth: int, #
recursive_limit_size: int) -> Optional[List[Candidate]]:
"""Scan binary files for ASCII strings"""
if strings := StringsScanner.get_enumerated_lines(data_provider.data):
string_data_provider = StringContentProvider(lines=[x[1] for x in strings],
line_numbers=[x[0] for x in strings],
file_path=data_provider.file_path,
file_type=data_provider.file_type,
info=f"{data_provider.info}|STRINGS")
return self.scanner.scan(string_data_provider)
return None if strings is None else []