使用Python自动化破解自定义字体混淆信息的方法实例

# -*- coding: utf-8 -*-本例采用 tesseract OCR 引擎，根据字体文件自动生成密文与明文的字符映射表，实现解密功能。@author: 李毅from tesserocr import PyTessBaseAPI, PSMfrom PIL import Image, ImageDraw, ImageFontfrom fontTools.ttLib import TTFontimport stringclass OCR(object): default_config = { # ocr engine 'data_path': None, 'lang': 'chi_sim', 'white_list': None, 'black_list': None, # image 'font': None, 'image_size': (60, 60), 'font_size': 30, 'text_offset': (15, 15), } def __init__(self, config={}): c = dict(self.default_config) c.update(config) self.api = PyTessBaseAPI(path=c['data_path'], lang=c['lang'], psm=PSM.SINGLE_CHAR) self.img = Image.new('RGB', c['image_size'], color='white') self.draw = ImageDraw.Draw(self.img) self.font = ImageFont.truetype(c['font'], size=c['font_size']) self.text_offset = c['text_offset'] if c['white_list']:  self.api.SetVariable('tessedit_char_whitelist', c['white_list']) if c['black_list']:  self.api.SetVariable('tessedit_char_blacklist', c['black_list']) self.font_tool = TTFont(c['font']) self.empty_char = self._predict_empty_char() def _predict_empty_char(self): self.api.SetImage(self.img) return self.api.GetUTF8Text().strip() def is_char_in_font(self, char): for t in self.font_tool['cmap'].tables:  if t.isUnicode():  if ord(char) in t.cmap:   return True return False def predict(self, char): ''' 返回转换后的字符，或空串'' ''' if not self.is_char_in_font(char):  return char # 若字体无法渲染该字符，则原样返回。此处可酌情移除。 self.img.paste('white', (0, 0, self.img.size[0], self.img.size[1])) self.draw.text(self.text_offset, char, fill='black', font=self.font) self.api.SetImage(self.img) c2 = self.api.GetUTF8Text().strip() if c2 == self.empty_char:  return '' # 某些字符可能渲染成空白，此时返回空串。 return c2class Decoder(object): def __init__(self, data_path, font): self.cache = {} # 缓存已知的映射关系。 OCR.default_config.update(dict(data_path=data_path, font=font)) self.ocr_digit = OCR(dict(  lang='eng',  white_list=string.digits,  black_list=string.ascii_letters, )) self.ocr_letter = OCR(dict(  lang='eng',  black_list=string.digits,  white_list=string.ascii_letters, )) self.ocr_other = OCR() def decode(self, char): if char not in self.cache:  c2 = self._decode_when_cache_miss(char)  self.cache[char] = c2 or char return self.cache[char] def _decode_when_cache_miss(self, char): ocr = self.ocr_other if char in string.digits:  ocr = self.ocr_digit elif char in string.ascii_letters:  ocr = self.ocr_letter return ocr.predict(char)if __name__ == '__main__': s = '''你好，青划长务, 8175-13-79''' d = Decoder('tessdata/', 'a.ttf') print(''.join(map(d.decode, s)))