Question

我正在使用“用Python自动化乏味的东西”做一个挑战性的问题。任务是编写一个程序，该程序将使用提供的dictionary.txt文件“强力”使用pdf密码。

使用我加密并知道密码的文件以及包含该密码的字典文件，我无法获取代码来“弄清楚”它是密码。而是运行到字典文件的末尾，然后停止。

我以为我可能会误解pdfObject.decrypt（）在“ if”语句中的工作方式，因此我编写了一个小测试程序来使用该语法，但是该程序在该程序中使用的语法与我的“主”程序。在“测试”程序中，我从input（）而不是argv和列表中提供密码，但是我看不到是否/如何影响密码。

#My Program (that blitzes right past the correct password):

#/usr/bin/python

# bruteForce.py - Uses a dictionary attack to crack the password of an
# encrypted pdf

from sys import argv
import PyPDF2

# Take the argument for the file you want to attack and open it
if len(argv) > 1:
    pdfFilename = argv[1]
else:
    print('User must specify a file.')
    exit()

# Open the pdf as an object
pdfFile = open(pdfFilename, 'rb')
pdfObject = PyPDF2.PdfFileReader(pdfFile)

# Add the contents of the dictionary file to a data structure
dictionaryList = []
dictionaryFile = open('dictionary.txt')
for word in dictionaryFile.readlines():
    dictionaryList.append(word)
    wordLower = word.lower()
    dictionaryList.append(wordLower)
dictionaryFile.close()

# Iterate over the data structure, trying each password as lowercase
print('Trying passwords...')
for word in dictionaryList:
    password = str(word)
    print('Trying ' + password)
    if pdfObject.decrypt(password) == 1:
        print('Password is ' + word)
        exit()
    else:
        continue

print('Password not found')

##My Test (that works and returns 'Yup, that's it!'):

#!/usr/bin/python
# Figuring out how to deal with foo.decrypt to get a value of 1 or 0
# This first test returns the correct result with the correct password,
# so presumably bruteForce is not feeding it the right password somehow

import PyPDF2

filename = input('What file?')
password = input('What password?')

pdfFile = open(filename, 'rb')
pdfObject = PyPDF2.PdfFileReader(pdfFile)

if pdfObject.decrypt(password) == 1:
    print('Yup, that\'s it!')
else:
    print('Nope!')



I expect the program to arrive at the correct word in the dictionary, try it, and stop. Instead, it runs to the end of the list and says "Password not found."

Answer 1

词典条目包含文本文件中的换行符，因此它们与密码不匹配。在将它们添加到字典中之前，我用wordStripped = word.strip('\n')对其进行了剥离，该程序可以按预期运行（速度约为后者的两倍）。

如何使用pypdf2检查pdf密码是否正确

1 个答案: