利用Python暴力爆破PDF密码

一个简单的Python脚本，可用于暴力破解受密码保护的PDF文件的密码
脚本已在使用128位RC4（大多数信用卡对帐单）加密的PDF上进行了测试，成功率为100％

pasword='<password>'--decrypt

Import sys
from pyPdf import PdfFileReader

helpmsg = "Simple PDF brute force script\n"
helpmsg += "Cracks pwds of the format <first 4 chars of email>0000-9999."
helpmsg += "Example: snow0653\n\n"
helpmsg += "Usage: pdfbrute.py <encrypted_pdf_file> <email_address>"
if len(sys.argv) < 2:
        print helpmsg
        sys.exit()
        
pdffile = PdfFileReader(file(sys.argv[1], "rb"))
if pdffile.isEncrypted == False:
        print "[!] The file is not protected with any password. Exiting."
        exit

print "[+] Attempting to Brute force. This could take some time..."

z = ""
for i in range(0,9999):
        z = str (i)
        while (len(z) < 4):
                z = "0" + z
        
        a = str(sys.argv[2][:4] + str(z))
               
        if pdffile.decrypt(a) > 0:
                print "[+] Password is: " + a
                print "[...] Exiting.."
                sys.exit()