暑假集训7.04

宁波赛

BlackAndWhite

336张黑白照片，应该是写成二进制再转成字符串

写脚本处理一下，得到flag

from PIL import Image
result = ""
for i in range(336):
    img = Image.open(f"C:\\Users\\LEGION-Y7000P\\Desktop\\11\\宁波赛\\1\\target\\{i}.png")
    im_RGB = img.convert("RGB") # 将图片转换为RGB模式
    r,g,b =im_RGB.getpixel((1,1)) #获得x,y坐标的rgb值
    print(r,g,b)# 这题中白色图片rgb值:255,255,255 黑色图片rgb值：12,12,0
    if r !=255: #255是白色
        result +="1"
    else:
        result +="0"
#将二进制转换为ascii码
for i in range(0,len(result),8):
    byte = result[i:i+8]
    print(chr(int(byte,2)),end="")

Analyze

pdf里得到一串密文，解码得到提示

pdf里还可以分离一个加密的压缩包，以及和压缩包里面一样的一个png和一个txt，应该是明文爆破，将解密内容写进txt里，进行爆破

用Stegsolve打开，lsb隐写，得到flag

DocDocDoc

docx文件，没什么信息，改成zip后缀找信息

一般文字信息存在document.xml，但也没找到什么信息，然后找到了png文件，png文件被修改了宽高，用脚本爆破一下，得到了密文

解码得到flag

Digtal_plate

usb流量分析，前三位是088，后8位是八个0，是数位板数据

提取数据

用脚本整理数据

f = open('1.txt','r')
fi = open('result.txt','w')
while 1:
    a = f.readline()
    if not a:
        break
    a = a.strip('\n')
    if a[3] == '1':
        x = int(a[4:6],16) + int(a[6:8],16)*256
        fi.write(str(x))
        fi.write(' ')
        y = int(a[8:10],16) + int(a[10:12],16)*256
        fi.write(str(-y))
        fi.write('\n')
fi.close()

用gnuplot画图，得到key

binwalk分析一下流量包发现还存在zip，分离出来，用key打开压缩包，得到jpg

放进SilentEye，发现还要密码，在jpg备注找到提示

用脚本整理数位板的压感数据

f = open('1.txt','r')
fi = open('3.txt','w')
while 1:
    a = f.readline()
    if not a:
        break
    a = a.strip('\n')
    # a[3] == '1':
    if a[3] == '1' and int(a[12], 16) < 15:
        x = int(a[4:6],16) + int(a[6:8],16)*256
        fi.write(str(x))
        fi.write(' ')
        y = int(a[8:10],16) + int(a[10:12],16)*256
        fi.write(str(-y))
        fi.write('\n')
fi.close()

用gnuplot画图，得到key

再放进SilentEye，得到flag

国赛

ez_usb

usb键盘流量，提取数据

跑一下usb键盘的脚本

import os
# os.system("tshark -r test.pcapng -T fields -e usb.capdata > usbdata.txt")
normalKeys = {"04":"a", "05":"b", "06":"c", "07":"d", "08":"e", "09":"f", "0a":"g", "0b":"h", "0c":"i", "0d":"j", "0e":"k", "0f":"l", "10":"m", "11":"n", "12":"o", "13":"p", "14":"q", "15":"r", "16":"s", "17":"t", "18":"u", "19":"v", "1a":"w", "1b":"x", "1c":"y", "1d":"z","1e":"1", "1f":"2", "20":"3", "21":"4", "22":"5", "23":"6","24":"7","25":"8","26":"9","27":"0","28":"<RET>","29":"<ESC>","2a":"<DEL>", "2b":"\t","2c":"<SPACE>","2d":"-","2e":"=","2f":"[","30":"]","31":"\\","32":"<NON>","33":";","34":"'","35":"<GA>","36":",","37":".","38":"/","39":"<CAP>","3a":"<F1>","3b":"<F2>", "3c":"<F3>","3d":"<F4>","3e":"<F5>","3f":"<F6>","40":"<F7>","41":"<F8>","42":"<F9>","43":"<F10>","44":"<F11>","45":"<F12>"}

shiftKeys = {"04":"A", "05":"B", "06":"C", "07":"D", "08":"E", "09":"F", "0a":"G", "0b":"H", "0c":"I", "0d":"J", "0e":"K", "0f":"L", "10":"M", "11":"N", "12":"O", "13":"P", "14":"Q", "15":"R", "16":"S", "17":"T", "18":"U", "19":"V", "1a":"W", "1b":"X", "1c":"Y", "1d":"Z","1e":"!", "1f":"@", "20":"#", "21":"$", "22":"%", "23":"^","24":"&","25":"*","26":"(","27":")","28":"<RET>","29":"<ESC>","2a":"<DEL>", "2b":"\t","2c":"<SPACE>","2d":"_","2e":"+","2f":"{","30":"}","31":"|","32":"<NON>","33":"\"","34":":","35":"<GA>","36":"<","37":">","38":"?","39":"<CAP>","3a":"<F1>","3b":"<F2>", "3c":"<F3>","3d":"<F4>","3e":"<F5>","3f":"<F6>","40":"<F7>","41":"<F8>","42":"<F9>","43":"<F10>","44":"<F11>","45":"<F12>"}


nums = []
keys = open('281.txt')
for line in keys:
    if len(line)!=17: #首先过滤掉鼠标等其他设备的USB流量
         continue
    nums.append(line[0:2]+line[4:6]) #取一、三字节
keys.close()
output = ""
for n in nums:
    if n[2:4] == "00" :
        continue

    if n[2:4] in normalKeys:
        if n[0:2]=="02": #表示按下了shift
            output += shiftKeys [n[2:4]]
        else :
            output += normalKeys [n[2:4]]
    else:
        output += '[unknown]'
print('output :n' + output)