HGAME-2022

​ 主要记录2022年hgame密码方向的题目wp（脑洞题未记录），也有一点点misc（实际上目前misc是ak了的，比较简单就不记录了）。

大概的最终Rank：47/1200

​

Week1

Dancing Line

​ 这题出的比较新颖，将ASCII码值放在bmp的像素信息中。一个字符的 ASCII码有 8 位，图像中的每两个黑色色块间的路程也为 8 步。从左上角的色块出发，向右为 0，向下为 1，连起来就是对应字符的 ASCII 码。做题的时候我直接人工对应的ascii码，比较麻烦，可以用脚本梭：

import numpy as np
from PIL import Image
# 判断下一步往哪走
def search(arr, x, y):
    if y + 1 < arr.shape[1] and (arr[x, y + 1, :] != 255).all():
        #(255,255,255)表示白色 (0,0,0)表示黑色
        return x, y + 1, 0
    elif x + 1 < arr.shape[0]:
        return x + 1, y, 1
    else:return -1, -1, -1

if __name__ == "__main__":
    image = Image.open("Dancing Line.bmp")
    array = np.array(image)
    print(array.shape[1])
    x = y = 0
    while True:
        asc = 0
    # 每八步拼接成一个字符的 ASCII 码
        for _ in range(8):
            x, y, v = search(array, x, y)
            if v < 0:
                exit()
            asc <<= 1
            asc |= v
        print(chr(asc), end = "")
       	#hgame{Danc1ng_L1ne_15_fun,_15n't_1t?}

English Novel

​ 已知明文攻击。

import os

def if_length(ori_content, enc_content, match_result):
	if len(ori_content) == len(enc_content):
		match_result = True
	else:
		match_result = False
	return match_result

def if_match(ori_name, enc_name):
	match_result = True
	ori_path = ori_folder + '/' + ori_name
	enc_path = enc_folder + '/' + enc_name
	with open(ori_path, 'r') as f:
		ori_content = f.read()
	with open(enc_path, 'r') as f:
		enc_content = f.read()
	match_result = True
	if match_result:
		match_result = if_length(ori_content, enc_content, match_result)
		if match_result:
			for i in range(len(ori_content)):
				if ori_content[i] == enc_content[i]:
					continue
				elif ori_content[i].isupper() and enc_content[i].isupper():
					continue
				elif ori_content[i].islower() and enc_content[i].islower():
					continue
				else:
					match_result = False
	return match_result

def match_process(ori_folder, enc_folder):
	all_match = []
	original_list = os.listdir(ori_folder)
	encrypt_list = os.listdir(enc_folder)
	for ori_name in original_list:
		for enc_name in encrypt_list:
			match_result = if_match(ori_name, enc_name)
			if match_result:
				ori_path = ori_folder + '/' + ori_name
				enc_path = enc_folder + '/' + enc_name
				match_group = [ori_path, enc_path]
				all_match.append(match_group)
				encrypt_list.remove(enc_name)
			else:
				continue
	return all_match

def decrypt(ori_data, enc_data, enc_flag):
	keys = []
	for i in range(len(enc_data)):
		key = ord(enc_data[i]) - ord(ori_data[i])
		keys.append(key)
	result = ""
	enc_data = enc_flag
	for i in range(len(enc_data)):
		if enc_data[i].isupper():
			result += chr((ord(enc_data[i]) - ord('A') - keys[i]) % 26 + ord('A'))
		elif enc_data[i].islower():
			result += chr((ord(enc_data[i]) - ord('a') - keys[i]) % 26 + ord('a'))
		else:
			result += enc_data[i]
	return result

if __name__ == '__main__':
	ori_folder = './original'
	enc_folder = './encrypt'
	enc_flag = open('./flag.enc', 'r').read()
	match_list = match_process(ori_folder, enc_folder)
	for match_group in match_list:
		with open(match_group[0], 'r') as f:
			ori_data = f.read()
		with open(match_group[1], 'r') as f:
			enc_data = f.read()
		flag = decrypt(ori_data, enc_data, enc_flag)
		print("{:<30}{:<30}{:<30}".format(match_group[0], match_group[1], flag))

week2

The Password Plus Pro Max Ultra

​

​ exp：

from functools import reduce
from operator import xor
from libnum import n2s

def move(n, k):
    s = bin(n)[2:].zfill(64)
    k &= 63
    return int(s[k:] + s[:k], 2)

def encrypt(x, ks):
    return xor(x, reduce(xor, map(lambda k: move(x, k), ks)))

def decrypt(y, ks):
    for _ in range(6):
        y = encrypt(y, ks)
        ks = [k << 1 for k in ks]
    return y

if __name__ == "__main__":
    ys = [2656224875120172108,1261711348908201279,18219282869614004824,15279054981769814589,7966355346882200701,5641592208539483808,1502927090219059154,3996223120734273799,18295033054788808618,18126228466291248047,9413762634844369954,8964324149921197550,6962485320551449848]
    kss = ([8, 35],[19, 29, 30, 45],[6, 16, 18, 21, 44, 55],[10, 26, 30, 46, 51, 54, 58, 63],[5, 13, 25, 29, 37, 39, 43, 52, 53, 59],[1, 26, 31, 39, 40, 41, 43, 45, 49, 52, 54, 62],
           [8, 12, 19, 20, 30, 32, 34, 40, 41, 45, 46, 49, 55, 58],[2, 3, 5, 6, 8, 10, 15, 19, 26, 27, 33, 40, 42, 47, 52, 61],[1, 16, 17, 27, 28, 30, 32, 36, 37, 38, 39, 48, 49, 51, 55, 57, 59, 62],
           [5, 11, 12, 20, 22, 23, 25, 27, 31, 32, 33, 37, 44, 45, 49, 52, 53, 59, 61, 62],[2, 7, 10, 12, 18, 19, 20, 22, 26, 29, 33, 34, 38, 40, 41, 45, 46, 51, 54, 56, 57, 60],
           [3, 4, 5, 9, 12, 13, 18, 19, 21, 23, 24, 25, 30, 33, 34, 35, 37, 39, 43, 44, 46, 49, 50, 53],[1, 3, 6, 7, 10, 11, 13, 14, 23, 27, 32, 33, 35, 37, 39, 41, 46, 48, 49, 50, 51, 53, 54, 56, 58, 62])
    flag =''
    for i in ys:
        flag = flag + str(n2s(decrypt(i,kss[ys.index(i)])))[2:10]
    print(flag)
    #hgame{XOr|RoR&rOl|Is+vERY#coMmon*BiTwisE$OPeraTiOn*IT@is%oFten,ENCOUntErED*in.syMMeTRic?encryPtION}

奇妙小游戏（misc）

​ nc连接，会收到一段sha256散列值，需要输入其哈希之前的原始值，长度为4位，所以这里可以爆破，输入正确以后游戏开始，如下图；反复输入不同结果发现其逻辑为鬼脚图，我的exp写的比较复杂。

​

# -*- coding:utf-8 -*-

from pwn import *
import numpy as np

def jm_sha256_single(value):
    """
    sha256加密
    :param value: 加密字符串
    :return: 加密结果转换为16进制字符串
    """
    hsobj = hashlib.sha256()
    hsobj.update(value.encode("utf-8"))
    return hsobj.hexdigest().lower()

#爆破哈希
def hashs(hashs):

    chart1 = list(range(65, 123))
    chart2 = list(range(48, 57))
    chart1.extend(chart2)
    for i1 in chart1:
        for i2 in chart1 :
            for i3 in chart1:
                for i4 in chart1:
                    s = chr(i1)+chr(i2)+chr(i3)+chr(i4)
                    if jm_sha256_single(s) == hashs:
                        print(s)
                        io.sendline(s.encode())
                        io.sendline(s.encode())
                        return 0

def short(row,col,msg,have_gone,max):
    #have_gone是一个列表，用来存储走过的节点
    have_gone.append((row,col))
    if msg[row,col-1] != " " and col-1 >= 0 and (row,col-5) not in have_gone:
        col = col - 5
        print(row,col)
        print(have_gone)
        return short(row,col,msg,have_gone,max)
    elif col+5 < max and msg[row,col+1] != " " and col >= 0 and (row,col+5) not in have_gone :
        col = col +5
        print(row,col)
        print(have_gone)
        return short(row,col,msg,have_gone,max)
    else:
        row = row - 1
        print(row,col)
        print(have_gone)
        if row == 0:
            return col//5
        else:
            return short(row,col,msg,have_gone,max)



if __name__ == '__main__':

    io = remote('chuj.top',51009)
    hello = str(io.recvuntil(">".encode()))
    start = hello.find(') =')
    hashstr = hello[start+5:start+69]
    print(hashstr)
    hashs(hashstr)

    for i in range(15):
        p = str(io.recvuntil(b"answer"))
        if p :
            print(p)
            num_start = p.find('is')+3
            recv_num = p[num_start]
            col = p.count("-") //3
            print(col)
            start1 = p.find('level') + col + 11
            p = p[start1:]
            tail1 = p.find('-')
            p = p[:tail1]
            row = p.count('\\')
            #  col = (len(p) - row*2)//row
            p = p.replace("\\n",'')
            p = "0"*col + p
            msg = np.array(list(p)).reshape(row+1,col)
            print(msg)
            print(p)
            print(row,col)
            print(recv_num)
            enter_col = int(recv_num) * 5
            maxcol = col
            #start_point = msg[row-1,enter_col]
            have_gone = []
            d=short(row,enter_col,msg,have_gone,maxcol)

            io.sendline(str(d).encode())

            print(d)


        else:
                print("no answer")

    p = str(io.recvrepeat(timeout=5))
    print(p)

week3

Block Cipher

import operator
import random
import re
from functools import reduce

def pad(s):
    padding_length = (8 - len(s)) % 8
    return s + chr(padding_length) * padding_length

def xor(a, b):
    assert len(a) == len(b)
    return bytes(map(operator.xor, a, b))


def encrypt(s):
    iv = bytes(random.randint(0, 255) for _ in range(8)) #生成8字节的字节流（字符串）
    key = bytes(random.randint(0, 255) for _ in range(8)) #同上
    parts = list(map(str.encode, map(pad, re.findall(r'.{1,8}', s)))) #进行填充
    results = []
    for index, part in enumerate(parts):
        results.append(reduce(xor, [part, iv if index == 0 else results[-1], key]))

iv = b'Up\x14\x98r\x14%\xb9'
key = b'\r\xe8\xb86\x9c33^'
parts = [b'0\xff\xcd\xc3\x8b\\T\x8b', b'RT\x1e\x89t&\x17\xbd', b'\x1a\xee\x8d\xd6\x9b>w\x8c', b'9CT\xb3^pF\xd0']
flag1 = reduce(xor,[parts[0],key,iv])
print(flag1)
flag2 = reduce(xor,[parts[1],iv,flag1])
print(flag2)
flag3 = reduce(xor,[parts[2],parts[0],flag2])
print(flag3)
flag4 = reduce(xor,[parts[3],parts[1],flag3])
print(flag4)
print(flag1+flag2+flag3+flag4)
#hgame{BloCk|cIphER+is+So.EaSY}

Multi Prime RSA

from Crypto.Util.number import *
import gmpy2
#多因数rsa就用欧拉函数计算phi即可

p = 109056753224725357860050862987465749131702509174531265860789564184166504627089
q = 64871884070495743485110397060920534297122908609816622599229579748089451488127
r = 73817195552029165561107245309535744382442021553254903166961729774806232509583
s = 89907870347457693114161779597928900080173728317019344960807644151097370118553
n = 337945247991531188630780631650822497552908401425959508214145019590891175999570651678385514599227649321033438265588883204645721459926338248032512615537333971869461679586403649697114789385472197685140603238299768873935137939123021910982793481655218061907401584383081422244812725080939394854989735528833013780919908024635812696998644603525843637686545709789908672408993923182946718279531020289767042649725545073526307769817097790005360720650079676982379162926484355121626302801800589993422729725583400678081766553017405965706770238634252836827793877622715474210575752508172785712202444441372140501379422725172250199713113954442223362073485143579617841236442644760494913432967541691532709842303408702693199269606594116690052170245340072114122287646793344327315326489574192325790848798131621842606487734721409882742631176999703502149639410263361145441889337623403361569958342141903891414217371443118527025041591219747780100510414268546884029077010164415049298406632069845430841542680166802473749172801804659277821899576403669845353379213803866969800665351300325701817179936198902427032684058452719607840314873315299975603264092020097224735237221994922702705781103002327285724125001893421030923788361576161461965707958695720464547129911053732747399113017747456439027947305796290572816318795181398935020951025833913
e = 65537
c = 281020926647419736778465777714512241989738235339105762863874725870511725155101862585192241287617168165290485944476735304459717602798728005687755713662466866091315959960168862035396245078850168822145228676116894754613436735897122137945552880864031115366493898382809812977280234389519365119627504653135151731589924405933589175425427189436855517194951589952822691774400942764910734054237756669945324833759799471068481769516338068810710333940167779043544371586185132920304774984746129764220081092726473696111126293966890901487735046101991609292612206984184161394385767762455321150541601949740631911175736268756408775307673610842645555513631617648877296855194327486811545670357137463942744122553468603244298691801028147147418563982169678640270746871085722092365159546820433098926679284504740402248142173715649451061037156261913601096905601577932894877435316535261789072594174871292814951406337447799051502635390866434813419165738873787323716033378045850292413169255965421404580559241351577058726176436504950558398769061998430771982995850759810867299728407860522399699076192754977454139708618158667289120827143703464056583125568576691058753072898162981956883451252542611323974071518397220203389962420073122776649094369816178685947397943358134020598211306649724455966463885765977564934172273334309312046278116760547
phi = p*(p-1)*(q-1)*q**2*(r-1)*r**4*(s-1)*s**6
d = gmpy2.invert(e,phi)
print(long_to_bytes(pow(c,d,n)))
#hgame{EulEr:fUNcTIon;iS.So*IMpORTaNt*In&RsA}

RSA Attack 3

import gmpy2
from Crypto.Util.number import *

d = 13094612077654083919 #维纳攻击先求d
n = 507419170088344932990702256911694788408493968749527614421614568612944144764889717229444020813658893362983714454159980719026366361318789415279417172858536381938870379267670180128174798344744371725609827872339512302232610590888649555446972990419313445687852636305518801236132032618350847705234643521557851434711389664130274468354405273873218264222293858509477860634889001898462547712800153111774564939279190835857445378261920532206352364005840238252284065587291779196975457288580812526597185332036342330147250312262816994625317482869849388424397437470502449815132000588425028055964432298176942124697105509057090546600330760364385753313923003549670107599757996810939165300581847068233156887269181096893089415302163770884312255957584660964506028002922164767453287973102961910781312351686488047510932997937700597992705557881172640175117476017503918294534205898046483981707558521558992058512940087192655700351675718815723840568640509355338482631416345193176708501897458649841539192993142790402734898948352382350766125000186026261167277014748183012844440603384989647664190074853086693408529737767147592432979469020671772152652865219092597717869942730499507426269170189547020660681363276871874469322437194397171763927907099922324375991793759
e = 77310199867448677782081572109343472783781135641712597643597122591443011229091533516758925238949755491395489408922437493670252550920826641442189683907973926843505436730014899918587477913032286153545247063493885982941194996251799882984145155733050069564485120660716110828110738784644223519725613280140006783618393995138076030616463398284819550627612102010214315235269945251741407899692274978642663650687157736417831290404871181902463904311095448368498432147292938825418930527188720696497596867575843476810225152659244529481480993843168383016583068747733118703000287423374094051895724494193455175131120243097065270804457787026492578916584536863548445813916819417857064037664101684455000184987531252344582899589746272173970083733130106407810619258077266603898529285634495710846838011858287024329514491058790557305041389614650730267774482954666726949886313386881066593946789460028399523245777171320319444673551268379126203862576627540177888290265714418064334752499940587750374552330008143708562065940245637685833371348603338834447212248648869514585047871442060412622164276894766238383894693759347590977926306581080390685360615407766600573527565016914830132066428454738135380178959590692145577418811677639050929791996313180297924833690095
c = 165251729917394529793163344300848992394021337429474789711805041655116845722480301677817165053253655027459227404782607373107477419083333844871948673626672704233977397989843349633720167495862807995411682262559392496273163155214888276398332204954185252030616473235814999366132031184631541209554169938146205402400412307638567132128690379079483633171535375278689326189057930259534983374296873110199636558962144635514392282351103900375366360933088605794654279480277782805401749872568584335215630740265944133347038070337891035560658434763924576508969938866566235926587685108811154229747423410476421860059769485356567301897413767088823807510568561254627099309752215808220067495561412081320541540679503218232020279947159175547517811501280846596226165148013762293861131544331444165070186672186027410082671602892508739473724143698396105392623164025712124329254933353509384748403154342322725203183050328143736631333990445537119855865348221215277608372952942702104088940952142851523651639574409075484106857403651453121036577767672430612728022444370874223001778580387635197325043524719396707713385963432915855227152371800527536048555551237729690663544828830627192867570345853910196397851763591543484023134551876591248557980182981967782409054277224
print(long_to_bytes(pow(c,d,n)))
#hgame{dO|YOU:kNOw!tHE*PRINcIplE*bEhInd%WInNEr#aTTacK}'