使用binwalk，binwalk -e task_1 ，得到一个压缩包，bandizip打开发现base64编码的注释SSBsaWtlIHNpeC1kaWdpdCBudW1iZXJzIGJlY2F1c2UgdGhleSBhcmUgdmVyeSBjb25jaXNlIGFuZCBlYXN5IHRvIHJlbWVtYmVyLg==，base64解密后得到I like six-digit numbers because they are very concise and easy to remember.，拿爆破工具直接爆破密码，得到232311，拿到flag：flag{y0u_ar3_the_m4ter_of_z1111ppp_606a4adc}
arrr=[ 1968519710, 2069379587, 1297621516, 2068854845, 1936406553, 0 ] for i in arrr: h=((i^0x12345678)) value = h
nums = [] while value > 0: nums.append(hex(value & 0xFF)) # 取出低位部分，并转换为16进制字符串 value >>= 8# 右移8位，获取下一个位置的部分 nums_str = [chr(int(num,16)) for num in nums] result_str = ''.join(nums_str) print(result_str,end='')
# annotations .annotation system Ldalvik/annotation/EnclosingMethod; value = Lcom/droidlearn/activity_travel/FlagActivity;->onCreate(Landroid/os/Bundle;)V .end annotation
.annotation system Ldalvik/annotation/InnerClass; accessFlags = 0x0 name = null .end annotation
# instance fields .field final synthetic this$0:Lcom/droidlearn/activity_travel/FlagActivity;
.field final synthetic val$str:Landroid/widget/EditText;
.field final synthetic val$tv_cnt:Landroid/widget/TextView;
# direct methods .method constructor <init>(Lcom/droidlearn/activity_travel/FlagActivity;Landroid/widget/TextView;Landroid/widget/EditText;)V .locals 0
from Crypto.Util.number import * from flag import flag
defgen_prime(n): res = 1
for i inrange(15): res *= getPrime(n)
return res
if __name__ == '__main__': n = gen_prime(32) e = 65537 m = bytes_to_long(flag) c = pow(m,e,n) print(n) print(c) # 17290066070594979571009663381214201320459569851358502368651245514213538229969915658064992558167323586895088933922835353804055772638980251328261 # 14322038433761655404678393568158537849783589481463521075694802654611048898878605144663750410655734675423328256213114422929994037240752995363595
from secret import flag from Crypto.Util.number import *
p = getPrime(1024) q = getPrime(1024)
d = getPrime(32) e = inverse(d, (p-1)*(q-1)) n = p*q m = bytes_to_long(flag)
c = pow(m,e,n)
print(c) print(e) print(n)
# c = 6755916696778185952300108824880341673727005249517850628424982499865744864158808968764135637141068930913626093598728925195859592078242679206690525678584698906782028671968557701271591419982370839581872779561897896707128815668722609285484978303216863236997021197576337940204757331749701872808443246927772977500576853559531421931943600185923610329322219591977644573509755483679059951426686170296018798771243136530651597181988040668586240449099412301454312937065604961224359235038190145852108473520413909014198600434679037524165523422401364208450631557380207996597981309168360160658308982745545442756884931141501387954248 # e = 8614531087131806536072176126608505396485998912193090420094510792595101158240453985055053653848556325011409922394711124558383619830290017950912353027270400567568622816245822324422993074690183971093882640779808546479195604743230137113293752897968332220989640710311998150108315298333817030634179487075421403617790823560886688860928133117536724977888683732478708628314857313700596522339509581915323452695136877802816003353853220986492007970183551041303875958750496892867954477510966708935358534322867404860267180294538231734184176727805289746004999969923736528783436876728104351783351879340959568183101515294393048651825 # n = 19873634983456087520110552277450497529248494581902299327237268030756398057752510103012336452522030173329321726779935832106030157682672262548076895370443461558851584951681093787821035488952691034250115440441807557595256984719995983158595843451037546929918777883675020571945533922321514120075488490479009468943286990002735169371404973284096869826357659027627815888558391520276866122370551115223282637855894202170474955274129276356625364663165723431215981184996513023372433862053624792195361271141451880123090158644095287045862204954829998614717677163841391272754122687961264723993880239407106030370047794145123292991433
import gmpy2 from Crypto.PublicKey import RSA from Crypto.Util.number import long_to_bytes
defrational_to_contfrac(x,y): ''' Converts a rational x/y fraction into a list of partial quotients [a0, ..., an] ''' a = x//y pquotients = [a] while a * y != x: x,y = y,x-a*y a = x//y pquotients.append(a) return pquotients
defconvergents_from_contfrac(frac): ''' computes the list of convergents using the list of partial quotients ''' convs = []; for i inrange(len(frac)): convs.append(contfrac_to_rational(frac[0:i])) return convs
defcontfrac_to_rational (frac): '''Converts a finite continued fraction [a0, ..., an] to an x/y rational. ''' iflen(frac) == 0: return (0,1) num = frac[-1] denom = 1 for _ inrange(-2,-len(frac)-1,-1): num, denom = frac[_]*num+denom, num return (num,denom)
defegcd(a,b): ''' Extended Euclidean Algorithm returns x, y, gcd(a,b) such that ax + by = gcd(a,b) ''' u, u1 = 1, 0 v, v1 = 0, 1 while b: q = a // b u, u1 = u1, u - q * u1 v, v1 = v1, v - q * v1 a, b = b, a - q * b return u, v, a
defgcd(a,b): ''' 2.8 times faster than egcd(a,b)[2] ''' a,b=(b,a) if a<b else (a,b) while b: a,b=b,a%b return a
defmodInverse(e,n): ''' d such that de = 1 (mod n) e must be coprime to n this is assumed to be true ''' return egcd(e,n)[0]%n
deftotient(p,q): ''' Calculates the totient of pq ''' return (p-1)*(q-1)
defbitlength(x): ''' Calculates the bitlength of x ''' assert x >= 0 n = 0 while x > 0: n = n+1 x = x>>1 return n
defisqrt(n): ''' Calculates the integer square root for arbitrary large nonnegative integers ''' if n < 0: raise ValueError('square root not defined for negative numbers')
if n == 0: return0 a, b = divmod(bitlength(n), 2) x = 2**(a+b) whileTrue: y = (x + n//x)//2 if y >= x: return x x = y
defis_perfect_square(n): ''' If n is a perfect square it returns sqrt(n), otherwise returns -1 ''' h = n & 0xF; #last hexadecimal "digit"
if h > 9: return -1# return immediately in 6 cases out of 16.
# Take advantage of Boolean short-circuit evaluation if ( h != 2and h != 3and h != 5and h != 6and h != 7and h != 8 ): # take square root if you must t = isqrt(n) if t*t == n: return t else: return -1
return -1
defwiener_hack(e, n): frac = rational_to_contfrac(e, n) convergents = convergents_from_contfrac(frac) for (k, d) in convergents: if k != 0and (e * d - 1) % k == 0: phi = (e * d - 1) // k s = n - phi + 1 discr = s * s - 4 * n if (discr >= 0): t = is_perfect_square(discr) if t != -1and (s + t) % 2 == 0: print("Hacked!") return d returnFalse defmain(): n = 19873634983456087520110552277450497529248494581902299327237268030756398057752510103012336452522030173329321726779935832106030157682672262548076895370443461558851584951681093787821035488952691034250115440441807557595256984719995983158595843451037546929918777883675020571945533922321514120075488490479009468943286990002735169371404973284096869826357659027627815888558391520276866122370551115223282637855894202170474955274129276356625364663165723431215981184996513023372433862053624792195361271141451880123090158644095287045862204954829998614717677163841391272754122687961264723993880239407106030370047794145123292991433 e = 8614531087131806536072176126608505396485998912193090420094510792595101158240453985055053653848556325011409922394711124558383619830290017950912353027270400567568622816245822324422993074690183971093882640779808546479195604743230137113293752897968332220989640710311998150108315298333817030634179487075421403617790823560886688860928133117536724977888683732478708628314857313700596522339509581915323452695136877802816003353853220986492007970183551041303875958750496892867954477510966708935358534322867404860267180294538231734184176727805289746004999969923736528783436876728104351783351879340959568183101515294393048651825 c = 6755916696778185952300108824880341673727005249517850628424982499865744864158808968764135637141068930913626093598728925195859592078242679206690525678584698906782028671968557701271591419982370839581872779561897896707128815668722609285484978303216863236997021197576337940204757331749701872808443246927772977500576853559531421931943600185923610329322219591977644573509755483679059951426686170296018798771243136530651597181988040668586240449099412301454312937065604961224359235038190145852108473520413909014198600434679037524165523422401364208450631557380207996597981309168360160658308982745545442756884931141501387954248 d = wiener_hack(e, n) m = pow(c,d,n) print (long_to_bytes(m)) if __name__=="__main__": main()
# 计算key[0]的模数逆 defmod_inverse(a, m): m0, x0, x1 = m, 0, 1 while a > 1: q = a // m m, a = a % m, m x0, x1 = x1 - q * x0, x0 return x1 + m0 if x1 < 0else x1
# 将密文转换为字节列表 ciphertext_bytes = bytes.fromhex(ciphertext_hex) flag = []
# 逆向解密 for c in ciphertext_bytes: original_byte = ((c - key[1]) * mod_inverse(key[0], 256)) % 256 flag.append(original_byte)
v1 = __readfsqword(0x28u); if ( chance ) { puts("You shouldn't choose this"); puts("Please remember, the shop owner doesn't like his secret to be found"); puts("To punish your choice, you will lose 50$ and you will never be able to choose it!"); puts("\n"); money -= 50; --chance; } return v1 - __readfsqword(0x28u); }
