from AITMCLab.libnum import n2s, s2n
flag = 'flag{Congratulation!_quiz1_passed!!!}'
def nextPrime(n):
n += 2 if n & 1 else 1
while not isPrime(n):
n += 2
return n
e = 11248112333656902878308992204660514716130692202019193081806766887380465145401754698746718075268681481388695805324253817155823465013590321091178897918430457
c1 = 5120829596353532760839054347975234579355835073413768618360492980516438193909447500996222328143719619379838946544412967584025416378147246422705451415437468
c2 = 17985907282297772406857113433926323639543183645704827789984971602150950301590677893419082
c1, c2 = n2s(c1), n2s(c2)
E = nextPrime(e)
f = 1
for i in range(E - 2, e, -1):
f = f * inverse(i, E) % E
print f
f = n2s(f)
def xor(s1, s2):
length = min(len(s1), len(s2))
res = ''
for i in range(length):
res = res + chr(ord(s1[i]) ^ ord(s2[i]))
return res
now_x = 0
for i in range(r):
now_g = pow(g, pow(p, r - 1 - i), n)
now_y = pow(y, pow(p, r - 1 - i), n)
now = pow(now_g, now_x, n)
for now_a in range(p + 1):
if now == now_y:
a[i] = now_a
break
now = now * pow(now_g, pow(p, i), n) % n
now_x += a[i] * pow(p, i)
xs.append(now_x)
print xs
for i in range(len(ps)):
ps[i] = pow(ps[i], rs[i])
Ms = []
m = 1
for p in ps:
m *= p
for i in range(len(ps)):
now_m = m // ps[i]
now_m = now_m * invmod(now_m, ps[i]) % n
Ms.append(now_m)
res = 0
for i in range(len(ps)):
res = (res + xs[i] * Ms[i]) % m
print(n2s(res))
# Welcome to lab3, I am going to introduct some interesting functions to you!
# We need to import what we want
from AITMCLab.libnum import n2s, s2n, invmod
from AITMCLab.Crypto.Util.number import long_to_bytes, bytes_to_long
from AITMCLab.Crypto.Util.number import getPrime, isPrime
# Use s2n(acronym for 'string to number') to convert string to number
# and use n2s to revert
s = 'I love algorithm design'
n = s2n(s) # int
print 'n =',n
new_s = n2s(n)
assert new_s == s
# Feel free to replace n2s with long_to_bytes, or replace s2n with bytes_to_long
# They are equavalant!!
assert long_to_bytes(bytes_to_long('hahaha')) == 'hahaha'
assert n2s(bytes_to_long('heiheihei')) == 'heiheihei'
assert long_to_bytes(s2n('xixixi')) == 'xixixi'
# x * invmod(x, n) % n == 1, as you suppose
n = 23
for x in range(1, n):
assert x * invmod(x, n) % n == 1
assert invmod(x, n) * x % n == 1
# Use function 'getPrime' to generate a prime RANDOMLY
# namely, you will get different result every time you execute this program
p = getPrime(5)
q = getPrime(5)
print p, q
from AITMCLab.libnum import invmod, n2s
n = 3914224287795636809861368015178301501372188634077669936495180785846977608060045377653931855350462641602739528638098085015546367841148708574573569280349292403464473463818042817457266362325488737681832840764568002910598017717058689969512296099
c = 3678716732847973069496233717035619410810008982881832778108057662379358563168669345659610269104838531535596938088040391434969949131327247362326079375825722973572861874365364217648459622237827463731017181656549460372354778250000173854890274241
e = 0x10001
d = invmod(e, n - 1)
print n2s(pow(c, d, n)) # flag{this_is_a_flag,hahaha}
s += i
print s # 20
# You can program easier with built-in function, such as 'ord' and 'chr'
# ord: str(length=1) -> int Transfer character into ascii number
# chr: int -> str(length=1) Transfer ascii number into character
# Want to know more?
# https://www.runoob.com/python/python-func-ord.html
# https://www.runoob.com/python/python-func-chr.html
print ord('a') # 97
print chr(97) # 'a'
# Use keyword 'import' to import other function from ctflab
from AITMCLab.libnum import n2s, s2n
print s2n('Happy Hacking') # 5734583677810927947475323547239
print n2s(5734583677810927947475323547239) # 'Happy Hacking'
# Want to know more about AITMCLab.libnum? https://github.com/hellman/libnum
# Explore more grammars, use baidu
# Lab1
# Here is an encoding procedure, try to understand
# what happened and findout the message
message = 'flag{*************}' # You can't see the message here!! hahaha
cipher = ''
key = 3
for char in message:
if 'a' <= char <= 'z':
now_cipher = (ord(char) - ord('a') + key) % 26
cipher += chr(now_cipher + ord('a'))
else:
message = padding << m**(p-1) % p + m % 2
cipher = pow(message, e, N)
f.write(hex(cipher)+'\n')
m /= 2"""
p = 23
m = 5
#(2 * pad * pad + 0) ** e + kn = enc
#
#(2 * pad * pad + 0) + (kn) % e = enc % e
#(2 * pad * pad + 1) ** e + kn = enc
i = 0
m = 0
with open("./key.enc", "r") as f:
info = f.readlines()
f.close()
for i in range(len(info)):
x = int(info[i].strip()[:-1], 16)
#print libnum.jacobi(x,N)
#print x,hex(x)
#raw_input()
if libnum.jacobi(x, N) == 1:
m += (1 << i)
else:
m += 0
n = N
temp = random.randint(0, 2**1000)**2
print libnum.jacobi(pow(2 * temp, e, n), n)
print libnum.jacobi(pow(4 * temp, e, n), n)
print libnum.n2s(m)
M.append(nowm)
r = 0
for i in range(10):
r += M[i] * res[i]
r = r % N
# print r
return r
def solve_sig():
ls = []
with open('sig', 'rb') as f:
line = f.readline().split('=')[-1]
y = int(line)
for i in range(95):
line = f.readline().split('=')[-1].strip().split(',')
ls.append((int(line[0]), int(line[1])))
res = []
for i in range(95):
r, s = ls[i]
res.append(1 if elgamal_sig_verify(1024, r, s, p, g, y) else 0)
r = int(''.join(map(str, res[::-1])), 2)
# print r
return r
f1 = solve_enc()
f2 = solve_sig()
from AITMCLab.libnum import n2s
f = n2s(f1) + n2s(f2)
print 'flag{' + f + '}'