Crypto Easy Crypto

get buf unsign s[256]

get buf t[256]

we have key:hello world

we have flag:????????????????????????????????


for i:0 to 256 

set s[i]:i

for i:0 to 256 
    set t[i]:key[(i)mod(key.lenth)]                                                                                                           

for i:0 to 256 
    set j:(j+s[i]+t[i])mod(256)
        swap:s[i],s[j]

for m:0 to 37
    set i:(i + 1)mod(256)
    set j:(j + S[i])mod(256)
    swap:s[i],s[j]
    set x:(s[i] + (s[j]mod(256))mod(256))
    set flag[m]:flag[m]^s[x]

fprint flagx to file

f=open("enc.txt", "rb")
data=f.read()
f.close()

key="hello world"
s = []
t = []
for i in range(256):
    s.append(i)
    c = key[ i % (len(key))]
    t.append(ord(c))

j = 0
for i in range(256):
    j = (j+ s[i] + t[i]) % 256
    s[i], s[j] = s[j], s[i]

i = 0
j = 0
flag = []
for m in range(37):
    i = (i + 1) % 256
    j = (j+s[i]) % 256
    s[i], s[j] = s[j], s[i]
    x = (s[i] + s[j]) % 256
    flag.append(data[m]^s[x])

print(bytes(flag))  # EIS{55a0a84f86a6ad40006f014619577ad3}