順序的代替表
class Caesar:
def __init__(self, offset=3):
l = list("abcdefghijklmnopqrstuvwxyz")
u = list("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
a = list('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ')
offset %= 26
b = l[offset:]+l[:offset] + u[offset:]+u[:offset]
self.emap = dict(zip(a, b))
self.dmap = dict(zip(b, a))
def encode(self, text):
tmp = [ (x in self.emap and self.emap[x] or x) for x in text]
return ''.join(tmp)
def decode(self, text):
tmp = [ (x in self.dmap and self.dmap[x] or x) for x in text]
return ''.join(tmp)
sr1 = "VprPGS{jnvg_bar_cyhf_1_vf_3?}"
ca8 = Caesar(8)
ca5 = Caesar(5)
sr1 = ca8.decode(sr1)
sr1 = ca5.decode(sr1)
print(sr1)
IceCTF{wait_one_plus_1_is_3?}
