栅栏密码加解密

单行版本

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railFence = lambda s: [[i, ''.join([s[k * i + j] for j in range(i) for k in range(len(s) / i)])] for i in range(1, len(s)) if not len(s) % i]
print railFence('hello world , 2017 ! ')

正常版本

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def railFence(s):
ll = len(s)
res = dict()
for i in range(1, ll):
r = ''
if ll % i == 0:
for j in range(i):
for k in range(ll / i):
r += s[k * i + j]
res[i] = r
return res

# test
print railFence('hello world , 2017 ! ')
# {1: 'hello world , 2017 ! ', 3: 'hlwl,0 eood 1!l r 27 ', 7: 'ho2er0ll1ld7o ,!w '}

凯撒密码加解密

单行版本

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def caesar(s): return [[off, ''.join([chr((ord(i) - 97 + off) % 26 + 97) if 'a' <= i <= 'z' else chr((ord(i) - 65 + off) % 26 + 65) if 'A' <= i <= 'Z' else i for i in str(s)])] for off in range(26)]
print caesar('h3llo')

正常版本

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def caesar(s):
cycle = 26
res = []
for offset in range(26):
r = ''
for i in str(s):
if 'a' <= i <= 'z':
r += chr((ord(i) - ord('a') + offset) % cycle + ord('a'))
elif 'A' <= i <= 'Z':
r += chr((ord(i) - ord('A') + offset) % cycle + ord('A'))
else:
r += i
res.append([offset, r])
return res

# test
print caesar('h3llo')
#[ [0, 'h3llo'], [1, 'i3mmp'], [2, 'j3nnq'], [3, 'k3oor'], [4, 'l3pps'], [5, 'm3qqt'], [6, 'n3rru'], [7, 'o3ssv'],
# [8, 'p3ttw'], [9, 'q3uux'], [10, 'r3vvy'], [11, 's3wwz'], [12, 't3xxa'], [13, 'u3yyb'], [14, 'v3zzc'],
# [15, 'w3aad'], [16, 'x3bbe'], [17, 'y3ccf'], [18, 'z3ddg'], [19, 'a3eeh'], [20, 'b3ffi'], [21, 'c3ggj'],
# [22, 'd3hhk'], [23, 'e3iil'], [24, 'f3jjm'], [25, 'g3kkn']]

莫尔斯电码加解密

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# by https://findneo.github.io/
import re


def morse(s):
morseChart = ['.-', '-...', '-.-.', '-..', '.', '..-.', '--.',
'....', '..', '.---', '-.-', '.-..', '--', '-.',
'---', '.--.', '--.-', '.-.', '...', '-', '..-',
'...-', '.--', '-..-', '-.--', '--..', '-----', '.----',
'..---', '...--', '....-', '.....', '-....', '--...', '---..',
'----.', '.-.-.-', '--..--', '..--..', '-....-', '.----.', '---...',
'.-..-.', '-..-.', '.--.-.', '-.-.-.', '-...-', '-.-.--', '..--.-',
'-.--.', '-.--.-', '...-..-', '.-...', '.-.-.', ' ', '*'
]
alphaChart = ['a', 'b', 'c', 'd', 'e', 'f', 'g',
'h', 'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't', 'u',
'v', 'w', 'x', 'y', 'z', '0', '1',
'2', '3', '4', '5', '6', '7', '8',
'9', '.', ',', '?', '-', "'", ':',
'"', '/', '@', ';', '=', '!', '_',
'(', ')', '$', '&', '+', ' ', '#'
]

# or as a dict -> {c[1][i]: c[0][i] for i in xrange(len(c[0]))}
c = [morseChart, alphaChart]

s = s.lower()

# replace characters not in alphaChart with '#' ,which shall be '*' in
# encoded string
s = re.sub('[^a-z0-9.,?\-\':"/@;=!_()$&+ ]', '#', s)

# for convenience sake, I choose not to deal with space in morse.
s = re.sub('\s+', ' ', s)

m = 1 # default to decode
# if mot mismatch that condition,we are to encode.
if not re.match('[^-._ ]', s):
# occasionally we meet [ ._]+ instead of [ .-]+
s = s.replace('_', '-')
s = re.split(' ', s)
m = 0 # we are to encode by morse

r = []
# list().extend(foo) returns None so we use 'or r'
return (m * ' ').join(r.extend([c[1 - m][c[m].index(i)] for i in s]) or r)

# test
print morse('Hello word,2017!')
print morse('.... . .-.. .-.. --- .-- --- .-. -.. --..-- ..--- ----- .---- --... -.-.--')

base64混合编码

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from base64 import *
import random


def baseRandomEncode(s, depth=3):
for i in xrange(depth):
s = random.choice([b64encode, b32encode, b16encode])(s)
return s


print baseRandomEncode('hello world!') # test

base64混合解码

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# by https://findneo.github.io/
from base64 import *
import re


res = []
# repattern is a self-defining item.
# In CTF games,flag often comes as a printable string containing '{' and '}'.
repattern = "[ -~]*{[ -~]*}[ -~]*|[ -~]*}[ -~]*{[ -~]*"


def basefuzzDecode(s):
global res
for f in [b64decode, b32decode, b16decode]:
try:
t = f(s)
if re.match(repattern, t):
res.append(t)
return 0
else:
basefuzzDecode(t)
except:
pass
return res


print basefuzzDecode(baseRandomEncode('flag{hello ctf!}')) # test