import random as r

#5x5

def set_playfair(key):

#암호키 가공

enc_key = ""

for i in key:

k = 0

if i == "I" or i == "J": k += 1

if i != " ":

if k <= 1 and not(i in enc_key):

enc_key += i

playfair = []

for i in range(5):

playfair.append([None]*5)

#내용 집어넣기

m = 0; i = 65; jp = 0; kp = 0; error = 0

#가공한 암호키 집어넣기

for j in range(5):

for k in range(5):

try:

l = enc_key[j*5+k]

if l == "I" or l == "J":

playfair[j][k] = ["I", "J"]

m = 1

continue

playfair[j][k] = l

except:

jp = j; kp =k; error = 1

break

if error == 1: break

#그 외의 알파벳 집어넣기

for j in range(jp, 5):

if j == jp:

for k in range(kp, 5):

while chr(i) in enc_key:

i += 1

if i == 73 or i == 74:

if m == 1:

i = 75

else:

playfair[j][k] = [chr(i), chr(i+1)]

i += 2

playfair[j][k] = chr(i)

i += 1

if i == 73 or i == 74:

if m == 1:

i = 75

else:

playfair[j][k] = [chr(i), chr(i+1)]

i += 2

else:

for k in range(0, 5):

while chr(i) in enc_key:

i += 1

if i == 73 or i == 74:

if m == 1:

i = 75

else:

playfair[j][k] = [chr(i), chr(i+1)]

i += 2

playfair[j][k] = chr(i)

i += 1

if i == 73 or i == 74:

if m == 1:

i = 75

else:

playfair[j][k] = [chr(i), chr(i+1)]

i += 2

"""

#테스트 출력

print("Playfair 표")

for i in range(5):

for j in range(5):

print(playfair[i][j], end = "\t")

print()

"""

return playfair

#평문 가공하기

def manuorigin(origin):

ori = ""; originm = ""

for i in origin:

if i == " ": continue

else: originm += i

if len(originm) % 2 == 0:

for i in range(0, len(originm), 2):

ori += originm[i]

if ori[i] != originm[i+1] and not(ord(ori[i]) == 73 and originm[i+1] == 74) and not(ord(ori[i]) == 74 and originm[i+1] == 73):

ori += originm[i+1]

else: ori += "X" + orginm[i+1]

else:

for i in range(0, len(originm)-1, 2):

ori += originm[i]

if ori[i] != originm[i+1] and not(ord(ori[i]) == 73 and originm[i+1] == 74) and not(ord(ori[i]) == 74 and originm[i+1] == 73):

ori += originm[i+1]

else:

ori += "X" + originm[i+1]

ori += originm[-1]

if len(ori) % 2 != 0: ori += "X"

return ori

#암호화

def enc_playfair(ori, playfair):

enc = ""

for i in range(0, len(ori), 2):

one = ori[i]; two = ori[i+1]

onexy = [0, 0]; twoxy = [0, 0]

#가공한 평문의 좌표값 찾기

if one in ["I", "J"]:

for i in range(len(playfair)):

if ["I", "J"] in playfair[i]:

onexy = [playfair[i].index(["I", "J"]), i]

break

else:

for i in range(len(playfair)):

if one in playfair[i]:

onexy = [playfair[i].index(one), i]

break

if two in ["I", "J"]:

for i in range(len(playfair)):

if ["I", "J"] in playfair[i]:

twoxy = [playfair[i].index(["I", "J"]), i]

break

else:

for i in range(len(playfair)):

if two in playfair[i]:

twoxy = [playfair[i].index(two), i]

break

#1. 행렬 모두 일치 X

if onexy[0] != twoxy[0] and onexy[1] != twoxy[1]:

try:

enc += playfair[twoxy[1]][onexy[0]]

except:

enc += r.choice(["I", "J"])

try:

enc += playfair[onexy[1]][twoxy[0]]

except:

enc += r.choice(["I", "J"])

#2. 행ㅡ만 일치

elif onexy[1] == twoxy[1]:

onex = onexy[0] + 1; twox = twoxy[0] + 1

if onex >= 5: onex = 0

if twox >= 5: twox = 0

try:

enc += playfair[onexy[1]][onex]

except:

enc += r.choice(["I", "J"])

try:

enc += playfair[onexy[1]][twox]

except:

enc += r.choice(["I", "J"])

#3. 열ㅣ만 일치

else:

oney = onexy[1] + 1; twoy = twoxy[1] + 1

if oney >= 5: oney = 0

if twoy >= 5: twoy = 0

try:

enc += playfair[oney][onexy[0]]

except:

enc += r.choice(["I", "J"])

try:

enc += playfair[twoy][onexy[0]]

except:

enc += r.choice(["I", "J"])

return enc

#playfair

def playfair(key, origin):

playfair = set_playfair(key)

ori = manuorigin(origin)

enc = enc_playfair(ori, playfair)

print(f"평문 : {origin}")

print(f"가공한 평문 : {ori}")

print("\t Playfair 표")

for i in range(5):

for j in range(5):

print(playfair[i][j], end = "\t")

print()

print(f"암호문 : {enc}")

return enc

playfair("GENGHIS KHAN WAS A GREAT KING AND WARRIOR", "WOMAN SCHOOL")