Hi,
My script:
The flag was 3DS{3.1423405966415094}
In this task we were given several punching cards (DEC9 model). To solve the task I wrote a script to create a table to map each character to its corresponding code. Than I decoded the content of the punch cards. The decoded content was a FORTRAN program. I fixed the code(missing lines) and I run it to get the required value which was 3.1423405966415094.
My script:
''' dec9.card
________________________________________________________________
/&-0123456789ABCDEFGHIJKLMNOPQR/STUVWXYZ:#@'="[.<(+^!$*);\],%_>?
12 / O OOOOOOOOO OOOOOO
11| O OOOOOOOOO OOOOOO
0| O OOOOOOOOO OOOOOO
1| O O O O
2| O O O O O O O O
3| O O O O O O O O
4| O O O O O O O O
5| O O O O O O O O
6| O O O O O O O O
7| O O O O O O O O
8| O O O O OOOOOOOOOOOOOOOOOOOOOOOO
9| O O O O
|__________________________________________________________________
'''
import os
def gen_from_template():
f = open("dec9.card")
card = f.readlines()
f.close()
for i in range(5,68):
pcode = ""
for j in range(2,14):
if card[j][i] == "O":
pcode += "y"+card[j][0:2].replace(" ","")
print '"'+pcode+"\":"+'"'+card[1][i]+"\",\n"
pcode_template ={"y12":"&","y11":"-","y0":"0","y1":"1","y2":"2","y3":"3",
"y4":"4","y5":"5","y6":"6","y7":"7","y8":"8","y9":"9","y12y1":"A","y12y2":"B",
"y12y3":"C","y12y4":"D","y12y5":"E","y12y6":"F","y12y7":"G","y12y8":"H","y12y9":"I",
"y11y1":"J","y11y2":"K","y11y3":"L","y11y4":"M","y11y5":"N","y11y6":"O","y11y7":"P",
"y11y8":"Q","y11y9":"R","y0y1":"/","y0y2":"S","y0y3":"T","y0y4":"U","y0y5":"V",
"y0y6":"W","y0y7":"X","y0y8":"Y","y0y9":"Z","y2y8":":","y3y8":"#","y4y8":"@","y5y8":"'",
"y6y8":"=","y7y8":"\"","y12y2y8":"[","y12y3y8":".","y12y4y8":"<","y12y5y8":"(","y12y6y8":"+",
"y12y7y8":"^","y11y2y8":"!","y11y3y8":"$","y11y4y8":"*","y11y5y8":")","y11y6y8":";",
"y11y7y8":"\"","y0y2y8":"]","y0y3y8":",","y0y4y8":"%","y0y5y8":"_","y0y6y8":">",
"y0y7y8":"?"}
def decode_card(fcard):
dec = ""
f = open(fcard)
card = f.readlines()
f.close()
for i in range(4,len(card[0])):
pcode = ""
for j in range(4,16):
if card[j][i] == "O":
pcode += "y"+card[j][0:2].replace(" ","")
if len(pcode):
dec+=pcode_template[pcode]
return dec
t = ""
path = "misc400"
for root, dirs, files in os.walk('misc400'):
for fcard in sorted(files):
t+=decode_card(os.path.join(path, fcard))+ " "
'''
for fcard in os.listdir(path):
if os.path.isfile(os.path.join(path, fcard)):
t+=decode_card(os.path.join(path, fcard))+ " "
'''
print t
PROGRAM PRGM
INTEGER C,X
DOUBLE PRECISION I,R,A
DOUBLE PRECISION RES
1598 C=1337
RES=1
X=0
GO TO 5523
1599 A=1/RES
GO TO 2852
7599 A=-1/RES
GO TO 2852
2852 I=I+A
GO TO 9513
9513 RES=RES+2
X=X+1
IF(X.EQ.C) THEN
GO TO 1318
ENDIF
5523 IF(MOD(X,2).EQ.0) THEN
GO TO 1599
ELSE
GO TO 7599
END IF
1318 I=I*4
PRINT*,I
END PROGRAM PRGM
Build and run
The flag was 3DS{3.1423405966415094}
