enedil/foo.py

## foo.py
#!/usr/bin/env python3
import cgi
import os
import json
from base64 import b64decode, b64encode
from Crypto.Cipher import AES
from Crypto.Util.strxor import strxor
from Crypto.Util.Padding import pad, unpad
from Crypto.Util.number import long_to_bytes

from secret import key, secret_message

block_length = 16
aes = AES.new(key, AES.MODE_ECB)

def chunk(data, length):
    return [data[i:i+length] for i in range(0, len(data), length)]

def sign(msg, iv=None):
    msg = pad(msg, block_length)
    if not iv:
        iv = os.urandom(block_length)
    blocks = chunk(msg, block_length)

    signature = iv
    for block in [long_to_bytes(len(blocks), block_length)] + blocks:
        signature = aes.encrypt(strxor(signature, block))
    return iv, signature

def verify(msg, iv, signature):
    _, computed_signature = sign(msg, iv)
    return computed_signature == signature

msg_ = b'{"authenticated":false,"text":"oto_przyklad_uzycia_podpisu"}'
iv_, sig_ = sign(msg_)

print("Content-type: text/html")
print()
print( """
<html>
<head><title>Zadanie 2: AES CBC MAC</title></head>
<meta charset="utf-8">
<body>
""")
print("""
<p> sign(%r) == b64decode(%r), b64decode(%r) </p>
""" % (msg_, b64encode(iv_), b64encode(sig_)))

form = cgi.FieldStorage()
message = form.getvalue('message', '')
iv = form.getvalue('iv', '')
signature = form.getvalue('signature', '')

print('<p>')
def x(message, iv, signature):
    try:
        message = b64decode(message)
        iv = b64decode(iv)
        signature = b64decode(signature)
    except Exception as e:
        print('niepoprawne kodowanie: ', e)
    if len(iv) != 16 or len(signature) != 16:
        print('Zła długość.')
        return

    try:
        if verify(message, iv, signature):
            d = json.loads(message)
            if d['authenticated']:
                print('Oto sekretna wiadomość: ', secret_message)
            else:
                print('Tym razem niestety nic')
        else:
            print('Niepoprawny podpis.')
    except Exception as e:
        print(e)
if message and iv and signature:
    x(message, iv, signature)

print('</p>')

print("""


  <p>Wszystkie rzeczy trzeba najpierw zakodować za pomocą base64!

  <form method="post">
    <p>message: <input type="text" name="message"/></p>
    <p>iv: <input type="text" name="iv"/></p>
    <p>signature: <input type="text" name="signature"/></p>
  <input type="submit">
  </form>

</body>

</html>
""")


## zadanie3.cgi
#!/usr/bin/env python3
import cgi

from secret import N, e, d

def encrypt(m):
    return pow(m, e, N)

def decrypt(c):
    return pow(c, d, N)

print("Content-type: text/html\n")
print( """
<html>
<head><title>Zadanie 3: RSA</title></head>
<meta charset="utf-8">
<body>
""")
print("""
<p>
Oto klucz publiczny: <br/>
N = %d <br/>
e = %d <br/>
</p>
""" % (N, e))
print("""
<p>
Kluczem tym zaszyfrowano pewną wiadomość (jest to liczba): <br/>
928066735300335970761240687353165144477163930660377590215387151172657023088092014506935678554845211540813156
</p>
""")

form = cgi.FieldStorage()
szyfrogram = form.getvalue('szyfrogram', '')

if szyfrogram:
    try:
        dec = decrypt(int(szyfrogram))
        print("Po odszyfrowaniu, stwierdzam że odpowiadająca jemu odszyfrowana liczba jest ", end='')
        if dec % 2:
            print('parzysta.')
        else:
            print('nieparzysta.')
    except Exception as e:
        print("Wystąpił błąd:", e)

print(
 """<form method="post">
    <p>Wprowadź szyfrogram: <input type="text" name="szyfrogram"/></p>
  <input type="submit">
  </form>

</body>

</html>""")
	#!/usr/bin/env python3
	import cgi
	import os
	import json
	from base64 import b64decode, b64encode
	from Crypto.Cipher import AES
	from Crypto.Util.strxor import strxor
	from Crypto.Util.Padding import pad, unpad
	from Crypto.Util.number import long_to_bytes

	from secret import key, secret_message

	block_length = 16
	aes = AES.new(key, AES.MODE_ECB)

	def chunk(data, length):
	return [data[i:i+length] for i in range(0, len(data), length)]

	def sign(msg, iv=None):
	msg = pad(msg, block_length)
	if not iv:
	iv = os.urandom(block_length)
	blocks = chunk(msg, block_length)

	signature = iv
	for block in [long_to_bytes(len(blocks), block_length)] + blocks:
	signature = aes.encrypt(strxor(signature, block))
	return iv, signature

	def verify(msg, iv, signature):
	_, computed_signature = sign(msg, iv)
	return computed_signature == signature

	msg_ = b'{"authenticated":false,"text":"oto_przyklad_uzycia_podpisu"}'
	iv_, sig_ = sign(msg_)

	print("Content-type: text/html")
	print()
	print( """
	<html>
	<head><title>Zadanie 2: AES CBC MAC</title></head>
	<meta charset="utf-8">
	<body>
	""")
	print("""
	<p> sign(%r) == b64decode(%r), b64decode(%r) </p>
	""" % (msg_, b64encode(iv_), b64encode(sig_)))

	form = cgi.FieldStorage()
	message = form.getvalue('message', '')
	iv = form.getvalue('iv', '')
	signature = form.getvalue('signature', '')

	print('<p>')
	def x(message, iv, signature):
	try:
	message = b64decode(message)
	iv = b64decode(iv)
	signature = b64decode(signature)
	except Exception as e:
	print('niepoprawne kodowanie: ', e)
	if len(iv) != 16 or len(signature) != 16:
	print('Zła długość.')
	return

	try:
	if verify(message, iv, signature):
	d = json.loads(message)
	if d['authenticated']:
	print('Oto sekretna wiadomość: ', secret_message)
	else:
	print('Tym razem niestety nic')
	else:
	print('Niepoprawny podpis.')
	except Exception as e:
	print(e)
	if message and iv and signature:
	x(message, iv, signature)

	print('</p>')

	print("""


	<p>Wszystkie rzeczy trzeba najpierw zakodować za pomocą base64!

	<form method="post">
	<p>message: <input type="text" name="message"/></p>
	<p>iv: <input type="text" name="iv"/></p>
	<p>signature: <input type="text" name="signature"/></p>
	<input type="submit">
	</form>

	</body>

	</html>
	""")
	#!/usr/bin/env python3
	import cgi

	from secret import N, e, d

	def encrypt(m):
	return pow(m, e, N)

	def decrypt(c):
	return pow(c, d, N)

	print("Content-type: text/html\n")
	print( """
	<html>
	<head><title>Zadanie 3: RSA</title></head>
	<meta charset="utf-8">
	<body>
	""")
	print("""
	<p>
	Oto klucz publiczny: <br/>
	N = %d <br/>
	e = %d <br/>
	</p>
	""" % (N, e))
	print("""
	<p>
	Kluczem tym zaszyfrowano pewną wiadomość (jest to liczba): <br/>
	928066735300335970761240687353165144477163930660377590215387151172657023088092014506935678554845211540813156
	</p>
	""")

	form = cgi.FieldStorage()
	szyfrogram = form.getvalue('szyfrogram', '')

	if szyfrogram:
	try:
	dec = decrypt(int(szyfrogram))
	print("Po odszyfrowaniu, stwierdzam że odpowiadająca jemu odszyfrowana liczba jest ", end='')
	if dec % 2:
	print('parzysta.')
	else:
	print('nieparzysta.')
	except Exception as e:
	print("Wystąpił błąd:", e)

	print(
	"""<form method="post">
	<p>Wprowadź szyfrogram: <input type="text" name="szyfrogram"/></p>
	<input type="submit">
	</form>

	</body>

	</html>""")