def fun2(self,s):
try:
c10.cbcdecrypt(s,self.iv,self.key)
return True
except:
return False
Bob = c33.dh(random.randint(0,10000),p,g)
Bob_secret = Bob.shsecret(Alice.A)
# B->A Send "B"
Alice_secret = Alice.shsecret(Bob.A)
# on Alice
Alice_msg = "Alice says Hi"
Alice_iv = open("/dev/urandom").read(16)
Alice_enc = c10.cbcencrypt(Alice_msg,Alice_iv,c28.sha1(str(Alice_secret)).digest()[:16])
print "msg Alice send: "+Alice_msg
# A->B Send AES-CBC(SHA1(s)[0:16], iv=random(16), msg) + iv
# on Bob
print "msg Bob received: "+c10.cbcdecrypt(Alice_enc,Alice_iv,c28.sha1(str(Bob_secret)).digest()[:16])
Bob_msg = "Bob says Hi"
Bob_iv = open("/dev/urandom").read(16)
Bob_enc = c10.cbcencrypt(Bob_msg,Bob_iv,c28.sha1(str(Bob_secret)).digest()[:16])
print "msg Bob send: "+Bob_msg
# B->A Send AES-CBC(SHA1(s)[0:16], iv=random(16), A's msg) + iv
# on Alice
print "msg Alice received: "+c10.cbcdecrypt(Bob_enc,Bob_iv,c28.sha1(str(Alice_secret)).digest()[:16])
print "\n\n############### Mallory in the middle"
##### now Mallory comes into play
Alice = c33.dh(random.randint(0,10000),p,g)
# A->M Send "p", "g", "A"
# B->M Send "B"
# Mallory changes B to p # B^a mod p = p^a mod p = 0
# M->A Send "p"
Alice_secret = Alice.shsecret(Bob.A)
print "shared key="+binascii.b2a_hex(c28.sha1(str(Alice_secret)).digest()[:16])
print "attack key="+binascii.b2a_hex(c28.sha1(str(1)).digest()[:16])
Alice_msg = "Alice hello OneA"
Alice_iv=''
for i in range(16):
Alice_iv = Alice_iv+chr(random.randint(0,255))
Alice_enc = c10.cbcencrypt(Alice_msg,Alice_iv,c28.sha1(str(Alice_secret)).digest()[:16])
print "Alice发送: "+str(Alice_msg)
# A->M Send AES-CBC(SHA1(s)[0:16], iv=random(16), msg) + iv
# the secret is 0
print "攻击者解密出: "+c10.cbcdecrypt(Alice_enc,Alice_iv,c28.sha1(str(1)).digest()[:16])
# M->B Relay that to B
print "Bob收到: "+c10.cbcdecrypt(Alice_enc,Alice_iv,c28.sha1(str(Bob_secret)).digest()[:16])
Bob_msg = "Bob HELLO OneA"
Bob_iv=''
for i in range(16):
Bob_iv = Bob_iv+chr(random.randint(0,255))
Bob_enc = c10.cbcencrypt(Bob_msg,Bob_iv,c28.sha1(str(Bob_secret)).digest()[:16])
print "Bob发送: "+Bob_msg
# B->M Send AES-CBC(SHA1(s)[0:16], iv=random(16), A's msg) + iv
# the secret is 0
print "攻击者解密出: "+c10.cbcdecrypt(Bob_enc,Bob_iv,c28.sha1(str(1)).digest()[:16])
# M->A Relay that to A
def exchange(p,g,Mallory=False,mg=0):
# A->B Send "p", "g"
# B->A Send ACK
# with Mallory, M would send NACK to Alice suggesting new p and g values
# and would send the same weak values to Bob, assuming there is no
# check on weak values, the communications would be screwed
if Mallory:
g = mg
Alice = c33.dh(random.randint(0,10000),p,g)
# A->B Send "p", "g", "A"
Bob = c33.dh(random.randint(0,10000),p,g)
Bob_secret = Bob.shsecret(Alice.A)
# B->A Send "B"
Alice_secret = Alice.shsecret(Bob.A)
# on Alice
Alice_msg = "Alice says Hi"
Alice_iv = open("/dev/urandom").read(16)
Alice_enc = c10.cbcencrypt(Alice_msg,Alice_iv,c28.sha1(str(Alice_secret)).digest()[:16])
print "msg Alice send: "+Alice_msg
# A->B Send AES-CBC(SHA1(s)[0:16], iv=random(16), msg) + iv
if Mallory:
print "Mallory intercepts:",
if g == 1:
print c10.cbcdecrypt(Alice_enc,Alice_iv,c28.sha1(str(1)).digest()[:16])
elif g == p:
print c10.cbcdecrypt(Alice_enc,Alice_iv,c28.sha1(str(0)).digest()[:16])
elif g == p - 1:
try:
msg = c10.cbcdecrypt(Alice_enc,Alice_iv,c28.sha1(str(1)).digest()[:16])
except:
msg = c10.cbcdecrypt(Alice_enc,Alice_iv,c28.sha1(str(p-1)).digest()[:16])
print msg
else:
print ""
# on Bob
print "msg Bob received: "+c10.cbcdecrypt(Alice_enc,Alice_iv,c28.sha1(str(Bob_secret)).digest()[:16])
Bob_msg = "Bob says Hi"
Bob_iv = open("/dev/urandom").read(16)
Bob_enc = c10.cbcencrypt(Bob_msg,Bob_iv,c28.sha1(str(Bob_secret)).digest()[:16])
print "msg Bob send: "+Bob_msg
# B->A Send AES-CBC(SHA1(s)[0:16], iv=random(16), A's msg) + iv
if Mallory:
print "Mallory intercepts:",
if g == 1:
print c10.cbcdecrypt(Bob_enc,Bob_iv,c28.sha1(str(1)).digest()[:16])
elif g == p:
print c10.cbcdecrypt(Bob_enc,Bob_iv,c28.sha1(str(0)).digest()[:16])
elif g == p - 1:
try:
msg = c10.cbcdecrypt(Bob_enc,Bob_iv,c28.sha1(str(1)).digest()[:16])
except:
msg = c10.cbcdecrypt(Bob_enc,Bob_iv,c28.sha1(str(p-1)).digest()[:16])
print msg
else:
print ""
# on Alice
print "msg Alice received: "+c10.cbcdecrypt(Bob_enc,Bob_iv,c28.sha1(str(Alice_secret)).digest()[:16])
