commit 96cc82e1ca073f78f8576dc78e4299f7af835738
parent ad1d321637d963112799df8d7add5b70c222371d
Author: mpizzzle <michael.770211@gmail.com>
Date: Sat, 16 Feb 2019 18:03:31 +0000
refactoring duplicate classes
Diffstat:
3 files changed, 13 insertions(+), 92 deletions(-)
diff --git a/set3/clone_mt_rng_state.py b/set3/clone_mt_rng_state.py
@@ -1,49 +1,9 @@
+from mt19937 import MersenneTwister
+
def _int32(x):
# Get the 32 least significant bits.
return int(0xffffffff & x)
-class MT19937:
- def __init__(self, seed):
- # Initialize the index to 0
- self.index = 624
- self.mt = [0] * 624
- self.mt[0] = seed # Initialize the initial state to the seed
- for i in range(1, 624):
- self.mt[i] = _int32(1812433253 * (self.mt[i - 1] ^ self.mt[i - 1] >> 30) + i)
-
- def set_state(self, cloned_state):
- self.mt = cloned_state
-
- def extract_number(self):
- if self.index >= 624:
- self.twist()
-
- y = self.mt[self.index]
-
- # Right shift by 11 bits
- y = y ^ y >> 11
- # Shift y left by 7 and take the bitwise and of 2636928640
- y = y ^ y << 7 & 2636928640
- # Shift y left by 15 and take the bitwise and of y and 4022730752
- y = y ^ y << 15 & 4022730752
- # Right shift by 18 bits
- y = y ^ y >> 18
-
- self.index = self.index + 1
-
- return _int32(y)
-
- def twist(self):
- for i in range(624):
- # Get the most significant bit and add it to the less significant
- # bits of the next number
- y = _int32((self.mt[i] & 0x80000000) + (self.mt[(i + 1) % 624] & 0x7fffffff))
- self.mt[i] = self.mt[(i + 397) % 624] ^ y >> 1
-
- if y % 2 != 0:
- self.mt[i] = self.mt[i] ^ 0x9908b0df
- self.index = 0
-
def untemper_11(yy):
y = yy ^ ((yy & 0xffe00000) >> 11)
y = yy ^ ((y & 0xfffffc00) >> 11)
@@ -79,14 +39,14 @@ def untemper(yy):
return _int32(y)
unknown_seed = 12668778
-mt = MT19937(unknown_seed)
+mt = MersenneTwister(unknown_seed)
cloned_mt_state = [0] * 624
for i in range(624):
cloned_mt_state[i] = untemper(mt.extract_number())
-cloned_mt = MT19937(0)
+cloned_mt = MersenneTwister(0)
cloned_mt.set_state(cloned_mt_state)
print mt.extract_number()
diff --git a/set3/crack_mt_seed.py b/set3/crack_mt_seed.py
@@ -1,58 +1,20 @@
import time
import random
-
-class mersenne_twister:
- #Initialize the generator from a seed
- def __init__(self, seed):
- self.MT = [0] * 624
- self.MT[0] = seed
- self.index = 624
- for i in range(1, 624): #loop over each element
- self.MT[i] = int(0xFFFFFFFF & (1812433253 * (self.MT[i - 1] ^ (self.MT[i - 1] >> (30))) + i))
-
- #Extract a tempered value based on MT[index]
- #calling twist() every n numbers
- def extract_number(self):
- if self.index >= 624:
- if self.index > 624:
- raise Exception("Generator was never seeded")
- #Alternatively, seed with constant value; 5489 is used in reference C code[49]
- self.twist()
-
- y = self.MT[self.index]
- y = y ^ ((y >> 11) & 0xFFFFFFFF)
- y = y ^ ((y << 7) & 0x9D2C5680)
- y = y ^ ((y << 15) & 0xEFC60000)
- y = y ^ (y >> 18)
-
- self.index += 1
- return int(0xFFFFFFFF & y)
-
- #Generate the next n values from the series x_i
- def twist(self):
- for i in range(624):
- x = int(0xFFFFFFFF & ((self.MT[i] & 0x80000000) + (self.MT[(i + 1) % 624] & 0x7fffffff)))
- xA = x >> 1
-
- if (x % 2) != 0: #lowest bit of x is 1
- xA = xA ^ 0x9908B0DF
-
- self.MT[i] = self.MT[(i + 397) % 624] ^ xA
- self.index = 0
+from mt19937 import MersenneTwister
secret_seed = int(time.time())
time.sleep(random.randint(40, 1000))
-secret_seed_output = mersenne_twister(secret_seed).extract_number()
+secret_seed_output = MersenneTwister(secret_seed).extract_number()
print secret_seed_output
current_time = int(time.time())
cracked_seed = 0
for i in range(1001):
- if mersenne_twister(current_time - i).extract_number() == secret_seed_output:
+ if MersenneTwister(current_time - i).extract_number() == secret_seed_output:
cracked_seed = current_time - i
break
-print mersenne_twister(cracked_seed).extract_number()
+print MersenneTwister(cracked_seed).extract_number()
print cracked_seed
print secret_seed == cracked_seed
diff --git a/set3/mt19937.py b/set3/mt19937.py
@@ -1,8 +1,8 @@
def _int32(x):
# Get the 32 least significant bits.
- return int(0xFFFFFFFF & x)
+ return int(0xffffffff & x)
-class MT19937:
+class MersenneTwister:
def __init__(self, seed):
# Initialize the index to 0
@@ -13,6 +13,9 @@ class MT19937:
self.mt[i] = _int32(
1812433253 * (self.mt[i - 1] ^ self.mt[i - 1] >> 30) + i)
+ def set_state(self, cloned_state):
+ self.mt = cloned_state
+
def extract_number(self):
if self.index >= 624:
self.twist()
@@ -43,7 +46,3 @@ class MT19937:
if y % 2 != 0:
self.mt[i] = self.mt[i] ^ 0x9908b0df
self.index = 0
- #test
-
-mt = MT19937(0)
-print mt.extract_number()
