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Fixed Chrome code. Thanks Paweł Srokosz. Generated random numbers are used in reverse.

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This commit is contained in:
Douglas Goddard
2016-11-02 15:49:52 -04:00
parent a12e7e3c10
commit 05f0cd3a93
1 changed files with 42 additions and 11 deletions
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53
xs128p.py
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@@ -2,7 +2,7 @@ import sys
import math
import struct
import random
sys.path.append('/home/dgoddard/tools/z3/build/')
sys.path.append('/home/taxicat/prog/z3/build')
from z3 import *
# xor_shift_128_plus algorithm
@@ -41,6 +41,26 @@ def sym_xs128p(slvr, sym_state0, sym_state1, generated, browser):
slvr.add(impl)
return sym_state0, sym_state1, [condition]
def reverse23(val):
bot46 = (val ^ (val << 23)) & 0x3fffffffffff
original = (val ^ (bot46 << 23)) & 0xFFFFFFFFFFFFFFFF
return original
def reverse17(val):
top34 = (val ^ (val >> 17)) & 0xFFFFFFFFC0000000
top51 = (val ^ (top34 >> 17)) & 0xFFFFFFFFFFFFE000
original = (val ^ (top51 >> 17))
return original
def xs128p_backward(state0, state1):
prev_state1 = state0
prev_state0 = state1 ^ (state0 >> 26)
prev_state0 = prev_state0 ^ state0
prev_state0 = reverse17(prev_state0)
prev_state0 = reverse23(prev_state0)
generated = (prev_state0 + prev_state1) & 0xFFFFFFFFFFFFFFFF
return prev_state0, prev_state1, generated
# Print 'last seen' random number
# and winning numbers following that.
# This was for debugging. We know that Math.random()
@@ -73,7 +93,7 @@ def power_ball(generated, browser):
nums.append(val)
# print indicator
if idx == 4 and browser == 'chrome':
if idx == 0 and browser == 'chrome':
print '--->',
elif idx == 2 and browser == 'firefox':
print '--->',
@@ -93,6 +113,16 @@ def power_ball(generated, browser):
# ((rand_uint64 & ((1 << 52) - 1)) | 0x3FF0000000000000) - 1.0
# Safari weakRandom.get():
# (rand_uint64 & ((1 << 53) - 1) * (1.0 / (1 << 53)))
def to_double(browser, out):
if browser == 'chrome':
double_bits = (out & 0xFFFFFFFFFFFFF) | 0x3FF0000000000000
double = struct.unpack('d', struct.pack('<Q', double_bits))[0] - 1
elif browser == 'firefox':
double = float(out & 0x1FFFFFFFFFFFFF) / (0x1 << 53)
elif browser == 'safari':
double = float(out & 0x1FFFFFFFFFFFFF) * (1.0 / (0x1 << 53))
return double
def main():
# Note:
@@ -105,8 +135,11 @@ def main():
# In your browser's JavaScript console:
# _ = []; for(var i=0; i<5; ++i) { _.push(Math.random()) } ; console.log(_)
# Enter at least 3 random numbers you observed here:
dubs = [ 0.8817331322829662, 0.31765120036119443, 0.3301985901101909 ]
# Enter at least the 3 first random numbers you observed here:
dubs = [0.4752549301773037, 0.08162196013326506, 0.8333085432653353]
if browser == 'chrome':
dubs = dubs[::-1]
print dubs
# from the doubles, generate known piece of the original uint64
@@ -142,14 +175,12 @@ def main():
generated = []
# generate random numbers from recovered state
for idx in xrange(15):
state0, state1, out = xs128p(state0, state1)
if browser == 'chrome':
double_bits = (out & 0xFFFFFFFFFFFFF) | 0x3FF0000000000000
double = struct.unpack('d', struct.pack('<Q', double_bits))[0] - 1
elif browser == 'firefox':
double = float(out & 0x1FFFFFFFFFFFFF) / (0x1 << 53)
elif browser == 'safari':
double = float(out & 0x1FFFFFFFFFFFFF) * (1.0 / (0x1 << 53))
state0, state1, out = xs128p_backward(state0, state1)
else:
state0, state1, out = xs128p(state0, state1)
double = to_double(browser, out)
generated.append(double)
# use generated numbers to predict powerball numbers