cryptopals

commit 91cd6a94aa2449837cab04623b06cf216f1d08f4
parent 76ef9a2ed10fb1c13d1e980166cee16e5a2cc7a4
Author: mpizzzle <michael770211@gmail.com>
Date:   Sun, 23 Dec 2018 00:34:54 +0000

initial idea for xor untempering

Diffstat:
A
set3/clone_mt_rng_state.py
 | 
93
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 93 insertions(+), 0 deletions(-)
diff --git a/set3/clone_mt_rng_state.py b/set3/clone_mt_rng_state.py
@@ -0,0 +1,93 @@
+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 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 test_temper(yy):
+        y = _int32(yy)
+        y = y ^ y >> 11
+        #y = y ^ y << 7 & 2636928640
+        #y = y ^ y << 15 & 4022730752
+        y = y ^ y >> 18
+        return _int32(y)
+
+def untemper_11(yy):
+        y = _int32(yy)
+        print format(y, '#034b')
+        temp1 = y >> (32 - 11)
+        print format(temp1, '#034b')
+        temp2 = (y & 0x1fffff) >> (32 - 11 - 11)
+        print format(temp2, '#034b')
+        temp3 = temp1 ^ temp2# >> 1
+        print format(temp3, '#034b')
+        temp4 = int(str(format(temp1, '#011b')) + str(format(temp3, '011b')), 2) >> 1
+        print format(temp4, '#034b')
+        temp5 = temp4 ^ y
+        print format(temp5, '#034b')
+        return _int32(temp5)
+
+def untemper_18(yy):
+        y = _int32(yy)
+        print format(y, '#034b')
+        temp1 = y >> (32 - 11)
+        print format(temp1, '#034b')
+        temp2 = (y & 0x1fffff) >> (32 - 11 - 11)
+        print format(temp2, '#034b')
+        temp3 = temp1 ^ temp2# >> 1
+        print format(temp3, '#034b')
+        temp4 = int(str(format(temp1, '#011b')) + str(format(temp3, '011b')), 2) >> 1
+        print format(temp4, '#034b')
+        temp5 = temp4 ^ y
+        print format(temp5, '#034b')
+        return _int32(temp5)
+
+def test_untemper(yy):
+        y = _int32(yy)
+        y = untemper_18(y)
+        #y = y ^ y << 15 & 4022730752
+        #y = y ^ y << 7 & 2636928640
+        y = untemper_11(y)
+        return _int32(y)
+
+print _int32(48762549)
+print _int32(48762549) == test_untemper(test_temper(48762549))