Merge pull request #12 from Zcholm/master

use math package instead of fractions for gcd

Author: bdauvergne

pkcs1/keys.py

@@ -1,4 +1,4 @@
-import fractions
+import math
 from . import primitives
 from . import exceptions
 
@@ -146,7 +146,7 @@ def generate_key_pair(size=512, number=2, rnd=default_crypto_random, k=DEFAULT_I
         prime = get_prime(bits, rnd, k, algorithm=primality_algorithm)
         if prime in primes:
             continue
-        if e is not None and fractions.gcd(e, lbda) != 1:
+        if e is not None and math.gcd(e, lbda) != 1:
             continue
         if strict_size and number - len(primes) == 1 and primitives.integer_bit_size(n*prime) != size:
             continue
@@ -156,10 +156,10 @@ def generate_key_pair(size=512, number=2, rnd=default_crypto_random, k=DEFAULT_I
     if e is None:
         e = 0x10001
         while e < lbda:
-            if fractions.gcd(e, lbda) == 1:
+            if math.gcd(e, lbda) == 1:
                 break
             e += 2
     assert 3 <= e <= n-1
     public = RsaPublicKey(n, e)
     private = MultiPrimeRsaPrivateKey(primes, e, blind=True, rnd=rnd)
-    return public, private
+    return public, private

pkcs1/primes.py

@@ -1,4 +1,4 @@
-import fractions
+import math
 from . import primitives
 
 from .defaults import default_pseudo_random, default_crypto_random
@@ -138,7 +138,7 @@ def miller_rabin(n, k, rnd=default_pseudo_random):
     # Find nearest power of 2
     s = primitives.integer_bit_size(n)
     # Find greatest factor which is a power of 2
-    s = fractions.gcd(2**s, n-1)
+    s = math.gcd(2**s, n-1)
     d = (n-1) // s
     s = primitives.integer_bit_size(s) - 1
     while k:
@@ -161,4 +161,4 @@ def miller_rabin(n, k, rnd=default_pseudo_random):
     xrange
 except NameError:
     # Python 3
-    xrange = range
+    xrange = range