allowing support for large numbers in estimating attack times

.gitignore

@@ -5,3 +5,4 @@ venv*
 dist
 build
 zxcvbn_python.egg-info
+.vscode

tests/time_estimates_test.py

@@ -0,0 +1,13 @@
+from zxcvbn.time_estimates import estimate_attack_times
+import sys
+
+def test_long_ints_dont_overflow():
+    try:
+        long_guesses = sys.maxsize + 1
+    except expression as identifier:
+        long_guesses = sys.maxint + 1
+
+    attack_times = estimate_attack_times(long_guesses)
+    assert 'crack_times_seconds' in attack_times
+    assert 'crack_times_display' in attack_times
+    assert 'score' in attack_times

zxcvbn/time_estimates.py

@@ -1,9 +1,11 @@
+from decimal import Decimal
+
 def estimate_attack_times(guesses):
     crack_times_seconds = {
-        'online_throttling_100_per_hour': float(guesses) / (100.0 / 3600.0),
-        'online_no_throttling_10_per_second': float(guesses) / 10.0,
-        'offline_slow_hashing_1e4_per_second': float(guesses) / float(1e4),
-        'offline_fast_hashing_1e10_per_second': float(guesses) / float(1e10),
+        'online_throttling_100_per_hour': Decimal(guesses) / Decimal(100.0 / 3600.0),
+        'online_no_throttling_10_per_second': Decimal(guesses) / Decimal(10.0),
+        'offline_slow_hashing_1e4_per_second': Decimal(guesses) / Decimal(1e4),
+        'offline_fast_hashing_1e10_per_second': Decimal(guesses) / Decimal(1e10),
     }
 
     crack_times_display = {}