Merge pull request #3611 from SomberNight/mnemonic_enforce_num_words

avoid shorter seeds 'by luck'
spesmilo · Jan 6, 2018 · 1fe18ab · 1fe18ab
2 parents c4e4d8a + 295dc12
commit 1fe18ab
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/lib/mnemonic.py b/lib/mnemonic.py
@@ -171,7 +171,10 @@ def make_seed(self, seed_type='standard', num_bits=132, custom_entropy=1):
         n_custom = int(math.ceil(math.log(custom_entropy, 2)))
         n = max(16, num_bits - n_custom)
         print_error("make_seed", prefix, "adding %d bits"%n)
-        my_entropy = ecdsa.util.randrange(pow(2, n))
+        my_entropy = 1
+        while my_entropy < pow(2, n - bpw):
+            # try again if seed would not contain enough words
+            my_entropy = ecdsa.util.randrange(pow(2, n))
         nonce = 0
         while True:
             nonce += 1