Merge pull request #3611 from SomberNight/mnemonic_enforce_num_words

avoid shorter seeds 'by luck'
2018-01-06 12:51:30 +01:00 · 2018-01-06 12:51:30 +01:00 · 1fe18ab1ce
parent c4e4d8a1dd 295dc12612
commit 1fe18ab1ce
1 changed files with 4 additions and 1 deletions
--- a/lib/mnemonic.py
+++ b/lib/mnemonic.py
@ -171,7 +171,10 @@ class Mnemonic(object):
        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