Hashcat fails to run some valid masks

[die-github-die]

Describe the bug

Hashcat doesn't accept some masks it should (because of the buggy overflow_check_u64_mul function).

Some of the masks (but not all):

?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?l?l?l?l?l?d?d?u?l?l?l?l?l
?u?s?l?l?l?l?l?l?l?l?l?l?d?d
?u?l?l?l?l?l?l?l?u?l?l?l?d?d
?u?d?l?d?l?l?l?l?l?l?l?l?l?s
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?l?l?l?l?l?l?l?d?d?d?d?d?d?s
?u?l?l?l?l?l?l?l?s?d?d?d?d?d?d
?u?l?l?l?l?l?l?l?l?l?l?s?d?d
?u?l?l?l?l?l?u?l?l?l?l?s?d?d
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?l?l?l?l?l?l?l?d?d?d?d?d?d?s
?u?l?l?l?l?l?l?l?l?l?l?s?d?d
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?l?l?l?l?l?l?l?d?d?d?d?d?d?s
?l?l?l?l?l?l?l?l?l?l?l?l?d?d
?l?u?u?u?u?u?u?u?u?u?u?d?d?s
?u?l?l?l?l?l?l?l?d?d?d?d?s?d?d
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?l?l?l?l?l?l?l?l?l?l?d?d?s?u
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?l?l?l?l?l?l?l?l?l?l?l?l?d?d
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?d?d?l?l?l?l?l?l?l?l?l?l?u?s
?u?l?l?l?l?l?l?l?l?l?l?s?d?d
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?l?l?l?l?l?l?l?d?d?d?d?d?d?s
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?s?l?l?l?l?l?l?l?d?d?d?d?d?d
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?l?l?l?l?l?l?l?d?d?d?d?d?d?s
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?l?l?l?l?l?u?l?l?l?l?l?d?d
?l?l?l?l?l?l?l?l?l?l?l?l?d?d
?u?l?l?l?l?l?l?l?l?l?l?d?s?d
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?d?d?u?l?l?l?l?l?u?l?l?l?l?l
?l?l?l?l?l?l?d?d?l?l?l?l?l?l
?u?l?l?l?l?l?l?l?l?l?l?d?d?s
?u?u?u?u?u?u?l?l?l?l?l?d?d?s
?u?l?l?l?l?l?l?l?l?l?l?s?d?d
?u?l?l?l?l?l?l?l?l?l?l?l?d?d
?u?l?l?l?l?l?u?l?s?d?d?d?d?d?d
?u?l?l?l?l?l?u?l?l?l?l?l?d?d
?u?l?l?l?l?l?l?l?l?l?l?d?d?s

Hashcat says "integer overflow detected" while in fact there's no overflow.

This patch solves the issue:

diff --git a/src/shared.c b/src/shared.c
index 5b2375009..19cf02c1c 100644
--- a/src/shared.c
+++ b/src/shared.c
@@ -183,10 +183,8 @@ bool overflow_check_u64_add (const u64 a, const u64 b)
 
 bool overflow_check_u64_mul (const u64 a, const u64 b)
 {
-  const int a_msb = get_msb64 (a);
-  const int b_msb = get_msb64 (b);
-
-  return ((a_msb + b_msb) < 64);
+  u64 c = a * b;
+  return c / a == b;
 }
 
 bool is_power_of_2 (const u32 v)

Expected behavior

These masks should work because their keyspaces fit in 64 bits.

Hashcat version: 6.2.6

[faiyaz-libscr]

How to fix this ? I am running the latest hashcat 6.2.6 release file.
any help is appreciated !

[PenguinKeeper7]

How to fix this ? I am running the latest hashcat 6.2.6 release file. any help is appreciated !

This isn't related to the above topic. Your mask is far, far too large to ever be exhausted in a lifetime. It has 36^15 possible combinations, it would take 23,197 years to fully run on an RTX 4090. If you need additional help on this, try the Discord or the Forum instead