Avoid signed overflow in MSVC AMR64 secp256k1_mul128

sipa · Nov 17, 2022 · 3afce0a · 3afce0a
1 parent 9b5f589
commit 3afce0a
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/int128_struct_impl.h b/src/int128_struct_impl.h
@@ -19,7 +19,7 @@ static SECP256K1_INLINE uint64_t secp256k1_umul128(uint64_t a, uint64_t b, uint6
 
 static SECP256K1_INLINE int64_t secp256k1_mul128(int64_t a, int64_t b, int64_t* hi) {
     *hi = __mulh(a, b);
-    return a * b;
+    return (uint64_t)a * (uint64_t)b;
 }
 #    else
 /* On x84_64 MSVC, use native _(u)mul128 for 64x64->128 multiplications. */