From 8e2a5fe908faa2ad0b847b3e5c42662614c8fa88 Mon Sep 17 00:00:00 2001
From: roconnor-blockstream <roconnor@blockstream.com>
Date: Mon, 6 Nov 2023 17:40:17 -0500
Subject: [PATCH] correct assertion for secp256k1_fe_mul_inner

Based on the surrounding asserts, 112 bits before this line, and 61 bits after this line, this assertion should be 113 bits.  Notably the commensurate line in secp256k1_fe_sqr_inner is correctly assert to be 113 bits.
---
 src/field_5x52_int128_impl.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/field_5x52_int128_impl.h b/src/field_5x52_int128_impl.h
index b2a391de..f7de0fd1 100644
--- a/src/field_5x52_int128_impl.h
+++ b/src/field_5x52_int128_impl.h
@@ -100,7 +100,7 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(uint64_t *r, const uint64_t
     VERIFY_BITS(u0, 56);
     /* [d 0 t4+(u0<<48) t3 0 0 c] = [p8 0 0 p5 p4 p3 0 0 p0] */
     secp256k1_u128_accum_mul(&c, u0, R >> 4);
-    VERIFY_BITS_128(&c, 115);
+    VERIFY_BITS_128(&c, 113);
     /* [d 0 t4 t3 0 0 c] = [p8 0 0 p5 p4 p3 0 0 p0] */
     r[0] = secp256k1_u128_to_u64(&c) & M; secp256k1_u128_rshift(&c, 52);
     VERIFY_BITS(r[0], 52);