From 1ce223ac672aba9e1d955ebac21162d281b013b2 Mon Sep 17 00:00:00 2001
From: jsing <>
Date: Fri, 25 Apr 2025 08:19:22 +0000
Subject: Use the OPENSSL_SMALL_FOOTPRINT code in gcm_init_4bit().

A modern compiler will unroll these loops - LLVM produces identical code
(at least on arm64). Drop the manually unrolled version and have code that
is more readable and maintainable.

ok tb@
---
 src/lib/libcrypto/modes/gcm128.c | 34 ++--------------------------------
 1 file changed, 2 insertions(+), 32 deletions(-)

(limited to 'src')

diff --git a/src/lib/libcrypto/modes/gcm128.c b/src/lib/libcrypto/modes/gcm128.c
index fb03f72754..db1f2b9a1c 100644
--- a/src/lib/libcrypto/modes/gcm128.c
+++ b/src/lib/libcrypto/modes/gcm128.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: gcm128.c,v 1.32 2025/04/23 14:15:19 jsing Exp $ */
+/* $OpenBSD: gcm128.c,v 1.33 2025/04/25 08:19:22 jsing Exp $ */
 /* ====================================================================
  * Copyright (c) 2010 The OpenSSL Project.  All rights reserved.
  *
@@ -232,16 +232,13 @@ static void
 gcm_init_4bit(u128 Htable[16], u64 H[2])
 {
 	u128 V;
-#if defined(OPENSSL_SMALL_FOOTPRINT)
 	int  i;
-#endif
 
 	Htable[0].hi = 0;
 	Htable[0].lo = 0;
 	V.hi = H[0];
 	V.lo = H[1];
 
-#if defined(OPENSSL_SMALL_FOOTPRINT)
 	for (Htable[8] = V, i = 4; i > 0; i >>= 1) {
 		REDUCE1BIT(V);
 		Htable[i] = V;
@@ -255,34 +252,7 @@ gcm_init_4bit(u128 Htable[16], u64 H[2])
 			Hi[j].lo = V.lo ^ Htable[j].lo;
 		}
 	}
-#else
-	Htable[8] = V;
-	REDUCE1BIT(V);
-	Htable[4] = V;
-	REDUCE1BIT(V);
-	Htable[2] = V;
-	REDUCE1BIT(V);
-	Htable[1] = V;
-	Htable[3].hi = V.hi ^ Htable[2].hi, Htable[3].lo = V.lo ^ Htable[2].lo;
-	V = Htable[4];
-	Htable[5].hi = V.hi ^ Htable[1].hi, Htable[5].lo = V.lo ^ Htable[1].lo;
-	Htable[6].hi = V.hi ^ Htable[2].hi, Htable[6].lo = V.lo ^ Htable[2].lo;
-	Htable[7].hi = V.hi ^ Htable[3].hi, Htable[7].lo = V.lo ^ Htable[3].lo;
-	V = Htable[8];
-	Htable[9].hi = V.hi ^ Htable[1].hi, Htable[9].lo = V.lo ^ Htable[1].lo;
-	Htable[10].hi = V.hi ^ Htable[2].hi,
-	    Htable[10].lo = V.lo ^ Htable[2].lo;
-	Htable[11].hi = V.hi ^ Htable[3].hi,
-	    Htable[11].lo = V.lo ^ Htable[3].lo;
-	Htable[12].hi = V.hi ^ Htable[4].hi,
-	    Htable[12].lo = V.lo ^ Htable[4].lo;
-	Htable[13].hi = V.hi ^ Htable[5].hi,
-	    Htable[13].lo = V.lo ^ Htable[5].lo;
-	Htable[14].hi = V.hi ^ Htable[6].hi,
-	    Htable[14].lo = V.lo ^ Htable[6].lo;
-	Htable[15].hi = V.hi ^ Htable[7].hi,
-	    Htable[15].lo = V.lo ^ Htable[7].lo;
-#endif
+
 #if defined(GHASH_ASM) && (defined(__arm__) || defined(__arm))
 	/*
 	 * ARM assembler expects specific dword order in Htable.
-- 
cgit v1.2.3-55-g6feb