From ccbe55b7cd9e373cc5dbdb6a1ebded87c9bde054 Mon Sep 17 00:00:00 2001
From: tb <tb@openbsd.org>
Date: Thu, 1 Dec 2022 22:31:59 +0000
Subject: [PATCH] Check that the bn_isqrt -C output isn't changed

bn_isqrt -C generates code included in lib/libcrypto/lib/bn_isqrt.c. The
regress tests already ensure that the content of the tables don't change.
Ensure further that the code generation doesn't get out of sync.
---
 regress/lib/libcrypto/bn/Makefile            | 14 ++++++++-
 regress/lib/libcrypto/bn/bn_isqrt_tables.txt | 30 ++++++++++++++++++++
 2 files changed, 43 insertions(+), 1 deletion(-)
 create mode 100644 regress/lib/libcrypto/bn/bn_isqrt_tables.txt

diff --git a/regress/lib/libcrypto/bn/Makefile b/regress/lib/libcrypto/bn/Makefile
index b5d146c71b4..7dc5ef75c8e 100644
--- a/regress/lib/libcrypto/bn/Makefile
+++ b/regress/lib/libcrypto/bn/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.9 2022/12/01 21:21:51 tb Exp $
+#	$OpenBSD: Makefile,v 1.10 2022/12/01 22:31:59 tb Exp $
 
 PROGS +=	bn_add_sub
 PROGS +=	bn_cmp
@@ -32,9 +32,21 @@ run-$p: $p
 	./$p
 .endfor
 
+# Verify that the bn_isqrt -C output isn't changed by accident.
 isqrt-print-tables: bn_isqrt
 	@./bn_isqrt -C
 
+CLEANFILES += bn_isqrt_gen_tables.txt.tmp bn_isqrt_gen_tables.txt
+bn_isqrt_gen_tables.txt: bn_isqrt
+	${.MAKE} -C ${.CURDIR} isqrt-print-tables > $@.tmp
+	mv -f $@.tmp $@
+
+REGRESS_TARGETS +=	run-bn_isqrt_check_tables
+.PHONY:			run-bn_isqrt_check_tables
+run-bn_isqrt_check_tables: bn_isqrt_gen_tables.txt
+	diff -pu ${.CURDIR}/bn_isqrt_tables.txt bn_isqrt_gen_tables.txt
+
+
 # Keep bn_test last since it is special
 PROGS +=	bn_test
 STATIC_LINK +=	bn_test
diff --git a/regress/lib/libcrypto/bn/bn_isqrt_tables.txt b/regress/lib/libcrypto/bn/bn_isqrt_tables.txt
new file mode 100644
index 00000000000..bc045a220e0
--- /dev/null
+++ b/regress/lib/libcrypto/bn/bn_isqrt_tables.txt
@@ -0,0 +1,30 @@
+const uint8_t is_square_mod_11[] = {
+	1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0,
+};
+CTASSERT(sizeof(is_square_mod_11) == 11);
+
+const uint8_t is_square_mod_63[] = {
+	1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0,
+	1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0,
+	0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0,
+	0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
+};
+CTASSERT(sizeof(is_square_mod_63) == 63);
+
+const uint8_t is_square_mod_64[] = {
+	1, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
+	1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
+	0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
+	0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
+};
+CTASSERT(sizeof(is_square_mod_64) == 64);
+
+const uint8_t is_square_mod_65[] = {
+	1, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0,
+	1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0,
+	0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0,
+	0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0,
+	1,
+};
+CTASSERT(sizeof(is_square_mod_65) == 65);
+
-- 
2.20.1