From 75d0c2055bd9a0ead97a9eaa83b7887c8a89f10e Mon Sep 17 00:00:00 2001
From: tb <>
Date: Mon, 6 Jan 2025 12:35:27 +0000
Subject: Shuffle functions into a more sensible order

BN_reciprocal() is only called by BN_div_recp() which in turn is only
called by BN_mod_mul_reciprocal(). So use this order and make the first
two static.
---
 src/lib/libcrypto/bn/bn_local.h |  6 +---
 src/lib/libcrypto/bn/bn_recp.c  | 75 +++++++++++++++++++++--------------------
 2 files changed, 39 insertions(+), 42 deletions(-)

diff --git a/src/lib/libcrypto/bn/bn_local.h b/src/lib/libcrypto/bn/bn_local.h
index 58b5d54903..bfdff56b0e 100644
--- a/src/lib/libcrypto/bn/bn_local.h
+++ b/src/lib/libcrypto/bn/bn_local.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: bn_local.h,v 1.43 2024/04/16 13:07:14 jsing Exp $ */
+/* $OpenBSD: bn_local.h,v 1.44 2025/01/06 12:35:27 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -280,8 +280,6 @@ int bn_rand_interval(BIGNUM *rnd, BN_ULONG lower_word, const BIGNUM *upper_exc);
 
 void	BN_init(BIGNUM *);
 
-int	BN_reciprocal(BIGNUM *r, const BIGNUM *m, int len, BN_CTX *ctx);
-
 void	BN_RECP_CTX_init(BN_RECP_CTX *recp);
 BN_RECP_CTX *BN_RECP_CTX_new(void);
 void	BN_RECP_CTX_free(BN_RECP_CTX *recp);
@@ -290,8 +288,6 @@ int	BN_mod_mul_reciprocal(BIGNUM *r, const BIGNUM *x, const BIGNUM *y,
     BN_RECP_CTX *recp, BN_CTX *ctx);
 int	BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
     const BIGNUM *m, BN_CTX *ctx);
-int	BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m,
-    BN_RECP_CTX *recp, BN_CTX *ctx);
 
 /* Explicitly const time / non-const time versions for internal use */
 int BN_mod_exp_ct(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
diff --git a/src/lib/libcrypto/bn/bn_recp.c b/src/lib/libcrypto/bn/bn_recp.c
index 35390e30d4..c567a5b017 100644
--- a/src/lib/libcrypto/bn/bn_recp.c
+++ b/src/lib/libcrypto/bn/bn_recp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: bn_recp.c,v 1.19 2023/03/27 10:25:02 tb Exp $ */
+/* $OpenBSD: bn_recp.c,v 1.20 2025/01/06 12:35:27 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -107,37 +107,35 @@ BN_RECP_CTX_set(BN_RECP_CTX *recp, const BIGNUM *d, BN_CTX *ctx)
 	return (1);
 }
 
-int
-BN_mod_mul_reciprocal(BIGNUM *r, const BIGNUM *x, const BIGNUM *y,
-    BN_RECP_CTX *recp, BN_CTX *ctx)
+/* len is the expected size of the result
+ * We actually calculate with an extra word of precision, so
+ * we can do faster division if the remainder is not required.
+ */
+/* r := 2^len / m */
+static int
+BN_reciprocal(BIGNUM *r, const BIGNUM *m, int len, BN_CTX *ctx)
 {
-	int ret = 0;
-	BIGNUM *a;
-	const BIGNUM *ca;
+	int ret = -1;
+	BIGNUM *t;
 
 	BN_CTX_start(ctx);
-	if ((a = BN_CTX_get(ctx)) == NULL)
+	if ((t = BN_CTX_get(ctx)) == NULL)
 		goto err;
-	if (y != NULL) {
-		if (x == y) {
-			if (!BN_sqr(a, x, ctx))
-				goto err;
-		} else {
-			if (!BN_mul(a, x, y, ctx))
-				goto err;
-		}
-		ca = a;
-	} else
-		ca = x; /* Just do the mod */
 
-	ret = BN_div_recp(NULL, r, ca, recp, ctx);
+	if (!BN_set_bit(t, len))
+		goto err;
+
+	if (!BN_div_ct(r, NULL, t,m, ctx))
+		goto err;
+
+	ret = len;
 
 err:
 	BN_CTX_end(ctx);
 	return (ret);
 }
 
-int
+static int
 BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, BN_RECP_CTX *recp,
     BN_CTX *ctx)
 {
@@ -231,28 +229,31 @@ err:
 	return (ret);
 }
 
-/* len is the expected size of the result
- * We actually calculate with an extra word of precision, so
- * we can do faster division if the remainder is not required.
- */
-/* r := 2^len / m */
+
 int
-BN_reciprocal(BIGNUM *r, const BIGNUM *m, int len, BN_CTX *ctx)
+BN_mod_mul_reciprocal(BIGNUM *r, const BIGNUM *x, const BIGNUM *y,
+    BN_RECP_CTX *recp, BN_CTX *ctx)
 {
-	int ret = -1;
-	BIGNUM *t;
+	int ret = 0;
+	BIGNUM *a;
+	const BIGNUM *ca;
 
 	BN_CTX_start(ctx);
-	if ((t = BN_CTX_get(ctx)) == NULL)
-		goto err;
-
-	if (!BN_set_bit(t, len))
-		goto err;
-
-	if (!BN_div_ct(r, NULL, t,m, ctx))
+	if ((a = BN_CTX_get(ctx)) == NULL)
 		goto err;
+	if (y != NULL) {
+		if (x == y) {
+			if (!BN_sqr(a, x, ctx))
+				goto err;
+		} else {
+			if (!BN_mul(a, x, y, ctx))
+				goto err;
+		}
+		ca = a;
+	} else
+		ca = x; /* Just do the mod */
 
-	ret = len;
+	ret = BN_div_recp(NULL, r, ca, recp, ctx);
 
 err:
 	BN_CTX_end(ctx);
-- 
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