From d2653aa9c6933014dc657b9b42ee3d1fc682e340 Mon Sep 17 00:00:00 2001
From: jsing <jsing@openbsd.org>
Date: Wed, 15 Dec 2021 17:30:20 +0000
Subject: [PATCH] Provide CBS_get_u64().

This will be used in the libcrypto certificate transparency code.

ok tb@
---
 lib/libssl/bs_cbs.c     | 19 ++++++++++++++++++-
 lib/libssl/bytestring.h |  8 +++++++-
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/lib/libssl/bs_cbs.c b/lib/libssl/bs_cbs.c
index 627c609bb9e..97b0163f3fb 100644
--- a/lib/libssl/bs_cbs.c
+++ b/lib/libssl/bs_cbs.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bs_cbs.c,v 1.22 2021/12/15 17:23:34 jsing Exp $	*/
+/*	$OpenBSD: bs_cbs.c,v 1.23 2021/12/15 17:30:20 jsing Exp $	*/
 /*
  * Copyright (c) 2014, Google Inc.
  *
@@ -190,6 +190,23 @@ CBS_get_u32(CBS *cbs, uint32_t *out)
 	return cbs_get_u(cbs, out, 4);
 }
 
+int
+CBS_get_u64(CBS *cbs, uint64_t *out)
+{
+	uint32_t a, b;
+
+	if (cbs->len < 8)
+		return 0;
+
+	if (!CBS_get_u32(cbs, &a))
+		return 0;
+	if (!CBS_get_u32(cbs, &b))
+		return 0;
+
+	*out = (uint64_t)a << 32 | b;
+	return 1;
+}
+
 int
 CBS_get_last_u8(CBS *cbs, uint8_t *out)
 {
diff --git a/lib/libssl/bytestring.h b/lib/libssl/bytestring.h
index 4ab2828d09f..fa5e05fa27b 100644
--- a/lib/libssl/bytestring.h
+++ b/lib/libssl/bytestring.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bytestring.h,v 1.20 2021/12/15 17:23:34 jsing Exp $	*/
+/*	$OpenBSD: bytestring.h,v 1.21 2021/12/15 17:30:20 jsing Exp $	*/
 /*
  * Copyright (c) 2014, Google Inc.
  *
@@ -133,6 +133,12 @@ int CBS_get_u24(CBS *cbs, uint32_t *out);
  */
 int CBS_get_u32(CBS *cbs, uint32_t *out);
 
+/*
+ * CBS_get_u64 sets |*out| to the next, big-endian uint64_t value from |cbs|
+ * and advances |cbs|. It returns one on success and zero on error.
+ */
+int CBS_get_u64(CBS *cbs, uint64_t *out);
+
 /*
  * CBS_get_last_u8 sets |*out| to the last uint8_t from |cbs| and shortens
  * |cbs|. It returns one on success and zero on error.
-- 
2.20.1