Provide CBB_add_u32_length_prefixed().

This is needed for an upcoming change in libcrypto.

ok tb@

2 files changed, 15 insertions, 2 deletions

diff --git a/src/lib/libssl/bs_cbb.c b/src/lib/libssl/bs_cbb.c
index 059f9abd06..9d7ad7d46d 100644
--- a/src/lib/libssl/bs_cbb.c
+++ b/src/lib/libssl/bs_cbb.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: bs_cbb.c,v 1.29 2024/05/25 15:14:26 tb Exp $  */
+/*      $OpenBSD: bs_cbb.c,v 1.30 2024/06/22 15:25:06 jsing Exp $       */
 /*
  * Copyright (c) 2014, Google Inc.
  *
@@ -329,6 +329,12 @@ CBB_add_u24_length_prefixed(CBB *cbb, CBB *out_contents)
 }
 
 int
+CBB_add_u32_length_prefixed(CBB *cbb, CBB *out_contents)
+{
+        return cbb_add_length_prefixed(cbb, out_contents, 4);
+}
+
+int
 CBB_add_asn1(CBB *cbb, CBB *out_contents, unsigned int tag)
 {
         if (tag > UINT8_MAX)
diff --git a/src/lib/libssl/bytestring.h b/src/lib/libssl/bytestring.h
index 51284da8db..750343d4fa 100644
--- a/src/lib/libssl/bytestring.h
+++ b/src/lib/libssl/bytestring.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: bytestring.h,v 1.24 2022/11/09 23:14:51 jsing Exp $   */
+/*      $OpenBSD: bytestring.h,v 1.25 2024/06/22 15:25:06 jsing Exp $   */
 /*
  * Copyright (c) 2014, Google Inc.
  *
@@ -460,6 +460,13 @@ int CBB_add_u16_length_prefixed(CBB *cbb, CBB *out_contents);
 int CBB_add_u24_length_prefixed(CBB *cbb, CBB *out_contents);
 
 /*
+ * CBB_add_u32_length_prefixed sets |*out_contents| to a new child of |cbb|.
+ * The data written to |*out_contents| will be prefixed in |cbb| with a 32-bit,
+ * big-endian length. It returns one on success or zero on error.
+ */
+int CBB_add_u32_length_prefixed(CBB *cbb, CBB *out_contents);
+
+/*
  * CBB_add_asn sets |*out_contents| to a |CBB| into which the contents of an
  * ASN.1 object can be written. The |tag| argument will be used as the tag for
  * the object. Passing in |tag| number 31 will return in an error since only