Instead of starting a 'zero-sized' CBB at the size of the first addition

to the CBB, then doubling, start with an initial size of 64 bytes. Almost
all uses will exceed this size and we avoid multiple small recallocarray()
calls during the initial usage.

ok beck@

1 files changed, 8 insertions, 5 deletions

diff --git a/src/lib/libssl/bs_cbb.c b/src/lib/libssl/bs_cbb.c
index 154a7964e6..dd1dc73d09 100644
--- a/src/lib/libssl/bs_cbb.c
+++ b/src/lib/libssl/bs_cbb.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: bs_cbb.c,v 1.15 2017/04/14 15:20:55 jsing Exp $       */
+/*      $OpenBSD: bs_cbb.c,v 1.16 2017/05/07 05:03:41 jsing Exp $       */
 /*
  * Copyright (c) 2014, Google Inc.
  *
@@ -22,6 +22,8 @@
 
 #include "bytestring.h"
 
+#define CBB_INITIAL_SIZE 64
+
 static int
 cbb_init(CBB *cbb, uint8_t *buf, size_t cap)
 {
@@ -49,10 +51,11 @@ CBB_init(CBB *cbb, size_t initial_capacity)
 
         memset(cbb, 0, sizeof(*cbb));
 
-        if (initial_capacity > 0) {
-                if ((buf = malloc(initial_capacity)) == NULL)
-                        return 0;
-        }
+        if (initial_capacity == 0)
+                initial_capacity = CBB_INITIAL_SIZE;
+
+        if ((buf = malloc(initial_capacity)) == NULL)
+                return 0;
 
         if (!cbb_init(cbb, buf, initial_capacity)) {
                 free(buf);