sync ibuf_realloc() copy with libutil

This pulls in an overflow check and the change from recallocarray() to
realloc(). claudio tells me that we might soon get rid of this copy.

ok claudio

diff --git a/usr.sbin/rpki-client/io.c b/usr.sbin/rpki-client/io.c
index 3d8b79d..ecadce6 100644 (file)
--- a/usr.sbin/rpki-client/io.c
+++ b/usr.sbin/rpki-client/io.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: io.c,v 1.24 2023/12/12 15:54:18 claudio Exp $ */
+/*     $OpenBSD: io.c,v 1.25 2024/08/28 09:39:17 tb Exp $ */
 /*
  * Copyright (c) 2021 Claudio Jeker <claudio@openbsd.org>
  * Copyright (c) 2019 Kristaps Dzonsons <kristaps@bsd.lv>
@@ -151,14 +151,15 @@ ibuf_realloc(struct ibuf *buf, size_t len)
        unsigned char   *b;
 
        /* on static buffers max is eq size and so the following fails */
-       if (buf->wpos + len > buf->max) {
+       if (len > SIZE_MAX - buf->wpos || buf->wpos + len > buf->max) {
                errno = ERANGE;
                return (-1);
        }
 
-       b = recallocarray(buf->buf, buf->size, buf->wpos + len, 1);
+       b = realloc(buf->buf, buf->wpos + len);
        if (b == NULL)
                return (-1);
+       memset(b + buf->size, 0, buf->wpos + len - buf->size);
        buf->buf = b;
        buf->size = buf->wpos + len;