+ if (!WPACKET_reserve_bytes(pkt, len, allocbytes))
+ return 0;
+
+ pkt->written += len;
+ pkt->curr += len;
+ return 1;
+}
+
+int WPACKET_sub_allocate_bytes__(WPACKET *pkt, size_t len,
+ unsigned char **allocbytes, size_t lenbytes)
+{
+ if (!WPACKET_start_sub_packet_len__(pkt, lenbytes)
+ || !WPACKET_allocate_bytes(pkt, len, allocbytes)
+ || !WPACKET_close(pkt))
+ return 0;
+
+ return 1;
+}
+
+#define GETBUF(p) (((p)->staticbuf != NULL) \
+ ? (p)->staticbuf : (unsigned char *)(p)->buf->data)
+
+int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)
+{
+ /* Internal API, so should not fail */
+ if (!ossl_assert(pkt->subs != NULL && len != 0))