upstream: Make zlib optional. This adds a "ZLIB" build time option

that allows building without zlib compression and associated options.  With
feedback from markus@, ok djm@

OpenBSD-Commit-ID: 44c6e1133a90fd15a3aa865bdedc53bab28b7910

1 files changed, 5 insertions, 2 deletions

diff --git a/kex.c b/kex.c
index 2195cea4e..ce85f0439 100644
--- a/kex.c
+++ b/kex.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kex.c,v 1.155 2019/10/08 22:40:39 dtucker Exp $ */
+/* $OpenBSD: kex.c,v 1.156 2020/01/23 10:24:29 dtucker Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  *
@@ -798,11 +798,14 @@ choose_comp(struct sshcomp *comp, char *client, char *server)
 
         if (name == NULL)
                 return SSH_ERR_NO_COMPRESS_ALG_MATCH;
+#ifdef WITH_ZLIB
         if (strcmp(name, "zlib@openssh.com") == 0) {
                 comp->type = COMP_DELAYED;
         } else if (strcmp(name, "zlib") == 0) {
                 comp->type = COMP_ZLIB;
-        } else if (strcmp(name, "none") == 0) {
+        } else
+#endif  /* WITH_ZLIB */
+        if (strcmp(name, "none") == 0) {
                 comp->type = COMP_NONE;
         } else {
                 error("%s: unsupported compression scheme %s", __func__, name);