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, 15 insertions, 4 deletions

diff --git a/ssh.c b/ssh.c
index c0511f2a0..851d85b50 100644
--- a/ssh.c
+++ b/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.512 2020/01/23 07:10:22 dtucker Exp $ */
+/* $OpenBSD: ssh.c,v 1.513 2020/01/23 10:24:29 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -602,6 +602,7 @@ main(int ac, char **av)
         struct addrinfo *addrs = NULL;
         struct ssh_digest_ctx *md;
         u_char conn_hash[SSH_DIGEST_MAX_LENGTH];
+        size_t n, len;
 
         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
         sanitise_stdfd();
@@ -753,10 +754,16 @@ main(int ac, char **av)
                                 cp = sshkey_alg_list(0, 1, 1, '\n');
                         else if (strcmp(optarg, "protocol-version") == 0)
                                 cp = xstrdup("2");
-                        else if (strcmp(optarg, "help") == 0) {
+                        else if (strcmp(optarg, "compression") == 0) {
+                                cp = xstrdup(compression_alg_list(0));
+                                len = strlen(cp);
+                                for (n = 0; n < len; n++)
+                                        if (cp[n] == ',')
+                                                cp[n] = '\n';
+                        } else if (strcmp(optarg, "help") == 0) {
                                 cp = xstrdup(
-                                    "cipher\ncipher-auth\nkex\nkey\n"
-                                    "key-cert\nkey-plain\nmac\n"
+                                    "cipher\ncipher-auth\ncompression\nkex\n"
+                                    "key\nkey-cert\nkey-plain\nmac\n"
                                     "protocol-version\nsig");
                         }
                         if (cp == NULL)
@@ -959,7 +966,11 @@ main(int ac, char **av)
                         break;
 
                 case 'C':
+#ifdef WITH_ZLIB
                         options.compression = 1;
+#else
+                        error("Compression not supported, disabling.");
+#endif
                         break;
                 case 'N':
                         no_shell_flag = 1;