Add DebianBanner server configuration option

Setting this to "no" causes sshd to omit the Debian revision from its
initial protocol handshake, for those scared by package-versioning.patch.

Bug-Debian: http://bugs.debian.org/562048
Forwarded: not-needed
Last-Update: 2020-02-21

Patch-Name: debian-banner.patch

1 files changed, 3 insertions, 2 deletions

diff --git a/kex.c b/kex.c
index f638942d3..2abfbb95a 100644
--- a/kex.c
+++ b/kex.c
@@ -1226,7 +1226,7 @@ send_error(struct ssh *ssh, char *msg)
  */
 int
 kex_exchange_identification(struct ssh *ssh, int timeout_ms,
-    const char *version_addendum)
+    int debian_banner, const char *version_addendum)
 {
         int remote_major, remote_minor, mismatch;
         size_t len, i, n;
@@ -1244,7 +1244,8 @@ kex_exchange_identification(struct ssh *ssh, int timeout_ms,
         if (version_addendum != NULL && *version_addendum == '\0')
                 version_addendum = NULL;
         if ((r = sshbuf_putf(our_version, "SSH-%d.%d-%.100s%s%s\r\n",
-           PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2, SSH_RELEASE,
+           PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2,
+            debian_banner ? SSH_RELEASE : SSH_RELEASE_MINIMUM,
             version_addendum == NULL ? "" : " ",
             version_addendum == NULL ? "" : version_addendum)) != 0) {
                 error("%s: sshbuf_putf: %s", __func__, ssh_err(r));