GSSAPI key exchange support

This patch has been rejected upstream: "None of the OpenSSH developers are
in favour of adding this, and this situation has not changed for several
years.  This is not a slight on Simon's patch, which is of fine quality, but
just that a) we don't trust GSSAPI implementations that much and b) we don't
like adding new KEX since they are pre-auth attack surface.  This one is
particularly scary, since it requires hooks out to typically root-owned
system resources."

However, quite a lot of people rely on this in Debian, and it's better to
have it merged into the main openssh package rather than having separate
-krb5 packages (as we used to have).  It seems to have a generally good
security history.

Author: Simon Wilkinson <simon@sxw.org.uk>
Author: Colin Watson <cjwatson@debian.org>
Author: Jakub Jelen <jjelen@redhat.com>
Origin: other, https://github.com/openssh-gsskex/openssh-gsskex/commits/debian/master
Bug: https://bugzilla.mindrot.org/show_bug.cgi?id=1242
Last-Updated: 2020-06-07

Patch-Name: gssapi.patch

1 files changed, 6 insertions, 0 deletions

diff --git a/readconf.h b/readconf.h
index e143a1082..c405b837f 100644
--- a/readconf.h
+++ b/readconf.h
@@ -41,7 +41,13 @@ typedef struct {
         int     challenge_response_authentication;
                                         /* Try S/Key or TIS, authentication. */
         int     gss_authentication;     /* Try GSS authentication */
+        int     gss_keyex;              /* Try GSS key exchange */
         int     gss_deleg_creds;        /* Delegate GSS credentials */
+        int     gss_trust_dns;          /* Trust DNS for GSS canonicalization */
+        int     gss_renewal_rekey;      /* Credential renewal forces rekey */
+        char    *gss_client_identity;   /* Principal to initiate GSSAPI with */
+        char    *gss_server_identity;   /* GSSAPI target principal */
+        char    *gss_kex_algorithms;    /* GSSAPI kex methods to be offered by client. */
         int     password_authentication;        /* Try password
                                                  * authentication. */
         int     kbd_interactive_authentication; /* Try keyboard-interactive auth. */