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.

Bug: https://bugzilla.mindrot.org/show_bug.cgi?id=1242
Last-Updated: 2014-10-07

Patch-Name: gssapi.patch

1 files changed, 14 insertions, 0 deletions

diff --git a/kex.h b/kex.h
index 4c40ec851..c179a4d06 100644
--- a/kex.h
+++ b/kex.h
@@ -76,6 +76,9 @@ enum kex_exchange {
         KEX_DH_GEX_SHA256,
         KEX_ECDH_SHA2,
         KEX_C25519_SHA256,
+        KEX_GSS_GRP1_SHA1,
+        KEX_GSS_GRP14_SHA1,
+        KEX_GSS_GEX_SHA1,
         KEX_MAX
 };
 
@@ -135,6 +138,12 @@ struct Kex {
         int     flags;
         int     hash_alg;
         int     ec_nid;
+#ifdef GSSAPI
+        int     gss_deleg_creds;
+        int     gss_trust_dns;
+        char    *gss_host;
+        char    *gss_client;
+#endif
         char    *client_version_string;
         char    *server_version_string;
         int     (*verify_host_key)(Key *);
@@ -167,6 +176,11 @@ void	 kexecdh_server(Kex *);
 void     kexc25519_client(Kex *);
 void     kexc25519_server(Kex *);
 
+#ifdef GSSAPI
+void    kexgss_client(Kex *);
+void    kexgss_server(Kex *);
+#endif
+
 void
 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
     BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);