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authorSimon Wilkinson <simon@sxw.org.uk>2014-02-09 16:09:48 +0000
committerColin Watson <cjwatson@debian.org>2020-02-21 12:01:36 +0000
commit34aff3aa136e5a65f441b25811dd466488fda087 (patch)
treee2170faeed03d67545255d3d3c9d62280414c0b2 /ssh_config.5
parentf0de78bd4f29fa688c5df116f3f9cd43543a76d0 (diff)
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. Origin: other, https://github.com/openssh-gsskex/openssh-gsskex/commits/debian/master Bug: https://bugzilla.mindrot.org/show_bug.cgi?id=1242 Last-Updated: 2020-02-21 Patch-Name: gssapi.patch
Diffstat (limited to 'ssh_config.5')
-rw-r--r--ssh_config.557
1 files changed, 57 insertions, 0 deletions
diff --git a/ssh_config.5 b/ssh_config.5
index 06a32d314..3f4906972 100644
--- a/ssh_config.5
+++ b/ssh_config.5
@@ -766,10 +766,67 @@ The default is
766Specifies whether user authentication based on GSSAPI is allowed. 766Specifies whether user authentication based on GSSAPI is allowed.
767The default is 767The default is
768.Cm no . 768.Cm no .
769.It Cm GSSAPIClientIdentity
770If set, specifies the GSSAPI client identity that ssh should use when
771connecting to the server. The default is unset, which means that the default
772identity will be used.
769.It Cm GSSAPIDelegateCredentials 773.It Cm GSSAPIDelegateCredentials
770Forward (delegate) credentials to the server. 774Forward (delegate) credentials to the server.
771The default is 775The default is
772.Cm no . 776.Cm no .
777.It Cm GSSAPIKeyExchange
778Specifies whether key exchange based on GSSAPI may be used. When using
779GSSAPI key exchange the server need not have a host key.
780The default is
781.Dq no .
782.It Cm GSSAPIRenewalForcesRekey
783If set to
784.Dq yes
785then renewal of the client's GSSAPI credentials will force the rekeying of the
786ssh connection. With a compatible server, this will delegate the renewed
787credentials to a session on the server.
788.Pp
789Checks are made to ensure that credentials are only propagated when the new
790credentials match the old ones on the originating client and where the
791receiving server still has the old set in its cache.
792.Pp
793The default is
794.Dq no .
795.Pp
796For this to work
797.Cm GSSAPIKeyExchange
798needs to be enabled in the server and also used by the client.
799.It Cm GSSAPIServerIdentity
800If set, specifies the GSSAPI server identity that ssh should expect when
801connecting to the server. The default is unset, which means that the
802expected GSSAPI server identity will be determined from the target
803hostname.
804.It Cm GSSAPITrustDns
805Set to
806.Dq yes
807to indicate that the DNS is trusted to securely canonicalize
808the name of the host being connected to. If
809.Dq no ,
810the hostname entered on the
811command line will be passed untouched to the GSSAPI library.
812The default is
813.Dq no .
814.It Cm GSSAPIKexAlgorithms
815The list of key exchange algorithms that are offered for GSSAPI
816key exchange. Possible values are
817.Bd -literal -offset 3n
818gss-gex-sha1-,
819gss-group1-sha1-,
820gss-group14-sha1-,
821gss-group14-sha256-,
822gss-group16-sha512-,
823gss-nistp256-sha256-,
824gss-curve25519-sha256-
825.Ed
826.Pp
827The default is
828.Dq gss-gex-sha1-,gss-group14-sha1- .
829This option only applies to protocol version 2 connections using GSSAPI.
773.It Cm HashKnownHosts 830.It Cm HashKnownHosts
774Indicates that 831Indicates that
775.Xr ssh 1 832.Xr ssh 1