Bug#1131206: openssh: Do not default to weak GSS-API exchange algorithms
Athos Ribeiro <[email protected]> Wed, 18 Mar 2026 16:11:05 -0300
| Newsgroups | gmane.linux.debian.devel.ssh |
|---|---|
| Message-ID | <abr4yYikBJ6ay9EH__28117.8904276871$1773861216$gmane$org@pollux> |
Package: openssh Severity: normal Tags: patch Dear Maintainer, As per RFC 8732, gss-group14-sha1- and gss-gex-sha1- are considered deprecated and should not be used [1]. Should we consider removing them from the default algorithms list? I am proposing the attached patch to drop those algorithms in Ubuntu. [1] https://www.rfc-editor.org/rfc/rfc8732#name-deprecated-algorithms -- Athos Ribeiro
gss-api-defaults.patch
(text/x-diff, 1.1 KB)
--- a/ssh-gss.h
+++ b/ssh-gss.h
@@ -80,9 +80,7 @@
KEX_GSS_GRP14_SHA256_ID "," \
KEX_GSS_GRP16_SHA512_ID "," \
KEX_GSS_NISTP256_SHA256_ID "," \
- KEX_GSS_C25519_SHA256_ID "," \
- KEX_GSS_GRP14_SHA1_ID "," \
- KEX_GSS_GEX_SHA1_ID
+ KEX_GSS_C25519_SHA256_ID
typedef struct {
char *filename;
--- a/ssh_config.5
+++ b/ssh_config.5
@@ -1065,7 +1065,7 @@
.Ed
.Pp
The default is
-.Dq gss-group14-sha256-,gss-group16-sha512-,gss-nistp256-sha256-,gss-curve25519-sha256-,gss-gex-sha1-,gss-group14-sha1- .
+.Dq gss-group14-sha256-,gss-group16-sha512-,gss-nistp256-sha256-,gss-curve25519-sha256- .
This option only applies to connections using GSSAPI.
.It Cm HashKnownHosts
Indicates that
--- a/sshd_config.5
+++ b/sshd_config.5
@@ -815,7 +815,7 @@
.Ed
.Pp
The default is
-.Dq gss-group14-sha256-,gss-group16-sha512-,gss-nistp256-sha256-,gss-curve25519-sha256-,gss-gex-sha1-,gss-group14-sha1- .
+.Dq gss-group14-sha256-,gss-group16-sha512-,gss-nistp256-sha256-,gss-curve25519-sha256- .
This option only applies to connections using GSSAPI.
.It Cm HostbasedAcceptedAlgorithms
Specifies the signature algorithms that will be accepted for hostbased