nixos/sshd: update kexAlgorithms, fix links

The `curve25519-sha256` key exchange method is defined in RFC 8731 that
is identical to curve25519-sha256@libssh.org. OpenSSH supports the
method since version 7.4, released on 2016-12-19. It is literally a
violation of the "both in Secure Secure Shell and Mozilla guidelines"
rule, but it provides essentially the same but a future-proof default.

Also, links to the Mozilla OpenSSH guidelines are updated to refer to
the current place.

Signed-off-by: Masanori Ogino <167209+omasanori@users.noreply.github.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/nixos/modules/services/networking/ssh/sshd.nix b/nixos/modules/services/networking/ssh/sshd.nix
index 5365b8b9b10..1b745931c4f 100644
--- a/nixos/modules/services/networking/ssh/sshd.nix
+++ b/nixos/modules/services/networking/ssh/sshd.nix
@@ -269,6 +269,7 @@ in
       kexAlgorithms = mkOption {
         type = types.listOf types.str;
         default = [
+          "curve25519-sha256"
           "curve25519-sha256@libssh.org"
           "diffie-hellman-group-exchange-sha256"
         ];
@@ -279,7 +280,7 @@ in
           Defaults to recommended settings from both
           <link xlink:href="https://stribika.github.io/2015/01/04/secure-secure-shell.html" />
           and
-          <link xlink:href="https://wiki.mozilla.org/Security/Guidelines/OpenSSH#Modern_.28OpenSSH_6.7.2B.29" />
+          <link xlink:href="https://infosec.mozilla.org/guidelines/openssh#modern-openssh-67" />
         '';
       };
 
@@ -300,7 +301,7 @@ in
           Defaults to recommended settings from both
           <link xlink:href="https://stribika.github.io/2015/01/04/secure-secure-shell.html" />
           and
-          <link xlink:href="https://wiki.mozilla.org/Security/Guidelines/OpenSSH#Modern_.28OpenSSH_6.7.2B.29" />
+          <link xlink:href="https://infosec.mozilla.org/guidelines/openssh#modern-openssh-67" />
         '';
       };
 
@@ -321,7 +322,7 @@ in
           Defaults to recommended settings from both
           <link xlink:href="https://stribika.github.io/2015/01/04/secure-secure-shell.html" />
           and
-          <link xlink:href="https://wiki.mozilla.org/Security/Guidelines/OpenSSH#Modern_.28OpenSSH_6.7.2B.29" />
+          <link xlink:href="https://infosec.mozilla.org/guidelines/openssh#modern-openssh-67" />
         '';
       };