From 1086ae52fbf3a4c3446a49261c1259fab79185d2 Mon Sep 17 00:00:00 2001
From: Izorkin <izorkin@elven.pw>
Date: Wed, 22 May 2019 14:41:32 +0300
Subject: [PATCH] nixos/ssh: add crypto options

---
 nixos/modules/programs/ssh.nix | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/nixos/modules/programs/ssh.nix b/nixos/modules/programs/ssh.nix
index 44e65ee8a9a0..a983ffa4b890 100644
--- a/nixos/modules/programs/ssh.nix
+++ b/nixos/modules/programs/ssh.nix
@@ -194,6 +194,33 @@ in
         '';
       };
 
+      kexAlgorithms = mkOption {
+        type = types.nullOr (types.listOf types.str);
+        default = null;
+        example = [ "curve25519-sha256@libssh.org" "diffie-hellman-group-exchange-sha256" ];
+        description = ''
+          Specifies the available KEX (Key Exchange) algorithms.
+        '';
+      };
+
+      ciphers = mkOption {
+        type = types.nullOr (types.listOf types.str);
+        default = null;
+        example = [ "chacha20-poly1305@openssh.com" "aes256-gcm@openssh.com" ];
+        description = ''
+          Specifies the ciphers allowed and their order of preference.
+        '';
+      };
+
+      macs = mkOption {
+        type = types.nullOr (types.listOf types.str);
+        default = null;
+        example = [ "hmac-sha2-512-etm@openssh.com" "hmac-sha1" ];
+        description = ''
+          Specifies the MAC (message authentication code) algorithms in order of preference. The MAC algorithm is used
+          for data integrity protection.
+        '';
+      };
     };
 
   };
@@ -232,6 +259,9 @@ in
 
         ${optionalString (cfg.pubkeyAcceptedKeyTypes != []) "PubkeyAcceptedKeyTypes ${concatStringsSep "," cfg.pubkeyAcceptedKeyTypes}"}
         ${optionalString (cfg.hostKeyAlgorithms != []) "HostKeyAlgorithms ${concatStringsSep "," cfg.hostKeyAlgorithms}"}
+        ${optionalString (cfg.kexAlgorithms != null) "KexAlgorithms ${concatStringsSep "," cfg.kexAlgorithms}"}
+        ${optionalString (cfg.ciphers != null) "Ciphers ${concatStringsSep "," cfg.ciphers}"}
+        ${optionalString (cfg.macs != null) "MACs ${concatStringsSep "," cfg.macs}"}
       '';
 
     environment.etc."ssh/ssh_known_hosts".text = knownHostsText;