From d70336f37c3cc6f19d85a5fb4852de25c2ee82b9 Mon Sep 17 00:00:00 2001
From: Aristid Breitkreuz <aristidb@gmail.com>
Date: Thu, 13 Nov 2014 21:46:02 +0100
Subject: [PATCH 1/3] limit the amount of time ssh-agent keeps a key (default:
 1h)

---
 nixos/modules/programs/ssh.nix | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/nixos/modules/programs/ssh.nix b/nixos/modules/programs/ssh.nix
index ee9cb81a027f..c1c1582ed787 100644
--- a/nixos/modules/programs/ssh.nix
+++ b/nixos/modules/programs/ssh.nix
@@ -59,6 +59,14 @@ in
         '';
       };
 
+      agentTimeout = mkOption {
+        type = types.string;
+        default = "1h";
+        description = ''
+          How long to keep the private keys in memory.
+        '';
+      };
+
       package = mkOption {
         default = pkgs.openssh;
         description = ''
@@ -99,7 +107,7 @@ in
         wantedBy = [ "default.target" ];
         serviceConfig =
           { ExecStartPre = "${pkgs.coreutils}/bin/rm -f %t/ssh-agent";
-            ExecStart = "${cfg.package}/bin/ssh-agent -a %t/ssh-agent";
+            ExecStart = "${cfg.package}/bin/ssh-agent -t ${cfg.agentTimeout} -a %t/ssh-agent";
             StandardOutput = "null";
             Type = "forking";
             Restart = "on-failure";

From d57110fabc92116e8a47fc708580fe1a1d10d98e Mon Sep 17 00:00:00 2001
From: Aristid Breitkreuz <aristidb@gmail.com>
Date: Sat, 15 Nov 2014 12:13:19 +0100
Subject: [PATCH 2/3] ssh-agent: make key timeout optional

---
 nixos/modules/programs/ssh.nix | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/nixos/modules/programs/ssh.nix b/nixos/modules/programs/ssh.nix
index c1c1582ed787..6b7295722485 100644
--- a/nixos/modules/programs/ssh.nix
+++ b/nixos/modules/programs/ssh.nix
@@ -63,7 +63,7 @@ in
         type = types.string;
         default = "1h";
         description = ''
-          How long to keep the private keys in memory.
+          How long to keep the private keys in memory. Use null to keep them forever.
         '';
       };
 
@@ -107,7 +107,10 @@ in
         wantedBy = [ "default.target" ];
         serviceConfig =
           { ExecStartPre = "${pkgs.coreutils}/bin/rm -f %t/ssh-agent";
-            ExecStart = "${cfg.package}/bin/ssh-agent -t ${cfg.agentTimeout} -a %t/ssh-agent";
+            ExecStart =
+                "${cfg.package}/bin/ssh-agent " +
+                optionalString (cfg.agentTimeout != null) ("-t ${cfg.agentTimeout} ") +
+                "-a %t/ssh-agent";
             StandardOutput = "null";
             Type = "forking";
             Restart = "on-failure";

From 2fd7e5f39d8fd18646bba2fa7fbf69baf21a86ff Mon Sep 17 00:00:00 2001
From: Aristid Breitkreuz <aristidb@gmail.com>
Date: Sat, 15 Nov 2014 12:33:01 +0100
Subject: [PATCH 3/3] ssh-agent: use types.nullOr

---
 nixos/modules/programs/ssh.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nixos/modules/programs/ssh.nix b/nixos/modules/programs/ssh.nix
index 6b7295722485..c9bfe2fe0f70 100644
--- a/nixos/modules/programs/ssh.nix
+++ b/nixos/modules/programs/ssh.nix
@@ -60,7 +60,7 @@ in
       };
 
       agentTimeout = mkOption {
-        type = types.string;
+        type = types.nullOr types.string;
         default = "1h";
         description = ''
           How long to keep the private keys in memory. Use null to keep them forever.