diff --git a/nixos/modules/tests/node.pem b/nixos/modules/tests/node.pem
new file mode 100644
index 0000000000000000000000000000000000000000..592e15d3741b3d2eab4e846332319074015b3e31
--- /dev/null
+++ b/nixos/modules/tests/node.pem
@@ -0,0 +1,45 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
+-----BEGIN PRIVATE KEY-----
+MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQDXMrjAfRm+MUKc
+Wj4+9P8A0EnYfullANEcUeaFbbxV5DicKqWJ+PEn8w5amopgrqvEc4oM1MNHkxuQ
+U7uXTKq4HT8UCs/1ESt7MpqRfPypIuGKkNmTvL7R8pYw/FyB1LObbxnzXtjOnWdp
+c8dBFyejczd6jnwXKhMMA5c/eGJL5sWbxEZUg0tIEm0gsqimW+BJ3IP/VeDjNuHY
+Ur6BLR/3aN6XknIBp5u3cRA+IjHBSu+LlrXDkRAqLXewnbZErkfqxyFeDvoYwwEJ
+yQuz6DzHNrm4ctui0ydZvt11b6kLRJCyuKFTHP3TaVChS7GrZomKDqhOLrCx61Rz
+G04St/LrAgMBAAECggEAfRKjwmxzK9Fhj5H7n4exNf3ZDZUlfWiuILGRM3eGAL22
+ET3QHJKtRrTDYPF0/6BFgNZOJAr8vHrJiGbCHruWdY+5+6IVH7As/1t37psgFgWJ
+5Ikvi+glV8yQckQaV/MRuIMoKAS2Kc/eLLH32uLkTOFIG1j40lXH4DGuFFuZddbH
+Ie2TsgUmI3LXTSGSq4qSgXyB46uGuGOn4WKIAKp7O4kN2jBB5y3q9C2YltQ+Dv+k
+T64wBNK3ZnHHNKli0A86kzPLVQJfHgjzC76QRlC+guKgRoV9Kut3LLfoi6ep5yJr
+RT6Pr/hTNKCluIZUTPhmB0u3xGr9gj6vDsMCanvrsQKBgQD5y7ZJqFvgh9MlhSLN
+20p7jlyu+cYSDWktUjA4109ior8oaCVUXziSuPsr9JfwYRaYsJTUpCYKECFYLibA
+qI+Jj/auJljuCmrfWuS9Z08sAmVoU+O4FZt2UVbui5l5spU41Ze09f81DpzkHhZ0
+SEVH2SgChdy7KdPPhxcVhJHqJQKBgQDciwameP0WaazTY77ZRE4Yt+dPyPFkpSer
+bibeMmss5d+QVo4B4YEL20CrmaJq+FB9u99nL1d6VsvtWuovvHKMmoM//D8Si7PW
+ieAm9mN0L+2Xf25UVFBewQkzNuJJG+z1OtHFfIDDGnNzL2yx//3YFJnR/ehftsK7
+lIlXUElzzwKBgGUW1cx1P8lb7k0u1ejtJ/VcpZGCL3A60SewLSezqsLGDgoyK3k7
+l8944Nzm/V4gTF66h2COlX5ZDMV819372SrYggH0LuUWfi2pwQwNdPLgfV19JZjn
+1aRKQp4DDLc9WDpJ5j0rmH5GTaPbsUaZwL/U1+Y9ehicUsWXa/YfUlWpAoGBAJCZ
+7yBTj82UOCbZ7ZZS/MmkOtvLKssMpnf2XzGs6SylA/KFbdK54ny9oydgMmfkrBHk
+jtP+7GJgapET3RyzeH/MB2Z6o3grdRyjhf7F6euSSTvd558PMSsPclLMF45L6w/X
+IxdTTLGftDa/z4reB7gXucs/qY6oLAIFoA9Jqv9tAoGAIpw4GDw5IQFZhcHuHCOZ
+Xrq9L1fR5rYBQa6xcPHkMbWzigcNJz7FnLg0tB1SvF23egpmj5VAcnWyjyj883pn
+h2wuwJUFy8LALtjJwqhjUtQfv5LLiT5061/CUrhD3GEBNlYbOO4FA1Z0SIhFYn40
+VzowmHAqdxYvlfJsWe91UI0=
+-----END PRIVATE KEY-----
diff --git a/nixos/modules/tests/private-storage.nix b/nixos/modules/tests/private-storage.nix
index b863c1a4a22e7356a24c2914f14b58a80efbce8e..ea71c854f6da61b0b0fc0ed3f355e13de7e363bd 100644
--- a/nixos/modules/tests/private-storage.nix
+++ b/nixos/modules/tests/private-storage.nix
@@ -3,56 +3,7 @@ let
   # Here are the preconstructed secrets which we can assign to the introducer.
   # This is a lot easier than having the introducer generate them and then
   # discovering and configuring the other nodes with them.
-  pemFile = pkgs.writeTextFile {
-    name = "node.pem";
-    text = ''
------BEGIN CERTIFICATE-----
-MIICojCCAYoCAQEwDQYJKoZIhvcNAQELBQAwFzEVMBMGA1UEAwwMbmV3cGJfdGhp
-bmd5MB4XDTE5MDkyMDE4NDkzNloXDTIwMDkxOTE4NDkzNlowFzEVMBMGA1UEAwwM
-bmV3cGJfdGhpbmd5MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA1zK4
-wH0ZvjFCnFo+PvT/ANBJ2H7pZQDRHFHmhW28VeQ4nCqlifjxJ/MOWpqKYK6rxHOK
-DNTDR5MbkFO7l0yquB0/FArP9RErezKakXz8qSLhipDZk7y+0fKWMPxcgdSzm28Z
-817Yzp1naXPHQRcno3M3eo58FyoTDAOXP3hiS+bFm8RGVINLSBJtILKoplvgSdyD
-/1Xg4zbh2FK+gS0f92jel5JyAaebt3EQPiIxwUrvi5a1w5EQKi13sJ22RK5H6sch
-Xg76GMMBCckLs+g8xza5uHLbotMnWb7ddW+pC0SQsrihUxz902lQoUuxq2aJig6o
-Ti6wsetUcxtOErfy6wIDAQABMA0GCSqGSIb3DQEBCwUAA4IBAQC7ciESyktDoAus
-ni6zW30AXnoTxD/LNCf2HMUFcyFF57p5dcaTsAUhUd+aKX/iJyhy6bfgo8GGI5xN
-LvhvNQ6Cb6Z9qiCWDvEll+nbfuJNEanEd6bkR06/TX5bK5iDMYZD4Z+SSHsNDNEF
-DXJ96zp42UfQTdimxXHmZidAYvtYeLe4EDoJGhpuryEAIUwPdTvsPX+pLfCdtdyP
-595zbHkUPPnA3feWckcmN0FWiXisaE4ERXdPrcBnMB5TqY7KI0j2TjW59l1TnNFD
-dEKMyBD89ndBXvZq8JO8nzdM0WF32jSM/Yb+clS6PHoypHGo4jBTE3AEIXMUe//x
-MSwj51gz
------END CERTIFICATE-----
------BEGIN PRIVATE KEY-----
-MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQDXMrjAfRm+MUKc
-Wj4+9P8A0EnYfullANEcUeaFbbxV5DicKqWJ+PEn8w5amopgrqvEc4oM1MNHkxuQ
-U7uXTKq4HT8UCs/1ESt7MpqRfPypIuGKkNmTvL7R8pYw/FyB1LObbxnzXtjOnWdp
-c8dBFyejczd6jnwXKhMMA5c/eGJL5sWbxEZUg0tIEm0gsqimW+BJ3IP/VeDjNuHY
-Ur6BLR/3aN6XknIBp5u3cRA+IjHBSu+LlrXDkRAqLXewnbZErkfqxyFeDvoYwwEJ
-yQuz6DzHNrm4ctui0ydZvt11b6kLRJCyuKFTHP3TaVChS7GrZomKDqhOLrCx61Rz
-G04St/LrAgMBAAECggEAfRKjwmxzK9Fhj5H7n4exNf3ZDZUlfWiuILGRM3eGAL22
-ET3QHJKtRrTDYPF0/6BFgNZOJAr8vHrJiGbCHruWdY+5+6IVH7As/1t37psgFgWJ
-5Ikvi+glV8yQckQaV/MRuIMoKAS2Kc/eLLH32uLkTOFIG1j40lXH4DGuFFuZddbH
-Ie2TsgUmI3LXTSGSq4qSgXyB46uGuGOn4WKIAKp7O4kN2jBB5y3q9C2YltQ+Dv+k
-T64wBNK3ZnHHNKli0A86kzPLVQJfHgjzC76QRlC+guKgRoV9Kut3LLfoi6ep5yJr
-RT6Pr/hTNKCluIZUTPhmB0u3xGr9gj6vDsMCanvrsQKBgQD5y7ZJqFvgh9MlhSLN
-20p7jlyu+cYSDWktUjA4109ior8oaCVUXziSuPsr9JfwYRaYsJTUpCYKECFYLibA
-qI+Jj/auJljuCmrfWuS9Z08sAmVoU+O4FZt2UVbui5l5spU41Ze09f81DpzkHhZ0
-SEVH2SgChdy7KdPPhxcVhJHqJQKBgQDciwameP0WaazTY77ZRE4Yt+dPyPFkpSer
-bibeMmss5d+QVo4B4YEL20CrmaJq+FB9u99nL1d6VsvtWuovvHKMmoM//D8Si7PW
-ieAm9mN0L+2Xf25UVFBewQkzNuJJG+z1OtHFfIDDGnNzL2yx//3YFJnR/ehftsK7
-lIlXUElzzwKBgGUW1cx1P8lb7k0u1ejtJ/VcpZGCL3A60SewLSezqsLGDgoyK3k7
-l8944Nzm/V4gTF66h2COlX5ZDMV819372SrYggH0LuUWfi2pwQwNdPLgfV19JZjn
-1aRKQp4DDLc9WDpJ5j0rmH5GTaPbsUaZwL/U1+Y9ehicUsWXa/YfUlWpAoGBAJCZ
-7yBTj82UOCbZ7ZZS/MmkOtvLKssMpnf2XzGs6SylA/KFbdK54ny9oydgMmfkrBHk
-jtP+7GJgapET3RyzeH/MB2Z6o3grdRyjhf7F6euSSTvd558PMSsPclLMF45L6w/X
-IxdTTLGftDa/z4reB7gXucs/qY6oLAIFoA9Jqv9tAoGAIpw4GDw5IQFZhcHuHCOZ
-Xrq9L1fR5rYBQa6xcPHkMbWzigcNJz7FnLg0tB1SvF23egpmj5VAcnWyjyj883pn
-h2wuwJUFy8LALtjJwqhjUtQfv5LLiT5061/CUrhD3GEBNlYbOO4FA1Z0SIhFYn40
-VzowmHAqdxYvlfJsWe91UI0=
------END PRIVATE KEY-----
-'';
-  };
+  pemFile = ./node.pem;
   tubID = "rr7y46ixsg6qmck4jkkc7hke6xe4sv5f";
   swissnum = "2k6p3wrabat5jrj7otcih4cjdema4q3m";
   introducerPort = 35151;