secure-boot: refactor

linyinfeng · Dec 8, 2023 · ca09970 · ca09970
1 parent 7c8cdc9
commit ca09970
Show file tree

Hide file tree

Showing 24 changed files with 530 additions and 122 deletions.
diff --git a/devshell/terraform.nix b/devshell/terraform.nix
@@ -73,6 +73,7 @@
         openssl
         ruby
         yq-go
+        efitools
         encryptTo
       ];
       text = ''

diff --git a/lib/data/data.json b/lib/data/data.json
diff --git a/lib/data/template.yq b/lib/data/template.yq
@@ -5,8 +5,6 @@
     "as198764_v6_cidr": .as198764_v6_cidr.value,
     "as198764_anycast_address": .as198764_anycast_address.value,
 
-    "ca_cert_pem": .ca_cert_pem.value,
-
     "cache_s3_url": .b2_s3_api_url.value,
     "cache_s3_host": .b2_s3_api_host.value,
     "mastodon_media_region": .b2_s3_region.value,
@@ -37,6 +35,26 @@
         }
     },
 
+    "ca_cert_pem": .ca_cert_pem.value,
+    "secure_boot": {
+        "signature_owner_guid": .secure_boot_signature_owner_guid.value,
+        "platform_key": {
+            "certificate_pem": .secure_boot_pk_cert_pem.value,
+            "efi_signature_list_base64": .secure_boot_pk_esl_base64.value,
+            "signed_efi_signature_list_base64": .secure_boot_pk_signed_esl_base64.value
+        },
+        "key_exchange_key": {
+            "certificate_pem": .secure_boot_kek_cert_pem.value,
+            "efi_signature_list_base64": .secure_boot_kek_esl_base64.value,
+            "signed_efi_signature_list_base64": .secure_boot_kek_signed_esl_base64.value
+        },
+        "database": {
+            "certificate_pem": .secure_boot_db_cert_pem.value,
+            "efi_signature_list_base64": .secure_boot_db_esl_base64.value,
+            "signed_efi_signature_list_base64": .secure_boot_db_signed_esl_base64.value
+        }
+    },
+
     "hosts": .hosts.value | map_values(
         with_entries(
             select(

diff --git a/nixos/hosts/framework/_hardware.nix b/nixos/hosts/framework/_hardware.nix
@@ -112,8 +112,8 @@
       # currently nothing
     ];
   };
-  # out-of-tree module "kvmfr" required
   # because kernel needs to be recompiled
-  # enable lockdown by the way
+  # enable module signing and lockdown by the way
+  boot.kernelModuleSigning.enable = true;
   boot.kernelLockdown = true;
 }
diff --git a/nixos/hosts/framework/default.nix b/nixos/hosts/framework/default.nix
@@ -27,6 +27,7 @@ in {
       nix.access-tokens
       nix.nixbuild
       nix.hydra-builder-client
+      nix.hydra-builder-server
       security.tpm
       networking.wireguard-home
       networking.behind-fw
@@ -43,6 +44,7 @@ in {
       programs.service-mail
       programs.tg-send
       hardware.backlight
+      hardware.sr-iov
       users.yinfeng
     ])
     ++ [
@@ -145,7 +147,6 @@ in {
       fileSystems."/persist" = btrfsSubvolMain "@persist" {neededForBoot = true;};
       fileSystems."/var/log" = btrfsSubvolMain "@var-log" {neededForBoot = true;};
       fileSystems."/nix" = btrfsSubvolMain "@nix" {neededForBoot = true;};
-      fileSystems."/sbkeys" = btrfsSubvolMain "@sbkeys" {};
       fileSystems."/boot" = {
         device = "/dev/disk/by-uuid/5C56-7693";
         fsType = "vfat";
@@ -160,65 +161,6 @@ in {
       ];
     }
 
-    # sr-iov of intel gpu
-    {
-      boot.kernelParams = ["intel_iommu=on" "i915.enable_guc=3" "i915.max_vfs=7"];
-      systemd.services.setup-sriov = let
-        num = 1;
-      in {
-        script = ''
-          set -e
-          echo ${toString num} | tee /sys/devices/pci0000:00/0000:00:02.0/sriov_numvfs
-        '';
-        serviceConfig = {
-          Type = "oneshot";
-        };
-        requiredBy = ["libvirtd.service"];
-        before = ["libvirtd.service"];
-      };
-      systemd.services.detach-sriov-devices = {
-        script = ''
-          set -e
-          virsh nodedev-detach pci_0000_00_02_1
-        '';
-        path = with pkgs; [
-          libvirt
-        ];
-        serviceConfig = {
-          Type = "oneshot";
-        };
-        requiredBy = ["libvirtd.service"];
-        after = ["libvirtd.service"];
-        before = ["libvirt-guests.service"];
-      };
-      environment.systemPackages = with pkgs; [
-        looking-glass-client
-      ];
-      # https://looking-glass.io/docs/B6/module/#vm-host
-      boot = {
-        extraModulePackages = with config.boot.kernelPackages; [
-          kvmfr
-        ];
-        kernelModules = [
-          "kvmfr"
-        ];
-        extraModprobeConfig = ''
-          options kvmfr static_size_mb=64
-        '';
-      };
-      services.udev.extraRules = ''
-        ACTION=="add", SUBSYSTEM=="kvmfr", GROUP="libvirtd", MODE="0660"
-      '';
-      virtualisation.libvirtd.qemu.verbatimConfig = ''
-        cgroup_device_acl = [
-          "/dev/null", "/dev/full", "/dev/zero",
-          "/dev/random", "/dev/urandom",
-          "/dev/ptmx", "/dev/kvm",
-          "/dev/kvmfr0"
-        ]
-      '';
-    }
-
     # windows fonts
     (
       let

diff --git a/nixos/profiles/boot/secure-boot/default.nix b/nixos/profiles/boot/secure-boot/default.nix
@@ -1,22 +1,78 @@
 {
   config,
   lib,
+  pkgs,
   ...
 }: {
   options = {
+    boot.secureBoot = {
+      publicKeyFile = lib.mkOption {
+        type = lib.types.path;
+        default = pkgs.writeText "module-signing.crt" config.lib.self.data.secure_boot.database.certificate_pem;
+      };
+      privateKeyFile = lib.mkOption {
+        type = lib.types.path;
+        default = config.sops.secrets."secure_boot_db_private_key".path;
+      };
+    };
+    boot.kernelModuleSigning = {
+      enable = lib.mkEnableOption "kernel module signing";
+      hash = lib.mkOption {
+        type = lib.types.enum ["SHA1" "SHA224" "SHA256" "SHA384" "SHA512"];
+        default = "SHA512";
+      };
+      certificate = lib.mkOption {
+        type = lib.types.path;
+        # just the same as the database key
+        default = config.boot.secureBoot.publicKeyFile;
+      };
+      key = lib.mkOption {
+        type = lib.types.path;
+        default = config.boot.secureBoot.privateKeyFile;
+      };
+      # defined in profiles/nix/hydra-builder-server
+      # kernel and modules must be built on thess servers
+      combined = lib.mkOption {
+        type = lib.types.path;
+        default = config.sops.templates."linux-module-signing-key.pem".path;
+      };
+      signModule = lib.mkOption {
+        type = lib.types.path;
+        default = pkgs.writeShellApplication {
+          name = "signModule";
+          text = let
+            inherit (config.boot.kernelPackages) kernel;
+          in ''
+            echo "Signing kernel module '$1'..."
+            "${kernel.dev}/lib/modules/${kernel.modDirVersion}/build/scripts/sign-file" \
+              "${config.boot.kernelModuleSigning.hash}" \
+              "${config.boot.kernelModuleSigning.key}" \
+              "${config.boot.kernelModuleSigning.certificate}" \
+              "$@"
+          '';
+        };
+      };
+    };
     boot.kernelLockdown = lib.mkEnableOption "kernel lockdown";
   };
 
   config = lib.mkMerge [
+    {
+      assertions = [
+        {
+          assertion = config.boot.kernelLockdown -> config.boot.kernelModuleSigning.enable;
+          message = "boot.kernelLockdown requires boot.kernelModuleSigning.enable";
+        }
+      ];
+    }
     {
       boot.lanzaboote = {
         enable = true;
-        publicKeyFile = "/sbkeys/generated/db.crt";
-        privateKeyFile = "/sbkeys/generated/db.key";
+        inherit (config.boot.secureBoot) publicKeyFile privateKeyFile;
       };
       boot.kernelPatches = [
         {
-          name = "keyring";
+          name = "uefi-keyring";
           patch = null;
           extraConfig = ''
             INTEGRITY_MACHINE_KEYRING y
@@ -30,27 +86,34 @@
         }
       ];
     }
+    (lib.mkIf config.boot.kernelModuleSigning.enable {
+      boot.kernelPatches = [
+        # this patch makes the linux kernel unreproducible
+        {
+          name = "moduel-signing";
+          patch = null;
+          extraConfig = ''
+            MODULE_SIG y
+            MODULE_SIG_SHA512 y
+            MODULE_SIG_HASH sha512
+            MODULE_SIG_KEY ${config.boot.kernelModuleSigning.combined}
+          '';
+        }
+      ];
+    })
     (lib.mkIf config.boot.kernelLockdown {
       boot.kernelParams = [
         "lockdown=integrity"
       ];
       boot.kernelPatches = [
-        # this patch makes the linux kernel unreproducible
         {
           name = "lockdown";
           patch = null;
           extraConfig = ''
-            MODULE_SIG y
             SECURITY_LOCKDOWN_LSM y
           '';
         }
       ];
-      # assertions = [
-      #   {
-      #     assertion = lib.length config.boot.extraModulePackages == 0;
-      #     message = "out-of-tree and unsigned kernel module not supported";
-      #   }
-      # ];
     })
   ];
 }
diff --git a/nixos/profiles/hardware/sr-iov/default.nix b/nixos/profiles/hardware/sr-iov/default.nix
@@ -0,0 +1,79 @@
+{
+  config,
+  pkgs,
+  ...
+}: {
+  boot.kernelParams = ["intel_iommu=on" "i915.enable_guc=3" "i915.max_vfs=7"];
+  systemd.services.setup-sriov = let
+    num = 1;
+  in {
+    script = ''
+      set -e
+      echo ${toString num} | tee /sys/devices/pci0000:00/0000:00:02.0/sriov_numvfs
+    '';
+    serviceConfig = {
+      Type = "oneshot";
+    };
+    requiredBy = ["libvirtd.service"];
+    before = ["libvirtd.service"];
+  };
+  systemd.services.detach-sriov-devices = {
+    script = ''
+      set -e
+      virsh nodedev-detach pci_0000_00_02_1
+    '';
+    path = with pkgs; [
+      libvirt
+    ];
+    serviceConfig = {
+      Type = "oneshot";
+    };
+    requiredBy = ["libvirtd.service"];
+    after = ["libvirtd.service"];
+    before = ["libvirt-guests.service"];
+  };
+  environment.systemPackages = with pkgs; [
+    looking-glass-client
+  ];
+  # https://looking-glass.io/docs/B6/module/#vm-host
+  boot = {
+    extraModulePackages = with config.boot.kernelPackages; [
+      (
+        if (config.boot ? kernelModuleSigning && config.boot.kernelModuleSigning.enable)
+        then
+          (kvmfr.overrideAttrs (old: {
+            nativeBuildInputs =
+              (old.nativeBuildInputs or [])
+              ++ [
+                config.boot.kernelModuleSigning.signModule
+              ];
+            # signature will be stripped
+            dontStrip = true;
+            postBuild =
+              (old.postBuild or "")
+              + ''
+                signModule kvmfr.ko
+              '';
+          }))
+        else kvmfr
+      )
+    ];
+    kernelModules = [
+      "kvmfr"
+    ];
+    extraModprobeConfig = ''
+      options kvmfr static_size_mb=64
+    '';
+  };
+  services.udev.extraRules = ''
+    ACTION=="add", SUBSYSTEM=="kvmfr", GROUP="libvirtd", MODE="0660"
+  '';
+  virtualisation.libvirtd.qemu.verbatimConfig = ''
+    cgroup_device_acl = [
+      "/dev/null", "/dev/full", "/dev/zero",
+      "/dev/random", "/dev/urandom",
+      "/dev/ptmx", "/dev/kvm",
+      "/dev/kvmfr0"
+    ]
+  '';
+}
diff --git a/nixos/profiles/nix/hydra-builder-server/default.nix b/nixos/profiles/nix/hydra-builder-server/default.nix
@@ -16,4 +16,23 @@
     gid = config.ids.gids.hydra-builder;
   };
   nix.settings.trusted-users = ["@hydra-builder"];
+
+  nix.settings.extra-sandbox-paths = [
+    config.sops.templates."linux-module-signing-key.pem".path
+    config.sops.secrets."secure_boot_db_private_key".path
+  ];
+  sops.templates."linux-module-signing-key.pem" = {
+    content = ''
+      ${config.lib.self.data.secure_boot.database.certificate_pem}
+      ${config.sops.placeholder."secure_boot_db_private_key"}
+    '';
+    group = "nixbld";
+    mode = "440";
+  };
+  sops.secrets."secure_boot_db_private_key" = {
+    sopsFile = config.sops-file.terraform;
+    group = "nixbld";
+    mode = "440";
+    restartUnits = []; # no need to restart any unit
+  };
 }
diff --git a/nixos/profiles/programs/tools/default.nix b/nixos/profiles/programs/tools/default.nix
@@ -41,9 +41,11 @@ in {
     gptfdisk
     htop
     jq
+    keyutils
     lm_sensors
     moreutils
     ncdu
+    openssl
     parted
     pciutils
     procs

diff --git a/nixos/profiles/services/matrix/default.nix b/nixos/profiles/services/matrix/default.nix
@@ -87,7 +87,7 @@ in
       };
 
       systemd.services.matrix-synapse = {
-        # copy singing key to signing key path
+        # copy signing key to signing key path
         serviceConfig.ExecStartPre = lib.mkBefore [
           ("+"
             + (pkgs.writeShellScript "matrix-synapse-fix-permissions" ''
-Original file line number
+Diff line change
@@ Expand Up / @@ -73,6 +73,7 @@ @@
             openssl
             ruby
             yq-go
+            efitools
             encryptTo
           ];
           text = ''
@@ Expand Down @@