Refactor secrets handling

[perso/Immae/Config/Nix.git] / modules / secrets.nix

diff --git a/modules/secrets.nix b/modules/secrets.nix
index ecc1ebc56a976023911fb1ac8b88968b6e9e85df..86d276a27e1ebb6947963da3b95343b63a4b4c59 100644 (file)
--- a/modules/secrets.nix
+++ b/modules/secrets.nix
@@ -6,11 +6,36 @@
       default = [];
       description = "Keys to upload to server";
     };
+    gpgKeys = lib.mkOption {
+      type = lib.types.listOf lib.types.path;
+      default = [];
+      description = "GPG public keys files to encrypt to";
+    };
+    ageKeys = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [];
+      description = "AGE keys to encrypt to";
+    };
+    decryptKey = lib.mkOption {
+      type = lib.types.str;
+      default = "/etc/ssh/ssh_host_ed25519_key";
+      description = "ed25519 key used to decrypt with AGE";
+    };
     location = lib.mkOption {
       type = lib.types.path;
       default = "/var/secrets";
       description = "Location where to put the keys";
     };
+    secretsVars = lib.mkOption {
+      type = lib.types.path;
+      default = "/run/keys/vars.yml";
+      description = "Location where the secrets variables are defined, to be used to fill the templates in secrets";
+    };
+    deleteSecretsVars = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      description = "Delete secrets file after deployment";
+    };
     # Read-only variables
     fullPaths = lib.mkOption {
       type = lib.types.attrsOf lib.types.path;
@@ -33,56 +58,56 @@
         ${v.user or "root"} ${v.group or "root"} ${v.permissions or "0600"} ${fpath v}
         EOF
         '';
-    secrets = pkgs.runCommand "secrets.tar" {} ''
+    secrets = pkgs.runCommand "secrets.tar.enc" {
+      buildInputs = [ pkgs.gnupg pkgs.sops ];
+      } ''
       touch mods
       tar --format=ustar --mtime='1970-01-01' -P --transform="s@${empty}@secrets@" -cf $out ${empty}/done
       ${builtins.concatStringsSep "\n" (map dumpKey keys)}
       cat mods | while read u g p k; do
       tar --format=ustar --mtime='1970-01-01' --owner="$u" --group="$g" --mode="$p" --append -f $out "$k"
       done
+      export HOME=$(pwd)
+      fingerprints=
+      for key in ${builtins.concatStringsSep " " config.secrets.gpgKeys}; do
+        gpg --import $key 2>/dev/null
+        fingerprints=$fingerprints,$(cat $key | gpg --with-colons --import-options show-only --import 2>/dev/null | grep ^fpr | cut -d: -f10 | head -n1)
+      done
+
+      sops --age ${builtins.concatStringsSep "," config.secrets.ageKeys} --pgp ''${fingerprints#,} --input-type binary -i -e $out 2>/dev/null
       '';
   in lib.mkIf (builtins.length keys > 0) {
     system.activationScripts.secrets = {
       deps = [ "users" "wrappers" ];
       text = ''
         install -m0750 -o root -g keys -d ${location}
-        if [ -f /run/keys/secrets.tar ]; then
-          if [ ! -f ${location}/currentSecrets ] || ! sha512sum -c --status "${location}/currentSecrets"; then
-            echo "rebuilding secrets"
-            TMP=$(${pkgs.coreutils}/bin/mktemp -d)
-            if [ -n "$TMP" ]; then
-              install -m0750 -o root -g keys -d $TMP
-              ${pkgs.gnutar}/bin/tar --strip-components 1 -C $TMP -xf /run/keys/secrets.tar
-              if [ -f /run/keys/vars.yml ]; then
-                find $TMP -name "*.gucci.tpl" -exec \
-                  /bin/sh -c 'f="{}"; ${pkgs.gucci}/bin/gucci -f /run/keys/vars.yml "$f" > "''${f%.gucci.tpl}"; touch --reference "$f" ''${f%.gucci.tpl} ; chmod --reference="$f" ''${f%.gucci.tpl} ; chown --reference="$f" ''${f%.gucci.tpl}' \;
-                sha512sum /run/keys/secrets.tar /run/keys/vars.yml > $TMP/currentSecrets
-              else
-                sha512sum /run/keys/secrets.tar > $TMP/currentSecrets
-              fi
-              find $TMP -type d -exec chown root:keys {} \; -exec chmod o-rx {} \;
-              ${pkgs.rsync}/bin/rsync --exclude="*.gucci.tpl" -O -c -av --delete $TMP/ ${location}
-              rm -rf $TMP
-            fi
+        TMP=$(${pkgs.coreutils}/bin/mktemp -d)
+        TMPWORK=$(${pkgs.coreutils}/bin/mktemp -d)
+        chmod go-rwx $TMPWORK
+        if [ -n "$TMP" -a -n "$TMPWORK" ]; then
+          install -m0750 -o root -g keys -d $TMP
+          ${pkgs.ssh-to-age}/bin/ssh-to-age -private-key -i ${config.secrets.decryptKey} -o $TMPWORK/keys.txt
+          SOPS_AGE_KEY_FILE=$TMPWORK/keys.txt ${pkgs.sops}/bin/sops -d ${secrets} | ${pkgs.gnutar}/bin/tar --strip-components 1 -C $TMP -x
+          if [ -f ${config.secrets.secretsVars} ]; then
+            SOPS_AGE_KEY_FILE=$TMPWORK/keys.txt ${pkgs.sops}/bin/sops -d ${config.secrets.secretsVars} > $TMPWORK/vars.yml
           fi
+          if [ -f $TMPWORK/vars.yml ]; then
+            find $TMP -name "*.gucci.tpl" -exec \
+              /bin/sh -c 'f="{}"; ${pkgs.gucci}/bin/gucci -f '$TMPWORK'/vars.yml "$f" > "''${f%.gucci.tpl}"; touch --reference "$f" ''${f%.gucci.tpl} ; chmod --reference="$f" ''${f%.gucci.tpl} ; chown --reference="$f" ''${f%.gucci.tpl}' \;
+          fi
+          find $TMP -type d -exec chown root:keys {} \; -exec chmod o-rx {} \;
+          ${pkgs.rsync}/bin/rsync --exclude="*.gucci.tpl" -O -c -av --delete $TMP/ ${location}
+          rm -rf $TMP $TMPWORK ${lib.optionalString config.secrets.deleteSecretsVars config.secrets.secretsVars}
         fi
         '';
     };
 
-    system.extraDependencies = [ secrets ];
     deployment.secrets."secret_vars.yml" = {
-      source = builtins.toString <privateFiles/vars.yml>;
-      destination = "/run/keys/vars.yml";
+      source = builtins.toString ../nixops/secrets/vars.yml;
+      destination = config.secrets.secretsVars;
       owner.user = "root";
       owner.group = "root";
       permissions = "0400";
      };
-    deployment.secrets."secrets.tar" = {
-      source = "${secrets}";
-      destination = "/run/keys/secrets.tar";
-      owner.user = "root";
-      owner.group = "root";
-      permissions = "0400";
-    };
   };
 }