vault: run as an unpivileged user

1 files changed, 97 insertions, 172 deletions

diff --git a/nixos/modules/services/security/vault.nix b/nixos/modules/services/security/vault.nix
index eae3a8ca618..dc06f89cce8 100644
--- a/nixos/modules/services/security/vault.nix
+++ b/nixos/modules/services/security/vault.nix
@@ -1,207 +1,132 @@
-{ config, lib, pkgs, utils, ... }:
+{ config, lib, pkgs, ... }:
 
 with lib;
 let
-
-  inherit (pkgs) vault;
-
   cfg = config.services.vault;
- 
+
   configFile = pkgs.writeText "vault.hcl" ''
     listener "tcp" {
-      address = "${cfg.listener.address}"
-   
-      ${optionalString (cfg.listener.cluster_address != null)''
-        cluster_address = "${cfg.listener.cluster_address}"
-      ''}
-      
-      ${optionalString (cfg.listener.tls_cert_file != null)''
-        tls_cert_file = "${cfg.listener.tls_cert_file}"
-      ''}
-      
-      ${optionalString (cfg.listener.tls_key_file != null)''
-        tls_key_file = "${cfg.listener.tls_key_file}"
-      ''}
-      
-      ${if cfg.listener.tls_disable then "tls_disable = \"1\"" else "" } 
-
-      tls_min_version = "${cfg.listener.tls_min_version}" 
-
-      ${optionalString (cfg.listener.tls_cipher_suites != null)''
-        tls_cipher_suites = \"${cfg.listener.tls_cipher_suites}\"
-      ''}
-
-      tls_prefer_server_cipher_suites = "${boolToString cfg.listener.tls_prefer_server_cipher_suites}"
-
-      tls_require_and_verify_client_cert = "${boolToString cfg.listener.tls_require_and_verify_client_cert}"
-
+      address = "${cfg.address}"
+      tls_cert_file = "${cfg.tlsCertFile}"
+      tls_key_file = "${cfg.tlsKeyFile}"
+      ${cfg.listenerExtraConfig}
     }
-
-    storage "${cfg.storage.backend}" {
-      ${cfg.storage.extraConfig}
+    storage "${cfg.storageBackend}" {
+      ${cfg.storageConfig}
     }
-
-    ${if cfg.telemetry.extraConfig != "" then "
-      telemetry { 
-        ${if cfg.telemetry.disable_hostname then "disable_hostname = \"true\"" else ""}
-        ${cfg.telemetry.extraConfig}
-      }" else ""}
-
+    ${optionalString (cfg.telemetryConfig != "") ''
+        telemetry {
+          ${cfg.telemetryConfig}
+        }
+      ''}
   '';
-
 in
 {
   options = {
 
     services.vault = {
 
-      enable = mkOption {
-        type = types.bool;
-        default = false;
-        description = ''
-          Enables the vault daemon.
-        '';
-      };
-
-      listener = {
-
-        address = mkOption {
-          type = types.str;
-          default = "127.0.0.1:8200";
-          description = ''
-            The name of the ip interface to listen to.
-          '';
-        };
-
-        cluster_address = mkOption {
-          type = types.nullOr types.str;
-          default = null;
-          description = ''
-            The name of the address to bind to for cluster server-to-server requests.
-          '';
-        };
-
-        tls_cert_file = mkOption {
-          type = types.str;
-          default = "";
-          description = ''
-            The name of the crt file for the ssl certificate.
-          '';
-        };
-        
-        tls_key_file = mkOption {
-          type = types.str;
-          default = "";
-          description = ''
-            The name of the key file for the ssl certificate.
-          '';
-        };
-
-        tls_disable = mkOption {
-          type = types.bool;
-          default = false;
-          description = ''
-            Specifies if TLS will be disabled. Vault assumes TLS by default, so you must explicitly disable TLS to opt-in to insecure communication.
-          '';
-        };
-        
-        tls_min_version = mkOption {
-          type = types.enum [ "tls10" "tls11" "tls12" ];
-          default = "tls12";
-          description = ''
-             The minimum supported version of TLS. Accepted values are "tls10", "tls11" or "tls12".
-          '';
-        };
-
-        tls_cipher_suites = mkOption {
-          type = types.nullOr types.str;
-          default = null;
-          description = ''
-             The list of supported ciphersuites as a comma-separated-list.
-          '';
-        };
-
-        tls_prefer_server_cipher_suites = mkOption {
-          type = types.bool;
-          default = false;
-          description = ''
-             Specifies to prefer the server's ciphersuite over the client ciphersuites.
-          '';
-        };
-
-        tls_require_and_verify_client_cert = mkOption {
-          type = types.bool;
-          default = false;
-          description = ''
-             Turns on client authentication for this listener.
-          '';
-        };
+      enable = mkEnableOption "Vault daemon";
 
+      address = mkOption {
+        type = types.str;
+        default = "127.0.0.1:8200";
+        description = "The name of the ip interface to listen to";
       };
 
-      storage = {
-    
-        backend = mkOption {
-          type =  types.str;
-          default = "inMemory";
-          description = ''
-            The name of the type of storage backend.
-          '';
-        };
-
-        extraConfig = mkOption {
-          type = types.lines;
-          default = "";
-          description = ''
-            Configuration for storage
-          '';
-        };
- 
+      tlsCertFile = mkOption {
+        type = types.str;
+        default = "/etc/vault/cert.pem";
+        example = "/path/to/your/cert.pem";
+        description = "TLS certificate file. A self-signed certificate will be generated if file not exists";
       };
 
+      tlsKeyFile = mkOption {
+        type = types.str;
+        default = "/etc/vault/key.pem";
+        example = "/path/to/your/key.pem";
+        description = "TLS private key file. A self-signed certificate will be generated if file not exists";
+      };
 
-      telemetry = {
-
-        disable_hostname = mkOption {
-          type =  types.bool;
-          default = false;
-          description = ''
-            Specifies if gauge values should be prefixed with the local hostname. 
-          '';
-        };
+      listenerExtraConfig = mkOption {
+        type = types.lines;
+        default = ''
+          tls_min_version = "tls12"
+        '';
+        description = "extra configuration";
+      };
 
-        extraConfig = mkOption {
-          type = types.lines;
-          default = "";
-          description = ''
-            configuration for telemetry
-          '';
-        };        
+      storageBackend = mkOption {
+        type = types.enum ["inmem" "consul" "zookeeper" "file" "s3" "azure" "dynamodb" "etcd" "mssql" "mysql" "postgresql" "swift" "gcs"];
+        default = "inmem";
+        description = "The name of the type of storage backend";
+      };
 
+      storageConfig = mkOption {
+        type = types.lines;
+        description = "Storage configuration";
+        default = "";
       };
 
+      telemetryConfig = mkOption {
+        type = types.lines;
+        default = "";
+        description = "Telemetry configuration";
+      };
     };
-
   };
 
   config = mkIf cfg.enable {
 
-    systemd.services.vault =
-    { description = "Vault server daemon";
-
-      wantedBy = ["multi-user.target"];
+    users.extraUsers.vault = {
+      name = "vault";
+      group = "vault";
+      uid = config.ids.uids.vault;
+      description = "Vault daemon user";
+    };
+    users.extraGroups.vault.gid = config.ids.gids.vault;
 
-      preStart =
-        ''
-          mkdir -m 0755 -p /var/lib/vault
-        '';
+    systemd.services.vault = {
+      description = "Vault server daemon";
 
-      serviceConfig =
-        { ExecStart =
-            "${pkgs.vault}/bin/vault server -config ${configFile}";
-          KillMode = "process";
-        };
-    };   
+      wantedBy = ["multi-user.target"];
+      after = [ "network.target" ];
+
+      preStart = ''
+        mkdir -m 0755 -p /var/lib/vault
+        chown -R vault:vault /var/lib/vault
+
+        # generate a self-signed certificate, you will have to set environment variable "VAULT_SKIP_VERIFY=1" in the client
+        if [ ! -s ${cfg.tlsCertFile} -o ! -s ${cfg.tlsKeyFile} ]; then
+          mkdir -p $(dirname ${cfg.tlsCertFile}) || true
+          mkdir -p $(dirname ${cfg.tlsKeyFile }) || true
+          ${pkgs.openssl.bin}/bin/openssl req -x509 -newkey rsa:2048 -sha256 -nodes -days 99999 \
+            -subj /C=US/ST=NY/L=NYC/O=vault/CN=${cfg.address} \
+            -keyout ${cfg.tlsKeyFile} -out ${cfg.tlsCertFile}
+
+          chown root:vault ${cfg.tlsKeyFile} ${cfg.tlsCertFile}
+          chmod 440 ${cfg.tlsKeyFile} ${cfg.tlsCertFile}
+        fi
+      '';
+
+      serviceConfig = {
+        User = "vault";
+        Group = "vault";
+        PermissionsStartOnly = true;
+        ExecStart = "${pkgs.vault}/bin/vault server -config ${configFile}";
+        PrivateDevices = true;
+        PrivateTmp = true;
+        ProtectSystem = "full";
+        ProtectHome = "read-only";
+        AmbientCapabilities = "cap_ipc_lock";
+        NoNewPrivileges = true;
+        KillSignal = "SIGINT";
+        TimeoutStopSec = "30s";
+        Restart = "on-failure";
+        StartLimitInterval = "60s";
+        StartLimitBurst = 3;
+      };
+    };
   };
 
 }