config/internal: add clevis override support

config/shared/errors/errors.go

@@ -55,6 +55,9 @@ var (
 	ErrLuksLabelTooLong          = errors.New("luks device labels cannot be longer than 47 characters")
 	ErrLuksNameContainsSlash     = errors.New("device names cannot contain slashes")
 	ErrInvalidLuksKeyFile        = errors.New("invalid key-file source")
+	ErrUnknownClevisPin          = errors.New("unsupported clevis pin")
+	ErrClevisConfigRequired      = errors.New("missing required custom clevis config")
+	ErrClevisCustomWithOthers    = errors.New("cannot use custom clevis config with tpm2, tang, or threshold")
 	ErrTangThumbprintRequired    = errors.New("thumbprint is required")
 	ErrFileIllegalMode           = errors.New("illegal file mode")
 	ErrBothIDAndNameSet          = errors.New("cannot set both id and name")

config/v3_2_experimental/schema/ignition.json

@@ -262,6 +262,24 @@
             "clevis": {
               "type": ["object", "null"],
               "properties": {
+                "custom": {
+                  "type": ["object", "null"],
+                  "properties": {
+                    "pin": {
+                      "type": "string"
+                    },
+                    "config": {
+                      "type": "string"
+                    },
+                    "needsNetwork": {
+                      "type": ["boolean", "null"]
+                    }
+                  },
+                  "required": [
+                    "pin",
+                    "config"
+                  ]
+                },
                 "tpm2": {
                   "type": ["boolean", "null"]
                 },

config/v3_2_experimental/types/custom.go

@@ -0,0 +1,41 @@
+// Copyright 2020 Red Hat, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package types
+
+import (
+	"github.com/coreos/ignition/v2/config/shared/errors"
+
+	"github.com/coreos/vcontext/path"
+	"github.com/coreos/vcontext/report"
+)
+
+func (cu Custom) Key() string {
+	return cu.Pin
+}
+
+func (cu Custom) Validate(c path.ContextPath) (r report.Report) {
+	if cu.Pin == "" && cu.Config == "" {
+		return
+	}
+	switch cu.Pin {
+	case "tpm2", "tang", "sss":
+	default:
+		r.AddOnError(c.Append("pin"), errors.ErrUnknownClevisPin)
+	}
+	if cu.Config == "" {
+		r.AddOnError(c.Append("config"), errors.ErrClevisConfigRequired)
+	}
+	return
+}

config/v3_2_experimental/types/luks.go

@@ -45,6 +45,12 @@ func (l Luks) Validate(c path.ContextPath) (r report.Report) {
 		r.AddOnError(c.Append("device"), validatePath(*l.Device))
 	}
 
+	if l.Clevis != nil {
+		if l.Clevis.Custom != nil && (len(l.Clevis.Tang) > 0 || (l.Clevis.Tpm2 != nil && *l.Clevis.Tpm2) || (l.Clevis.Threshold != nil && *l.Clevis.Threshold != 0)) {
+			r.AddOnError(c.Append("clevis"), errors.ErrClevisCustomWithOthers)
+		}
+	}
+
 	// fail if a key file is provided and is not valid
 	if err := validateURLNilOK(l.KeyFile.Source); err != nil {
 		r.AddOnError(c.Append("keys"), errors.ErrInvalidLuksKeyFile)

config/v3_2_experimental/types/schema.go

@@ -3,9 +3,10 @@ package types
 // generated by "schematyper --package=types config/v3_2_experimental/schema/ignition.json -o config/v3_2_experimental/types/schema.go --root-type=Config" -- DO NOT EDIT
 
 type Clevis struct {
-	Tang      []Tang `json:"tang,omitempty"`
-	Threshold *int   `json:"threshold,omitempty"`
-	Tpm2      *bool  `json:"tpm2,omitempty"`
+	Custom    *Custom `json:"custom,omitempty"`
+	Tang      []Tang  `json:"tang,omitempty"`
+	Threshold *int    `json:"threshold,omitempty"`
+	Tpm2      *bool   `json:"tpm2,omitempty"`
 }
 
 type Config struct {
@@ -15,6 +16,12 @@ type Config struct {
 	Systemd  Systemd  `json:"systemd,omitempty"`
 }
 
+type Custom struct {
+	Config       string `json:"config"`
+	NeedsNetwork *bool  `json:"needsNetwork,omitempty"`
+	Pin          string `json:"pin"`
+}
+
 type Device string
 
 type Directory struct {

docs/configuration-v3_2_experimental.md

@@ -144,6 +144,10 @@ The Ignition configuration is a JSON document conforming to the following specif
         * **thumbprint** (string): thumbprint of a trusted signing key.
       * **_tpm2_** (bool): whether or not to use a tpm2 device.
       * **_threshold_** (int): sets the minimum number of pieces required to decrypt the device.
+      * **_custom_** (object): overrides the clevis configuration. The `pin` & `config` will be passed directly to `clevis luks bind`. If specified, all other clevis options must be omitted.
+        * **pin** (string): the clevis pin.
+        * **config** (string): the clevis configuration JSON.
+        * **_needsNetwork_** (bool): whether or not the device requires networking.
 * **_systemd_** (object): describes the desired state of the systemd units.
   * **_units_** (list of objects): the list of systemd units.
     * **name** (string): the name of the unit. This must be suffixed with a valid unit type (e.g. "thing.service"). Every unit must have a unique `name`.

internal/exec/stages/disks/luks.go

@@ -247,27 +247,41 @@ func (s *stage) createLuks(config types.Config) error {
 		}
 
 		if luks.Clevis != nil {
-			c := Clevis{
-				Threshold: 1,
-			}
-			if luks.Clevis.Threshold != nil {
-				c.Threshold = *luks.Clevis.Threshold
-			}
-			for _, tang := range luks.Clevis.Tang {
-				c.Pins.Tang = append(c.Pins.Tang, Tang{
-					URL:        tang.URL,
-					Thumbprint: *tang.Thumbprint,
-				})
-			}
-			if luks.Clevis.Tpm2 != nil {
-				c.Pins.Tpm = *luks.Clevis.Tpm2
+			var pin string
+			var config string
+
+			if luks.Clevis.Custom != nil {
+				pin = luks.Clevis.Custom.Pin
+				config = luks.Clevis.Custom.Config
 			}
-			clevisJson, err := json.Marshal(c)
-			if err != nil {
-				return fmt.Errorf("creating clevis json: %v", err)
+
+			// if the override pin is empty the config must also be empty
+			if pin == "" {
+				pin = "sss"
+				c := Clevis{
+					Threshold: 1,
+				}
+				if luks.Clevis.Threshold != nil {
+					c.Threshold = *luks.Clevis.Threshold
+				}
+				for _, tang := range luks.Clevis.Tang {
+					c.Pins.Tang = append(c.Pins.Tang, Tang{
+						URL:        tang.URL,
+						Thumbprint: *tang.Thumbprint,
+					})
+				}
+				if luks.Clevis.Tpm2 != nil {
+					c.Pins.Tpm = *luks.Clevis.Tpm2
+				}
+				clevisJson, err := json.Marshal(c)
+				if err != nil {
+					return fmt.Errorf("creating clevis json: %v", err)
+				}
+				config = string(clevisJson)
 			}
+
 			if _, err := s.Logger.LogCmd(
-				exec.Command(distro.ClevisCmd(), "luks", "bind", "-f", "-k", keyFilePath, "-d", devAlias, "sss", string(clevisJson)), "Clevis bind",
+				exec.Command(distro.ClevisCmd(), "luks", "bind", "-f", "-k", keyFilePath, "-d", devAlias, pin, config), "Clevis bind",
 			); err != nil {
 				return fmt.Errorf("binding clevis device: %v", err)
 			}

internal/exec/stages/files/filesystemEntries.go

@@ -62,7 +62,7 @@ func (s *stage) createCrypttabEntries(config types.Config) error {
 		}
 		uuid := strings.TrimSpace(string(out))
 		netdev := ""
-		if luks.Clevis != nil && len(luks.Clevis.Tang) > 0 {
+		if luks.Clevis != nil && (len(luks.Clevis.Tang) > 0 || (luks.Clevis.Custom != nil && luks.Clevis.Custom.NeedsNetwork != nil && *luks.Clevis.Custom.NeedsNetwork)) {
 			netdev = ",_netdev"
 		}
 		keyfile := "none"