Add direct tpm support for spire-agent (#216)

* Add direct tpm support for spire-agent

Signed-off-by: Kevin Fox <[email protected]>

* Add fingerprinting support

Signed-off-by: Kevin Fox <[email protected]>

* Add example

Signed-off-by: Kevin Fox <[email protected]>

* Update charts/spire/charts/spire-agent/templates/configmap.yaml

Signed-off-by: kfox1111 <[email protected]>

* Update charts/spire/charts/spire-agent/templates/configmap.yaml

Signed-off-by: kfox1111 <[email protected]>

* Fix broken tests

Signed-off-by: Kevin Fox <[email protected]>

* Fix hardcoded nodeAttestor and keyManager in spire-agent

Fixes: https://github.com/spiffe/helm-charts-hardened/issues/220

Signed-off-by: Kevin Fox <[email protected]>

* Fix merge issues

Signed-off-by: Kevin Fox <[email protected]>

* Fix unit tests

Signed-off-by: Kevin Fox <[email protected]>

* Pass the agent's securityContext on to Kubernetes

Currently its ignored.

Signed-off-by: Kevin Fox <[email protected]>

* Update example to be usable

Signed-off-by: Kevin Fox <[email protected]>

* Apply suggestions from code review

Signed-off-by: kfox1111 <[email protected]>

* Incorperate feedback

Signed-off-by: Kevin Fox <[email protected]>

* Incorperate feedback

Signed-off-by: Kevin Fox <[email protected]>

* Update to the newest release

Signed-off-by: Kevin Fox <[email protected]>

* Incorperate feedback

Signed-off-by: Kevin Fox <[email protected]>

* Incorperate feedback

Signed-off-by: Kevin Fox <[email protected]>

* Apply suggestions from code review

Signed-off-by: kfox1111 <[email protected]>

---------

Signed-off-by: Kevin Fox <[email protected]>
Signed-off-by: kfox1111 <[email protected]>
Co-authored-by: Faisal Memon <[email protected]>

charts/spire/charts/spire-agent/README.md

@@ -75,6 +75,18 @@ A Helm chart to install the SPIRE agent.
 | `fsGroupFix.resources`                            | Specify resource needs as per https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/                                                                                      | `{}`                                                                             |
 | `keyManager.memory.enabled`                       | Enable the memory based Key Manager                                                                                                                                                               | `true`                                                                           |
 | `nodeAttestor.k8sPsat.enabled`                    | Enable Psat k8s Node Attestor                                                                                                                                                                     | `true`                                                                           |
+| `nodeAttestor.tpmDirect.enabled`                  | Enable the direct TPM node attestor, a 3rd party plugin by Boxboat. This plugin is experimental.                                                                                                  | `false`                                                                          |
+| `nodeAttestor.tpmDirect.plugin.image.registry`    | The OCI registry to pull the image from                                                                                                                                                           | `docker.io`                                                                      |
+| `nodeAttestor.tpmDirect.plugin.image.repository`  | The repository within the registry                                                                                                                                                                | `boxboat/spire-tpm-plugin-tpm-attestor-agent`                                    |
+| `nodeAttestor.tpmDirect.plugin.image.pullPolicy`  | The image pull policy                                                                                                                                                                             | `IfNotPresent`                                                                   |
+| `nodeAttestor.tpmDirect.plugin.image.tag`         | Overrides the image tag                                                                                                                                                                           | `v1.8.7`                                                                         |
+| `nodeAttestor.tpmDirect.plugin.checksum`          | The sha256 checksum of the plugin binary                                                                                                                                                          | `1d7c73ccac948ee86cbd78ddde2d30128a1838b403f7bb2100d38d916a252244`               |
+| `nodeAttestor.tpmDirect.plugin.path`              | The filename in the container of the plugin                                                                                                                                                       | `/app/tpm_attestor_agent`                                                        |
+| `nodeAttestor.tpmDirect.pubHash.enabled`          | Enable Psat k8s nodeattestor                                                                                                                                                                      | `true`                                                                           |
+| `nodeAttestor.tpmDirect.pubHash.image.registry`   | The OCI registry to pull the image from                                                                                                                                                           | `docker.io`                                                                      |
+| `nodeAttestor.tpmDirect.pubHash.image.repository` | The repository within the registry                                                                                                                                                                | `boxboat/spire-tpm-plugin-get-tpm-pubhash`                                       |
+| `nodeAttestor.tpmDirect.pubHash.image.pullPolicy` | The image pull policy                                                                                                                                                                             | `IfNotPresent`                                                                   |
+| `nodeAttestor.tpmDirect.pubHash.image.tag`        | Overrides the image tag                                                                                                                                                                           | `v1.8.7`                                                                         |
 | `workloadAttestors.unix.enabled`                  | Enables the Unix workload attestor                                                                                                                                                                | `false`                                                                          |
 | `workloadAttestors.k8s.enabled`                   | Enables the Kubernetes workload attestor                                                                                                                                                          | `true`                                                                           |
 | `workloadAttestors.k8s.skipKubeletVerification`   | If true, kubelet certificate verification is skipped                                                                                                                                              | `true`                                                                           |

charts/spire/charts/spire-agent/templates/configmap.yaml

@@ -79,6 +79,15 @@ plugins:
         cluster: {{ include "spire-lib.cluster-name" . | quote }}
     {{- $nodeAttestorUsed = add1 $nodeAttestorUsed }}
     {{- end }}
+    {{- with .Values.nodeAttestor.tpmDirect }}
+    {{- if eq (.enabled | toString) "true" }}
+    tpm:
+      plugin_cmd: "/tpm/tpm_attestor_agent"
+      plugin_checksum: {{ .plugin.checksum }}
+      plugin_data: {}
+    {{- $nodeAttestorUsed = add1 $nodeAttestorUsed }}
+    {{- end }}
+    {{- end }}
 {{- if ne $nodeAttestorUsed 1 }}
 {{- fail (printf "You have to enable exactly one Node Attestor. There are %d enabled." $nodeAttestorUsed) }}
 {{- end }}

charts/spire/charts/spire-agent/templates/daemonset.yaml

@@ -1,5 +1,10 @@
 {{- $configSum := (include (print $.Template.BasePath "/configmap.yaml") . | sha256sum) }}
 {{- $podSecurityContext := fromYaml (include "spire-lib.podsecuritycontext" .) }}
+{{- $mainSecurityContext := deepCopy .Values.securityContext }}
+{{- if .Values.nodeAttestor.tpmDirect.enabled }}
+{{-   $podSecurityContext =  mergeOverwrite (dict "runAsUser" 0 "runAsGroup" 0) .Values.podSecurityContext }}
+{{-   $_ := set $mainSecurityContext "privileged" true }}
+{{- end }}
 {{- $cbh := eq (include "spire-agent.connect-by-hostname" .) "true" }}
 {{- $socketAlternateNames := index (include "spire-agent.socket-alternate-names" . | fromYaml) "names" }}
 {{- $socketPath := include "spire-agent.socket-path" . }}
@@ -41,6 +46,47 @@ spec:
         {{- toYaml .Values.hostAliases | nindent 8 }}
       {{- end }}
       initContainers:
+        {{- if .Values.nodeAttestor.tpmDirect.enabled }}
+        {{- if .Values.nodeAttestor.tpmDirect.pubHash.enabled }}
+        - name: fingerprint-tpm
+          securityContext:
+            {{- $mainSecurityContext | toYaml | nindent 12 }}
+          image: {{ template "spire-lib.image" (dict "appVersion" $.Chart.AppVersion "image" .Values.nodeAttestor.tpmDirect.pubHash.image "global" .Values.global) }}
+          command:
+            - sh
+            - -c
+            - |
+              # Fetch the TPM's fingerprint from the TPM and output it on the Computers Console. This enables secure bootstrapping of the Node with the Server.
+              TPM=`/app/get_tpm_pubhash 2> /dev/null`
+              if [ $? -eq 0 ]; then
+                echo "TPM Fingerprint: $TPM"
+                (echo -n '<1>'; echo "TPM Fingerprint: $TPM") | tee /dev/kmsg
+              else
+                /app/get_tpm_pubhash
+              fi
+          volumeMounts:
+            - name: tpm
+              mountPath: /dev/tpmrm0
+              readOnly: true
+            - name: kmsg
+              mountPath: /dev/kmsg
+          imagePullPolicy: {{ .Values.nodeAttestor.tpmDirect.pubHash.image.pullPolicy }}
+        {{- end }}
+        - name: init-tpm-direct
+          securityContext:
+            {{- .Values.securityContext | toYaml | nindent 12 }}
+          image: {{ template "spire-lib.image" (dict "appVersion" $.Chart.AppVersion "image" .Values.nodeAttestor.tpmDirect.plugin.image "global" .Values.global) }}
+          command:
+            - sh
+            - -ec
+            - |
+              # SPIRE must be able to fork the plugin directly within its container. Copy the plugin into a volume that can be mounted where SPIRE can execute it.
+              cp -a {{ .Values.nodeAttestor.tpmDirect.plugin.path }} /tpm/tpm_attestor_agent
+          volumeMounts:
+            - name: tpm-direct
+              mountPath: /tpm
+          imagePullPolicy: {{ .Values.nodeAttestor.tpmDirect.plugin.image.pullPolicy }}
+        {{- end }}
         - name: init
           # This is a small image with wait-for-it, choose whatever image
           # you prefer that waits for a service to be up. This image is built
@@ -48,6 +94,8 @@ spec:
           image: {{ template "spire-lib.image" (dict "image" .Values.waitForIt.image "global" .Values.global) }}
           imagePullPolicy: {{ .Values.waitForIt.image.pullPolicy }}
           args: ["-t", "30", "-h", "{{ include "spire-agent.server-address" . | trim }}", "-p", {{ .Values.server.port | quote }}]
+          securityContext:
+            {{- .Values.securityContext | toYaml | nindent 12 }}
           resources:
             {{- toYaml .Values.waitForIt.resources | nindent 12 }}
           securityContext:
@@ -104,7 +152,7 @@ spec:
           imagePullPolicy: {{ .Values.image.pullPolicy }}
           args: ["-config", "/opt/spire/conf/agent/agent.conf"]
           securityContext:
-            {{ toYaml .Values.securityContext | nindent 12 }}
+            {{- $mainSecurityContext | toYaml | nindent 12 }}
           env:
             - name: PATH
               value: "/opt/spire/bin:/bin"
@@ -138,6 +186,14 @@ spec:
               mountPath: /run/spire/bundle
               readOnly: true
             {{- end }}
+            {{- if .Values.nodeAttestor.tpmDirect.enabled }}
+            - name: tpm-direct
+              mountPath: /tpm
+              readOnly: true
+            - name: tpm
+              mountPath: /dev/tpmrm0
+              readOnly: true
+            {{- end }}
             - name: spire-agent-socket-dir
               mountPath: /tmp/spire-agent/public
               readOnly: false
@@ -191,6 +247,10 @@ spec:
           configMap:
             name: {{ include "spire-lib.bundle-configmap" . }}
         {{- end }}
+        {{- if .Values.nodeAttestor.tpmDirect.enabled }}
+        - name: tpm-direct
+          emptyDir: {}
+        {{- end }}
         - name: spire-token
           projected:
             sources:
@@ -202,6 +262,16 @@ spec:
           hostPath:
             path: {{ $socketPath | dir }}
             type: DirectoryOrCreate
+        {{- if .Values.nodeAttestor.tpmDirect.enabled }}
+        - name: tpm
+          hostPath:
+            path: /dev/tpmrm0
+            type: CharDevice
+        - name: kmsg
+          hostPath:
+            path: /dev/kmsg
+            type: CharDevice
+        {{- end }}
         {{- if gt (len .Values.extraVolumes) 0 }}
         {{- toYaml .Values.extraVolumes | nindent 8 }}
         {{- end }}

charts/spire/charts/spire-agent/values.yaml

@@ -171,6 +171,37 @@ nodeAttestor:
   k8sPsat:
     ## @param nodeAttestor.k8sPsat.enabled Enable Psat k8s Node Attestor
     enabled: true
+  tpmDirect:
+    ## @param nodeAttestor.tpmDirect.enabled Enable the direct TPM node attestor, a 3rd party plugin by Boxboat. This plugin is experimental.
+    enabled: false
+    plugin:
+      ## @param nodeAttestor.tpmDirect.plugin.image.registry The OCI registry to pull the image from
+      ## @param nodeAttestor.tpmDirect.plugin.image.repository The repository within the registry
+      ## @param nodeAttestor.tpmDirect.plugin.image.pullPolicy The image pull policy
+      ## @param nodeAttestor.tpmDirect.plugin.image.tag Overrides the image tag
+      ##
+      image:
+        registry: docker.io
+        repository: boxboat/spire-tpm-plugin-tpm-attestor-agent
+        pullPolicy: IfNotPresent
+        tag: "v1.8.7"
+      ## @param nodeAttestor.tpmDirect.plugin.checksum The sha256 checksum of the plugin binary
+      checksum: 1d7c73ccac948ee86cbd78ddde2d30128a1838b403f7bb2100d38d916a252244
+      ## @param nodeAttestor.tpmDirect.plugin.path The filename in the container of the plugin
+      path: /app/tpm_attestor_agent
+    pubHash:
+      ## @param nodeAttestor.tpmDirect.pubHash.enabled Enable Psat k8s nodeattestor
+      enabled: true
+      ## @param nodeAttestor.tpmDirect.pubHash.image.registry The OCI registry to pull the image from
+      ## @param nodeAttestor.tpmDirect.pubHash.image.repository The repository within the registry
+      ## @param nodeAttestor.tpmDirect.pubHash.image.pullPolicy The image pull policy
+      ## @param nodeAttestor.tpmDirect.pubHash.image.tag Overrides the image tag
+      ##
+      image:
+        registry: docker.io
+        repository: boxboat/spire-tpm-plugin-get-tpm-pubhash
+        pullPolicy: IfNotPresent
+        tag: "v1.8.7"
 
 # workloadAttestors determine a workload's properties and then generate a set of selectors associated with it.
 workloadAttestors:

examples/tpm-direct/values.yaml

@@ -0,0 +1,15 @@
+spire-agent:
+  nodeAttestor:
+    k8sPsat:
+      enabled: false
+    tpmDirect:
+      enabled: true
+
+spire-server:
+  controllerManager:
+    # K8s labels have a 63 character limit. TPM hashes are 64 chars. So you need to label the node with two labels with half of the tpm's hash each. The 'node-restriction.kubernetes.io/' prefix is so that the
+    # nodes can't update the hash themselves, an important security constraint.
+    parentIDTemplate: 'spiffe://{{ .TrustDomain }}/spire/agent/tpm/{{ index .NodeMeta.Labels "node-restriction.kubernetes.io/tpm-pubhash" }}{{ index .NodeMeta.Labels "node-restriction.kubernetes.io/tpm-pubhash2" }}'
+  nodeAttestor:
+    tpmDirect:
+      enabled: true