Merge pull request #521 from flatcar/kai/pcr-bind

kola: Add tests for encrypted root disks with TPM PCR binding

kola/tests/misc/tpm.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"strings"
+	"time"
 
 	"github.com/coreos/go-semver/semver"
 	"github.com/coreos/pkg/capnslog"
@@ -17,16 +18,22 @@ import (
 	"github.com/flatcar/mantle/util"
 )
 
+const (
+	VariantDefault    string = ""
+	VariantNoUpdate   string = "noupdate"
+	VariantWithUpdate string = "withupdate"
+)
+
 var (
 	// For now Ignition has no systemd-cryptenroll support and a helper service is used
 	IgnitionConfigRootCryptenroll = conf.Butane(`---
 variant: flatcar
 version: 1.0.0
 storage:
   luks:
-  - name: rootencrypted
-    wipe_volume: true
-    device: "/dev/disk/by-partlabel/ROOT"
+    - name: rootencrypted
+      wipe_volume: true
+      device: "/dev/disk/by-partlabel/ROOT"
   filesystems:
     - device: /dev/mapper/rootencrypted
       format: ext4
@@ -47,6 +54,127 @@ systemd:
         ExecStart=rm /etc/luks/rootencrypted
         [Install]
         WantedBy=multi-user.target
+`)
+	// Note: Keep the two below configs in sync with those
+	// documented in the Flatcar TPM docs.
+	// Ideally the reboot wouldn't be needed (or done in the initrd?)
+	IgnitionConfigRootCryptenrollPcrNoUpdate = conf.Butane(`---
+variant: flatcar
+version: 1.0.0
+storage:
+  files:
+    - path: /etc/flatcar/update.conf
+      overwrite: true
+      contents:
+        inline: |
+          SERVER=disabled
+  luks:
+    - name: rootencrypted
+      wipe_volume: true
+      device: "/dev/disk/by-partlabel/ROOT"
+  filesystems:
+    - device: /dev/mapper/rootencrypted
+      format: ext4
+      label: ROOT
+systemd:
+  units:
+    - name: cryptenroll-helper-first.service
+      enabled: true
+      contents: |
+        [Unit]
+        ConditionFirstBoot=true
+        OnFailure=emergency.target
+        OnFailureJobMode=isolate
+        After=first-boot-complete.target multi-user.target
+        [Service]
+        Type=oneshot
+        RemainAfterExit=yes
+        ExecStart=systemd-cryptenroll --tpm2-device=auto --unlock-key-file=/etc/luks/rootencrypted --tpm2-pcrs= /dev/disk/by-partlabel/ROOT
+        ExecStart=mv /etc/luks/rootencrypted /etc/luks/rootencrypted-bind
+        ExecStart=sleep 10
+        ExecStart=systemctl reboot
+        [Install]
+        WantedBy=multi-user.target
+    - name: cryptenroll-helper-bind.service
+      enabled: true
+      contents: |
+        [Unit]
+        ConditionFirstBoot=false
+        ConditionPathExists=/etc/luks/rootencrypted-bind
+        OnFailure=emergency.target
+        OnFailureJobMode=isolate
+        [Service]
+        Type=oneshot
+        RemainAfterExit=yes
+        ExecStart=systemd-cryptenroll --tpm2-device=auto --unlock-key-file=/etc/luks/rootencrypted-bind --tpm2-pcrs=4+7+8+9+11+12+13 --wipe-slot=tpm2 /dev/disk/by-partlabel/ROOT
+        ExecStart=mv /etc/luks/rootencrypted-bind /etc/luks/rootencrypted
+        [Install]
+        WantedBy=multi-user.target
+`)
+	// The rebinding for the update is due to how GRUB measures things and
+	// we can only make this work without rebinding if we switch to sd-boot
+	IgnitionConfigRootCryptenrollPcrWithUpdate = conf.Butane(`---
+variant: flatcar
+version: 1.0.0
+storage:
+  files:
+    - path: /oem/bin/oem-postinst
+      overwrite: true
+      mode: 0755
+      contents:
+        inline: |
+          #!/bin/bash
+          set -euo pipefail
+          # When the update fails to correctly apply, this runs again
+          if [ -e /etc/luks/rootencrypted-bound ]; then
+            mv /etc/luks/rootencrypted-bound /etc/luks/rootencrypted-bind
+          fi
+          # But since a reboot inbetween could have bound it again,
+          # remove the PCR binding for every run
+          systemd-cryptenroll --tpm2-device=auto --unlock-key-file=/etc/luks/rootencrypted-bind --wipe-slot=tpm2 --tpm2-pcrs= /dev/disk/by-partlabel/ROOT
+  luks:
+    - name: rootencrypted
+      wipe_volume: true
+      device: "/dev/disk/by-partlabel/ROOT"
+  filesystems:
+    - device: /dev/mapper/rootencrypted
+      format: ext4
+      label: ROOT
+systemd:
+  units:
+    - name: cryptenroll-helper-first.service
+      enabled: true
+      contents: |
+        [Unit]
+        ConditionFirstBoot=true
+        OnFailure=emergency.target
+        OnFailureJobMode=isolate
+        After=first-boot-complete.target multi-user.target
+        [Service]
+        Type=oneshot
+        RemainAfterExit=yes
+        ExecStart=systemd-cryptenroll --tpm2-device=auto --unlock-key-file=/etc/luks/rootencrypted --tpm2-pcrs= /dev/disk/by-partlabel/ROOT
+        ExecStart=mv /etc/luks/rootencrypted /etc/luks/rootencrypted-bind
+        ExecStart=sleep 10
+        ExecStart=systemctl reboot
+        [Install]
+        WantedBy=multi-user.target
+    - name: cryptenroll-helper-bind.service
+      enabled: true
+      contents: |
+        [Unit]
+        ConditionFirstBoot=false
+        ConditionPathExists=/etc/luks/rootencrypted-bind
+        OnFailure=emergency.target
+        OnFailureJobMode=isolate
+        Before=update-engine.service
+        [Service]
+        Type=oneshot
+        RemainAfterExit=yes
+        ExecStart=systemd-cryptenroll --tpm2-device=auto --unlock-key-file=/etc/luks/rootencrypted-bind --tpm2-pcrs=4+7+8+9+11+12+13 --wipe-slot=tpm2 /dev/disk/by-partlabel/ROOT
+        ExecStart=mv /etc/luks/rootencrypted-bind /etc/luks/rootencrypted-bound
+        [Install]
+        WantedBy=multi-user.target
 `)
 	IgnitionConfigRootTPM = `{
 		"ignition": {
@@ -124,7 +252,7 @@ systemd:
 
 func init() {
 	runRootTPMCryptenroll := func(c cluster.TestCluster) {
-		tpmTest(c, IgnitionConfigRootCryptenroll, "/")
+		tpmTest(c, IgnitionConfigRootCryptenroll, "/", VariantDefault)
 	}
 	register.Register(&register.Test{
 		Run:         runRootTPMCryptenroll,
@@ -134,9 +262,31 @@ func init() {
 		Distros:     []string{"cl"},
 		MinVersion:  semver.Version{Major: 3913, Minor: 0, Patch: 1},
 	})
+	runRootTPMCryptenrollPcrNoUpdate := func(c cluster.TestCluster) {
+		tpmTest(c, IgnitionConfigRootCryptenrollPcrNoUpdate, "/", VariantNoUpdate)
+	}
+	register.Register(&register.Test{
+		Run:         runRootTPMCryptenrollPcrNoUpdate,
+		ClusterSize: 0,
+		Platforms:   []string{"qemu"},
+		Name:        "cl.tpm.root-cryptenroll-pcr-noupdate",
+		Distros:     []string{"cl"},
+		MinVersion:  semver.Version{Major: 3913, Minor: 0, Patch: 1},
+	})
+	runRootTPMCryptenrollPcrWithUpdate := func(c cluster.TestCluster) {
+		tpmTest(c, IgnitionConfigRootCryptenrollPcrWithUpdate, "/", VariantWithUpdate)
+	}
+	register.Register(&register.Test{
+		Run:         runRootTPMCryptenrollPcrWithUpdate,
+		ClusterSize: 0,
+		Platforms:   []string{"qemu"},
+		Name:        "cl.tpm.root-cryptenroll-pcr-withupdate",
+		Distros:     []string{"cl"},
+		MinVersion:  semver.Version{Major: 3913, Minor: 0, Patch: 1},
+	})
 
 	runRootTPM := func(c cluster.TestCluster) {
-		tpmTest(c, conf.Ignition(IgnitionConfigRootTPM), "/")
+		tpmTest(c, conf.Ignition(IgnitionConfigRootTPM), "/", VariantDefault)
 	}
 	register.Register(&register.Test{
 		Run:         runRootTPM,
@@ -148,7 +298,7 @@ func init() {
 	})
 
 	runNonRootTPM := func(c cluster.TestCluster) {
-		tpmTest(c, conf.Ignition(IgnitionConfigNonRootTPM), "/mnt/data")
+		tpmTest(c, conf.Ignition(IgnitionConfigNonRootTPM), "/mnt/data", VariantDefault)
 	}
 	register.Register(&register.Test{
 		Run:         runNonRootTPM,
@@ -160,7 +310,7 @@ func init() {
 	})
 }
 
-func tpmTest(c cluster.TestCluster, userData *conf.UserData, mountpoint string) {
+func tpmTest(c cluster.TestCluster, userData *conf.UserData, mountpoint string, variant string) {
 	swtpm, err := startSwtpm()
 	if err != nil {
 		c.Fatalf("could not start software TPM emulation: %v", err)
@@ -188,6 +338,13 @@ func tpmTest(c cluster.TestCluster, userData *conf.UserData, mountpoint string)
 		c.Fatal(err)
 	}
 
+	if variant == VariantNoUpdate || variant == VariantWithUpdate {
+		// Wait for the first reboot
+		time.Sleep(1 * time.Minute)
+		// Verify that the machine rebooted
+		_ = c.MustSSH(m, "grep -v flatcar.first_boot /proc/cmdline")
+	}
+
 	checkIfMountpointIsEncrypted(c, m, mountpoint)
 
 	// Make sure the change is reboot-safe. This is especially important for the case of an encrypted root disk because the
@@ -199,6 +356,19 @@ func tpmTest(c cluster.TestCluster, userData *conf.UserData, mountpoint string)
 	}
 
 	checkIfMountpointIsEncrypted(c, m, mountpoint)
+
+	if variant == VariantWithUpdate {
+		// Simulate update effect by
+		// affecting the GRUB PCR values for the next boot
+		_ = c.MustSSH(m, "echo 'set linux_append=\"flatcar.autologin console=ttyS0,115200 quiet\"' | sudo tee -a /oem/grub.cfg")
+		// and calling the OEM hook we set up
+		_ = c.MustSSH(m, "sudo /oem/bin/oem-postinst")
+		err := m.Reboot()
+		if err != nil {
+			c.Fatalf("could not reboot machine: %v", err)
+		}
+		checkIfMountpointIsEncrypted(c, m, "/")
+	}
 }
 
 type softwareTPM struct {