composefs and UKI support

.github/workflows/build.yaml

@@ -46,6 +46,15 @@ jobs:
       - name: Checkout
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
 
+      - name: Fetch Secboot key
+        env:
+          DB_CRT: ${{ secrets.DB_CRT }}
+          DB_KEY: ${{ secrets.DB_KEY }}
+        run: |
+          echo "Adding signing key from gha to db.crt"
+          echo "$DB_CRT" > keys/db.crt
+          echo "$DB_KEY" > keys/db.key
+
       - name: Get current date
         id: date
         run: |
@@ -86,14 +95,24 @@ jobs:
 
       - name: Build Image
         id: build_image
-        uses: redhat-actions/buildah-build@7a95fa7ee0f02d552a32753e7414641a04307056 # v2
-        with:
-          containerfiles: |
-            ./Containerfile
-          image: ${{ env.IMAGE_NAME }}
-          tags: ${{ steps.metadata.outputs.tags }}
-          labels: ${{ steps.metadata.outputs.labels }}
-          oci: true
+        shell: bash
+        run: |
+          BUILD_ELEVATE="" just build-containerfile "$IMAGE_NAME"
+
+      - name: Tag Image
+        id: tag
+        env:
+          TAGS: ${{ steps.metadata.outputs.tags }}
+          LABELS: ${{ steps.metadata.outputs.labels }}
+        shell: bash
+        run: |
+          set -xeuo pipefail
+          split=$(echo $TAGS | tr " " "\n")
+          for tag in $split
+          do
+            podman tag "$IMAGE_NAME" "$IMAGE_NAME:$tag"
+          done
+
 
       - name: Login to GitHub Container Registry
         uses: docker/login-action@184bdaa0721073962dff0199f1fb9940f07167d1 # v3

.gitignore

@@ -1,2 +1,5 @@
 cosign.key
 *.img
+target
+*.crt
+*.key

Containerfile

@@ -12,6 +12,7 @@ RUN --mount=type=tmpfs,dst=/tmp --mount=type=tmpfs,dst=/root \
     git clone "https://github.com/bootc-dev/bootc.git" /tmp/bootc && \
     make -C /tmp/bootc bin install-all && \
     printf "systemdsystemconfdir=/etc/systemd/system\nsystemdsystemunitdir=/usr/lib/systemd/system\n" | tee /usr/lib/dracut/dracut.conf.d/30-bootcrew-fix-bootc-module.conf && \
+    printf 'add_dracutmodules+=" fido2 tpm2-tss pkcs11 systemd-pcrphase "\n' | tee "/usr/lib/dracut/dracut.conf.d/20-bootcrew-tpm-luks.conf" && \
     printf 'reproducible=yes\nhostonly=no\ncompress=zstd\nadd_dracutmodules+=" ostree bootc "' | tee "/usr/lib/dracut/dracut.conf.d/30-bootcrew-bootc-container-build.conf" && \
     dracut --force "$(find /usr/lib/modules -maxdepth 1 -type d | grep -v -E "*.img" | tail -n 1)/initramfs.img" && \
     pacman -Rns --noconfirm make git rust && \

Dockerfile.cfsuki

@@ -0,0 +1,80 @@
+# from: https://github.com/bootc-dev/bootc/blob/main/Dockerfile.cfsuki
+
+# Override via --build-arg=base=<image> to use a different base
+ARG base=ghcr.io/bootcrew/arch-bootc:latest
+# This is where we get the tools to build the UKI
+ARG buildroot=docker.io/archlinux/archlinux:latest
+FROM $base AS base
+
+FROM $buildroot as buildroot-base
+RUN \
+# systemd-udev is required for /usr/lib/systemd/systemd-measure which
+# is used by ukify as invoked with the `--measure` flag below.  Not
+# strictly required, but nice to have the measured PCR values in the
+# output.
+# rm /var/lib/pacman/db.lck && \
+pacman -Sy --noconfirm systemd-ukify pesign openssl systemd-sysvcompat systemd && \
+pacman -S --clean --noconfirm
+
+FROM buildroot-base as kernel
+# Must be passed
+ARG COMPOSEFS_FSVERITY
+
+RUN --mount=type=secret,id=key \
+    --mount=type=secret,id=cert \
+    --mount=type=bind,from=base,target=/target \
+    # Should be generated externally
+    test -n "${COMPOSEFS_FSVERITY}" && \
+    # Inject the composefs kernel argument and specify a root with the x86_64 DPS UUID.
+    # TODO: Discoverable partition fleshed out, or drop root UUID as systemd-stub extension
+    # TODO: https://github.com/containers/composefs-rs/issues/183
+    cmdline="composefs=${COMPOSEFS_FSVERITY} console=ttyS0,115200n8 root=gpt-auto enforcing=0 rw" && \
+    # pesign uses NSS database so create it from input cert/key
+    mkdir pesign && \
+    certutil -N -d pesign --empty-password && \
+    openssl pkcs12 -export -password 'pass:' -inkey /run/secrets/key -in /run/secrets/cert -out db.p12 && \
+    pk12util -i db.p12 -W '' -d pesign && \
+    subject=$(openssl x509 -in /run/secrets/cert -subject | grep '^subject=CN=' | sed 's/^subject=CN=//') && \
+    kver=$(cd /target/usr/lib/modules && echo *) && \
+    ukify build \
+        --linux "/target/usr/lib/modules/$kver/vmlinuz" \
+        --initrd "/target/usr/lib/modules/$kver/initramfs.img" \
+        --uname="${kver}" \
+        --cmdline "${cmdline}" \
+        --os-release "@/target/usr/lib/os-release" \
+        --signtool pesign \
+        --secureboot-certificate-dir "pesign" \
+        --secureboot-certificate-name "${subject}" \
+        --measure \
+        --json pretty \
+        --output "/boot/$kver.efi" && \
+    # Sign systemd-boot as well
+    sdboot="/usr/lib/systemd/boot/efi/systemd-bootx64.efi" && \
+    pesign \
+        --certdir "pesign" \
+        --certificate "${subject}" \
+        --in "${sdboot}" \
+        --out "${sdboot}.signed" \
+        --sign && \
+    mv "${sdboot}.signed" "${sdboot}"
+# EOF
+
+FROM base as final
+
+RUN --mount=type=bind,from=kernel,target=/run/kernel  \
+kver=$(cd /usr/lib/modules && echo *) && \
+mkdir -p /boot/EFI/Linux && \
+# We put the UKI in /boot for now due to composefs verity not being the
+# same due to mtime of /usr/lib/modules being changed
+target=/boot/EFI/Linux/$kver.efi && \
+cp /run/kernel/boot/$kver.efi $target && \
+# And remove the defaults
+rm -v /usr/lib/modules/${kver}/{vmlinuz,initramfs.img} && \
+# Symlink into the /usr/lib/modules location
+ln -sr $target /usr/lib/modules/${kver}/$(basename $kver.efi) && \
+bootc container lint # --fatal-warnings, warnings no need to be fatel :))
+
+FROM base as final-final
+COPY --from=final /boot /boot
+# Override the default
+LABEL containers.bootc=sealed

Justfile

@@ -1,13 +1,45 @@
 image_name := env("BUILD_IMAGE_NAME", "arch-bootc")
 image_tag := env("BUILD_IMAGE_TAG", "latest")
-base_dir := env("BUILD_BASE_DIR", ".")
+base_dir := env("BUILD_BASE_DIR", "/tmp")
 filesystem := env("BUILD_FILESYSTEM", "ext4")
 
-build-containerfile $image_name=image_name:
-    sudo podman build -t "${image_name}:latest" .
+# variant can be either "ostree" or "composefs-sealeduki"
+# "ostree" here just means the image is "unsealed" and just gets tagged
+variant := env("BUILD_VARIANT", "ostree")
+
+namespace := env("BUILD_NAMESPACE", "bootcrew")
+sudo := env("BUILD_ELEVATE", "sudo")
+just_exe := just_executable()
+
+enroll-secboot-key:
+    #!/usr/bin/bash
+    ENROLLMENT_PASSWORD=""
+    SECUREBOOT_KEY=keys/db.cer
+    "{{sudo}}" mokutil --timeout -1
+    echo -e "$ENROLLMENT_PASSWORD\n$ENROLLMENT_PASSWORD" | "{{sudo}}" mokutil --import "$SECUREBOOT_KEY"
+    echo 'At next reboot, the mokutil UEFI menu UI will be displayed (*QWERTY* keyboard input and navigation).\nThen, select "Enroll MOK", and input "bootcrew" as the password'
+
+gen-secboot-keys:
+    #!/usr/bin/env bash
+    set -xeuo pipefail
+
+    openssl req -quiet -newkey rsa:4096 -nodes -keyout keys/db.key -new -x509 -sha256 -days 3650 -subj '/CN=Arch Bootc Signature Database key/' -out keys/db.crt
+    openssl x509 -outform DER -in keys/db.crt -out keys/db.cer
+
+build-containerfile $image_name=image_name $variant=variant:
+    #!/usr/bin/env bash
+    set -xeuo pipefail
+
+    {{sudo}} podman build -t "localhost/${image_name}_unsealed" .
+    # TODO: we can make this a CLI program with better UX: https://github.com/bootc-dev/bootc/issues/1498
+    {{sudo}} ./build-sealed "${variant}" "localhost/${image_name}_unsealed" "${image_name}" "keys"
+
+
+fix-var-containers-selinux:
+     {{sudo}} restorecon -RFv /var/lib/containers/storage
 
 bootc *ARGS:
-    sudo podman run \
+    {{sudo}} podman run \
         --rm --privileged --pid=host \
         -it \
         -v /sys/fs/selinux:/sys/fs/selinux \
@@ -19,9 +51,17 @@ bootc *ARGS:
         --security-opt label=type:unconfined_t \
         "{{image_name}}:{{image_tag}}" bootc {{ARGS}}
 
+
+# installs on a physical target device
+install-image $target_device $filesystem=filesystem:
+    #!/usr/bin/env bash
+    set -xeuo pipefail
+    {{just_exe}} bootc install to-disk --composefs-backend --filesystem "${filesystem}" --wipe --bootloader systemd {{target_device}}
+
+# installs onto an img file for testing in a VM
 generate-bootable-image $base_dir=base_dir $filesystem=filesystem:
     #!/usr/bin/env bash
     if [ ! -e "${base_dir}/bootable.img" ] ; then
         fallocate -l 20G "${base_dir}/bootable.img"
     fi
-    just bootc install to-disk --composefs-backend --via-loopback /data/bootable.img --filesystem "${filesystem}" --wipe --bootloader systemd
+    {{just_exe}} bootc install to-disk --composefs-backend --via-loopback /data/bootable.img --filesystem "${filesystem}" --wipe --bootloader systemd

build-sealed

@@ -0,0 +1,66 @@
+#!/bin/bash
+set -euo pipefail
+# This should turn into https://github.com/bootc-dev/bootc/issues/1498
+
+variant=$1
+shift
+# The un-sealed container image we want to use
+input_image=$1
+shift
+# The output container image
+output_image=$1
+shift
+# Optional directory with secure boot keys; if none are provided, then we'll
+# generate some under target/
+secureboot=${1:-}
+
+runv() {
+  set -x
+  "$@"
+}
+
+case $variant in
+  ostree)
+    # Nothing to do
+    echo "Not building a sealed image; forwarding tag"
+    runv podman tag $input_image $output_image
+    exit 0
+    ;;
+  composefs-sealeduki*)
+    ;;
+  *) 
+    echo "Unknown variant=$variant" 1>&2; exit 1
+    ;;
+esac
+
+
+graphroot=$(podman system info -f '{{.Store.GraphRoot}}')
+echo "Computing composefs digest..."
+cfs_digest=$(podman run --rm --privileged --read-only --security-opt=label=disable -v /sys:/sys:ro --net=none \
+  -v ${graphroot}:/run/host-container-storage:ro --tmpfs /var "$input_image" bootc container compute-composefs-digest)
+
+if test -z "${secureboot}"; then
+  secureboot=$(pwd)/keys
+  mkdir -p ${secureboot}
+  cd $secureboot
+  if test '!' -f db.cer; then
+    echo "Generating test Secure Boot keys"
+    systemd-id128 new -u > GUID.txt
+
+    openssl req -quiet -newkey rsa:4096 -nodes -keyout PK.key -new -x509 -sha256 -days 3650 -subj '/CN=Test Platform Key/' -out PK.crt
+    openssl x509 -outform DER -in PK.crt -out PK.cer
+
+    openssl req -quiet -newkey rsa:4096 -nodes -keyout KEK.key -new -x509 -sha256 -days 3650 -subj '/CN=Test Key Exchange Key/' -out KEK.crt
+    openssl x509 -outform DER -in KEK.crt -out KEK.cer
+
+    openssl req -quiet -newkey rsa:4096 -nodes -keyout db.key -new -x509 -sha256 -days 3650 -subj '/CN=Test Signature Database key/' -out db.crt
+    openssl x509 -outform DER -in db.crt -out db.cer
+  else 
+    echo "Reusing Secure Boot keys in ${secureboot}"
+  fi
+  cd -
+fi
+
+runv podman build -t $output_image --build-arg=COMPOSEFS_FSVERITY=${cfs_digest} --build-arg=base=${input_image} \
+  --secret=id=key,src=${secureboot}/db.key \
+  --secret=id=cert,src=${secureboot}/db.crt -f Dockerfile.cfsuki .