diff options
Diffstat (limited to 'meta-integrity/classes/ima-evm-rootfs.bbclass')
| -rw-r--r-- | meta-integrity/classes/ima-evm-rootfs.bbclass | 48 |
1 files changed, 39 insertions, 9 deletions
diff --git a/meta-integrity/classes/ima-evm-rootfs.bbclass b/meta-integrity/classes/ima-evm-rootfs.bbclass index 0acd6e7..7b73373 100644 --- a/meta-integrity/classes/ima-evm-rootfs.bbclass +++ b/meta-integrity/classes/ima-evm-rootfs.bbclass @@ -17,7 +17,7 @@ IMA_EVM_X509 ?= "${IMA_EVM_KEY_DIR}/x509_ima.der" # with a .x509 suffix. See linux-%.bbappend for details. # # ima-local-ca.x509 is what ima-gen-local-ca.sh creates. -IMA_EVM_ROOT_CA ?= "" +IMA_EVM_ROOT_CA ?= "${IMA_EVM_KEY_DIR}/ima-local-ca.pem" # Sign all regular files by default. IMA_EVM_ROOTFS_SIGNED ?= ". -type f" @@ -29,7 +29,10 @@ IMA_EVM_ROOTFS_HASHED ?= ". -depth 0 -false" IMA_EVM_ROOTFS_IVERSION ?= "" # Avoid re-generating fstab when ima is enabled. -WIC_CREATE_EXTRA_ARGS_append = "${@bb.utils.contains('DISTRO_FEATURES', 'ima', ' --no-fstab-update', '', d)}" +WIC_CREATE_EXTRA_ARGS:append = "${@bb.utils.contains('DISTRO_FEATURES', 'ima', ' --no-fstab-update', '', d)}" + +# Add necessary tools (e.g., keyctl) to image +IMAGE_INSTALL:append = "${@bb.utils.contains('DISTRO_FEATURES', 'ima', ' ima-evm-utils', '', d)}" ima_evm_sign_rootfs () { cd ${IMAGE_ROOTFS} @@ -59,17 +62,44 @@ ima_evm_sign_rootfs () { perl -pi -e 's;(\S+)(\s+)(${@"|".join((d.getVar("IMA_EVM_ROOTFS_IVERSION", True) or "no-such-mount-point").split())})(\s+)(\S+)(\s+)(\S+);\1\2\3\4\5\6\7,iversion;; s/(,iversion)+/,iversion/;' etc/fstab fi - # Sign file with private IMA key. EVM not supported at the moment. - bbnote "IMA/EVM: signing files 'find ${IMA_EVM_ROOTFS_SIGNED}' with private key '${IMA_EVM_PRIVKEY}'" - find ${IMA_EVM_ROOTFS_SIGNED} | xargs -d "\n" --no-run-if-empty --verbose evmctl ima_sign --key ${IMA_EVM_PRIVKEY} - bbnote "IMA/EVM: hashing files 'find ${IMA_EVM_ROOTFS_HASHED}'" - find ${IMA_EVM_ROOTFS_HASHED} | xargs -d "\n" --no-run-if-empty --verbose evmctl ima_hash + # Detect 32bit target to pass --m32 to evmctl by looking at libc + tmp="$(file "${IMAGE_ROOTFS}/lib/libc.so.6" | grep -o 'ELF .*-bit')" + if [ "${tmp}" = "ELF 32-bit" ]; then + evmctl_param="--m32" + elif [ "${tmp}" = "ELF 64-bit" ]; then + evmctl_param="" + else + bberror "Unknown target architecture bitness: '${tmp}'" >&2 + exit 1 + fi + + bbnote "IMA/EVM: Signing root filesystem at ${IMAGE_ROOTFS} with key ${IMA_EVM_PRIVKEY}" + evmctl sign --imasig ${evmctl_param} --portable -a sha256 --key ${IMA_EVM_PRIVKEY} -r "${IMAGE_ROOTFS}" + + # check signing key and signature verification key + evmctl ima_verify ${evmctl_param} --key "${IMA_EVM_X509}" "${IMAGE_ROOTFS}/lib/libc.so.6" || exit 1 + evmctl verify ${evmctl_param} --key "${IMA_EVM_X509}" "${IMAGE_ROOTFS}/lib/libc.so.6" || exit 1 # Optionally install custom policy for loading by systemd. - if [ "${IMA_EVM_POLICY_SYSTEMD}" ]; then + if [ "${IMA_EVM_POLICY}" ]; then install -d ./${sysconfdir}/ima rm -f ./${sysconfdir}/ima/ima-policy - install "${IMA_EVM_POLICY_SYSTEMD}" ./${sysconfdir}/ima/ima-policy + install "${IMA_EVM_POLICY}" ./${sysconfdir}/ima/ima-policy + + bbnote "IMA/EVM: Signing IMA policy with key ${IMA_EVM_PRIVKEY}" + evmctl sign --imasig ${evmctl_param} --portable -a sha256 --key "${IMA_EVM_PRIVKEY}" "${IMAGE_ROOTFS}/etc/ima/ima-policy" + fi + + # Optionally write the file names and ima and evm signatures into files + if [ "${IMA_FILE_SIGNATURES_FILE}" ]; then + getfattr -R -m security.ima --e hex --dump ./ 2>/dev/null | \ + sed -n -e 's|# file: |/|p' -e 's|security.ima=|ima:|p' | \ + sed '$!N;s/\n/ /' > ./${IMA_FILE_SIGNATURES_FILE} + fi + if [ "${EVM_FILE_SIGNATURES_FILE}" ]; then + getfattr -R -m security.evm --e hex --dump ./ 2>/dev/null | \ + sed -n -e 's|# file: |/|p' -e 's|security.evm=|evm:|p' | \ + sed '$!N;s/\n/ /' > ./${EVM_FILE_SIGNATURES_FILE} fi } |