Hi everyone (note for the infrastructure mailing list: please check if the changes I'm proposing could be tested in the Fedora infrastructure, like Copr) I made the first version of the rpm extension to sign fsverity digests with a GPG key. The patch set (with some bug fixes) is available here: https://github.com/robertosassu/rpm/commits/fsverity-gpg-v1 I tested it locally with my own GPG key. I took an existing Fedora 34 package and signed it with rpmsign: $ usr/bin/rpmsign --define "%_gpg_name testhost <testhost(a)test.test&gt;&quot; \ --define "%_file_signing_key _GPG_" \ --define "%_file_signing_cert _GPG_" \ --addsign --signverity tmux-3.1c-2.fc34.x86_64.rpm I then checked that the package has now fsverity signatures: $ usr/bin/rpm -qp tmux-3.1c-2.fc34.x86_64.rpm \ --queryformat '[%{RPMTAG_FILENAMES} %{RPMTAG_VERITYSIGNATURES}\n]' [...] /usr/bin/tmux iQHHBAABCgAxFiEEEiFa0dGZVYzTrIN+rxtXRMfK0McFAmHq0+4THHRlc3Rob3N0 QHRlc3QudGVzdAAKCRCvG1dEx8rQx81nC/42NW9xJx3rcTiR6/5oL55GPkan+OIq t2dW1clJUOrxOGVy/5JQTQf0MQXA7gzH1yPgcrskkahjSfWlp4pt7oOw3rukUyaO zVZxue4XE6XESYtolczK4VEhpc8lbm4hj0e4NCg/dKri/+L5wIdJvmqWNeCfl7uZ [...] In a VM I tried to install the modified package. The root filesystem is ext4 and has the fsverity feature enabled. The fsverity rpm plugin is also enabled and hasn't been modified to work with the new PGP signatures. The kernel includes the patch set I recently sent to the kernel mailing lists to add support for PGP keys and signatures: https://lore.kernel.org/linux-integrity/20220111180318.591029-1-roberto.s... and another patch that calls verify_pgp_signature() in fs/verity/signature.c. The first installation attempt fails, due to the missing key in the .fs-verity keyring: # usr/bin/rpm -Uhvi ../tmux-3.1c-2.fc34.x86_64.rpm --debug [...] D: Plugin: calling hook fsm_file_prepare in fsverity plugin D: applying signature: [...] D: failed to enable verity (errno 126) for /usr/bin/tmux;61ead62d Then, I added the required GPG key to the .fs-verity keyring: # cat /mnt/repos/linux/certs/pubring.gpg | keyctl padd asymmetric test %keyring:.fs-verity 76292211 The key is now loaded: # keyctl show %keyring:.fs-verity Keyring 66741466 --a-swrv 0 0 keyring: .fs-verity 76292211 --als--v 0 0 \_ asymmetric: test I retried the tmux installation: # usr/bin/rpm -Uhvi ../tmux-3.1c-2.fc34.x86_64.rpm --debug [...] D: Plugin: calling hook fsm_file_prepare in fsverity plugin D: applying signature: [...] D: fsverity enabled signature for: path /usr/bin/tmux;61ead713 dest /usr/bin/tmux This time the installation is successful, which means that the PGP signature has been successfully verified. Roberto HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063 Managing Director: Li Peng, Zhong Ronghua