systemd-sbsign1

Usage

Overview

systemd-sbsign can be used to sign PE binaries for EFI Secure Boot.

Commands

sign

Options

The following options are understood:

--output=PATH

Specifies the path where to write the signed PE binary or the data to be signed offline when using the --prepare-offline-signing option.

Added in version 257.

--private-key=PATH/URI, --private-key-source=TYPE[:NAME], --certificate=PATH, --certificate-source=TYPE[:NAME]

Set the Secure Boot private key and certificate for use with the sign verb. The --certificate= option takes a path to a PEM-encoded X.509 certificate or a URI that's passed to the OpenSSL provider configured with --certificate-source=. The --certificate-source= option takes one of "file" or "provider", with the latter being followed by a specific provider identifier, separated with a colon, e.g. "provider:pkcs11". The --private-key= option takes a path or a URI that will be passed to the OpenSSL engine or provider, as specified by --private-key-source= as a "type:name" tuple, such as "engine:pkcs11". The specified OpenSSL signing engine or provider will be used to sign the PE binary.

Added in version 257.

--prepare-offline-signing

When this option is specified, the sign command writes the data that should be signed to the path specified with --output= instead of writing the signed PE binary. This data can then be signed out of band after which the signature can be attached to the PE binary using the --signed-data= and --signed-data-signature= options.

Added in version 258.

--signed-data=PATH, --signed-data-signature=PATH

Configure the signed data (as written to the path specified with --output= when using the --prepare-offline-signing option) and corresponding signature for the sign command.

Added in version 258.

-h, --help

Print a short help text and exit.

--version

Print a short version string and exit.

Examples

Example 1. Offline EFI secure boot signing of a PE binary

The following does offline secure boot signing of systemd-boot:

SD_BOOT="$(find /usr/lib/systemd/boot/efi/ -name "systemd-boot*.efi" | head -n1)"
# Extract the data that should be signed offline.
/usr/lib/systemd/systemd-sbsign \
    sign \
    --certificate=secure-boot-certificate.pem \
    --output=signed-data.bin \
    --prepare-offline-signing \
    "$SD_BOOT"
# Sign the data out-of-band. This step usually happens out-of-band on a separate system.
openssl dgst -sha256 -sign secure-boot-private-key.pem -out signed-data.sig signed-data.bin
# Attach the signed data and its signature to the systemd-boot PE binary.
/usr/lib/systemd/systemd-sbsign \
    sign \
    --certificate=secure-boot-certificate.pem \
    --output="$SD_BOOT.signed" \
    --signed-data=signed-data.bin \
    --signed-data-signature=signed-data.sig \
    "$SD_BOOT"