Hi, This is the final piece of the puzzle of verifying kernel image signature during kexec_file_load() syscall. It relies on following two patch series. - kexec_file_load() syscall patches https://lkml.org/lkml/2014/6/26/497 This patch series is now available in -mm tree. - PE File parsing and signature verification http://thread.gmane.org/gmane.linux.kernel/1742967 This patch series is also available here. http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-modsign.git/log/?h=pefile This patch calls into PE file routines to verify signature of bzImage. If signature are valid, kexec_file_load() succeeds otherwise it fails. Two new config options have been intorduced. First one is CONFIG_KEXEC_VERIFY_SIG. This option enforces that kernel has to be validly signed otherwise kernel load will fail. If this option is not set, no signature verification will be done. Only exception will be when secureboot is enabled. In that case signature verification should be automatically enforced when secureboot is enabled. But that will happen when secureboot patches are merged. Second config option is CONFIG_KEXEC_BZIMAGE_VERIFY_SIG. This option enables signature verification support on bzImage. If this option is not set and previous one is set, kernel image loading will fail because kernel does not have support to verify signature of bzImage. I tested these patches with both "pesign" and "sbsign" signed bzImages. I used signing_key.priv key and signing_key.x509 cert for signing as generated during kernel build process (if module signing is enabled). Used following method to sign bzImage. pesign ====== - Convert DER format cert to PEM format cert openssl x509 -in signing_key.x509 -inform DER -out signing_key.x509.PEM -outform PEM - Generate a .p12 file from existing cert and private key file openssl pkcs12 -export -out kernel-key.p12 -inkey signing_key.priv -in signing_key.x509.PEM - Import .p12 file into pesign db pk12util -i /tmp/kernel-key.p12 -d /etc/pki/pesign - Sign bzImage pesign -i /boot/vmlinuz-3.16.0-rc3+ -o /boot/vmlinuz-3.16.0-rc3+.signed.pesign -c "Glacier signing key - Magrathea" -s sbsign ====== sbsign --key signing_key.priv --cert signing_key.x509.PEM --output /boot/vmlinuz-3.16.0-rc3+.signed.sbsign /boot/vmlinuz-3.16.0-rc3+ Thanks Vivek Vivek Goyal (1): kexec: Verify the signature of signed PE bzImage arch/x86/Kconfig | 22 ++++++++++++++++++++++ arch/x86/kernel/kexec-bzimage64.c | 21 +++++++++++++++++++++ arch/x86/kernel/machine_kexec_64.c | 11 +++++++++++ include/linux/kexec.h | 3 +++ kernel/kexec.c | 15 +++++++++++++++ 5 files changed, 72 insertions(+) -- 1.9.0
