grub2/conf/Makefile.common
Javier Martinez Canillas 578c95298b kern: Add lockdown support
When the GRUB starts on a secure boot platform, some commands can be
used to subvert the protections provided by the verification mechanism and
could lead to booting untrusted system.

To prevent that situation, allow GRUB to be locked down. That way the code
may check if GRUB has been locked down and further restrict the commands
that are registered or what subset of their functionality could be used.

The lockdown support adds the following components:

* The grub_lockdown() function which can be used to lockdown GRUB if,
  e.g., UEFI Secure Boot is enabled.

* The grub_is_lockdown() function which can be used to check if the GRUB
  was locked down.

* A verifier that flags OS kernels, the GRUB modules, Device Trees and ACPI
  tables as GRUB_VERIFY_FLAGS_DEFER_AUTH to defer verification to other
  verifiers. These files are only successfully verified if another registered
  verifier returns success. Otherwise, the whole verification process fails.

  For example, PE/COFF binaries verification can be done by the shim_lock
  verifier which validates the signatures using the shim_lock protocol.
  However, the verification is not deferred directly to the shim_lock verifier.
  The shim_lock verifier is hooked into the verification process instead.

* A set of grub_{command,extcmd}_lockdown functions that can be used by
  code registering command handlers, to only register unsafe commands if
  the GRUB has not been locked down.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:15 +01:00

141 lines
4.9 KiB
Makefile

# -*- makefile -*-
CFLAGS_PLATFORM=
export LC_COLLATE := C
unexport LC_ALL
# Platform specific options
if COND_sparc64_ieee1275
LDFLAGS_PLATFORM = -Wl,-melf64_sparc
endif
if COND_arm
if !COND_emu
LDFLAGS_PLATFORM = -Wl,--wrap=__clear_cache
endif
endif
if COND_arm64
CFLAGS_PLATFORM += -mcmodel=large
endif
if COND_powerpc_ieee1275
CFLAGS_PLATFORM += -mcpu=powerpc
endif
# Other options
CPPFLAGS_DEFAULT = -DGRUB_FILE=\"$(subst $(srcdir)/,,$<)\"
CPPFLAGS_DEFAULT += -I$(builddir)
CPPFLAGS_DEFAULT += -I$(srcdir)
CPPFLAGS_DEFAULT += -I$(top_builddir)
CPPFLAGS_DEFAULT += -I$(top_srcdir)
CPPFLAGS_DEFAULT += -I$(top_srcdir)/include
CPPFLAGS_DEFAULT += -I$(top_builddir)/include
CPPFLAGS_DEFAULT += -I$(top_srcdir)/grub-core/lib/libgcrypt-grub/src/
CCASFLAGS_DEFAULT = $(CPPFLAGS_DEFAULT) -DASM_FILE=1
BUILD_CPPFLAGS += $(CPPFLAGS_DEFAULT)
CFLAGS_KERNEL = $(CFLAGS_PLATFORM) -ffreestanding
LDFLAGS_KERNEL = $(LDFLAGS_PLATFORM) -nostdlib $(TARGET_LDFLAGS_OLDMAGIC)
CPPFLAGS_KERNEL = $(CPPFLAGS_CPU) $(CPPFLAGS_PLATFORM) -DGRUB_KERNEL=1
CCASFLAGS_KERNEL = $(CCASFLAGS_CPU) $(CCASFLAGS_PLATFORM)
STRIPFLAGS_KERNEL = -R .rel.dyn -R .reginfo -R .note -R .comment -R .drectve -R .note.gnu.gold-version -R .MIPS.abiflags -R .ARM.exidx
CFLAGS_MODULE = $(CFLAGS_PLATFORM) -ffreestanding
LDFLAGS_MODULE = $(LDFLAGS_PLATFORM) -nostdlib $(TARGET_LDFLAGS_OLDMAGIC) -Wl,-r,-d
CPPFLAGS_MODULE = $(CPPFLAGS_CPU) $(CPPFLAGS_PLATFORM)
CCASFLAGS_MODULE = $(CCASFLAGS_CPU) $(CCASFLAGS_PLATFORM)
CFLAGS_IMAGE = $(CFLAGS_PLATFORM) -fno-builtin
LDFLAGS_IMAGE = $(LDFLAGS_PLATFORM) -nostdlib $(TARGET_LDFLAGS_OLDMAGIC) -Wl,-S
CPPFLAGS_IMAGE = $(CPPFLAGS_CPU) $(CPPFLAGS_PLATFORM)
CCASFLAGS_IMAGE = $(CCASFLAGS_CPU) $(CCASFLAGS_PLATFORM)
CFLAGS_PROGRAM =
LDFLAGS_PROGRAM =
CPPFLAGS_PROGRAM =
CCASFLAGS_PROGRAM =
CFLAGS_LIBRARY =
CPPFLAGS_LIBRARY =
CCASFLAGS_LIBRARY =
# Other variables
grubconfdir = $(sysconfdir)/grub.d
platformdir = $(pkglibdir)/$(target_cpu)-$(platform)
starfielddir = $(pkgdatadir)/themes/starfield
CFLAGS_GNULIB = -Wno-undef -Wno-sign-compare -Wno-unused -Wno-unused-parameter -Wno-redundant-decls -Wno-unreachable-code -Wno-conversion
CPPFLAGS_GNULIB = -I$(top_builddir)/grub-core/lib/gnulib -I$(top_srcdir)/grub-core/lib/gnulib
CFLAGS_POSIX = -fno-builtin
CPPFLAGS_POSIX = -I$(top_srcdir)/grub-core/lib/posix_wrap
CFLAGS_GCRY = -Wno-error -Wno-missing-field-initializers -Wno-redundant-decls -Wno-undef $(CFLAGS_POSIX)
CPPFLAGS_GCRY = -I$(top_srcdir)/grub-core/lib/libgcrypt_wrap $(CPPFLAGS_POSIX) -D_GCRYPT_IN_LIBGCRYPT=1 -I$(top_srcdir)/include/grub/gcrypt
CPPFLAGS_EFIEMU = -I$(top_srcdir)/grub-core/efiemu/runtime
# List file macros for recognizing /interesting/ modules
CPPFLAGS_FS_LIST = -Dgrub_fs_register=FS_LIST_MARKER
CPPFLAGS_VIDEO_LIST= -Dgrub_video_register=VIDEO_LIST_MARKER
CPPFLAGS_PARTMAP_LIST = -Dgrub_partition_map_register=PARTMAP_LIST_MARKER
CPPFLAGS_PARTTOOL_LIST = -Dgrub_parttool_register=PARTTOOL_LIST_MARKER
CPPFLAGS_TERMINAL_LIST = '-Dgrub_term_register_input(...)=INPUT_TERMINAL_LIST_MARKER(__VA_ARGS__)'
CPPFLAGS_TERMINAL_LIST += '-Dgrub_term_register_output(...)=OUTPUT_TERMINAL_LIST_MARKER(__VA_ARGS__)'
CPPFLAGS_COMMAND_LIST = '-Dgrub_register_command(...)=COMMAND_LIST_MARKER(__VA_ARGS__)'
CPPFLAGS_COMMAND_LIST += '-Dgrub_register_command_lockdown(...)=COMMAND_LOCKDOWN_LIST_MARKER(__VA_ARGS__)'
CPPFLAGS_COMMAND_LIST += '-Dgrub_register_extcmd(...)=EXTCOMMAND_LIST_MARKER(__VA_ARGS__)'
CPPFLAGS_COMMAND_LIST += '-Dgrub_register_extcmd_lockdown(...)=EXTCOMMAND_LOCKDOWN_LIST_MARKER(__VA_ARGS__)'
CPPFLAGS_COMMAND_LIST += '-Dgrub_register_command_p1(...)=P1COMMAND_LIST_MARKER(__VA_ARGS__)'
CPPFLAGS_FDT_LIST := '-Dgrub_fdtbus_register(...)=FDT_DRIVER_LIST_MARKER(__VA_ARGS__)'
CPPFLAGS_MARKER = $(CPPFLAGS_FS_LIST) $(CPPFLAGS_VIDEO_LIST) \
$(CPPFLAGS_PARTTOOL_LIST) $(CPPFLAGS_PARTMAP_LIST) \
$(CPPFLAGS_TERMINAL_LIST) $(CPPFLAGS_COMMAND_LIST) \
$(CPPFLAGS_FDT_LIST)
# Define these variables to calm down automake
IMG_FILES =
MOD_FILES =
MODULE_FILES =
MARKER_FILES =
KERNEL_HEADER_FILES =
man_MANS =
noinst_DATA =
pkgdata_DATA =
bin_SCRIPTS =
sbin_SCRIPTS =
bin_PROGRAMS =
platform_DATA =
sbin_PROGRAMS =
check_SCRIPTS =
dist_grubconf_DATA =
check_PROGRAMS =
noinst_SCRIPTS =
noinst_PROGRAMS =
grubconf_SCRIPTS =
noinst_LIBRARIES =
dist_noinst_DATA =
platform_SCRIPTS =
platform_PROGRAMS =
TESTS =
EXTRA_DIST =
CLEANFILES =
BUILT_SOURCES =
# Rules for Automake input
.PRECIOUS: $(top_srcdir)/Makefile.util.am
$(top_srcdir)/Makefile.util.am: $(top_srcdir)/gentpl.py $(top_srcdir)/Makefile.util.def $(top_srcdir)/Makefile.utilgcry.def
$(PYTHON) $^ > $@.new || (rm -f $@.new; exit 1)
mv $@.new $@
.PRECIOUS: $(top_srcdir)/grub-core/Makefile.core.am
$(top_srcdir)/grub-core/Makefile.core.am: $(top_srcdir)/gentpl.py $(top_srcdir)/grub-core/Makefile.core.def $(top_srcdir)/grub-core/Makefile.gcry.def
if [ "x$$GRUB_CONTRIB" != x ]; then echo "You need to run ./bootstrap manually." >&2; exit 1; fi
$(PYTHON) $^ > $@.new || (rm -f $@.new; exit 1)
mv $@.new $@