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MFC r344840: Extend libsecureboot(old libve) to obtain trusted certif…

…icates from UEFI and implement revocation

UEFI related headers were copied from edk2.

A new build option "MK_LOADER_EFI_SECUREBOOT" was added to allow
loading of trusted anchors from UEFI.

Certificate revocation support is also introduced.
The forbidden certificates are loaded from dbx variable.
Verification fails in two cases:

There is a direct match between cert in dbx and the one in the chain.
The CA used to sign the chain is found in dbx.
One can also insert a hash of TBS section of a certificate into dbx.
In this case verifications fails only if a direct match with a
certificate in chain is found.

Submitted by: Kornel Duleba <mindal@semihalf.com>
Obtained from: Semihalf
Sponsored by: Stormshield
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mw mw
mw authored and mw committed Apr 26, 2019
1 parent 892af61 commit d0a2db0d1fb36f25c570e27238a6e0d76fb42d4b
@@ -31,6 +31,17 @@ BRSSL_SRCS+= \
${BEARSSL}/tools/xmem.c \
${BEARSSL}/tools/vector.c

BRSSL_DEPS= \
brf.c \
vets.c \
veta.c

.if ${MK_LOADER_EFI_SECUREBOOT} != "no"
BRSSL_DEPS+= \
efi_init.c \
efi_variables.c
.endif

# we do not need/want nested objdirs
OBJS_SRCS_FILTER = T R

@@ -134,7 +145,7 @@ vse.h:
echo 'NULL };' ) > ${.TARGET}


.for s in ${BRSSL_SRCS} brf.c vets.c veta.c
.for s in ${BRSSL_SRCS} ${BRSSL_DEPS}
.ifdef BRSSL_SED
$s: brssl.h
.endif
@@ -16,6 +16,19 @@ SRCS+= \
vepcr.c \
verify_file.c \

# Build library with support for the UEFI based authentication
.if ${MK_LOADER_EFI_SECUREBOOT} == "yes"
SRCS+= \
efi/efi_variables.c \
efi/efi_init.c

# Add includes required by efi part
CFLAGS+= \
-I${SRCTOP}/stand/efi/include \
-I${SRCTOP}/lib/libsecureboot/efi/include \
-I${SRCTOP}/stand/efi/include/${MACHINE}
.endif

# this is the list of paths (relative to a file
# that we need to verify) used to find a signed manifest.
# the signature extensions in VE_SIGNATURE_EXT_LIST
@@ -0,0 +1,74 @@
/*-
* Copyright (c) 2019 Stormshield.
* Copyright (c) 2019 Semihalf.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
*/

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#define NEED_BRSSL_H
#include "../libsecureboot-priv.h"
#include <brssl.h>

void
ve_efi_init(void)
{
br_x509_certificate *xcs;
hash_data *digests;
size_t num;
int result;
static int once = 0;

if (once > 0)
return;

once = 1;

result = efi_secure_boot_enabled();
if (result <= 0)
return;

xcs = efi_get_trusted_certs(&num);
if (num > 0 && xcs != NULL) {
num = ve_trust_anchors_add(xcs, num);
free_certificates(xcs, num);
}
xcs = efi_get_forbidden_certs(&num);
if (num > 0 && xcs != NULL) {
num = ve_forbidden_anchors_add(xcs, num);
free_certificates(xcs, num);
}
digests = efi_get_forbidden_digests(&num);
if (num > 0 && digests != NULL) {
ve_forbidden_digest_add(digests, num);
/*
* Don't free the buffors for digests,
* since they are shallow copied.
*/
xfree(digests);
}

return;
}

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