efi_loader: Fix EFI_VARIABLE_APPEND_WRITE hash check
According to UEFI v2.10 spec section 8.2.6, if a caller invokes the
SetVariables() service, it will produce a digest from hash(VariableName,
VendorGuid, Attributes, TimeStamp, DataNew_variable_content), then the
firmware that implements the SetVariable() service will compare the
digest with the result of applying the signer’s public key to the
signature. For EFI variable append write, efitools sign-efi-sig-list has
an option "-a" to add EFI_VARIABLE_APPEND_WRITE attr, and u-boot will
drop this attribute in efi_set_variable_int(). So if a caller uses
"sign-efi-sig-list -a" to create the authenticated variable, this append
write will fail in the u-boot due to "hash check failed".
This patch resumes writing the EFI_VARIABLE_APPEND_WRITE attr to ensure
that the hash check is correct. And also update the "test_efi_secboot"
test case to compliance with the change.
Signed-off-by: Weizhao Ouyang <o451686892@gmail.com>
diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index 1cc02ac..09651d4 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -288,7 +288,6 @@
/* check if a variable exists */
var = efi_var_mem_find(vendor, variable_name, NULL);
append = !!(attributes & EFI_VARIABLE_APPEND_WRITE);
- attributes &= ~EFI_VARIABLE_APPEND_WRITE;
delete = !append && (!data_size || !attributes);
/* check attributes */
@@ -304,7 +303,7 @@
/* attributes won't be changed */
if (!delete &&
- ((ro_check && var->attr != attributes) ||
+ ((ro_check && var->attr != (attributes & ~EFI_VARIABLE_APPEND_WRITE)) ||
(!ro_check && ((var->attr & ~EFI_VARIABLE_READ_ONLY)
!= (attributes & ~EFI_VARIABLE_READ_ONLY))))) {
return EFI_INVALID_PARAMETER;
@@ -378,7 +377,8 @@
for (; *old_data; ++old_data)
;
++old_data;
- ret = efi_var_mem_ins(variable_name, vendor, attributes,
+ ret = efi_var_mem_ins(variable_name, vendor,
+ attributes & ~EFI_VARIABLE_APPEND_WRITE,
var->length, old_data, data_size, data,
time);
} else {
diff --git a/test/py/tests/test_efi_secboot/conftest.py b/test/py/tests/test_efi_secboot/conftest.py
index ff7ac7c..0fa0747 100644
--- a/test/py/tests/test_efi_secboot/conftest.py
+++ b/test/py/tests/test_efi_secboot/conftest.py
@@ -64,6 +64,12 @@
check_call('cd %s; %scert-to-efi-sig-list -g %s db1.crt db1.esl; %ssign-efi-sig-list -t "2020-04-05" -c KEK.crt -k KEK.key db db1.esl db1.auth'
% (mnt_point, EFITOOLS_PATH, GUID, EFITOOLS_PATH),
shell=True)
+ # db2 (APPEND_WRITE)
+ check_call('cd %s; openssl req -x509 -sha256 -newkey rsa:2048 -subj /CN=TEST_db2/ -keyout db2.key -out db2.crt -nodes -days 365'
+ % mnt_point, shell=True)
+ check_call('cd %s; %scert-to-efi-sig-list -g %s db2.crt db2.esl; %ssign-efi-sig-list -a -c KEK.crt -k KEK.key db db2.esl db2.auth'
+ % (mnt_point, EFITOOLS_PATH, GUID, EFITOOLS_PATH),
+ shell=True)
# dbx (TEST_dbx certificate)
check_call('cd %s; openssl req -x509 -sha256 -newkey rsa:2048 -subj /CN=TEST_dbx/ -keyout dbx.key -out dbx.crt -nodes -days 365'
% mnt_point, shell=True)
@@ -84,6 +90,10 @@
check_call('cd %s; %scert-to-efi-hash-list -g %s -s 256 db1.crt dbx_hash1.crl; %ssign-efi-sig-list -t "2020-04-06" -c KEK.crt -k KEK.key dbx dbx_hash1.crl dbx_hash1.auth'
% (mnt_point, EFITOOLS_PATH, GUID, EFITOOLS_PATH),
shell=True)
+ # dbx_hash2 (digest of TEST_db2 certificate, with APPEND_WRITE)
+ check_call('cd %s; %scert-to-efi-hash-list -g %s -s 256 db2.crt dbx_hash2.crl; %ssign-efi-sig-list -a -c KEK.crt -k KEK.key dbx dbx_hash2.crl dbx_hash2.auth'
+ % (mnt_point, EFITOOLS_PATH, GUID, EFITOOLS_PATH),
+ shell=True)
# dbx_db (with TEST_db certificate)
check_call('cd %s; %ssign-efi-sig-list -t "2020-04-05" -c KEK.crt -k KEK.key dbx db.esl dbx_db.auth'
% (mnt_point, EFITOOLS_PATH),
diff --git a/test/py/tests/test_efi_secboot/test_authvar.py b/test/py/tests/test_efi_secboot/test_authvar.py
index f99b827..d5aeb65 100644
--- a/test/py/tests/test_efi_secboot/test_authvar.py
+++ b/test/py/tests/test_efi_secboot/test_authvar.py
@@ -183,7 +183,7 @@
assert 'db:' in ''.join(output)
output = u_boot_console.run_command_list([
- 'fatload host 0:1 4000000 db1.auth',
+ 'fatload host 0:1 4000000 db2.auth',
'setenv -e -nv -bs -rt -a -i 4000000:$filesize db'])
assert 'Failed to set EFI variable' in ''.join(output)
@@ -197,7 +197,7 @@
with u_boot_console.log.section('Test Case 3c'):
# Test Case 3c, update with correct signature
output = u_boot_console.run_command_list([
- 'fatload host 0:1 4000000 db1.auth',
+ 'fatload host 0:1 4000000 db2.auth',
'setenv -e -nv -bs -rt -at -a -i 4000000:$filesize db',
'printenv -e -n -guid d719b2cb-3d3a-4596-a3bc-dad00e67656f db'])
assert 'Failed to set EFI variable' not in ''.join(output)
diff --git a/test/py/tests/test_efi_secboot/test_signed.py b/test/py/tests/test_efi_secboot/test_signed.py
index 5000a4a..f604138 100644
--- a/test/py/tests/test_efi_secboot/test_signed.py
+++ b/test/py/tests/test_efi_secboot/test_signed.py
@@ -177,7 +177,7 @@
with u_boot_console.log.section('Test Case 5b'):
# Test Case 5b, authenticated if both signatures are verified
output = u_boot_console.run_command_list([
- 'fatload host 0:1 4000000 db1.auth',
+ 'fatload host 0:1 4000000 db2.auth',
'setenv -e -nv -bs -rt -at -a -i 4000000:$filesize db'])
assert 'Failed to set EFI variable' not in ''.join(output)
output = u_boot_console.run_command_list([
@@ -201,7 +201,7 @@
with u_boot_console.log.section('Test Case 5d'):
# Test Case 5d, rejected if both of signatures are revoked
output = u_boot_console.run_command_list([
- 'fatload host 0:1 4000000 dbx_hash1.auth',
+ 'fatload host 0:1 4000000 dbx_hash2.auth',
'setenv -e -nv -bs -rt -at -a -i 4000000:$filesize dbx'])
assert 'Failed to set EFI variable' not in ''.join(output)
output = u_boot_console.run_command_list([
@@ -223,7 +223,7 @@
'setenv -e -nv -bs -rt -at -i 4000000:$filesize KEK',
'fatload host 0:1 4000000 PK.auth',
'setenv -e -nv -bs -rt -at -i 4000000:$filesize PK',
- 'fatload host 0:1 4000000 db1.auth',
+ 'fatload host 0:1 4000000 db2.auth',
'setenv -e -nv -bs -rt -at -a -i 4000000:$filesize db',
'fatload host 0:1 4000000 dbx_hash1.auth',
'setenv -e -nv -bs -rt -at -i 4000000:$filesize dbx'])
@@ -300,7 +300,7 @@
'setenv -e -nv -bs -rt -at -i 4000000:$filesize KEK',
'fatload host 0:1 4000000 PK.auth',
'setenv -e -nv -bs -rt -at -i 4000000:$filesize PK',
- 'fatload host 0:1 4000000 db1.auth',
+ 'fatload host 0:1 4000000 db2.auth',
'setenv -e -nv -bs -rt -at -a -i 4000000:$filesize db',
'fatload host 0:1 4000000 dbx_hash384.auth',
'setenv -e -nv -bs -rt -at -i 4000000:$filesize dbx'])
@@ -323,7 +323,7 @@
'setenv -e -nv -bs -rt -at -i 4000000:$filesize KEK',
'fatload host 0:1 4000000 PK.auth',
'setenv -e -nv -bs -rt -at -i 4000000:$filesize PK',
- 'fatload host 0:1 4000000 db1.auth',
+ 'fatload host 0:1 4000000 db2.auth',
'setenv -e -nv -bs -rt -at -a -i 4000000:$filesize db',
'fatload host 0:1 4000000 dbx_hash512.auth',
'setenv -e -nv -bs -rt -at -i 4000000:$filesize dbx'])