[PATCH 8/8] test/py: efi_secboot: add test for intermediate certificates

Heinrich Schuchardt xypron.glpk at gmx.de
Tue Jun 9 12:33:07 CEST 2020


On 09.06.20 07:14, AKASHI Takahiro wrote:
> In this test case, an image may have a signature with additional
> intermediate certificates. A chain of trust will be followed and all
> the certificates in the middle of chain must be verified before loading.
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> ---
>  test/py/tests/test_efi_secboot/conftest.py    | 138 +++++++++++++++++-
>  test/py/tests/test_efi_secboot/defs.py        |  11 +-
>  test/py/tests/test_efi_secboot/openssl.cnf    |  48 ++++++
>  .../test_efi_secboot/test_signed_intca.py     | 135 +++++++++++++++++
>  4 files changed, 329 insertions(+), 3 deletions(-)
>  create mode 100644 test/py/tests/test_efi_secboot/openssl.cnf
>  create mode 100644 test/py/tests/test_efi_secboot/test_signed_intca.py
>
> diff --git a/test/py/tests/test_efi_secboot/conftest.py b/test/py/tests/test_efi_secboot/conftest.py
> index 5ac0389064e8..6c5415021610 100644
> --- a/test/py/tests/test_efi_secboot/conftest.py
> +++ b/test/py/tests/test_efi_secboot/conftest.py
> @@ -34,7 +34,7 @@ def efi_boot_env(request, u_boot_config):
>      global HELLO_PATH
>
>      image_path = u_boot_config.persistent_data_dir
> -    image_path = image_path + '/' + EFI_SECBOOT_IMAGE_NAME
> +    image_path = image_path + '/' + EFI_SECBOOT_IMAGE_NAME + '.img'
>      image_size = EFI_SECBOOT_IMAGE_SIZE
>      part_size = EFI_SECBOOT_PART_SIZE
>      fs_type = EFI_SECBOOT_FS_TYPE
> @@ -43,7 +43,7 @@ def efi_boot_env(request, u_boot_config):
>          HELLO_PATH = u_boot_config.build_dir + '/lib/efi_loader/helloworld.efi'
>
>      try:
> -        mnt_point = u_boot_config.persistent_data_dir + '/mnt_efisecure'
> +        mnt_point = u_boot_config.persistent_data_dir + MNTPNT
>          check_call('mkdir -p {}'.format(mnt_point), shell=True)
>
>          # create a disk/partition
> @@ -153,3 +153,137 @@ def efi_boot_env(request, u_boot_config):
>          yield image_path
>      finally:
>          call('rm -f %s' % image_path, shell=True)
> +
> +#
> +# Fixture for UEFI secure boot test of intermediate certificates
> +#
> + at pytest.fixture(scope='session')
> +def efi_boot_env_intca(request, u_boot_config):
> +    """Set up a file system to be used in UEFI secure boot test
> +    of intermediate certificates.
> +
> +    Args:
> +        request: Pytest request object.
> +	u_boot_config: U-boot configuration.
> +
> +    Return:
> +        A path to disk image to be used for testing
> +    """
> +    global HELLO_PATH
> +
> +    image_path = u_boot_config.persistent_data_dir
> +    image_path = image_path + '/' + EFI_SECBOOT_IMAGE_NAME + '_intca.img'
> +    image_size = EFI_SECBOOT_IMAGE_SIZE
> +    part_size = EFI_SECBOOT_PART_SIZE
> +    fs_type = EFI_SECBOOT_FS_TYPE
> +
> +    if HELLO_PATH == '':
> +        HELLO_PATH = u_boot_config.build_dir + '/lib/efi_loader/helloworld.efi'
> +
> +    try:
> +        mnt_point = u_boot_config.persistent_data_dir + MNTPNT
> +        check_call('mkdir -p {}'.format(mnt_point), shell=True)
> +
> +        # create a disk/partition
> +        check_call('dd if=/dev/zero of=%s bs=1MiB count=%d'
> +                            % (image_path, image_size), shell=True)
> +        check_call('sgdisk %s -n 1:0:+%dMiB'
> +                            % (image_path, part_size), shell=True)
> +        # create a file system
> +        check_call('dd if=/dev/zero of=%s.tmp bs=1MiB count=%d'
> +                            % (image_path, part_size), shell=True)
> +        check_call('mkfs -t %s %s.tmp' % (fs_type, image_path), shell=True)
> +        check_call('dd if=%s.tmp of=%s bs=1MiB seek=1 count=%d conv=notrunc'
> +                            % (image_path, image_path, 1), shell=True)
> +        check_call('rm %s.tmp' % image_path, shell=True)
> +        loop_dev = check_output('sudo losetup -o 1MiB --sizelimit %dMiB --show -f %s | tr -d "\n"'
> +                                % (part_size, image_path), shell=True).decode()
> +        check_output('sudo mount -t %s -o umask=000 %s %s'
> +                                % (fs_type, loop_dev, mnt_point), shell=True)
> +
> +        # Create signature database
> +        ## PK
> +        check_call('cd %s; openssl req -x509 -sha256 -newkey rsa:2048 -subj /CN=TEST_PK/ -keyout PK.key -out PK.crt -nodes -days 365'
> +                            % mnt_point, shell=True)
> +        check_call('cd %s; %scert-to-efi-sig-list -g %s PK.crt PK.esl; %ssign-efi-sig-list -c PK.crt -k PK.key PK PK.esl PK.auth'
> +                            % (mnt_point, EFITOOLS_PATH, GUID, EFITOOLS_PATH),
> +                            shell=True)
> +        ## KEK
> +        check_call('cd %s; openssl req -x509 -sha256 -newkey rsa:2048 -subj /CN=TEST_KEK/ -keyout KEK.key -out KEK.crt -nodes -days 365'
> +                            % mnt_point, shell=True)
> +        check_call('cd %s; %scert-to-efi-sig-list -g %s KEK.crt KEK.esl; %ssign-efi-sig-list -c PK.crt -k PK.key KEK KEK.esl KEK.auth'
> +                            % (mnt_point, EFITOOLS_PATH, GUID, EFITOOLS_PATH),
> +                            shell=True)
> +
> +        # We will have three-tier hierarchy of certificates:
> +        #   TestRoot: Root CA (self-signed)
> +        #   TestSub: Intermediate CA (signed by Root CA)
> +        #   TestCert: User certificate (signed by Intermediate CA, and used
> +        #             for signing an image)
> +        #
> +        # NOTE:
> +        # I consulted the following EDK2 document for certificate options:
> +        #     BaseTools/Source/Python/Pkcs7Sign/Readme.md
> +        # Please not use them as they are in product system. They are
> +        # for test purpose only.
> +
> +        # TestRoot
> +        check_call('cp %s/test/py/tests/test_efi_secboot/openssl.cnf %s' % (u_boot_config.source_dir, mnt_point), shell=True)
> +        check_call('cd %s; openssl genrsa -out TestRoot.key 2048; openssl req --config openssl.cnf -extensions v3_ca -new -x509 -days 365 -key TestRoot.key -out TestRoot.crt -subj "/CN=TEST_root/"; touch index.txt' % mnt_point, shell=True)
> +        # TestSub
> +        check_call('cd %s; openssl genrsa -out TestSub.key 2048; openssl req -new -key TestSub.key -out TestSub.csr -subj "/CN=TEST_sub/"; openssl ca --config openssl.cnf -in TestSub.csr -out TestSub.crt -extensions v3_int_ca -days 365 -batch -rand_serial -cert TestRoot.crt -keyfile TestRoot.key' % mnt_point, shell=True)

This line does not fit onto my screen. PEP-8 suggests a maximum of 79
characters (https://www.python.org/dev/peps/pep-0008/). At least try not
to exceed 100.

Best regards

Heinrich


> +        # TestCert
> +        check_call('cd %s; openssl genrsa -out TestCert.key 2048; openssl req -new -key TestCert.key -out TestCert.csr -subj "/CN=TEST_cert/"; openssl ca --config openssl.cnf -in TestCert.csr -out TestCert.crt -extensions usr_cert -days 365 -batch -rand_serial -cert TestSub.crt -keyfile TestSub.key' % mnt_point, shell=True)
> +        ## db
> +        #  for TestCert
> +        check_call('cd %s; %scert-to-efi-sig-list -g %s TestCert.crt TestCert.esl; %ssign-efi-sig-list -c KEK.crt -k KEK.key db TestCert.esl db_a.auth'
> +                            % (mnt_point, EFITOOLS_PATH, GUID, EFITOOLS_PATH),
> +                            shell=True)
> +        #  for TestSub
> +        check_call('cd %s; %scert-to-efi-sig-list -g %s TestSub.crt TestSub.esl; %ssign-efi-sig-list -c KEK.crt -k KEK.key db TestSub.esl db_b.auth'
> +                            % (mnt_point, EFITOOLS_PATH, GUID, EFITOOLS_PATH),
> +                            shell=True)
> +        #  for TestRoot
> +        check_call('cd %s; %scert-to-efi-sig-list -g %s TestRoot.crt TestRoot.esl; %ssign-efi-sig-list -c KEK.crt -k KEK.key db TestRoot.esl db_c.auth'
> +                            % (mnt_point, EFITOOLS_PATH, GUID, EFITOOLS_PATH),
> +                            shell=True)
> +        ## dbx (hash of certificate with revocation time)
> +        #  for TestCert
> +        check_call('cd %s; %scert-to-efi-hash-list -g %s -t 0 -s 256 TestCert.crt TestCert.crl; %ssign-efi-sig-list -c KEK.crt -k KEK.key dbx TestCert.crl dbx_a.auth'
> +                            % (mnt_point, EFITOOLS_PATH, GUID, EFITOOLS_PATH),
> +                            shell=True)
> +        #  for TestSub
> +        check_call('cd %s; %scert-to-efi-hash-list -g %s -t 0 -s 256 TestSub.crt TestSub.crl; %ssign-efi-sig-list -c KEK.crt -k KEK.key dbx TestSub.crl dbx_b.auth'
> +                            % (mnt_point, EFITOOLS_PATH, GUID, EFITOOLS_PATH),
> +                            shell=True)
> +        #  for TestRoot
> +        check_call('cd %s; %scert-to-efi-hash-list -g %s -t 0 -s 256 TestRoot.crt TestRoot.crl; %ssign-efi-sig-list -c KEK.crt -k KEK.key dbx TestRoot.crl dbx_c.auth'
> +                            % (mnt_point, EFITOOLS_PATH, GUID, EFITOOLS_PATH),
> +                            shell=True)
> +
> +        # Sign image
> +        # additional intermediate certificates may be included
> +        # in SignedData
> +
> +        check_call('cp %s %s' % (HELLO_PATH, mnt_point), shell=True)
> +        ## signed by TestCert
> +        check_call('cd %s; %ssbsign --key TestCert.key --cert TestCert.crt --out helloworld.efi.signed_a helloworld.efi'
> +                            % (mnt_point, SBSIGN_PATH), shell=True)
> +        ## signed by TestCert with TestSub in signature
> +        check_call('cd %s; %ssbsign --key TestCert.key --cert TestCert.crt --addcert TestSub.crt --out helloworld.efi.signed_ab helloworld.efi'
> +                            % (mnt_point, SBSIGN_PATH), shell=True)
> +        ## signed by TestCert with TestSub and TestRoot in signature
> +        check_call('cd %s; cat TestSub.crt TestRoot.crt > TestSubRoot.crt; %ssbsign --key TestCert.key --cert TestCert.crt --addcert TestSubRoot.crt --out helloworld.efi.signed_abc helloworld.efi'
> +                            % (mnt_point, SBSIGN_PATH), shell=True)
> +
> +        # Clean-up
> +        check_call('sudo umount %s' % loop_dev, shell=True)
> +        check_call('sudo losetup -d %s' % loop_dev, shell=True)
> +
> +    except CalledProcessError as e:
> +        pytest.skip('Setup failed: %s' % e.cmd)
> +        return
> +    else:
> +        yield image_path
> +    finally:
> +        call('rm -f %s' % image_path, shell=True)
> diff --git a/test/py/tests/test_efi_secboot/defs.py b/test/py/tests/test_efi_secboot/defs.py
> index d6222809c547..2c3a82d1681b 100644
> --- a/test/py/tests/test_efi_secboot/defs.py
> +++ b/test/py/tests/test_efi_secboot/defs.py
> @@ -1,7 +1,7 @@
>  # SPDX-License-Identifier:      GPL-2.0+
>
>  # Disk image name
> -EFI_SECBOOT_IMAGE_NAME='test_efi_secboot.img'
> +EFI_SECBOOT_IMAGE_NAME='test_efi_secboot'
>
>  # Size in MiB
>  EFI_SECBOOT_IMAGE_SIZE=16
> @@ -10,12 +10,21 @@ EFI_SECBOOT_PART_SIZE=8
>  # Partition file system type
>  EFI_SECBOOT_FS_TYPE='vfat'
>
> +# Mount point
> +MNTPNT='mnt'
> +
>  # Owner guid
>  GUID='11111111-2222-3333-4444-123456789abc'
>
>  # v1.5.1 or earlier of efitools has a bug in sha256 calculation, and
>  # you need build a newer version on your own.
> +# The path must terminate with '/'.
>  EFITOOLS_PATH=''
>
> +# "--addcert" option of sbsign must be available, otherwise
> +# you need build a newer version on your own.
> +# The path must terminate with '/'.
> +SBSIGN_PATH='/home/akashi/arm/misc/sbsigntools/src/'
> +
>  # Hello World application for sandbox
>  HELLO_PATH=''
> diff --git a/test/py/tests/test_efi_secboot/openssl.cnf b/test/py/tests/test_efi_secboot/openssl.cnf
> new file mode 100644
> index 000000000000..f684f1df7e69
> --- /dev/null
> +++ b/test/py/tests/test_efi_secboot/openssl.cnf
> @@ -0,0 +1,48 @@
> +[ ca ]
> +default_ca = CA_default
> +
> +[ CA_default ]
> +new_certs_dir = .
> +database = ./index.txt
> +serial = ./serial
> +default_md = sha256
> +policy = policy_min
> +
> +[ req ]
> +distinguished_name = def_distinguished_name
> +
> +[def_distinguished_name]
> +
> +# Extensions
> +#   -addext " ... = ..."
> +#
> +[ v3_ca ]
> +   # Extensions for a typical Root CA.
> +   basicConstraints = critical,CA:TRUE
> +   keyUsage = critical, digitalSignature, cRLSign, keyCertSign
> +   subjectKeyIdentifier = hash
> +   authorityKeyIdentifier = keyid:always,issuer
> +
> +[ v3_int_ca ]
> +   # Extensions for a typical intermediate CA.
> +   basicConstraints = critical, CA:TRUE
> +   keyUsage = critical, digitalSignature, cRLSign, keyCertSign
> +   subjectKeyIdentifier = hash
> +   authorityKeyIdentifier = keyid:always,issuer
> +
> +[ usr_cert ]
> +   # Extensions for user end certificates.
> +   basicConstraints = CA:FALSE
> +   keyUsage = critical, nonRepudiation, digitalSignature, keyEncipherment
> +   extendedKeyUsage = clientAuth, emailProtection
> +   subjectKeyIdentifier = hash
> +   authorityKeyIdentifier = keyid,issuer
> +
> +[ policy_min ]
> +   countryName		= optional
> +   stateOrProvinceName	= optional
> +   localityName		= optional
> +   organizationName	= optional
> +   organizationalUnitName = optional
> +   commonName		= supplied
> +   emailAddress		= optional
> diff --git a/test/py/tests/test_efi_secboot/test_signed_intca.py b/test/py/tests/test_efi_secboot/test_signed_intca.py
> new file mode 100644
> index 000000000000..8a3b152dc12f
> --- /dev/null
> +++ b/test/py/tests/test_efi_secboot/test_signed_intca.py
> @@ -0,0 +1,135 @@
> +# SPDX-License-Identifier:      GPL-2.0+
> +# Copyright (c) 2020, Linaro Limited
> +# Author: AKASHI Takahiro <takahiro.akashi at linaro.org>
> +#
> +# U-Boot UEFI: Image Authentication Test (signature with certificates chain)
> +
> +"""
> +This test verifies image authentication for a signed image which is signed
> +by user certificate and contains additional intermediate certificates in its
> +signature.
> +"""
> +
> +import pytest
> +from defs import *
> +
> + at pytest.mark.boardspec('sandbox')
> + at pytest.mark.buildconfigspec('efi_secure_boot')
> + at pytest.mark.buildconfigspec('cmd_efidebug')
> + at pytest.mark.buildconfigspec('cmd_fat')
> + at pytest.mark.buildconfigspec('cmd_nvedit_efi')
> + at pytest.mark.slow
> +class TestEfiSignedImageExt(object):
> +    def test_efi_signed_image_ext1(self, u_boot_console, efi_boot_env_intca):
> +        """
> +        Test Case 1 - authenticated by root CA in db
> +        """
> +        u_boot_console.restart_uboot()
> +        disk_img = efi_boot_env_intca
> +        with u_boot_console.log.section('Test Case 1a'):
> +            # Test Case 1a, with no Int CA and not authenticated by root CA
> +            output = u_boot_console.run_command_list([
> +                'host bind 0 %s' % disk_img,
> +                'fatload host 0:1 4000000 db_c.auth',
> +                'setenv -e -nv -bs -rt -at -i 4000000,$filesize db',
> +                'fatload host 0:1 4000000 KEK.auth',
> +                'setenv -e -nv -bs -rt -at -i 4000000,$filesize KEK',
> +                'fatload host 0:1 4000000 PK.auth',
> +                'setenv -e -nv -bs -rt -at -i 4000000,$filesize PK'])
> +            assert(not 'Failed to set EFI variable' in ''.join(output))
> +
> +            output = u_boot_console.run_command_list([
> +                'efidebug boot add 1 HELLO_a host 0:1 /helloworld.efi.signed_a ""',
> +                'efidebug boot next 1',
> +                'efidebug test bootmgr'])
> +            assert('\'HELLO_a\' failed' in ''.join(output))
> +            assert('efi_start_image() returned: 26' in ''.join(output))
> +
> +        with u_boot_console.log.section('Test Case 1b'):
> +            # Test Case 1b, signed and authenticated by root CA
> +            output = u_boot_console.run_command_list([
> +                'efidebug boot add 2 HELLO_ab host 0:1 /helloworld.efi.signed_ab ""',
> +                'efidebug boot next 2',
> +                'bootefi bootmgr'])
> +            assert('Hello, world!' in ''.join(output))
> +
> +    def test_efi_signed_image_ext2(self, u_boot_console, efi_boot_env_intca):
> +        """
> +        Test Case 2 - authenticated by root CA in db
> +        """
> +        u_boot_console.restart_uboot()
> +        disk_img = efi_boot_env_intca
> +        with u_boot_console.log.section('Test Case 2a'):
> +            # Test Case 2a, unsigned and not authenticated by root CA
> +            output = u_boot_console.run_command_list([
> +                'host bind 0 %s' % disk_img,
> +                'fatload host 0:1 4000000 KEK.auth',
> +                'setenv -e -nv -bs -rt -at -i 4000000,$filesize KEK',
> +                'fatload host 0:1 4000000 PK.auth',
> +                'setenv -e -nv -bs -rt -at -i 4000000,$filesize PK'])
> +            assert(not 'Failed to set EFI variable' in ''.join(output))
> +
> +            output = u_boot_console.run_command_list([
> +                'efidebug boot add 1 HELLO_abc host 0:1 /helloworld.efi.signed_abc ""',
> +                'efidebug boot next 1',
> +                'efidebug test bootmgr'])
> +            assert('\'HELLO_abc\' failed' in ''.join(output))
> +            assert('efi_start_image() returned: 26' in ''.join(output))
> +
> +        with u_boot_console.log.section('Test Case 2b'):
> +            # Test Case 2b, signed and authenticated by root CA
> +            output = u_boot_console.run_command_list([
> +                'fatload host 0:1 4000000 db_b.auth',
> +                'setenv -e -nv -bs -rt -at -i 4000000,$filesize db',
> +                'efidebug boot next 1',
> +                'efidebug test bootmgr'])
> +            assert('\'HELLO_abc\' failed' in ''.join(output))
> +            assert('efi_start_image() returned: 26' in ''.join(output))
> +
> +        with u_boot_console.log.section('Test Case 2c'):
> +            # Test Case 2c, signed and authenticated by root CA
> +            output = u_boot_console.run_command_list([
> +                'fatload host 0:1 4000000 db_c.auth',
> +                'setenv -e -nv -bs -rt -at -i 4000000,$filesize db',
> +                'efidebug boot next 1',
> +                'efidebug test bootmgr'])
> +            assert('Hello, world!' in ''.join(output))
> +
> +    def test_efi_signed_image_ext3(self, u_boot_console, efi_boot_env_intca):
> +        """
> +        Test Case 3 - revoked by dbx
> +        """
> +        u_boot_console.restart_uboot()
> +        disk_img = efi_boot_env_intca
> +        with u_boot_console.log.section('Test Case 3a'):
> +            # Test Case 3a, revoked by root CA in dbx
> +            output = u_boot_console.run_command_list([
> +                'host bind 0 %s' % disk_img,
> +                'fatload host 0:1 4000000 dbx_c.auth',
> +                'setenv -e -nv -bs -rt -at -i 4000000,$filesize dbx',
> +                'fatload host 0:1 4000000 db_c.auth',
> +                'setenv -e -nv -bs -rt -at -i 4000000,$filesize db',
> +                'fatload host 0:1 4000000 KEK.auth',
> +                'setenv -e -nv -bs -rt -at -i 4000000,$filesize KEK',
> +                'fatload host 0:1 4000000 PK.auth',
> +                'setenv -e -nv -bs -rt -at -i 4000000,$filesize PK'])
> +            assert(not 'Failed to set EFI variable' in ''.join(output))
> +
> +            output = u_boot_console.run_command_list([
> +                'efidebug boot add 1 HELLO_abc host 0:1 /helloworld.efi.signed_abc ""',
> +                'efidebug boot next 1',
> +                'efidebug test bootmgr'])
> +            assert('\'HELLO_abc\' failed' in ''.join(output))
> +            assert('efi_start_image() returned: 26' in ''.join(output))
> +
> +        with u_boot_console.log.section('Test Case 3b'):
> +            # Test Case 3b, revoked by int CA in dbx
> +            output = u_boot_console.run_command_list([
> +                'fatload host 0:1 4000000 dbx_b.auth',
> +                'setenv -e -nv -bs -rt -at -i 4000000,$filesize dbx',
> +                'efidebug boot next 1',
> +                'efidebug test bootmgr'])
> +            assert('Hello, world!' in ''.join(output))
> +            # Or,
> +            # assert('\'HELLO_abc\' failed' in ''.join(output))
> +            # assert('efi_start_image() returned: 26' in ''.join(output))
>



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