Generate u-boot-verified.rom image containing Secure Boot Manifest when secure boot option is enabled.
Signed-off-by: Anatolij Gustschin agust@denx.de --- NOTE: This patch applies on top of binman changes in binman-working branch in git://git.denx.de/u-boot-dm.git
Changes in v3: - New patch. Moved signing script functionality (secure_boot_helper.py in first series) to binman. The signing is enabled automatically via u-boot.dtsi when secure boot option is enabled - Clean up all temporary files generated by signing script
arch/x86/dts/u-boot.dtsi | 7 + tools/binman/signing/baytrail.py | 313 +++++++++++++++++++++++++++++++++++++++ tools/binman/signing/signer.py | 3 + 3 files changed, 323 insertions(+) create mode 100644 tools/binman/signing/baytrail.py
diff --git a/arch/x86/dts/u-boot.dtsi b/arch/x86/dts/u-boot.dtsi index 7e37d4f394..98e2309108 100644 --- a/arch/x86/dts/u-boot.dtsi +++ b/arch/x86/dts/u-boot.dtsi @@ -15,6 +15,13 @@ sort-by-pos; pad-byte = <0xff>; size = <CONFIG_ROM_SIZE>; +#ifdef CONFIG_BAYTRAIL_SECURE_BOOT + sign; +#ifdef CONFIG_SYS_SOC + socname = CONFIG_SYS_SOC; +#endif +#endif + #ifdef CONFIG_HAVE_INTEL_ME intel-descriptor { filename = CONFIG_FLASH_DESCRIPTOR_FILE; diff --git a/tools/binman/signing/baytrail.py b/tools/binman/signing/baytrail.py new file mode 100644 index 0000000000..3bfbbedb5d --- /dev/null +++ b/tools/binman/signing/baytrail.py @@ -0,0 +1,313 @@ +# Copyright (c) 2017 DENX Software Engineering +# Written by Markus Valentin mv@denx.de +# Adapted for binman integration: Anatolij Gustschin agust@denx.de +# +# SPDX-License-Identifier: GPL-2.0+ +# +# Functions for signing the binman output image for Bay Trail SoC +# + +import binascii +import logging, sys +import os + +from hashlib import sha256 +from os.path import basename, isfile, splitext +from os.path import join as pjoin +from struct import pack + +import OpenSSL +from OpenSSL import crypto +from cryptography import x509 +from cryptography.hazmat.backends import default_backend + +FSP_FILE_NAME = "fsp-sb.bin" +FSP_STAGE2_FILE_NAME = "fsp_stage2.bin" +U_BOOT_ROM_FILE_NAME = 'u-boot.rom' +OUTPUT_FILE_NAME = 'u-boot-verified.rom' +U_BOOT_TO_SIGN_FILE_NAME = 'u-boot-to-sign.bin' +IBB_FILE_NAME = 'ibb.bin' +FPF_CONFIG_FILE_NAME = 'fpf_config.txt' +SIGNED_MANIFEST_FILE_NAME = 'signed_manifest.bin' +UNSIGNED_MANIFEST_FILE_NAME = 'un'+SIGNED_MANIFEST_FILE_NAME +OEM_FILE_NAME = 'oemdata.bin' + +OEM_PRIV_KEY_FILE_NAME = 'oemkey.pem' +OEM_PUB_KEY_FILE_NAME = 'pub_oemkey.pem' +OEM_PUBKEY_BIN_FILE_NAME = 'pub_oemkey.bin' +OEM_PUBKEY_AND_SIG_FILE_NAME = 'oem_pub_sig.bin' + +FIT_PUB_KEY_FILE_NAME = "dev.crt" + +# FSP Stage2 size is 0x1f400. For debug FSP it is 0x2f400, +# you must change it here wenn building with debug FSP image! +FSP_STAGE_2_SIZE = 0x1f400 +FSP_UPD_SIZE = 0xc00 +IBB_SIZE = 0x1fc00 +MANIFEST_SIZE = 0x400 +OEM_BLOCK_MAX_SIZE = 0x190 +U_BOOT_ROM_SIZE = 0x800000 +ROMFILE_SYS_TEXT_BASE = 0x00700000 + +MANIFEST_IDENTIFIER = b'$VBM' +VERSION = 1 +SECURE_VERSION_NUMBER = 2 +OEM_DATA_PREAMBLE = '01000200' + +oem_data_hash_files = [] + + +def append_binary_files(first_file, second_file, new_file): + with open(new_file, 'wb') as f: + f.write(bytearray(open(first_file, 'rb').read())) + f.write(bytearray(open(second_file, 'rb').read())) + + +# This function creates the OEM-Data block which must be inserted +# into the Bay Trail Secure Boot Manifest. +def assemble_oem_data(file_path): + file_size = 0 + with open(file_path, 'wb') as f: + f.write(binascii.unhexlify(OEM_DATA_PREAMBLE)) + file_size += 4 + for hash_file in oem_data_hash_files: + f.write(open(hash_file, 'rb').read()) + file_size += 32 + pad_file_with_zeros(f, OEM_BLOCK_MAX_SIZE-file_size) + + +# This function creates the final U-Boot ROM image from +# the original u-boot.rom and the signed Initial Boot Block +# which contains the Secure Boot Manifest +def assemble_secure_boot_image(u_boot_rom, signed_ibb): + data = bytearray(open(u_boot_rom, 'rb').read()) + ibb = bytearray(open(signed_ibb, 'rb').read()) + data[-(MANIFEST_SIZE+IBB_SIZE):] = ibb + open(OUTPUT_FILE_NAME, 'wb').write(data) + + +# Constructs a complete Secure Boot Manifest which is just missing +# the OEM publickey and the manifest signature +def create_unsigned_secure_boot_manifest(unsigned_manifest, + oem_file='oemdata.bin', + ibb='ibb.bin'): + with open(unsigned_manifest, 'wb') as f: + f.write(MANIFEST_IDENTIFIER) + f.write(pack('i', VERSION)) + f.write(pack('i', MANIFEST_SIZE)) + f.write(pack('i', SECURE_VERSION_NUMBER)) + pad_file_with_zeros(f, 4) + hash_function = sha256() + hash_function.update(bytearray(open(ibb, 'rb').read())) + f.write(hash_function.digest()[::-1]) + pad_file_with_zeros(f, 36) + f.write(bytearray(open(oem_file, 'rb').read())) + pad_file_with_zeros(f, 20) + + +# Fetch part of a binary from from_byte to to_byte and write +# this part to a secondary file +def extract_binary_part(binary_to_extract_from, to_file, from_byte, to_byte): + data = open(binary_to_extract_from, 'rb').read() + open(to_file, 'wb').write(data[from_byte:to_byte]) + + +# Calculate a SHA256 checksum over a file and write a file with it to a +# file next to the original file. If requested, change endianness +# (sometimes needed because the TXE engine wants another byteorder) +def sha256_to_file(binary_dir, file_to_hash, change_endianness=False): + # We collect the hashes in a list (in the correct order) to be able + # to put them later to the OEM data section + if not oem_data_hash_files.__contains__(hashfile_path(binary_dir, + file_to_hash)): + oem_data_hash_files.append(hashfile_path(binary_dir, file_to_hash)) + with open(file_to_hash, 'rb') as f: + hash_function = sha256() + hash_function.update(f.read()) + # write as little to file + if change_endianness: + open(hashfile_path(binary_dir, file_to_hash), + 'wb').write(hash_function.digest()) + else: + open(hashfile_path(binary_dir, file_to_hash), + 'wb').write(hash_function.digest()[::-1]) + + +# Create hash filename using the file_to_hash name +def hashfile_path(binary_dir, file_to_hash): + hash_file_name = splitext( + basename(file_to_hash))[0].__add__('.sha256') + return pjoin(binary_dir, hash_file_name) + + +# Pad the given files with a given byte number of zeros. +# byte_count value must be divisible by 4 +def pad_file_with_zeros(file_handle, byte_count): + if byte_count % 4 != 0: + raise ValueError("Given byte_count must be divisible by 4 ...") + pad_count = 0 + while pad_count < byte_count: + file_handle.write(pack('i', 0)) + pad_count += 4 + + +# Extract the modulus of a public key. The TXE engine gets the public key +# split in modulus and exponent, for this reason we need to extract it. +def get_modulus_from_pubkey(public_key_path): + public_key = open(public_key_path, 'rb').read() + cert = x509.load_pem_x509_certificate(public_key, default_backend()) + return ("%X" % (cert.public_key().public_numbers().n)) + + +# Save a given modulus and exponent to a file as binary for use within +# the manifest +def save_binary_public_key(pub_key_file_path, modulus, exponent=0x10001): + with open(pub_key_file_path, 'wb') as f: + f.write(binascii.unhexlify(modulus)[::-1]) + f.write(pack('i', exponent)) + + +# Replace the public key hash in the fuse configuration text file +# and set the lock bit +def replace_oem_pubkey_hash(pubkey_hash, fpf_config_path, lock_fuses): + data = binascii.hexlify(pubkey_hash) + fpf_config_file = open(fpf_config_path, 'r').readlines() + + new_line_hash = "FUSE_FILE_OEM_KEY_HASH_1:{:s}:{}\n"\ + .format(data.upper().decode('ascii'), + str(lock_fuses).upper()) + new_line_sb_enabled = "FUSE_FILE_SECURE_BOOT_EN:01:{}\n"\ + .format(str(lock_fuses).upper()) + + with open(fpf_config_path, 'w') as f: + for line in fpf_config_file: + if line.startswith('FUSE_FILE_OEM_KEY_HASH_1'): + line = new_line_hash + if line.startswith('FUSE_FILE_SECURE_BOOT_EN'): + line = new_line_sb_enabled + f.write(line) + + +# For the TXE engine one needs to change the endianness +def reverse_endianness(file_to_reverse): + data = open(file_to_reverse, 'rb').read() + open(file_to_reverse, 'wb').write(data[::-1]) + + +# Sign the given file with the private_key using OpenSSL +# and write it to the signature_file +def sign_file(unsigned_file, private_key, signature_file): + key = open(private_key, 'r').read() + pkey_obj = crypto.load_privatekey(crypto.FILETYPE_PEM, key) + data = open(unsigned_file, 'rb').read() + signature = OpenSSL.crypto.sign(pkey_obj, data, "sha256") + open(signature_file, 'wb').write(signature) + + +# Perform IBB signing and generate Secure Boot Manifest for +# Bay Trail SoC, then create final ROM image containing the +# manifest and write it to u-boot-verified.rom file. +def baytrail_sign(u_boot_rom, keydir, indir, outdir): + FORMAT = ' BINMAN %(message)s' + logging.basicConfig(stream=sys.stderr, level=logging.INFO, format=FORMAT) + logging.info("Signing image %s" % u_boot_rom) + for dir in indir: + fsp = pjoin(dir, FSP_FILE_NAME) + if not isfile(fsp): + continue + + if not isfile(fsp): + raise ValueError("Can't find FSP file %s" % fsp) + + # Assemble file paths + fit_public_key = pjoin(keydir, FIT_PUB_KEY_FILE_NAME) + fit_public_key_modulus = pjoin(keydir, FIT_PUB_KEY_FILE_NAME+".mod") + fsp_stage2 = pjoin(outdir, FSP_STAGE2_FILE_NAME) + u_boot_to_sign = pjoin(outdir, U_BOOT_TO_SIGN_FILE_NAME) + ibb = pjoin(outdir, IBB_FILE_NAME) + signed_ibb = pjoin(outdir, "signed_" + IBB_FILE_NAME) + + signed_manifest = pjoin(outdir, SIGNED_MANIFEST_FILE_NAME) + unsigned_manifest = pjoin(outdir, UNSIGNED_MANIFEST_FILE_NAME) + manifest_signature = splitext(unsigned_manifest)[0] + ".signature" + + oem_file = pjoin(outdir, OEM_FILE_NAME) + oem_private_key = pjoin(keydir, OEM_PRIV_KEY_FILE_NAME) + oem_public_key = pjoin(keydir, OEM_PUB_KEY_FILE_NAME) + oem_pubkey_binary = pjoin(keydir, OEM_PUBKEY_BIN_FILE_NAME) + oem_pubkey_and_sig = pjoin(keydir, OEM_PUBKEY_AND_SIG_FILE_NAME) + + # Check for all needed files to be available + for f in [fsp, u_boot_rom, fit_public_key, oem_private_key]: + if not isfile(f): + raise ValueError("File %s not found..." % f) + + # Get everything from ROM file except IBB + Manfifest + UPD + FSP Stage2 + # (127KiB + 1KiB + 3KiB + 125Kib), then write it to a separated file and + # calculate the hash. FPS Stage2 is verified in FSP, so skip it here + extract_binary_part(u_boot_rom, u_boot_to_sign, ROMFILE_SYS_TEXT_BASE, + (U_BOOT_ROM_SIZE - (IBB_SIZE + MANIFEST_SIZE + + FSP_UPD_SIZE + FSP_STAGE_2_SIZE))) + sha256_to_file(outdir, u_boot_to_sign, True) + + # Extract Stage2 of the FSP and calculate its hash + extract_binary_part(fsp, fsp_stage2, 0, FSP_STAGE_2_SIZE) + sha256_to_file(outdir, fsp_stage2) + + with open(fit_public_key_modulus, 'wb') as f: + f.write(binascii.unhexlify(get_modulus_from_pubkey(fit_public_key))) + sha256_to_file(outdir, fit_public_key_modulus, True) + + # Assemble oemdata + logging.debug("Assembling OEM data from %d hashes: %s" % + (oem_data_hash_files.__len__(), oem_data_hash_files)) + assemble_oem_data(oem_file) + + logging.debug("Extracting last 127K from %s as %s" % + (u_boot_rom, ibb)) + extract_binary_part(u_boot_rom, ibb, + (U_BOOT_ROM_SIZE-IBB_SIZE), U_BOOT_ROM_SIZE) + + logging.debug("Creating Secure Boot Manifest") + create_unsigned_secure_boot_manifest(unsigned_manifest, oem_file, ibb) + + logging.debug("Signing manifest with OpenSSL and private key %s" % + (oem_private_key)) + sign_file(unsigned_manifest, oem_private_key, manifest_signature) + + logging.debug("Append public key and signature to unsigned manifest") + oem_pub_key_modulus = get_modulus_from_pubkey(oem_public_key) + save_binary_public_key(oem_pubkey_binary, oem_pub_key_modulus) + + reverse_endianness(manifest_signature) + append_binary_files(oem_pubkey_binary, manifest_signature, + oem_pubkey_and_sig) + + append_binary_files(unsigned_manifest, oem_pubkey_and_sig, + signed_manifest) + + if isfile(FPF_CONFIG_FILE_NAME): + hash_function = sha256() + hash_function.update(bytearray(open(oem_pubkey_binary, 'rb').read())) + replace_oem_pubkey_hash(hash_function.digest()[::-1], + FPF_CONFIG_FILE_NAME, False) + + logging.debug("Append manifest with signature to IBB") + append_binary_files(signed_manifest, ibb, signed_ibb) + + logging.debug("Assemble %s from %s and %s" % + (OUTPUT_FILE_NAME, u_boot_rom, signed_manifest)) + assemble_secure_boot_image(u_boot_rom, signed_ibb) + + # Cleanup temporary files + os.remove(fsp_stage2) + os.remove(ibb) + os.remove(signed_ibb) + os.remove(signed_manifest) + os.remove(manifest_signature) + os.remove(oem_file) + os.remove(u_boot_to_sign) + os.remove(unsigned_manifest) + os.remove(FIT_PUB_KEY_FILE_NAME + ".sha256") + os.remove(splitext(fsp_stage2)[0] + ".sha256") + os.remove(splitext(u_boot_to_sign)[0] + ".sha256") diff --git a/tools/binman/signing/signer.py b/tools/binman/signing/signer.py index 4ec43d424f..e9ce97f559 100644 --- a/tools/binman/signing/signer.py +++ b/tools/binman/signing/signer.py @@ -6,10 +6,13 @@ # Class for signing the output image of binman #
+from baytrail import baytrail_sign + # Dictionary with SoC names and corresponding signing functions. # Image signing support for not yet supported SoCs can be added # here soc_sign_dict = { + 'baytrail': baytrail_sign, }
class ImageSigner(object):