#!/usr/bin/env python
#
# Copyright (c) 2015, Linaro Limited
# All rights reserved.
#
# 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 COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT HOLDER OR CONTRIBUTORS 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.
#
def uuid_parse(s):
	from uuid import UUID
	return UUID(s)


def int_parse(str):
	return int(str, 0)

def get_args():
	from argparse import ArgumentParser

	parser = ArgumentParser()
	#parser.add_argument('--uuid', type=uuid_parse, help='UUID of TA')
	#parser.add_argument('--version', type=int_parse, default=0, help='Version')
	parser.add_argument('--key', required=True, help='Name of key file')
	parser.add_argument('--in', required=True, dest='inf', \
			help='Name of in file')
	#parser.add_argument('--out', required=True, help='Name of out file')
	return parser.parse_args()

def main():
	from Crypto.Signature import PKCS1_v1_5
	from Crypto.Hash import SHA256
	from Crypto.PublicKey import RSA
	import struct
	import sys

	args = get_args()

	f = open(args.key, 'rb')
	key = RSA.importKey(f.read())
	f.close()

	f = open(args.inf, 'rb')
	img = f.read()
	temp = img[0:4]
	ta_magic = temp.find('\x48\x53\x54\x4F')
	if ta_magic == -1:
		print("not find ta magic! input file is not a TA!")
		sys.exit(0)
	temp = img[4:8]
	ta_img_type0 = temp.find('\x00\x00\x00\x00')
	ta_img_type1 = temp.find('\x01\x00\x00\x00')
	f.close()
	
	if ta_img_type0 != -1:
		img = img[0x134:len(img)]
		signer = PKCS1_v1_5.new(key)
		h = SHA256.new()
	
		digest_len = h.digest_size
		sig_len = len(signer.sign(h))
		img_size = len(img)
	
		magic = 0x4f545348	# SHDR_MAGIC
		img_type = 0		# SHDR_TA
		algo = 0x70004830	# TEE_ALG_RSASSA_PKCS1_V1_5_SHA256
		shdr = struct.pack('<IIIIHH', \
			magic, img_type, img_size, algo, digest_len, sig_len)
	
		h.update(shdr)
		h.update(img)
		sig = signer.sign(h)
	
		f = open(args.inf, 'wb')
		f.write(shdr)
		f.write(h.digest())
		f.write(sig)
		f.write(img)
		f.close()
		print("resign TA sucess! ta_img_type is 0")
		sys.exit(0)
	if ta_img_type1 != -1:
		shdr_uuid = img[0x134:0x144]
		shdr_version = img[0x144:0x148]
		img = img[0x148:len(img)]
		signer = PKCS1_v1_5.new(key)
		h = SHA256.new()

		digest_len = h.digest_size
		sig_len = len(signer.sign(h))
		img_size = len(img)
		
		magic = 0x4f545348    # SHDR_MAGIC
		img_type = 1        # SHDR_BOOTSTRAP_TA
		algo = 0x70004830    # TEE_ALG_RSASSA_PKCS1_V1_5_SHA256
		shdr = struct.pack('<IIIIHH',
		                   magic, img_type, img_size, algo, digest_len, sig_len)
		#shdr_uuid = args.uuid.bytes
		#shdr_version = struct.pack('<I', args.version)
		
		h.update(shdr)
		h.update(shdr_uuid)
		h.update(shdr_version)
		h.update(img)
		sig = signer.sign(h)
		
		f = open(args.inf, 'wb')
		f.write(shdr)
		f.write(h.digest())
		f.write(sig)
		f.write(shdr_uuid)
		f.write(shdr_version)
		f.write(img)
		f.close()
		print("resign TA sucess! ta_img_type is 1")
		sys.exit(0)

	print("resign TA fail! ta_img_type are assert to 0 or 1")
	sys.exit(0)
			


if __name__ == "__main__":
	main()