forked from o-gs/dji-firmware-tools
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathdji_mvfc_fwpak.py
executable file
·332 lines (277 loc) · 13.3 KB
/
dji_mvfc_fwpak.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
""" DJI Mavic Flight Controller Firmware Crypto tool.
Handles the second level encryption used for Flight Controller modules
in Mavic and newer drones.
"""
# Copyright (C) 2018 Jan Dumon <[email protected]>
# Copyright (C) 2018 Freek van Tienen <[email protected]>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
__version__ = "0.5.2"
__author__ = "Jan Dumon, Freek van Tienen @ Original Gangsters"
__license__ = "GPL"
import sys
import re
import os
import hashlib
import binascii
import time
import argparse
from Crypto.Cipher import AES
from ctypes import *
from os.path import basename
encrypt_key = bytes([0x96, 0x70, 0x9a, 0xD3, 0x26, 0x67, 0x4A, 0xC3, 0x82, 0xB6, 0x69, 0x27, 0xE6, 0xd8, 0x84, 0x21])
encrypt_iv = bytes([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])
def eprint(*args, **kwargs):
print(*args, file=sys.stderr, **kwargs)
class EncHeader(LittleEndianStructure):
_pack_ = 1
_fields_ = [('target', c_ubyte), #0
('unk0', c_uint), #1 Always 0x01000001
('version', c_ubyte * 4), #5
('unk1', c_ubyte), #9 Always 0x01
('size', c_uint), #10
('unk2', c_uint), #14 Always 0x00000000
('time', c_uint), #18
('unk3', c_ubyte), #22 Always 0x04
('md5', c_ubyte * 16), #23
('crc16', c_ushort)] #39 end is 41
def __init__(self):
self.unk0 = 0x01000001
self.unk1 = 0x01
self.unk2 = 0x00000000
self.unk3 = 0x04
def dict_export(self):
d = dict()
for (varkey, vartype) in self._fields_:
#if not varkey.startswith('unk'):
d[varkey] = getattr(self, varkey)
return d
def __repr__(self):
d = self.dict_export()
from pprint import pformat
return pformat(d, indent=4, width=1)
def getTarget(self):
tg_kind = self.target & 31
tg_model = (self.target >> 5) & 7
return (str(tg_kind).zfill(2) + str(tg_model).zfill(2))
def getVersion(self):
return ('v' + str(self.version[3]).zfill(2) + '.' + str(self.version[2]).zfill(2) + '.' + str(self.version[1]).zfill(2) + '.' + str(self.version[0]).zfill(2))
def getTime(self):
return (time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(self.time)))
def __str__(self):
s = "Target: {:s}\n".format(self.getTarget())
s += "Version: {:s}\n".format(self.getVersion())
s += "Time: {:s}\n".format(self.getTime())
s += "Size: {:d}\n".format(self.size)
s += "Data MD5: {}\n".format(binascii.hexlify(self.md5))
s += "Header CRC: {:04x}".format(self.crc16)
return s
def calc_checksum(packet, plength):
crc = [0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf, 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e, 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd, 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c, 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb, 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a, 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9, 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738, 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7, 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036, 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5, 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134, 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3, 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232, 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1, 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330, 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78]
v = 0x3692
for i in range(0, plength):
vv = v >> 8
v = vv ^ crc[((packet[i] ^ v) & 0xFF)]
return v
def unpack(args):
header = EncHeader()
if args.input.readinto(header) != sizeof(header):
raise EOFError("Couldn't read image file header.")
print(header)
if (header.crc16 == calc_checksum(bytes(header), 39)):
if (args.verbose > 0):
print("{}: CRC of the header verified.".format(args.input.name))
elif (not args.force_continue):
raise ValueError("CRC of the header doesn't match!")
else:
eprint("Warning: CRC of the header doesn't match!")
data = args.input.read(((header.size + 255) // 256) * 256)
# MD5 of the entire file
md5_sum = hashlib.md5()
md5_sum.update(header)
md5_sum.update(data)
md5_calc = md5_sum.digest()
md5_read = args.input.read(16)
if md5_calc == md5_read:
if (args.verbose > 0):
print("{}: File MD5 matches.".format(args.input.name))
elif (not args.force_continue):
raise ValueError("File MD5 doesn't match!")
else:
eprint("Warning: File MD5 doesn't match!")
remaining = args.input.read()
if len(remaining) == 0:
if (args.verbose > 0):
print("{}: Trailing bytes verified.".format(args.input.name))
elif (not args.force_continue):
raise ValueError("Expected no trailing bytes, got {:d}!".format(len(remaining)))
else:
eprint("{}: Warning: Expected no trailing bytes, got {:d}!".format(args.input.name,len(remaining)))
dec_buffer = bytes()
for i in range((header.size + 255) // 256):
enc_buffer = data[(i * 256):((i + 1) * 256)]
cipher = AES.new(encrypt_key, AES.MODE_CBC, encrypt_iv)
dec_buffer += cipher.decrypt(enc_buffer)
md5_data = hashlib.md5()
md5_data.update(dec_buffer)
md5_calc = md5_data.digest()
if (args.verbose > 0):
print("{}: Decrypted data MD5: {}".format(args.input.name,binascii.hexlify(md5_calc)))
if md5_calc == bytes(header.md5):
if (args.verbose > 0):
print("{}: Decrypted data MD5 matches.".format(args.input.name))
elif (not args.force_continue):
raise ValueError("Decrypted data MD5 does not match!")
else:
eprint("{}: Warning: Decrypted data MD5 does not match!".format(args.input.name))
if args.cmd == 'dec':
args.output.write(dec_buffer[:header.size])
args.output.close()
print("{}: Decrypted file to '{}'".format(args.input.name,args.output.name))
return
def pack(args):
header = EncHeader()
data = args.input.read()
# Calculate the md5
header.md5 = (c_ubyte * 16)(*(hashlib.md5(data).digest()))
header.size = len(data)
# Target
if args.target == '0305':
header.target = 0xa3
elif args.target == '0306':
header.target = 0xc3
else:
raise ValueError("Unknown target: '{}'".format(args.target))
# Timestamp
if args.time == None:
header.time = int(time.time())
else:
if args.time.isdigit():
t = int(args.time, 10)
else:
t = time.strptime(args.time, '%Y-%m-%d %H:%M:%S')
if t == None:
raise ValueError("Wrong format for time: '{}'".format(args.time))
t = int(time.mktime(t))
header.time = t
ver = re.search('^v(\d+).(\d+).(\d+).(\d+)$', args.fwver)
if ver == None:
raise ValueError("Wrong firmware version string format (vAA.BB.CC.DD): '{}'".format(args.fwver))
# Version
header.version[3] = int(ver.group(1), 10)
header.version[2] = int(ver.group(2), 10)
header.version[1] = int(ver.group(3), 10)
header.version[0] = int(ver.group(4), 10)
# Calculate the header crc
header.crc16 = calc_checksum(bytes(header), 39)
print(header)
# Encrypt the file
enc_buffer = bytes()
for i in range(((len(data) + 255) // 256)):
dec_buffer = data[(i * 256):((i + 1) * 256)]
cipher = AES.new(encrypt_key, AES.MODE_CBC, encrypt_iv)
enc_buffer += cipher.encrypt(dec_buffer)
args.output.write(header)
args.output.write(enc_buffer)
# MD5 of the entire file
md5_sum = hashlib.md5()
md5_sum.update(header)
md5_sum.update(enc_buffer)
args.output.write(md5_sum.digest())
args.output.close()
print("{}: Encrypted file to '{}'".format(args.input.name,args.output.name))
def main():
""" Main executable function.
Its task is to parse command line options and call a function which performs requested command.
"""
# Parse command line options
parser = argparse.ArgumentParser(description=__doc__)
subparsers = parser.add_subparsers(dest='cmd')
parser.add_argument("--verbose", action="count", default=0,
help="increases verbosity level")
parser.add_argument("-f", "--force-continue", action="store_true",
help="force continuing execution despite warning signs of issues")
parser_dec = subparsers.add_parser('dec', help='Decrypt')
parser_dec.add_argument('-i', '--input', required=True, type=argparse.FileType('rb'),
help='name of the input encrypted FC firmware file')
parser_dec.add_argument('-o', '--output', type=argparse.FileType('wb'),
help='name of the output decrypted firmware file')
parser_enc = subparsers.add_parser('enc', help='Encrypt')
parser_enc.add_argument('-i', '--input', required=True, type=argparse.FileType('rb'),
help='name of the input unencrypted FC firmware file')
parser_enc.add_argument('-o', '--output', type=argparse.FileType('wb'),
help='name of the output encrypted firmware file')
parser_enc.add_argument('-T', '--time',
help='Timestamp. If omitted the current time will be used. The timestamp ' + \
'is either a number (seconds since epoch) or in the following format: ' + \
'"year-month-day hour:min:sec"' )
parser_enc.add_argument('-V', '--fwver', required=True,
help='firmware version string in the form "vAA.BB.CC.DD"')
parser_enc.add_argument('-t', '--target', required=True,
help='either 0305 or 0306')
parser_inf = subparsers.add_parser('info',
help='show header information')
parser_inf.add_argument('-i', '--input', required=True, type=argparse.FileType('rb'),
help='input file')
args = parser.parse_args()
if args.cmd == 'info':
if (args.verbose > 0):
print("{}: Opening for info display".format(args.input.name))
unpack(args)
elif args.cmd == 'dec':
if (args.verbose > 0):
print("{}: Opening for decryption".format(args.input.name))
if args.output == None:
if ".encrypted." in basename(args.input.name):
file_out = basename(args.input.name).replace(".encrypted", "")
else:
file_out = os.path.splitext(basename(args.input.name))[0] + '.decrypted.bin'
args.output = open(file_out, "wb")
unpack(args)
elif args.cmd == 'enc':
if (args.verbose > 0):
print("{}: Opening for encryption".format(args.input.name))
if args.output == None:
if ".decrypted." in basename(args.input.name):
file_out = basename(args.input.name).replace(".decrypted", "")
else:
file_out = os.path.splitext(basename(args.input.name))[0] + '.encrypted.bin'
args.output = open(file_out, "wb")
pack(args)
else:
raise NotImplementedError("Unknown command: '{}'.".format(args.cmd))
if __name__ == "__main__":
try:
main()
except Exception as ex:
eprint("Error: "+str(ex))
#raise
sys.exit(10)