Skip to content

Commit

Permalink
lib.platforms.director.unlock_dir_file: Improve robustness, remove de…
Browse files Browse the repository at this point in the history 
…pendency on parser
  • Loading branch information
@moralrecordings
moralrecordings committed Jul 4, 2021
1 parent 7cd3132 commit 144b517
Show file tree
Hide file tree
Showing 2 changed files with 68 additions and 169 deletions.
1 change: 1 addition & 0 deletions CHANGELOG.rst
View file
Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,7 @@ Unreleased
- sound: Replace pyaudio with miniaudio
- lib.hardware.tispeech: Avoid using all 0s and 1s for nearest energy lookups
- utils.find_iter: Fix binary searching
- lib.platforms.director.unlock_dir_file: Improve robustness, remove dependency on parser

0.9.0 - 2021-01-14
==================
Expand Down
236 changes: 67 additions & 169 deletions mrcrowbar/lib/platforms/director.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -909,163 +909,7 @@ class ConfigV4( mrc.Block ):

@property
def checksum_v4( self ):
mult = lambda a, b: (a * b) & 0xffffffff

stack = []
ax = self.movie_rect.right
ax += 6
stack.append( ax )
ax = self.movie_rect.bottom
ax += 5
stack.append( ax )
ax = self.movie_rect.left
ax += 4
stack.append( ax )
ax = self.movie_rect.top
ax += 3
stack.append( ax )
ax = self.ver1
ax += 2
cx = self.length
cx += 1
ax *= cx
stack.append( ax )
ax = stack.pop() // stack.pop()
stack.append( ax )
ax = mult( stack.pop(), stack.pop() )
stack.append( ax )
ax = stack.pop() // stack.pop()
stack.append( ax )
ax = mult( stack.pop(), stack.pop() )

bx = ax
ax = self.cast_array_start
ax += 7
bx -= ax
stack.append( bx )

ax = self.cast_array_end
ax += 8
stack.append( ax )
ax = mult( stack.pop(), stack.pop() )

temp_sum = ax

ax = self.frame_rate
ax += 9
temp_sum -= ax

ax = self.light_switch
ax += 10
temp_sum -= ax

ax = self.unk1
ax += 11
temp_sum += ax

stack.append( temp_sum )

ax = self.comment_font
ax += 12

stack.append( ax )

temp_sum = mult( stack.pop(), stack.pop() )

ax = self.comment_size
ax += 13
temp_sum += ax

stack.append( temp_sum )

ax = self.comment_style
ax += 14
stack.append( ax )

temp_sum = mult( stack.pop(), stack.pop() )

ax = self.stage_colour
ax += 15

temp_sum += ax

ax = self.bit_depth
ax += 16
temp_sum += ax

ax = self.colour_flag
ax += 17
temp_sum += ax

stack.append( temp_sum )

ax = self.unk5
ax += 18
stack.append( ax )

temp_sum = mult( stack.pop(), stack.pop() )

eax = self.unk6
eax += 19
temp_sum += eax
stack.append( temp_sum )

ax = self.unk7
ax += 20
stack.append( ax )

temp_sum = mult( stack.pop(), stack.pop() )

ax = self.unk8
ax += 21
temp_sum += ax

ax = self.unk9
ax += 22
temp_sum += ax

ax = self.unk10
ax += 23
temp_sum += ax

ax = self.unk11
ax += 24
temp_sum += ax

stack.append( temp_sum )

ax = self.unk12
ax += 25
stack.append( ax )

temp_sum = mult( stack.pop(), stack.pop() )

ax = self.unk13
ax += 26

temp_sum += ax
stack.append( temp_sum )

ax = self.unk14
ax += 27
stack.append( ax )

ax = mult( stack.pop(), stack.pop() )

stack.append( ax )

ax = 0xe06
ax = self.protection_bits * ax
ax -= 0x00bb0000
stack.append( ax )

ax = mult( stack.pop(), stack.pop() )

ax ^= 0x72616c66 # 'ralf'

return ax


return checksum_v4( self.export_data() )


class DirectorV4Map( riff.RIFXMap ):
Expand Down Expand Up @@ -1283,23 +1127,77 @@ def dump_scripts( self ):
print()


def unlock_dir_file( filename, klass=DirectorV4 ):

def checksum_v4( data ):
mul = lambda a, b: (a * b) & 0xffffffff
div = lambda a, b: (a // b) & 0xffffffff
add = lambda a, b: (a + b) & 0xffffffff
sub = lambda a, b: (a - b) & 0xffffffff

checksum = (utils.from_uint16_be( data[0x00:0x02] ) + 1)
checksum = mul( checksum, (utils.from_uint16_be( data[0x02:0x04] ) + 2) )
checksum = div( checksum, (utils.from_int16_be( data[0x04:0x06] ) + 3) )
checksum = mul( checksum, (utils.from_int16_be( data[0x06:0x08] ) + 4) )
checksum = div( checksum, (utils.from_int16_be( data[0x08:0x0a] ) + 5) )
checksum = mul( checksum, (utils.from_int16_be( data[0x0a:0x0c] ) + 6) )
checksum = sub( checksum, (utils.from_uint16_be( data[0x0c:0x0e] ) + 7) )
checksum = mul( checksum, (utils.from_uint16_be( data[0x0e:0x10] ) + 8) )
checksum = sub( checksum, (utils.from_uint8( data[0x10:0x11] ) + 9) )
checksum = sub( checksum, (utils.from_uint8( data[0x11:0x12] ) + 10) )
checksum = add( checksum, (utils.from_int16_be( data[0x12:0x14] ) + 11) )
checksum = mul( checksum, (utils.from_int16_be( data[0x14:0x16] ) + 12) )
checksum = add( checksum, (utils.from_int16_be( data[0x16:0x18] ) + 13) )
checksum = mul( checksum, (utils.from_uint8( data[0x18:0x19] ) + 14) )
checksum = add( checksum, (utils.from_int16_be( data[0x1a:0x1c] ) + 15) )
checksum = add( checksum, (utils.from_int16_be( data[0x1c:0x1e] ) + 16) )
checksum = add( checksum, (utils.from_uint8( data[0x1e:0x1f] ) + 17) )
checksum = mul( checksum, (utils.from_uint8( data[0x1f:0x20] ) + 18) )
checksum = add( checksum, (utils.from_int32_be( data[0x20:0x24] ) + 19) )
checksum = mul( checksum, (utils.from_int16_be( data[0x24:0x26] ) + 20) )
checksum = add( checksum, (utils.from_int16_be( data[0x26:0x28] ) + 21) )
checksum = add( checksum, (utils.from_int32_be( data[0x28:0x2c] ) + 22) )
checksum = add( checksum, (utils.from_int32_be( data[0x2c:0x30] ) + 23) )
checksum = add( checksum, (utils.from_int32_be( data[0x30:0x34] ) + 24) )
checksum = mul( checksum, (utils.from_uint8( data[0x34:0x35] ) + 25) )
checksum = add( checksum, (utils.from_int16_be( data[0x36:0x38] ) + 26) )
checksum = mul( checksum, (utils.from_int16_be( data[0x38:0x3a] ) + 27) )
protection_bits = utils.from_int16_be( data[0x3a:0x3c] )
checksum = mul( checksum, add( (protection_bits * 0xe06), 0xff450000 ) )
checksum ^= 0x72616c66 # 'ralf'
return checksum


def unlock_dir_file( filename, klass=DirectorV4, dry_run=False ):
f = open( filename, 'r+b' )

data = f.read()
d = klass( data )
f.seek( 0 )
parser = DirectorV4Parser( klass( data ) )
index, chunk = parser.get_all_from_mmap( b'VWCF' )[0]
if chunk.obj.protection_bits % 23:
configs = [x for x in d.map.stream if x.id == riff.Tag( b'VWCF' )]
if not configs:
print('Could not find a VWCF block! Aborting...')
return
chunk = configs[0].obj
print( f'Orig chunk: {chunk.export_data().hex()}' )
print( f'Orig checksum: {chunk.checksum:08x}' )
print( f'Calc checksum: {chunk.checksum_v4:08x}' )
if chunk.checksum != chunk.checksum_v4:
print('Checksums don\'t match! Algorithm must be busted, aborting')
return
if chunk.protection_bits % 23:
print('File is unprotected!')
else:
print('File is protected, fixing!')
old_data = chunk.obj.export_data()
chunk.obj.ver1 = 0x045D
chunk.obj.protection_bits += 1
chunk.obj.checksum = chunk.obj.checksum_v4
new_data = chunk.obj.export_data()
for location in utils.find_all( data, old_data ):
f.seek( location )
print('File is protected!')
old_data = chunk.export_data()
chunk.ver1 = 0x045D
chunk.protection_bits += 1
chunk.checksum = chunk.checksum_v4
print( f'Fixed chunk: {chunk.export_data().hex()}' )
print( f'Fixed checksum: {chunk.checksum_v4:08x}' )
new_data = chunk.export_data()
if dry_run:
return
for location in utils.find( old_data, data ):
f.seek( location[0] )
f.write( new_data )
f.close()

0 comments on commit 144b517

Please sign in to comment.