# 0.19 - It seems that multibyte entries aren't encrypted in a v6 file either.
# 0.20 - Correction: It seems that multibyte entries are encrypted in a v6 file.
# 0.21 - Added support for multiple pids
+# 0.22 - revised structure to hold MobiBook as a class to allow an extended interface
+# 0.23 - fixed problem with older files with no EXTH section
-__version__ = '0.21'
+__version__ = '0.23'
import sys
-import struct
-import binascii
class Unbuffered:
def __init__(self, stream):
self.stream.flush()
def __getattr__(self, attr):
return getattr(self.stream, attr)
+sys.stdout=Unbuffered(sys.stdout)
+
+import struct
+import binascii
class DrmException(Exception):
pass
+
+#
+# MobiBook Utility Routines
+#
+
# Implementation of Pukall Cipher 1
def PC1(key, src, decryption=True):
sum1 = 0;
wkey = []
for i in xrange(8):
wkey.append(ord(key[i*2])<<8 | ord(key[i*2+1]))
-
dst = ""
for i in xrange(len(src)):
temp1 = 0;
num += (ord(ptr[size - num - 1]) & 0x3) + 1
return num
-class DrmStripper:
+
+
+class MobiBook:
def loadSection(self, section):
if (section + 1 == self.num_sections):
endoff = len(self.data_file)
off = self.sections[section][0]
return self.data_file[off:endoff]
+ def __init__(self, infile):
+ # initial sanity check on file
+ self.data_file = file(infile, 'rb').read()
+ self.header = self.data_file[0:78]
+ if self.header[0x3C:0x3C+8] != 'BOOKMOBI':
+ raise DrmException("invalid file format")
+
+ # build up section offset and flag info
+ self.num_sections, = struct.unpack('>H', self.header[76:78])
+ self.sections = []
+ for i in xrange(self.num_sections):
+ offset, a1,a2,a3,a4 = struct.unpack('>LBBBB', self.data_file[78+i*8:78+i*8+8])
+ flags, val = a1, a2<<16|a3<<8|a4
+ self.sections.append( (offset, flags, val) )
+
+ # parse information from section 0
+ self.sect = self.loadSection(0)
+ self.records, = struct.unpack('>H', self.sect[0x8:0x8+2])
+ self.mobi_length, = struct.unpack('>L',self.sect[0x14:0x18])
+ self.mobi_version, = struct.unpack('>L',self.sect[0x68:0x6C])
+ print "MOBI header version = %d, length = %d" %(self.mobi_version, self.mobi_length)
+ self.extra_data_flags = 0
+ if (self.mobi_length >= 0xE4) and (self.mobi_version >= 5):
+ self.extra_data_flags, = struct.unpack('>H', self.sect[0xF2:0xF4])
+ print "Extra Data Flags = %d" % self.extra_data_flags
+ if self.mobi_version < 7:
+ # multibyte utf8 data is included in the encryption for mobi_version 6 and below
+ # so clear that byte so that we leave it to be decrypted.
+ self.extra_data_flags &= 0xFFFE
+
+ # if exth region exists parse it for metadata array
+ self.meta_array = {}
+ try:
+ exth_flag, = struct.unpack('>L', self.sect[0x80:0x84])
+ exth = 'NONE'
+ if exth_flag & 0x40:
+ exth = self.sect[16 + self.mobi_length:]
+ if (len(exth) >= 4) and (exth[:4] == 'EXTH'):
+ nitems, = struct.unpack('>I', exth[8:12])
+ pos = 12
+ for i in xrange(nitems):
+ type, size = struct.unpack('>II', exth[pos: pos + 8])
+ content = exth[pos + 8: pos + size]
+ self.meta_array[type] = content
+ pos += size
+ except:
+ self.meta_array = {}
+ pass
+
+ def getBookTitle(self):
+ title = ''
+ if 503 in self.meta_array:
+ title = self.meta_array[503]
+ else :
+ toff, tlen = struct.unpack('>II', self.sect[0x54:0x5c])
+ tend = toff + tlen
+ title = self.sect[toff:tend]
+ if title == '':
+ title = self.header[:32]
+ title = title.split("\0")[0]
+ return title
+
+ def getPIDMetaInfo(self):
+ rec209 = None
+ token = None
+ if 209 in self.meta_array:
+ rec209 = self.meta_array[209]
+ data = rec209
+ # Parse the 209 data to find the the exth record with the token data.
+ # The last character of the 209 data points to the record with the token.
+ # Always 208 from my experience, but I'll leave the logic in case that changes.
+ for i in xrange(len(data)):
+ if ord(data[i]) != 0:
+ if self.meta_array[ord(data[i])] != None:
+ token = self.meta_array[ord(data[i])]
+ return rec209, token
+
def patch(self, off, new):
self.data_file = self.data_file[:off] + new + self.data_file[off+len(new):]
self.patch(off + in_off, new)
def parseDRM(self, data, count, pidlist):
+ found_key = None
keyvec1 = "\x72\x38\x33\xB0\xB4\xF2\xE3\xCA\xDF\x09\x01\xD6\xE2\xE0\x3F\x96"
for pid in pidlist:
bigpid = pid.ljust(16,'\0')
break
return [found_key,pid]
- def __init__(self, data_file, pidlist):
- # initial sanity check on file
- self.data_file = data_file
- header = data_file[0:72]
- if header[0x3C:0x3C+8] != 'BOOKMOBI':
- raise DrmException("invalid file format")
- self.num_sections, = struct.unpack('>H', data_file[76:78])
-
- self.sections = []
- for i in xrange(self.num_sections):
- offset, a1,a2,a3,a4 = struct.unpack('>LBBBB', data_file[78+i*8:78+i*8+8])
- flags, val = a1, a2<<16|a3<<8|a4
- self.sections.append( (offset, flags, val) )
-
- sect = self.loadSection(0)
- records, = struct.unpack('>H', sect[0x8:0x8+2])
- mobi_length, = struct.unpack('>L',sect[0x14:0x18])
- mobi_version, = struct.unpack('>L',sect[0x68:0x6C])
- extra_data_flags = 0
- print "MOBI header version = %d, length = %d" %(mobi_version, mobi_length)
- if (mobi_length >= 0xE4) and (mobi_version >= 5):
- extra_data_flags, = struct.unpack('>H', sect[0xF2:0xF4])
- print "Extra Data Flags = %d" %extra_data_flags
- if mobi_version < 7:
- # multibyte utf8 data is included in the encryption for mobi_version 6 and below
- # so clear that byte so that we leave it to be decrypted.
- extra_data_flags &= 0xFFFE
-
- crypto_type, = struct.unpack('>H', sect[0xC:0xC+2])
+ def processBook(self, pidlist):
+ crypto_type, = struct.unpack('>H', self.sect[0xC:0xC+2])
if crypto_type == 0:
print "This book is not encrypted."
- else:
- if crypto_type == 1:
- raise DrmException("Cannot decode Mobipocket encryption type 1")
- if crypto_type != 2:
- raise DrmException("Cannot decode unknown Mobipocket encryption type %d" % crypto_type)
-
- goodpids = []
- for pid in pidlist:
- if len(pid)==10:
- if checksumPid(pid[0:-2]) != pid:
- print "PID " + pid + " has incorrect checksum, should have been "+checksumPid(pid[0:-2])
- else:
- goodpids.append(pid[0:-2])
- elif len(pid)==8:
- print "PID without checksum given. With checksum PID is "+checksumPid(pid)
- goodpids.append(pid)
-
- if len(goodpids) == 0:
- raise DrmException("No valid PIDs supplied.")
-
- # calculate the keys
- drm_ptr, drm_count, drm_size, drm_flags = struct.unpack('>LLLL', sect[0xA8:0xA8+16])
- if drm_count == 0:
- raise DrmException("Not yet initialised with PID. Must be opened with Mobipocket Reader first.")
- found_key, pid = self.parseDRM(sect[drm_ptr:drm_ptr+drm_size], drm_count, goodpids)
- if not found_key:
- raise DrmException("No key found. Most likely the correct PID has not been given.")
+ return self.data_file
+ if crypto_type == 1:
+ raise DrmException("Cannot decode Mobipocket encryption type 1")
+ if crypto_type != 2:
+ raise DrmException("Cannot decode unknown Mobipocket encryption type %d" % crypto_type)
+
+ goodpids = []
+ for pid in pidlist:
+ if len(pid)==10:
+ if checksumPid(pid[0:-2]) != pid:
+ print "Warning: PID " + pid + " has incorrect checksum, should have been "+checksumPid(pid[0:-2])
+ goodpids.append(pid[0:-2])
+ elif len(pid)==8:
+ goodpids.append(pid)
+
+ # calculate the keys
+ drm_ptr, drm_count, drm_size, drm_flags = struct.unpack('>LLLL', self.sect[0xA8:0xA8+16])
+ if drm_count == 0:
+ raise DrmException("Not yet initialised with PID. Must be opened with Mobipocket Reader first.")
+ found_key, pid = self.parseDRM(self.sect[drm_ptr:drm_ptr+drm_size], drm_count, goodpids)
+ if not found_key:
+ raise DrmException("No key found. Most likely the correct PID has not been given.")
- if pid=="00000000":
- print "File has default encryption, no specific PID."
- else:
- print "File is encoded with PID "+checksumPid(pid)+"."
-
- # kill the drm keys
- self.patchSection(0, "\0" * drm_size, drm_ptr)
- # kill the drm pointers
- self.patchSection(0, "\xff" * 4 + "\0" * 12, 0xA8)
- # clear the crypto type
- self.patchSection(0, "\0" * 2, 0xC)
-
- # decrypt sections
- print "Decrypting. Please wait . . .",
- new_data = self.data_file[:self.sections[1][0]]
- for i in xrange(1, records+1):
- data = self.loadSection(i)
- extra_size = getSizeOfTrailingDataEntries(data, len(data), extra_data_flags)
- if i%100 == 0:
- print ".",
- # print "record %d, extra_size %d" %(i,extra_size)
- new_data += PC1(found_key, data[0:len(data) - extra_size])
- if extra_size > 0:
- new_data += data[-extra_size:]
- if self.num_sections > records+1:
- new_data += self.data_file[self.sections[records+1][0]:]
- self.data_file = new_data
- print "done"
-
- def getResult(self):
+ if pid=="00000000":
+ print "File has default encryption, no specific PID."
+ else:
+ print "File is encoded with PID "+checksumPid(pid)+"."
+
+ # kill the drm keys
+ self.patchSection(0, "\0" * drm_size, drm_ptr)
+ # kill the drm pointers
+ self.patchSection(0, "\xff" * 4 + "\0" * 12, 0xA8)
+ # clear the crypto type
+ self.patchSection(0, "\0" * 2, 0xC)
+
+ # decrypt sections
+ print "Decrypting. Please wait . . .",
+ new_data = self.data_file[:self.sections[1][0]]
+ for i in xrange(1, self.records+1):
+ data = self.loadSection(i)
+ extra_size = getSizeOfTrailingDataEntries(data, len(data), self.extra_data_flags)
+ if i%100 == 0:
+ print ".",
+ # print "record %d, extra_size %d" %(i,extra_size)
+ new_data += PC1(found_key, data[0:len(data) - extra_size])
+ if extra_size > 0:
+ new_data += data[-extra_size:]
+ if self.num_sections > self.records+1:
+ new_data += self.data_file[self.sections[self.records+1][0]:]
+ self.data_file = new_data
+ print "done"
return self.data_file
def getUnencryptedBook(infile,pid):
- sys.stdout=Unbuffered(sys.stdout)
- data_file = file(infile, 'rb').read()
- strippedFile = DrmStripper(data_file, [pid])
- return strippedFile.getResult()
+ if not os.path.isfile(infile):
+ raise DrmException('Input File Not Found')
+ book = MobiBook(infile)
+ return book.processBook([pid])
def getUnencryptedBookWithList(infile,pidlist):
- sys.stdout=Unbuffered(sys.stdout)
- data_file = file(infile, 'rb').read()
- strippedFile = DrmStripper(data_file, pidlist)
- return strippedFile.getResult()
+ if not os.path.isfile(infile):
+ raise DrmException('Input File Not Found')
+ book = MobiBook(infile)
+ return book.processBook(pidlist)
def main(argv=sys.argv):
- sys.stdout=Unbuffered(sys.stdout)
print ('MobiDeDrm v%(__version__)s. '
'Copyright 2008-2010 The Dark Reverser.' % globals())
if len(argv)<4:
outfile = argv[2]
pidlist = argv[3].split(',')
try:
- stripped_file = getUnencryptedBook(infile, pidlist)
+ stripped_file = getUnencryptedBookWithList(infile, pidlist)
file(outfile, 'wb').write(stripped_file)
except DrmException, e:
print "Error: %s" % e
projects / DeDRM.git / commitdiff