--- /dev/null
+#!/usr/bin/python
+#
+# This is a python script. You need a Python interpreter to run it.
+# For example, ActiveState Python, which exists for windows.
+#
+# It can run standalone to convert files, or it can be installed as a
+# plugin for Calibre (http://calibre-ebook.com/about) so that
+# importing files with DRM 'Just Works'.
+#
+# To create a Calibre plugin, rename this file so that the filename
+# ends in '_plugin.py', put it into a ZIP file and import that Calibre
+# using its plugin configuration GUI.
+#
+# Changelog
+# 0.01 - Initial version
+# 0.02 - Huffdic compressed books were not properly decrypted
+# 0.03 - Wasn't checking MOBI header length
+# 0.04 - Wasn't sanity checking size of data record
+# 0.05 - It seems that the extra data flags take two bytes not four
+# 0.06 - And that low bit does mean something after all :-)
+# 0.07 - The extra data flags aren't present in MOBI header < 0xE8 in size
+# 0.08 - ...and also not in Mobi header version < 6
+# 0.09 - ...but they are there with Mobi header version 6, header size 0xE4!
+# 0.10 - Outputs unencrypted files as-is, so that when run as a Calibre
+# import filter it works when importing unencrypted files.
+# Also now handles encrypted files that don't need a specific PID.
+# 0.11 - use autoflushed stdout and proper return values
+# 0.12 - Fix for problems with metadata import as Calibre plugin, report errors
+# 0.13 - Formatting fixes: retabbed file, removed trailing whitespace
+# and extra blank lines, converted CR/LF pairs at ends of each line,
+# and other cosmetic fixes.
+# 0.14 - Working out when the extra data flags are present has been problematic
+# Versions 7 through 9 have tried to tweak the conditions, but have been
+# only partially successful. Closer examination of lots of sample
+# files reveals that a confusin has arisen because trailing data entries
+# are not encrypted, but it turns out that the multibyte entries
+# in utf8 file are encrypted. (Although neither kind gets compressed.)
+# This knowledge leads to a simplification of the test for the
+# trailing data byte flags - version 5 and higher AND header size >= 0xE4.
+
+__version__ = '0.14'
+
+import sys
+import struct
+import binascii
+
+class Unbuffered:
+ def __init__(self, stream):
+ self.stream = stream
+ def write(self, data):
+ self.stream.write(data)
+ self.stream.flush()
+ def __getattr__(self, attr):
+ return getattr(self.stream, attr)
+
+class DrmException(Exception):
+ pass
+
+# Implementation of Pukall Cipher 1
+def PC1(key, src, decryption=True):
+ sum1 = 0;
+ sum2 = 0;
+ keyXorVal = 0;
+ if len(key)!=16:
+ print "Bad key length!"
+ return None
+ 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;
+ byteXorVal = 0;
+ for j in xrange(8):
+ temp1 ^= wkey[j]
+ sum2 = (sum2+j)*20021 + sum1
+ sum1 = (temp1*346)&0xFFFF
+ sum2 = (sum2+sum1)&0xFFFF
+ temp1 = (temp1*20021+1)&0xFFFF
+ byteXorVal ^= temp1 ^ sum2
+ curByte = ord(src[i])
+ if not decryption:
+ keyXorVal = curByte * 257;
+ curByte = ((curByte ^ (byteXorVal >> 8)) ^ byteXorVal) & 0xFF
+ if decryption:
+ keyXorVal = curByte * 257;
+ for j in xrange(8):
+ wkey[j] ^= keyXorVal;
+ dst+=chr(curByte)
+ return dst
+
+def checksumPid(s):
+ letters = "ABCDEFGHIJKLMNPQRSTUVWXYZ123456789"
+ crc = (~binascii.crc32(s,-1))&0xFFFFFFFF
+ crc = crc ^ (crc >> 16)
+ res = s
+ l = len(letters)
+ for i in (0,1):
+ b = crc & 0xff
+ pos = (b // l) ^ (b % l)
+ res += letters[pos%l]
+ crc >>= 8
+ return res
+
+def getSizeOfTrailingDataEntries(ptr, size, flags):
+ def getSizeOfTrailingDataEntry(ptr, size):
+ bitpos, result = 0, 0
+ if size <= 0:
+ return result
+ while True:
+ v = ord(ptr[size-1])
+ result |= (v & 0x7F) << bitpos
+ bitpos += 7
+ size -= 1
+ if (v & 0x80) != 0 or (bitpos >= 28) or (size == 0):
+ return result
+ num = 0
+ testflags = flags >> 1
+ while testflags:
+ if testflags & 1:
+ num += getSizeOfTrailingDataEntry(ptr, size - num)
+ testflags >>= 1
+ # Multibyte data, if present, is included in the encryption, so
+ # we do not need to check the low bit.
+ # if flags & 1:
+ # num += (ord(ptr[size - num - 1]) & 0x3) + 1
+ return num
+
+class DrmStripper:
+ def loadSection(self, section):
+ if (section + 1 == self.num_sections):
+ endoff = len(self.data_file)
+ else:
+ endoff = self.sections[section + 1][0]
+ off = self.sections[section][0]
+ return self.data_file[off:endoff]
+
+ def patch(self, off, new):
+ self.data_file = self.data_file[:off] + new + self.data_file[off+len(new):]
+
+ def patchSection(self, section, new, in_off = 0):
+ if (section + 1 == self.num_sections):
+ endoff = len(self.data_file)
+ else:
+ endoff = self.sections[section + 1][0]
+ off = self.sections[section][0]
+ assert off + in_off + len(new) <= endoff
+ self.patch(off + in_off, new)
+
+ def parseDRM(self, data, count, pid):
+ pid = pid.ljust(16,'\0')
+ keyvec1 = "\x72\x38\x33\xB0\xB4\xF2\xE3\xCA\xDF\x09\x01\xD6\xE2\xE0\x3F\x96"
+ temp_key = PC1(keyvec1, pid, False)
+ temp_key_sum = sum(map(ord,temp_key)) & 0xff
+ found_key = None
+ for i in xrange(count):
+ verification, size, type, cksum, cookie = struct.unpack('>LLLBxxx32s', data[i*0x30:i*0x30+0x30])
+ cookie = PC1(temp_key, cookie)
+ ver,flags,finalkey,expiry,expiry2 = struct.unpack('>LL16sLL', cookie)
+ if verification == ver and cksum == temp_key_sum and (flags & 0x1F) == 1:
+ found_key = finalkey
+ break
+ if not found_key:
+ # Then try the default encoding that doesn't require a PID
+ temp_key = keyvec1
+ temp_key_sum = sum(map(ord,temp_key)) & 0xff
+ for i in xrange(count):
+ verification, size, type, cksum, cookie = struct.unpack('>LLLBxxx32s', data[i*0x30:i*0x30+0x30])
+ cookie = PC1(temp_key, cookie)
+ ver,flags,finalkey,expiry,expiry2 = struct.unpack('>LL16sLL', cookie)
+ if verification == ver and cksum == temp_key_sum:
+ found_key = finalkey
+ break
+ return found_key
+
+ def __init__(self, data_file, pid):
+ if checksumPid(pid[0:-2]) != pid:
+ raise DrmException("invalid PID checksum")
+ pid = pid[0:-2]
+
+ 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 length = %d" %mobi_length
+ print "MOBI header version = %d" %mobi_version
+ 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
+
+ crypto_type, = struct.unpack('>H', 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("unknown encryption type: %d" % crypto_type)
+
+ # calculate the keys
+ drm_ptr, drm_count, drm_size, drm_flags = struct.unpack('>LLLL', sect[0xA8:0xA8+16])
+ if drm_count == 0:
+ raise DrmException("no PIDs found in this file")
+ found_key = self.parseDRM(sect[drm_ptr:drm_ptr+drm_size], drm_count, pid)
+ if not found_key:
+ raise DrmException("no key found. maybe the PID is incorrect")
+
+ # 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...",
+ for i in xrange(1, records+1):
+ data = self.loadSection(i)
+ extra_size = getSizeOfTrailingDataEntries(data, len(data), extra_data_flags)
+ # print "record %d, extra_size %d" %(i,extra_size)
+ self.patchSection(i, PC1(found_key, data[0:len(data) - extra_size]))
+ print "done"
+
+ def getResult(self):
+ return self.data_file
+
+if not __name__ == "__main__":
+ from calibre.customize import FileTypePlugin
+
+ class MobiDeDRM(FileTypePlugin):
+ name = 'MobiDeDRM' # Name of the plugin
+ description = 'Removes DRM from secure Mobi files'
+ supported_platforms = ['linux', 'osx', 'windows'] # Platforms this plugin will run on
+ author = 'The Dark Reverser' # The author of this plugin
+ version = (0, 1, 4) # The version number of this plugin
+ file_types = set(['prc','mobi','azw']) # The file types that this plugin will be applied to
+ on_import = True # Run this plugin during the import
+
+ def run(self, path_to_ebook):
+ from calibre.gui2 import is_ok_to_use_qt
+ from PyQt4.Qt import QMessageBox
+ PID = self.site_customization
+ data_file = file(path_to_ebook, 'rb').read()
+ ar = PID.split(',')
+ for i in ar:
+ try:
+ unlocked_file = DrmStripper(data_file, i).getResult()
+ except DrmException:
+ # ignore the error
+ pass
+ else:
+ of = self.temporary_file('.mobi')
+ of.write(unlocked_file)
+ of.close()
+ return of.name
+ if is_ok_to_use_qt():
+ d = QMessageBox(QMessageBox.Warning, "MobiDeDRM Plugin", "Couldn't decode: %s\n\nImporting encrypted version." % path_to_ebook)
+ d.show()
+ d.raise_()
+ d.exec_()
+ return path_to_ebook
+
+ def customization_help(self, gui=False):
+ return 'Enter PID (separate multiple PIDs with comma)'
+
+if __name__ == "__main__":
+ sys.stdout=Unbuffered(sys.stdout)
+ print ('MobiDeDrm v%(__version__)s. '
+ 'Copyright 2008-2010 The Dark Reverser.' % globals())
+ if len(sys.argv)<4:
+ print "Removes protection from Mobipocket books"
+ print "Usage:"
+ print " %s <infile> <outfile> <PID>" % sys.argv[0]
+ sys.exit(1)
+ else:
+ infile = sys.argv[1]
+ outfile = sys.argv[2]
+ pid = sys.argv[3]
+ data_file = file(infile, 'rb').read()
+ try:
+ strippedFile = DrmStripper(data_file, pid)
+ file(outfile, 'wb').write(strippedFile.getResult())
+ except DrmException, e:
+ print "Error: %s" % e
+ sys.exit(1)
+ sys.exit(0)
\ No newline at end of file
projects / DeDRM.git / commitdiff