#!/usr/bin/env python # -*- coding: utf-8 -*- # vim:ts=4:sw=4:softtabstop=4:smarttab:expandtab from __future__ import unicode_literals, division, absolute_import, print_function import struct # note: struct pack, unpack, unpack_from all require bytestring format # data all the way up to at least python 2.7.5, python 3 okay with bytestring from .unipath import pathof # important pdb header offsets unique_id_seed = 68 number_of_pdb_records = 76 # important palmdoc header offsets book_length = 4 book_record_count = 8 first_pdb_record = 78 # important rec0 offsets length_of_book = 4 mobi_header_base = 16 mobi_header_length = 20 mobi_type = 24 mobi_version = 36 first_non_text = 80 title_offset = 84 first_resc_record = 108 first_content_index = 192 last_content_index = 194 kf8_fdst_index = 192 # for KF8 mobi headers fcis_index = 200 flis_index = 208 srcs_index = 224 srcs_count = 228 primary_index = 244 datp_index = 256 huffoff = 112 hufftbloff = 120 def getint(datain,ofs,sz=b'L'): i, = struct.unpack_from(b'>'+sz,datain,ofs) return i def writeint(datain,ofs,n,len=b'L'): if len==b'L': return datain[:ofs]+struct.pack(b'>L',n)+datain[ofs+4:] else: return datain[:ofs]+struct.pack(b'>H',n)+datain[ofs+2:] def getsecaddr(datain,secno): nsec = getint(datain,number_of_pdb_records,b'H') assert secno>=0 & secnoL',2*nsec+1)) datalst.append(datain[unique_id_seed+4:number_of_pdb_records]) datalst.append(struct.pack(b'>H',nsec)) newstart = zerosecstart for i in range(0,secno): ofs, flgval = struct.unpack_from(b'>2L',datain,first_pdb_record+i*8) datalst.append(struct.pack(b'>L',ofs) + struct.pack(b'>L', flgval)) datalst.append(struct.pack(b'>L', secstart) + struct.pack(b'>L', (2*secno))) for i in range(secno+1,nsec): ofs, flgval = struct.unpack_from(b'>2L',datain,first_pdb_record+i*8) ofs = ofs + dif datalst.append(struct.pack(b'>L',ofs) + struct.pack(b'>L',flgval)) lpad = newstart - (first_pdb_record + 8*nsec) if lpad > 0: datalst.append(b'\0' * lpad) datalst.append(datain[zerosecstart:secstart]) datalst.append(secdata) datalst.append(datain[secend:]) dataout = b''.join(datalst) return dataout def nullsection(datain,secno): # make it zero-length without deleting it datalst = [] nsec = getint(datain,number_of_pdb_records,b'H') secstart, secend = getsecaddr(datain,secno) zerosecstart, zerosecend = getsecaddr(datain, 0) dif = secend-secstart datalst.append(datain[:first_pdb_record]) for i in range(0,secno+1): ofs, flgval = struct.unpack_from(b'>2L',datain,first_pdb_record+i*8) datalst.append(struct.pack(b'>L',ofs) + struct.pack(b'>L', flgval)) for i in range(secno+1, nsec): ofs, flgval = struct.unpack_from(b'>2L',datain,first_pdb_record+i*8) ofs = ofs - dif datalst.append(struct.pack(b'>L',ofs) + struct.pack(b'>L',flgval)) lpad = zerosecstart - (first_pdb_record + 8*nsec) if lpad > 0: datalst.append(b'\0' * lpad) datalst.append(datain[zerosecstart: secstart]) datalst.append(datain[secend:]) dataout = b''.join(datalst) return dataout def deletesectionrange(datain,firstsec,lastsec): # delete a range of sections datalst = [] firstsecstart,firstsecend = getsecaddr(datain,firstsec) lastsecstart,lastsecend = getsecaddr(datain,lastsec) zerosecstart, zerosecend = getsecaddr(datain, 0) dif = lastsecend - firstsecstart + 8*(lastsec-firstsec+1) nsec = getint(datain,number_of_pdb_records,b'H') datalst.append(datain[:unique_id_seed]) datalst.append(struct.pack(b'>L',2*(nsec-(lastsec-firstsec+1))+1)) datalst.append(datain[unique_id_seed+4:number_of_pdb_records]) datalst.append(struct.pack(b'>H',nsec-(lastsec-firstsec+1))) newstart = zerosecstart - 8*(lastsec-firstsec+1) for i in range(0,firstsec): ofs, flgval = struct.unpack_from(b'>2L',datain,first_pdb_record+i*8) ofs = ofs-8*(lastsec-firstsec+1) datalst.append(struct.pack(b'>L',ofs) + struct.pack(b'>L', flgval)) for i in range(lastsec+1,nsec): ofs, flgval = struct.unpack_from(b'>2L',datain,first_pdb_record+i*8) ofs = ofs - dif flgval = 2*(i-(lastsec-firstsec+1)) datalst.append(struct.pack(b'>L',ofs) + struct.pack(b'>L',flgval)) lpad = newstart - (first_pdb_record + 8*(nsec - (lastsec - firstsec + 1))) if lpad > 0: datalst.append(b'\0' * lpad) datalst.append(datain[zerosecstart:firstsecstart]) datalst.append(datain[lastsecend:]) dataout = b''.join(datalst) return dataout def insertsection(datain,secno,secdata): # insert a new section datalst = [] nsec = getint(datain,number_of_pdb_records,b'H') # print("inserting secno" , secno, "into" ,nsec, "sections") secstart,secend = getsecaddr(datain,secno) zerosecstart,zerosecend = getsecaddr(datain,0) dif = len(secdata) datalst.append(datain[:unique_id_seed]) datalst.append(struct.pack(b'>L',2*(nsec+1)+1)) datalst.append(datain[unique_id_seed+4:number_of_pdb_records]) datalst.append(struct.pack(b'>H',nsec+1)) newstart = zerosecstart + 8 for i in range(0,secno): ofs, flgval = struct.unpack_from(b'>2L',datain,first_pdb_record+i*8) ofs += 8 datalst.append(struct.pack(b'>L',ofs) + struct.pack(b'>L', flgval)) datalst.append(struct.pack(b'>L', secstart + 8) + struct.pack(b'>L', (2*secno))) for i in range(secno,nsec): ofs, flgval = struct.unpack_from(b'>2L',datain,first_pdb_record+i*8) ofs = ofs + dif + 8 flgval = 2*(i+1) datalst.append(struct.pack(b'>L',ofs) + struct.pack(b'>L',flgval)) lpad = newstart - (first_pdb_record + 8*(nsec + 1)) if lpad > 0: datalst.append(b'\0' * lpad) datalst.append(datain[zerosecstart:secstart]) datalst.append(secdata) datalst.append(datain[secstart:]) dataout = b''.join(datalst) return dataout def insertsectionrange(sectionsource,firstsec,lastsec,sectiontarget,targetsec): # insert a range of sections # print("inserting secno" , firstsec, "to", lastsec, "into" ,targetsec, "sections") # dataout = sectiontarget # for idx in range(lastsec,firstsec-1,-1): # dataout = insertsection(dataout,targetsec,readsection(sectionsource,idx)) # return dataout datalst = [] nsec = getint(sectiontarget,number_of_pdb_records,b'H') zerosecstart, zerosecend = getsecaddr(sectiontarget,0) insstart, nul = getsecaddr(sectiontarget,targetsec) nins = lastsec - firstsec + 1 srcstart, nul = getsecaddr(sectionsource,firstsec) nul, srcend = getsecaddr(sectionsource,lastsec) newstart = zerosecstart + 8*nins datalst.append(sectiontarget[:unique_id_seed]) datalst.append(struct.pack(b'>L',2*(nsec+nins)+1)) datalst.append(sectiontarget[unique_id_seed+4:number_of_pdb_records]) datalst.append(struct.pack(b'>H',nsec+nins)) for i in range(0,targetsec): ofs, flgval = struct.unpack_from(b'>2L',sectiontarget,first_pdb_record+i*8) ofsnew = ofs + 8*nins flgvalnew = flgval datalst.append(struct.pack(b'>L',ofsnew) + struct.pack(b'>L', flgvalnew)) # print(ofsnew, flgvalnew, ofs, flgval) srcstart0, nul = getsecaddr(sectionsource,firstsec) for i in range(nins): isrcstart, nul = getsecaddr(sectionsource,firstsec+i) ofsnew = insstart + (isrcstart-srcstart0) + 8*nins flgvalnew = 2*(targetsec+i) datalst.append(struct.pack(b'>L',ofsnew) + struct.pack(b'>L', flgvalnew)) # print(ofsnew, flgvalnew) dif = srcend - srcstart for i in range(targetsec,nsec): ofs, flgval = struct.unpack_from(b'>2L',sectiontarget,first_pdb_record+i*8) ofsnew = ofs + dif + 8*nins flgvalnew = 2*(i+nins) datalst.append(struct.pack(b'>L',ofsnew) + struct.pack(b'>L',flgvalnew)) # print(ofsnew, flgvalnew, ofs, flgval) lpad = newstart - (first_pdb_record + 8*(nsec + nins)) if lpad > 0: datalst.append(b'\0' * lpad) datalst.append(sectiontarget[zerosecstart:insstart]) datalst.append(sectionsource[srcstart:srcend]) datalst.append(sectiontarget[insstart:]) dataout = b''.join(datalst) return dataout def get_exth_params(rec0): ebase = mobi_header_base + getint(rec0,mobi_header_length) elen = getint(rec0,ebase+4) enum = getint(rec0,ebase+8) return ebase,elen,enum def add_exth(rec0,exth_num,exth_bytes): ebase,elen,enum = get_exth_params(rec0) newrecsize = 8+len(exth_bytes) newrec0 = rec0[0:ebase+4]+struct.pack(b'>L',elen+newrecsize)+struct.pack(b'>L',enum+1)+\ struct.pack(b'>L',exth_num)+struct.pack(b'>L',newrecsize)+exth_bytes+rec0[ebase+12:] newrec0 = writeint(newrec0,title_offset,getint(newrec0,title_offset)+newrecsize) return newrec0 def read_exth(rec0,exth_num): exth_values = [] ebase,elen,enum = get_exth_params(rec0) ebase = ebase+12 while enum>0: exth_id = getint(rec0,ebase) if exth_id == exth_num: # We might have multiple exths, so build a list. exth_values.append(rec0[ebase+8:ebase+getint(rec0,ebase+4)]) enum = enum-1 ebase = ebase+getint(rec0,ebase+4) return exth_values def write_exth(rec0,exth_num,exth_bytes): ebase,elen,enum = get_exth_params(rec0) ebase_idx = ebase+12 enum_idx = enum while enum_idx>0: exth_id = getint(rec0,ebase_idx) if exth_id == exth_num: dif = len(exth_bytes)+8-getint(rec0,ebase_idx+4) newrec0 = rec0 if dif != 0: newrec0 = writeint(newrec0,title_offset,getint(newrec0,title_offset)+dif) return newrec0[:ebase+4]+struct.pack(b'>L',elen+len(exth_bytes)+8-getint(rec0,ebase_idx+4))+\ struct.pack(b'>L',enum)+rec0[ebase+12:ebase_idx+4]+\ struct.pack(b'>L',len(exth_bytes)+8)+exth_bytes+\ rec0[ebase_idx+getint(rec0,ebase_idx+4):] enum_idx = enum_idx-1 ebase_idx = ebase_idx+getint(rec0,ebase_idx+4) return rec0 def del_exth(rec0,exth_num): ebase,elen,enum = get_exth_params(rec0) ebase_idx = ebase+12 enum_idx = 0 while enum_idx < enum: exth_id = getint(rec0,ebase_idx) exth_size = getint(rec0,ebase_idx+4) if exth_id == exth_num: newrec0 = rec0 newrec0 = writeint(newrec0,title_offset,getint(newrec0,title_offset)-exth_size) newrec0 = newrec0[:ebase_idx]+newrec0[ebase_idx+exth_size:] newrec0 = newrec0[0:ebase+4]+struct.pack(b'>L',elen-exth_size)+struct.pack(b'>L',enum-1)+newrec0[ebase+12:] return newrec0 enum_idx += 1 ebase_idx = ebase_idx+exth_size return rec0 class mobi_split: def __init__(self, infile): datain = b'' with open(pathof(infile), 'rb') as f: datain = f.read() datain_rec0 = readsection(datain,0) ver = getint(datain_rec0,mobi_version) self.combo = (ver!=8) if not self.combo: return exth121 = read_exth(datain_rec0,121) if len(exth121) == 0: self.combo = False return else: # only pay attention to first exth121 # (there should only be one) datain_kf8, = struct.unpack_from(b'>L',exth121[0],0) if datain_kf8 == 0xffffffff: self.combo = False return datain_kfrec0 =readsection(datain,datain_kf8) # create the standalone mobi7 num_sec = getint(datain,number_of_pdb_records,b'H') # remove BOUNDARY up to but not including ELF record self.result_file7 = deletesectionrange(datain,datain_kf8-1,num_sec-2) # check if there are SRCS records and delete them srcs = getint(datain_rec0,srcs_index) num_srcs = getint(datain_rec0,srcs_count) if srcs != 0xffffffff and num_srcs > 0: self.result_file7 = deletesectionrange(self.result_file7,srcs,srcs+num_srcs-1) datain_rec0 = writeint(datain_rec0,srcs_index,0xffffffff) datain_rec0 = writeint(datain_rec0,srcs_count,0) # reset the EXTH 121 KF8 Boundary meta data to 0xffffffff datain_rec0 = write_exth(datain_rec0,121, struct.pack(b'>L', 0xffffffff)) # datain_rec0 = del_exth(datain_rec0,121) # datain_rec0 = del_exth(datain_rec0,534) # don't remove the EXTH 125 KF8 Count of Resources, seems to be present in mobi6 files as well # set the EXTH 129 KF8 Masthead / Cover Image string to the null string datain_rec0 = write_exth(datain_rec0,129, b'') # don't remove the EXTH 131 KF8 Unidentified Count, seems to be present in mobi6 files as well # need to reset flags stored in 0x80-0x83 # old mobi with exth: 0x50, mobi7 part with exth: 0x1850, mobi8 part with exth: 0x1050 # Bit Flags # 0x1000 = Bit 12 indicates if embedded fonts are used or not # 0x0800 = means this Header points to *shared* images/resource/fonts ?? # 0x0080 = unknown new flag, why is this now being set by Kindlegen 2.8? # 0x0040 = exth exists # 0x0010 = Not sure but this is always set so far fval, = struct.unpack_from(b'>L',datain_rec0, 0x80) # need to remove flag 0x0800 for KindlePreviewer 2.8 and unset Bit 12 for embedded fonts fval = fval & 0x07FF datain_rec0 = datain_rec0[:0x80] + struct.pack(b'>L',fval) + datain_rec0[0x84:] self.result_file7 = writesection(self.result_file7,0,datain_rec0) # no need to replace kf8 style fcis with mobi 7 one # fcis_secnum, = struct.unpack_from(b'>L',datain_rec0, 0xc8) # if fcis_secnum != 0xffffffff: # fcis_info = readsection(datain, fcis_secnum) # text_len, = struct.unpack_from(b'>L', fcis_info, 0x14) # new_fcis = 'FCIS\x00\x00\x00\x14\x00\x00\x00\x10\x00\x00\x00\x01\x00\x00\x00\x00' # new_fcis += struct.pack(b'>L',text_len) # new_fcis += '\x00\x00\x00\x00\x00\x00\x00\x20\x00\x00\x00\x08\x00\x01\x00\x01\x00\x00\x00\x00' # self.result_file7 = writesection(self.result_file7, fcis_secnum, new_fcis) firstimage = getint(datain_rec0,first_resc_record) lastimage = getint(datain_rec0,last_content_index,b'H') # print("Old First Image, last Image", firstimage,lastimage) if lastimage == 0xffff: # find the lowest of the next sections and copy up to that. ofs_list = [(fcis_index,b'L'),(flis_index,b'L'),(datp_index,b'L'),(hufftbloff, b'L')] for ofs,sz in ofs_list: n = getint(datain_rec0,ofs,sz) # print("n",n) if n > 0 and n < lastimage: lastimage = n-1 print("First Image, last Image", firstimage,lastimage) # Try to null out FONT and RES, but leave the (empty) PDB record so image refs remain valid for i in range(firstimage,lastimage): imgsec = readsection(self.result_file7,i) if imgsec[0:4] in [b'RESC',b'FONT']: self.result_file7 = nullsection(self.result_file7,i) # mobi7 finished # create standalone mobi8 self.result_file8 = deletesectionrange(datain,0,datain_kf8-1) target = getint(datain_kfrec0,first_resc_record) self.result_file8 = insertsectionrange(datain,firstimage,lastimage,self.result_file8,target) datain_kfrec0 =readsection(self.result_file8,0) # Only keep the correct EXTH 116 StartOffset, KG 2.5 carries over the one from the mobi7 part, which then points at garbage in the mobi8 part, and confuses FW 3.4 kf8starts = read_exth(datain_kfrec0,116) # If we have multiple StartOffset, keep only the last one kf8start_count = len(kf8starts) while kf8start_count > 1: kf8start_count -= 1 datain_kfrec0 = del_exth(datain_kfrec0,116) # update the EXTH 125 KF8 Count of Images/Fonts/Resources datain_kfrec0 = write_exth(datain_kfrec0,125,struct.pack(b'>L',lastimage-firstimage+1)) # need to reset flags stored in 0x80-0x83 # old mobi with exth: 0x50, mobi7 part with exth: 0x1850, mobi8 part with exth: 0x1050 # standalone mobi8 with exth: 0x0050 # Bit Flags # 0x1000 = Bit 12 indicates if embedded fonts are used or not # 0x0800 = means this Header points to *shared* images/resource/fonts ?? # 0x0080 = unknown new flag, why is this now being set by Kindlegen 2.8? # 0x0040 = exth exists # 0x0010 = Not sure but this is always set so far fval, = struct.unpack_from('>L',datain_kfrec0, 0x80) fval = fval & 0x1FFF fval |= 0x0800 datain_kfrec0 = datain_kfrec0[:0x80] + struct.pack(b'>L',fval) + datain_kfrec0[0x84:] # properly update other index pointers that have been shifted by the insertion of images ofs_list = [(kf8_fdst_index,b'L'),(fcis_index,b'L'),(flis_index,b'L'),(datp_index,b'L'),(hufftbloff, b'L')] for ofs,sz in ofs_list: n = getint(datain_kfrec0,ofs,sz) if n != 0xffffffff: datain_kfrec0 = writeint(datain_kfrec0,ofs,n+lastimage-firstimage+1,sz) self.result_file8 = writesection(self.result_file8,0,datain_kfrec0) # no need to replace kf8 style fcis with mobi 7 one # fcis_secnum, = struct.unpack_from(b'>L',datain_kfrec0, 0xc8) # if fcis_secnum != 0xffffffff: # fcis_info = readsection(self.result_file8, fcis_secnum) # text_len, = struct.unpack_from(b'>L', fcis_info, 0x14) # new_fcis = 'FCIS\x00\x00\x00\x14\x00\x00\x00\x10\x00\x00\x00\x01\x00\x00\x00\x00' # new_fcis += struct.pack(b'>L',text_len) # new_fcis += '\x00\x00\x00\x00\x00\x00\x00\x20\x00\x00\x00\x08\x00\x01\x00\x01\x00\x00\x00\x00' # self.result_file8 = writesection(self.result_file8, fcis_secnum, new_fcis) # mobi8 finished def getResult8(self): return self.result_file8 def getResult7(self): return self.result_file7