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Fixing some coding/encoding issues for decrypting PDFs

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pull/1418/head
Francesco Versaci 4 years ago
parent 13e9a14907
commit e69f19a376
1 changed files with 45 additions and 34 deletions
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79
DeDRM_plugin/ineptpdf.py
Unescape Escape View File

@ -63,6 +63,7 @@ import hashlib
from decimal import Decimal
import itertools
import xml.etree.ElementTree as etree
import codecs
# Wrap a stream so that output gets flushed immediately
# and also make sure that any unicode strings get
@ -430,8 +431,9 @@ def choplist(n, seq):
r = []
return
def nunpack(s, default=0):
def nunpack(ss, default=0):
'''Unpacks up to 4 bytes big endian.'''
s = ss.encode('cp437')
l = len(s)
if not l:
return default
@ -479,9 +481,9 @@ class PSLiteral(PSObject):
name = []
for char in self.name:
if not char.isalnum():
char = b'#%02x' % ord(char)
char = (b'#%02x' % ord(char)).decode('cp437')
name.append(char)
return b'/%s' % ''.join(name)
return '/%s' % ''.join(name)
# PSKeyword
class PSKeyword(PSObject):
@ -613,7 +615,7 @@ class PSBaseParser(object):
if self.charpos < len(self.buf): return
# fetch next chunk.
self.bufpos = self.fp.tell()
self.buf = self.fp.read(self.BUFSIZ)
self.buf = self.fp.read(self.BUFSIZ).decode('cp437')
if not self.buf:
raise PSEOF('Unexpected EOF')
self.charpos = 0
@ -845,7 +847,7 @@ class PSBaseParser(object):
prevpos = pos
pos = max(0, pos-self.BUFSIZ)
self.fp.seek(pos)
s = self.fp.read(prevpos-pos)
s = self.fp.read(prevpos-pos).decode('cp437')
if not s: break
while 1:
n = max(s.rfind('\r'), s.rfind('\n'))
@ -1020,7 +1022,7 @@ def resolve_all(x):
if isinstance(x, list):
x = [ resolve_all(v) for v in x ]
elif isinstance(x, dict):
for (k,v) in x.iteritems():
for (k,v) in x.items():
x[k] = resolve_all(v)
return x
@ -1029,12 +1031,12 @@ def decipher_all(decipher, objid, genno, x):
Recursively decipher X.
'''
if isinstance(x, str):
return decipher(objid, genno, x)
return decipher(objid, genno, x.encode('cp437')).decode('cp437')
decf = lambda v: decipher_all(decipher, objid, genno, v)
if isinstance(x, list):
x = [decf(v) for v in x]
elif isinstance(x, dict):
x = dict((k, decf(v)) for (k, v) in x.iteritems())
x = dict((k, decf(v)) for (k, v) in x.items())
return x
@ -1130,7 +1132,7 @@ class PDFStream(PDFObject):
cutdiv = len(rawdata) // 16
rawdata = rawdata[:16*cutdiv]
else:
if eol in (b'\r', b'\n', b'\r\n'):
if eol in ('\r', '\n', '\r\n'):
rawdata = rawdata[:length]
self.dic = dic
@ -1160,7 +1162,8 @@ class PDFStream(PDFObject):
data = self.rawdata
if self.decipher:
# Handle encryption
data = self.decipher(self.objid, self.genno, data)
data = self.decipher(self.objid, self.genno, data.encode('cp437'))\
.decode('cp437')
if gen_xref_stm:
self.decdata = data # keep decrypted data
if 'Filter' not in self.dic:
@ -1174,7 +1177,7 @@ class PDFStream(PDFObject):
for f in filters:
if f in LITERALS_FLATE_DECODE:
# will get errors if the document is encrypted.
data = zlib.decompress(data)
data = zlib.decompress(data.encode('cp437')).decode('cp437')
elif f in LITERALS_LZW_DECODE:
data = ''.join(LZWDecoder(BytesIO(data)).run())
elif f in LITERALS_ASCII85_DECODE:
@ -1201,14 +1204,14 @@ class PDFStream(PDFObject):
buf = b''
ent0 = b'\x00' * columns
for i in range(0, len(data), columns+1):
pred = data[i]
ent1 = data[i+1:i+1+columns]
pred = data[i].encode('cp437')
ent1 = data[i+1:i+1+columns].encode('cp437')
if pred == b'\x02':
ent1 = ''.join(bytes([(a+b) & 255]) \
ent1 = b''.join(bytes([(a+b) & 255]) \
for (a,b) in zip(ent0,ent1))
buf += ent1
ent0 = ent1
data = buf
data = buf.decode('cp437')
self.data = data
self.rawdata = None
return
@ -1227,7 +1230,8 @@ class PDFStream(PDFObject):
data = self.rawdata
if self.decipher and data:
# Handle encryption
data = self.decipher(self.objid, self.genno, data)
data = self.decipher(self.objid, self.genno, data.encode('cp437'))\
.decode('cp437')
return data
@ -1261,7 +1265,7 @@ class PDFXRef(object):
return '<PDFXRef: objs=%d>' % len(self.offsets)
def objids(self):
return self.offsets.iterkeys()
return self.offsets.keys()
def load(self, parser):
self.offsets = {}
@ -1587,16 +1591,18 @@ class PDFDocument(object):
def initialize_ebx(self, password, docid, param):
self.is_printable = self.is_modifiable = self.is_extractable = True
rsa = RSA(password)
length = int_value(param.get('Length', 0)) / 8
rights = str_value(param.get('ADEPT_LICENSE')).decode('base64')
length = int_value(param.get('Length', 0)) // 8
rights = str_value(param.get('ADEPT_LICENSE')).encode('cp437')
rights = codecs.decode(rights, 'base64')
rights = zlib.decompress(rights, -15)
rights = etree.fromstring(rights)
expr = './/{http://ns.adobe.com/adept}encryptedKey'
bookkey = ''.join(rights.findtext(expr)).decode('base64')
bookkey = ''.join(rights.findtext(expr)).encode('cp437')
bookkey = codecs.decode(bookkey, 'base64')
bookkey = rsa.decrypt(bookkey)
if bookkey[0] != '\x02':
if bookkey[0:1] != b'\x02':
raise ADEPTError('error decrypting book session key')
index = bookkey.index('\0') + 1
index = bookkey.index(b'\0') + 1
bookkey = bookkey[index:]
ebx_V = int_value(param.get('V', 4))
ebx_type = int_value(param.get('EBX_ENCRYPTIONTYPE', 6))
@ -1834,7 +1840,7 @@ class PDFParser(PSStackParser):
return
pos += len(line)
self.fp.seek(pos)
data = self.fp.read(objlen)
data = self.fp.read(objlen).decode('cp437')
self.seek(pos+objlen)
while 1:
try:
@ -1974,7 +1980,7 @@ class PDFSerializer(object):
def __init__(self, inf, userkey):
global GEN_XREF_STM, gen_xref_stm
gen_xref_stm = GEN_XREF_STM > 1
self.version = inf.read(8)
self.version = inf.read(8).decode('cp437')
inf.seek(0)
self.doc = doc = PDFDocument()
parser = PDFParser(doc, inf)
@ -1994,11 +2000,14 @@ class PDFSerializer(object):
def dump(self, outf):
self.outf = outf
self.write(self.version)
self.write('\n%\xe2\xe3\xcf\xd3\n')
self.write(b'\n%\xe2\xe3\xcf\xd3\n')
doc = self.doc
objids = self.objids
xrefs = {}
maxobj = max(objids)
if(objids):
maxobj = max(objids)
else:
raise Exception('Aaaargh! No objects!')
trailer = dict(self.trailer)
trailer['Size'] = maxobj + 1
for objid in objids:
@ -2072,21 +2081,23 @@ class PDFSerializer(object):
# f3 = objref[1]
f3 = 0
data.append(struct.pack('>B', f1))
data.append(struct.pack('>L', f2)[-fl2:])
data.append(struct.pack('>L', f3)[-fl3:])
data.append(struct.pack('>B', f1).decode('cp437'))
data.append(struct.pack('>L', f2)[-fl2:].decode('cp437'))
data.append(struct.pack('>L', f3)[-fl3:].decode('cp437'))
index.extend((first, prev - first + 1))
data = zlib.compress(''.join(data))
data = zlib.compress(''.join(data).encode('cp437'))
dic = {'Type': LITERAL_XREF, 'Size': prev + 1, 'Index': index,
'W': [1, fl2, fl3], 'Length': len(data),
'Filter': LITERALS_FLATE_DECODE[0],
'Root': trailer['Root'],}
if 'Info' in trailer:
dic['Info'] = trailer['Info']
xrefstm = PDFStream(dic, data)
xrefstm = PDFStream(dic, data.decode('cp437'))
self.serialize_indirect(maxobj, xrefstm)
self.write('startxref\n%d\n%%%%EOF' % startxref)
def write(self, data):
if (type(data)==str):
data = data.encode('cp437')
self.outf.write(data)
self.last = data[-1:]
@ -2098,7 +2109,7 @@ class PDFSerializer(object):
string = string.replace('\n', r'\n')
string = string.replace('(', r'\(')
string = string.replace(')', r'\)')
# get rid of ciando id
# get rid of ciando id
regularexp = re.compile(r'http://www.ciando.com/index.cfm/intRefererID/\d{5}')
if regularexp.match(string): return ('http://www.ciando.com')
return string
@ -2122,7 +2133,7 @@ class PDFSerializer(object):
self.serialize_object(val)
self.write(']')
elif isinstance(obj, str):
self.write('(%s)' % self.escape_string(obj))
self.write(f'({self.escape_string(obj)})'.encode())
elif isinstance(obj, bool):
if self.last.isalnum():
self.write(' ')
@ -2149,7 +2160,7 @@ class PDFSerializer(object):
data = obj.get_decdata()
self.serialize_object(obj.dic)
self.write('stream\n')
self.write(data)
self.write(data.encode('cp437'))
self.write('\nendstream')
else:
data = str(obj)

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