1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
import os
import mimetypes
import subprocess
import tempfile
import glob
import hachoir_core
import pdfrw
import mat
import parser
class TorrentStripper(parser.Generic_parser):
'''
A torrent file looks like:
-root
-start
-announce
-announce-list
-comment
-created_by
-creation_date
-encoding
-info
-end
'''
def remove_all(self):
for field in self.editor['root']:
if self._should_remove(field):
#FIXME : hachoir does not support torrent metadata editing :<
del self.editor['/root/' + field.name]
hachoir_core.field.writeIntoFile(self.editor,
self.filename + parser.POSTFIX)
if self.backup is False:
mat.secure_remove(self.filename) #remove the old file
os.rename(self.filename + parser.POSTFIX, self.filename)
def is_clean(self):
for field in self.editor['root']:
if self._should_remove(field):
return False
return True
def get_meta(self):
metadata = {}
for field in self.editor['root']:
if self._should_remove(field):
try:#FIXME
metadata[field.name] = field.value
except:
metadata[field.name] = 'harmful content'
return metadata
def _should_remove(self, field):
if field.name in ('comment', 'created_by', 'creation_date', 'info'):
return True
else:
return False
class PdfStripper(parser.Generic_parser):
'''
Represent a pdf file, with the help of pdfrw
'''
def __init__(self, filename, realname, backup):
self.filename = filename
self.backup = backup
self.realname = realname
self.shortname = os.path.basename(filename)
self.mime = mimetypes.guess_type(filename)[0]
self.trailer = pdfrw.PdfReader(self.filename)
self.writer = pdfrw.PdfWriter()
self.convert = 'gm convert -antialias -enhance %s %s'
def remove_all(self):
'''
Remove all the meta fields that are compromizing
'''
self.trailer.Info.Title = ''
self.trailer.Info.Author = ''
self.trailer.Info.Producer = ''
self.trailer.Info.Creator = ''
self.trailer.Info.CreationDate = ''
self.trailer.Info.ModDate = ''
self.writer.trailer = self.trailer
self.writer.write(self.filename + parser.POSTFIX)
if self.backup is False:
mat.secure_remove(self.filename) #remove the old file
os.rename(self.filename + parser.POSTFIX, self.filename)
def remove_all_ugly(self):
'''
Transform each pages into a jpg, clean them,
then re-assemble them into a new pdf
'''
output_file = self.realname + parser.POSTFIX + '.pdf'
_, self.tmpdir = tempfile.mkstemp()
subprocess.call(self.convert % (self.filename, self.tmpdir +
'temp.jpg'), shell=True)#Convert pages to jpg
for current_file in glob.glob(self.tmpdir + 'temp*'):
#Clean every jpg image
class_file = mat.create_class_file(current_file, False)
class_file.remove_all()
subprocess.call(self.convert % (self.tmpdir +
'temp.jpg*', output_file), shell=True)#Assemble jpg into pdf
for current_file in glob.glob(self.tmpdir + 'temp*'):
#remove jpg files
mat.secure_remove(current_file)
if self.backup is False:
mat.secure_remove(self.filename) #remove the old file
os.rename(output_file, self.filename)#rename the new
name = self.realname
else:
name = output_file
class_file = mat.create_class_file(name, False)
class_file.remove_all()
def is_clean(self):
'''
Check if the file is clean from harmful metadatas
'''
for field in self.trailer.Info:
if field != '':
return False
return True
def get_meta(self):
'''
return a dict with all the meta of the file
'''
metadata = {}
for key, value in self.trailer.Info.iteritems():
metadata[key[1:]] = value[1:-1]
return metadata
|
