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
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
METADATA:
Metadata consist of information that characterizes data.
Metadata are used to provide documentation for data products.
In essence, metadata answer who, what, when, where, why, and how about
every facet of the data that are being documented.
METADATA AND PRIVACY:
Metadata within a file can tell a lot about you.
Cameras record data about when a picture was taken and what
camera was used. Office documents like pdf or Office automatically adds
author and company information to documents and spreadsheets.
Maybe you don't want to disclose those information on the web.
WARNING :
Mat only removes metadata from your files, it does not anonymise their
content, nor can it handle watermarking, steganography, or any too custom
metadata field/system.
If you really want to be anonym, use format that does not contain any
metadata, or better : use plain-text.
DEPENDENCIES:
python2.6 (at least)
python-hachoir-core and python-hachoir-parser
shred (should be already installed)
OPTIONALS DEPENDENCIES:
python-poppler and python-cairo : for pdf support
python-mutagen : for massive audio format support
USAGE:
python cli.py --help
or
python gui.py
SUPPORTED FORMAT:
Portable Network Graphics (.png)
support : full
metadata : textual metadata + date
method : removal of harmful fields is done with hachoir
Jpeg (.jpeg, .jpg)
support : full
metadata : comment + exif/photoshop/adobe
method : removal of harmful fields is done with hachoir
Open Document (.odt, .odx, .ods, ...)
support : full
metadata : a meta.xml file
method : removal of the meta.xml file
Office Openxml (.docx, .pptx, .xlsx, ...)
support : full
metadata : a docProps folder containings xml metadata files
method : removal of the docProps folder
Portable Document Fileformat (.pdf)
support : full
metadata : a lot
method : rendering of the pdf file on a cairo surface with the help of
poppler in order to remove all the internal metadata,
then removal of the remaining metadata fields of the pdf itself with
pdfrw (the next version of python-cairo will support metadata,
so we should get rid of pdfrw)
Tape ARchive (.tar, .tar.bz2, .tar.gz)
support : full
metadata : metadata from the file itself, metadata from the file contained
into the archive, and metadata added by tar to the file at then
creation of the archive
method : extraction of each file, treatement of the file, add treated file
to a new archive, right before the add, remove the metadata added by tar
itself. When the new archive is complete, remove all his metadata.
Zip (.zip)
support : .partial
metadata : metadata from the file itself, metadata from the file contained
into the archive, and metadata added by zip to the file when added to
the archive.
method : extraction of each file, treatement of the file, add treated file
to a new archive. When the new archive is complete, remove all his metadata
MPEG Audio (.mp3, .mp2, .mp1)
support : full
metadata : id3
method : removal of harmful fields is done with hachoir
Ogg Vorbis (.ogg)
support : full
metadata : Vorbis
method : removal of harmful fields is done with mutagen
Free Lossless Audio Codec (.flac)
support : full
metadata : Flac, Vorbis
method : removal of harmful fields is done with mutagen
HOW TO IMPLEMENT NEW FORMATS:
1. add the format's mimetype to the STRIPPER list in mat.py
2. inherit the GenericParser class (parser.py)
3. read the parser.py module
4. implement at least these three methods:
- is_clean(self)
- remove_all(self)
- get_meta(self)
5. don't forget to call the do_backup() method when necessary
ALTERNATIVES AND COMPLEMENTS:
for images:
exiftool (perl) : metadata manipulation
exiv2 (C++) : metadata manipulation
graphicsmagick (a fork from imagemagick) : cli image manipulation
for pdf:
pdfminer (python) : pdf manipulation
other tools:
an hexadecimal editor
LICENSE:
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA.
THANKS:
Mat would not exist without :
- the Google Summer of Code,
- the Python language
- the amazing (and messy) hachoir library,
- poppler and cairo's python bindings,
- and the mutagen library
many thanks to them !
KNOWN BUGS:
Zipfiles are not totally cleaned, I know.
I am working on a patch for zipfile.py
|
