4 Coquelicot is a "one-click" file sharing web application with specific
5 thoughts on protecting users privacy.
7 Basic principle: users can upload a file to the server, it return they
8 get a unique URL which can be shared to others in order to download the
11 Coquelicot aims to protect, to some extents, users and system
12 administrators from disclosure of the files exchanged from passive
13 and not so active attackers.
18 * Uploading a file is protected by a common password
20 In order to prevent random Internet users to eat bandwidth and disk
21 space, uploading a file to share is protected by a common password.
23 * Mandatory expiration
25 When uploading, a time limit has to be specified. The file will be
26 unavailable once this limit has been reached.
28 During a configurable period of time, trying to download the file
29 will return a page saying "too late" instead of "not found".
31 * Support for one-time download
33 An user might want to allow exactly _one_ download of a file,
34 to more closely replace an email attachment. The file will be removed after
35 the first complete download and concurrent download are prevented.
39 If the web server tracks upload progress, users having javascript
40 enabled will see a nice progress bar during the file upload.
44 The application works fine without javascript or CSS.
46 * Download URL are hand-writing compatible
48 URLs generated to download files uses the Base32 character set. This
49 set is specifically designed to overcome misread of 'l', '1', '0' and
50 'O' characters. Coquelicot will automatically convert case and
51 ambiguous characters to facilitate URL exchanges through
54 * Files are stored encrypted on the server
56 Upon upload, files are written to the disk using symmetric
57 encryption. The encryption key is _not_ stored directly by
58 Coquelicot. It is either generated randomly and given as part of the
59 download URL, or specified by the uploader.
61 * Download can be protected by a password
63 When uploading, a password can be specified which will be used as
64 the encryption key. In order to download the file, the password
65 must be entered through in a POST'ed form, preventing the password
66 from appearing in the server logs.
68 * Files are stored with a random name
70 To prevent disclosure of the shared file name, it is stored encrypted
71 together with the file content. On the server, this encrypted file is
72 stored with a random name.
74 * Download URLs do not reflect stored file names
76 The random names given in download URLs do not map directly to file
77 names on the server. This prevent server logs from giving a direct
78 mapping to the shared files.
80 * File content is zero'ed before removal
82 When a file has expired, it is removed from the server. In order
83 to make it harder to retrieve its content through filesystem
84 analysis, it is filled with zeroes first.
89 Coquelicot is written in Ruby using the Sinatra web framework.
91 On Debian, one can fulfill its dependencies by issueing:
93 apt-get install libsinatra-ruby1.8 libopenssl-ruby1.8 \
94 libhaml-ruby1.8 liblockfile-ruby libgettext-ruby1.8 \
97 Then create the translation catalog through:
101 Finally you need to figure out the best way to host a Rack application
102 depending on your setup. *evil grin*
107 Coquelicot test suite is written using RSpec.
109 On Debian, you will need those extra packages:
111 apt-get install librspec-ruby1.8 libhpricot-ruby1.8
113 You will also need the unpackaged gems "timecop" and "rack-test".
115 Then, running the test suite is just a matter of typing:
117 spec test_coquelicot.rb
122 Jyraphe [1] is another free software web file sharing application.
123 Coquelicot provides a migration script to import Jyraphe 0.5 repositories in
124 `tools/migrate_jyraphe.rb`.
126 [1] http://home.gna.org/jyraphe/
131 * Integrate other authentication systems for uploads
133 A common password is a pretty limited authentication scheme.
134 One could like to also configure no password or integrate with
135 webmails or other authentication system.
137 * More flexible expiration
139 It might be interesting to also offer a calendar for specifying
140 an exact date after which the file will be unavailable.
142 * Hide file size (padding)
144 There is currently a real close mapping from original file size to
145 stored file size. Original file size will also be recorded in server
146 logs. Padding could be used to improve this situation.
150 Most Ruby stuff is installed using Gem, so Coquelicot should be one.
154 A Debian package would be nice to spread Coquelicot setups.
156 * Describe more setups
158 Describe how to setup Coquelicot with mod_passenger, Mongrel and
164 Files are stored in the directory specified by the 'depot_path'
167 The format is the following:
171 Salt: <8 bytes stored as Base64>
172 Expire-at: <expiration time in seconds since epoch>
176 Encryption is done using OpenSSL. Cipher is AES-256-CBC with key and IV
177 created using the pbkdf2_hmac_sha1() implementation of PKCS5. The later
178 is fead using the former 'Salt' and the given passphrase.
180 Once decrypted, content has the following format:
183 Created-at: <upload time in seconds since epoch>
184 Filename: "<original file name>"
185 Content-Type: "<MIME type>"
186 Length: <file length is bytes>
187 One-time-only: <true|false>
189 <original bytes forming the file content>
191 Headers must be parseable using the YAML standard.
193 File are truncated to zero length when they are "expired".
195 In order to map download URLs to file name, a simple text file ".links"
196 is used. It contains a line for each file in the form:
198 <URL name> <file name>
203 Coquelicot © 2010 potager.org <jardiniers@potager.org>
205 Coquelicot is distributed under the GNU Affero General Public License
206 version 3. See LICENSE for details.