148 lines
5.7 KiB
Plaintext
148 lines
5.7 KiB
Plaintext
/*! @file
|
|
|
|
@id $Id$
|
|
*/
|
|
// 1 2 3 4 5 6 7 8
|
|
// 45678901234567890123456789012345678901234567890123456789012345678901234567890
|
|
|
|
/** @mainpage SafeChat
|
|
|
|
SafeChat runs on:
|
|
https://safechat.ch
|
|
|
|
SafeChat development is on:
|
|
https://dev.marc.waeckerlin.org/redmine/projects/safechat
|
|
|
|
Implementation Details: @ref security, @ref api, @ref protocol,
|
|
@ref database
|
|
|
|
SafeChat is a chat program designed to protect your privacy. It is
|
|
designed to be:
|
|
|
|
-# extremely easy to use
|
|
-# zero installation
|
|
-# simple registration, within seconds
|
|
-# web 2.0 - works in any modern browser
|
|
-# user does not have to care about keys, security, encryption
|
|
-# all cool features
|
|
-# pseudonym accounts, no phone number, no email,nothing required
|
|
-# send images and other attachments
|
|
-# build groups
|
|
-# no need to be online, receive messages on next login
|
|
-# central user directory
|
|
-# absolutely secure
|
|
-# tap-proof
|
|
-# no metadata available
|
|
-# all messages are sent to all users, only the authorized users can decrypt it
|
|
-# server can be untrusted
|
|
-# thin server, rich client
|
|
-# all encryption is done in the client
|
|
-# server only stores minimal user data (name, public key) and encrypted messages
|
|
-# no access to plain data, not even through server confiscation
|
|
-# double secured internet transport
|
|
-# messages are encrypted for the recipents only
|
|
-# server connection is SSL secured in addition
|
|
-# private data fully in the user's hand
|
|
-# password is stored in the user's brain only
|
|
-# private key is password encrypted
|
|
-# private key is stored in the user's local machine only
|
|
-# two factor security, access needs two tokens
|
|
-# the password in the user's brain
|
|
-# the private key in the user's browser memory
|
|
-# fully open source
|
|
|
|
@section why Why I Created SafeChat
|
|
|
|
The Swiss parliament has decided to increase the power of police
|
|
(BÜPF: Bundesgesetz zur Überwachung des Post- und
|
|
Fernmeldeverkehrs) and secret service (NDG:
|
|
Nachrichtendienstgesetz). This increases global enforced data
|
|
preservation without any suspicion. This even allows the police to
|
|
run a trojan in computers of suspicious persons.
|
|
|
|
That was the point, when I started to think about secure
|
|
communication that defeats these attacks against our
|
|
privacy. Noone should be able to read what's not for his eyes,
|
|
even if he controls the server. There should be no metadata,
|
|
i.e. no one should know, who is communicating to each other.
|
|
|
|
There are secure means of communication, i.e. Jabber/OTR and
|
|
PGP-Mail (but with unprotected metadata). But these are too
|
|
complicated for the avarage user. He has to take care about keys
|
|
and their distribution. In some chat programs, there is no offline
|
|
message store, so you can only send a message, if the receiver is
|
|
online. Some chat programs require to identify you, they ask your
|
|
phone number and some even steal your address book
|
|
(i.e. WhatsApp). Not here! Use any pseudonym. No special knowledge
|
|
needed. User is guided as much as possible, the interface is as
|
|
simple as possible. Data is only collected, if it is necessary.
|
|
|
|
So I present here the safe chat program for dummies
|
|
|
|
@page security Password and Secrets Concept
|
|
|
|
Neither the password nor the private key are sent to the
|
|
server. They remain under the user's control and in the user's
|
|
property. Only the user name and the public key are sent to the
|
|
server.
|
|
|
|
- The password is only kept in the browser's transient memory.
|
|
- The private key is kept in encrypted form in the browser's
|
|
persistent local storage.
|
|
- The public key is stored on server, so that other users can
|
|
lookup for a user's public key.
|
|
|
|
There are two secret security tokens: The password, that is in the
|
|
user's mind and the private key, which is in the user's device, in
|
|
the local storage of his browser. Messages can only be sent or
|
|
read with access to both security tokens.
|
|
|
|
@page protocol SafeChat Protocol
|
|
|
|
@tableofcontents
|
|
|
|
@section newuser Create New User
|
|
|
|
If no credentials exist in the browser's local storage, the
|
|
browser asks the user for a user name and a password and creates a
|
|
private key that is encrypted with the password.
|
|
|
|
In the login(), the browser sends the user's name and public key
|
|
to the server. The server creates a new user, if the user does not
|
|
exist yet. Then the server returns, whether user name and public
|
|
key match to what he has in his table.
|
|
|
|
@msc
|
|
user, browser, server;
|
|
user -> browser [label="https://safechat.ch"];
|
|
browser -> server [label="index.html"];
|
|
browser <- server [label="safechat.js",URL="\ref safechat.js"];
|
|
user <- browser [label="register new user"];
|
|
user -> browser [label="username / password"];
|
|
browser -> browser [label="create openpgp-public/private keys"];
|
|
browser -> server [label="login.php(username, public-key)"];
|
|
server -> server [label="if user name does not exist:\nstore username/public-key"];
|
|
server -> browser [label="success"];
|
|
@endmsc
|
|
|
|
*/
|
|
|
|
/** @page api Server API Calls
|
|
|
|
@tableofcontents
|
|
|
|
List of server REST API calls. SafeChat server implement s REST
|
|
API, so that all API calls are in the following form, where
|
|
parameters and values are url encoded:
|
|
|
|
@code
|
|
https://safechat.ch/api-call.php?param1=value1¶m2=value2[...]
|
|
@endcode
|
|
|
|
So for method get() a valid call could be:
|
|
@code
|
|
https://safechat.ch/get.php?start=100
|
|
@endcode
|
|
|
|
*/
|