+ <item>
+ <title>Experience and updated recipe for Using the Signal app without a mobile phone</title>
+ <link>http://people.skolelinux.org/pere/blog/Experience_and_updated_recipe_for_Using_the_Signal_app_without_a_mobile_phone.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Experience_and_updated_recipe_for_Using_the_Signal_app_without_a_mobile_phone.html</guid>
+ <pubDate>Mon, 10 Oct 2016 11:30:00 +0200</pubDate>
+ <description><p>In July
+<a href="http://people.skolelinux.org/pere/blog/How_to_use_the_Signal_app_if_you_only_have_a_land_line__ie_no_mobile_phone_.html">I
+wrote how to get the Signal Chrome/Chromium app working</a> without
+the ability to receive SMS messages (aka without a cell phone). It is
+time to share some experiences and provide an updated setup.</p>
+
+<p>The Signal app have worked fine for several months now, and I use
+it regularly to chat with my loved ones. I had a major snag at the
+end of my summer vacation, when the the app completely forgot my
+setup, identify and keys. The reason behind this major mess was
+running out of disk space. To avoid that ever happening again I have
+started storing everything in <tt>userdata/</tt> in git, to be able to
+roll back to an earlier version if the files are wiped by mistake. I
+had to use it once after introducing the git backup. When rolling
+back to an earlier version, one need to use the 'reset session' option
+in Signal to get going, and notify the people you talk with about the
+problem. I assume there is some sequence number tracking in the
+protocol to detect rollback attacks. The git repository is rather big
+(674 MiB so far), but I have not tried to figure out if some of the
+content can be added to a .gitignore file due to lack of spare
+time.</p>
+
+<p>I've also hit the 90 days timeout blocking, and noticed that this
+make it impossible to send messages using Signal. I could still
+receive them, but had to patch the code with a new timestamp to send.
+I believe the timeout is added by the developers to force people to
+upgrade to the latest version of the app, even when there is no
+protocol changes, to reduce the version skew among the user base and
+thus try to keep the number of support requests down.</p>
+
+<p>Since my original recipe, the Signal source code changed slightly,
+making the old patch fail to apply cleanly. Below is an updated
+patch, including the shell wrapper I use to start Signal. The
+original version required a new user to locate the JavaScript console
+and call a function from there. I got help from a friend with more
+JavaScript knowledge than me to modify the code to provide a GUI
+button instead. This mean that to get started you just need to run
+the wrapper and click the 'Register without mobile phone' to get going
+now. I've also modified the timeout code to always set it to 90 days
+in the future, to avoid having to patch the code regularly.</p>
+
+<p>So, the updated recipe for Debian Jessie:</p>
+
+<ol>
+
+<li>First, install required packages to get the source code and the
+browser you need. Signal only work with Chrome/Chromium, as far as I
+know, so you need to install it.
+
+<pre>
+apt install git tor chromium
+git clone https://github.com/WhisperSystems/Signal-Desktop.git
+</pre></li>
+
+<li>Modify the source code using command listed in the the patch
+block below.</li>
+
+<li>Start Signal using the run-signal-app wrapper (for example using
+<tt>`pwd`/run-signal-app</tt>).
+
+<li>Click on the 'Register without mobile phone', will in a phone
+number you can receive calls to the next minute, receive the
+verification code and enter it into the form field and press
+'Register'. Note, the phone number you use will be user Signal
+username, ie the way others can find you on Signal.</li>
+
+<li>You can now use Signal to contact others. Note, new contacts do
+not show up in the contact list until you restart Signal, and there is
+no way to assign names to Contacts. There is also no way to create or
+update chat groups. I suspect this is because the web app do not have
+a associated contact database.</li>
+
+</ol>
+
+<p>I am still a bit uneasy about using Signal, because of the way its
+main author moxie0 reject federation and accept dependencies to major
+corporations like Google (part of the code is fetched from Google) and
+Amazon (the central coordination point is owned by Amazon). See for
+example
+<a href="https://github.com/LibreSignal/LibreSignal/issues/37">the
+LibreSignal issue tracker</a> for a thread documenting the authors
+view on these issues. But the network effect is strong in this case,
+and several of the people I want to communicate with already use
+Signal. Perhaps we can all move to <a href="https://ring.cx/">Ring</a>
+once it <a href="https://bugs.debian.org/830265">work on my
+laptop</a>? It already work on Windows and Android, and is included
+in <a href="https://tracker.debian.org/pkg/ring">Debian</a> and
+<a href="https://launchpad.net/ubuntu/+source/ring">Ubuntu</a>, but not
+working on Debian Stable.</p>
+
+<p>Anyway, this is the patch I apply to the Signal code to get it
+working. It switch to the production servers, disable to timeout,
+make registration easier and add the shell wrapper:</p>
+
+<pre>
+cd Signal-Desktop; cat &lt;&lt;EOF | patch -p1
+diff --git a/js/background.js b/js/background.js
+index 24b4c1d..579345f 100644
+--- a/js/background.js
++++ b/js/background.js
+@@ -33,9 +33,9 @@
+ });
+ });
+
+- var SERVER_URL = 'https://textsecure-service-staging.whispersystems.org';
++ var SERVER_URL = 'https://textsecure-service-ca.whispersystems.org';
+ var SERVER_PORTS = [80, 4433, 8443];
+- var ATTACHMENT_SERVER_URL = 'https://whispersystems-textsecure-attachments-staging.s3.amazonaws.com';
++ var ATTACHMENT_SERVER_URL = 'https://whispersystems-textsecure-attachments.s3.amazonaws.com';
+ var messageReceiver;
+ window.getSocketStatus = function() {
+ if (messageReceiver) {
+diff --git a/js/expire.js b/js/expire.js
+index 639aeae..beb91c3 100644
+--- a/js/expire.js
++++ b/js/expire.js
+@@ -1,6 +1,6 @@
+ ;(function() {
+ 'use strict';
+- var BUILD_EXPIRATION = 0;
++ var BUILD_EXPIRATION = Date.now() + (90 * 24 * 60 * 60 * 1000);
+
+ window.extension = window.extension || {};
+
+diff --git a/js/views/install_view.js b/js/views/install_view.js
+index 7816f4f..1d6233b 100644
+--- a/js/views/install_view.js
++++ b/js/views/install_view.js
+@@ -38,7 +38,8 @@
+ return {
+ 'click .step1': this.selectStep.bind(this, 1),
+ 'click .step2': this.selectStep.bind(this, 2),
+- 'click .step3': this.selectStep.bind(this, 3)
++ 'click .step3': this.selectStep.bind(this, 3),
++ 'click .callreg': function() { extension.install('standalone') },
+ };
+ },
+ clearQR: function() {
+diff --git a/options.html b/options.html
+index dc0f28e..8d709f6 100644
+--- a/options.html
++++ b/options.html
+@@ -14,7 +14,10 @@
+ &lt;div class='nav'>
+ &lt;h1>{{ installWelcome }}&lt;/h1>
+ &lt;p>{{ installTagline }}&lt;/p>
+- &lt;div> &lt;a class='button step2'>{{ installGetStartedButton }}&lt;/a> &lt;/div>
++ &lt;div> &lt;a class='button step2'>{{ installGetStartedButton }}&lt;/a>
++ &lt;br> &lt;a class="button callreg">Register without mobile phone&lt;/a>
++
++ &lt;/div>
+ &lt;span class='dot step1 selected'>&lt;/span>
+ &lt;span class='dot step2'>&lt;/span>
+ &lt;span class='dot step3'>&lt;/span>
+--- /dev/null 2016-10-07 09:55:13.730181472 +0200
++++ b/run-signal-app 2016-10-10 08:54:09.434172391 +0200
+@@ -0,0 +1,12 @@
++#!/bin/sh
++set -e
++cd $(dirname $0)
++mkdir -p userdata
++userdata="`pwd`/userdata"
++if [ -d "$userdata" ] && [ ! -d "$userdata/.git" ] ; then
++ (cd $userdata && git init)
++fi
++(cd $userdata && git add . && git commit -m "Current status." || true)
++exec chromium \
++ --proxy-server="socks://localhost:9050" \
++ --user-data-dir=$userdata --load-and-launch-app=`pwd`
+EOF
+chmod a+rx run-signal-app
+</pre>
+
+<p>As usual, if you use Bitcoin and want to show your support of my
+activities, please send Bitcoin donations to my address
+<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&label=PetterReinholdtsenBlog">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
+</description>
+ </item>
+
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