- <title>Easier recipe to observe the cell phones around you</title>
- <link>http://people.skolelinux.org/pere/blog/Easier_recipe_to_observe_the_cell_phones_around_you.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Easier_recipe_to_observe_the_cell_phones_around_you.html</guid>
- <pubDate>Sun, 24 Sep 2017 08:30:00 +0200</pubDate>
- <description><p>A little more than a month ago I wrote
-<a href="http://people.skolelinux.org/pere/blog/Simpler_recipe_on_how_to_make_a_simple__7_IMSI_Catcher_using_Debian.html">how
-to observe the SIM card ID (aka IMSI number) of mobile phones talking
-to nearby mobile phone base stations using Debian GNU/Linux and a
-cheap USB software defined radio</a>, and thus being able to pinpoint
-the location of people and equipment (like cars and trains) with an
-accuracy of a few kilometer. Since then we have worked to make the
-procedure even simpler, and it is now possible to do this without any
-manual frequency tuning and without building your own packages.</p>
-
-<p>The <a href="https://tracker.debian.org/pkg/gr-gsm">gr-gsm</a>
-package is now included in Debian testing and unstable, and the
-IMSI-catcher code no longer require root access to fetch and decode
-the GSM data collected using gr-gsm.</p>
-
-<p>Here is an updated recipe, using packages built by Debian and a git
-clone of two python scripts:</p>
-
-<ol>
-
-<li>Start with a Debian machine running the Buster version (aka
- testing).</li>
-
-<li>Run '<tt>apt install gr-gsm python-numpy python-scipy
- python-scapy</tt>' as root to install required packages.</li>
-
-<li>Fetch the code decoding GSM packages using '<tt>git clone
- github.com/Oros42/IMSI-catcher.git</tt>'.</li>
-
-<li>Insert USB software defined radio supported by GNU Radio.</li>
-
-<li>Enter the IMSI-catcher directory and run '<tt>python
- scan-and-livemon</tt>' to locate the frequency of nearby base
- stations and start listening for GSM packages on one of them.</li>
-
-<li>Enter the IMSI-catcher directory and run '<tt>python
- simple_IMSI-catcher.py</tt>' to display the collected information.</li>
-
-</ol>
-
-<p>Note, due to a bug somewhere the scan-and-livemon program (actually
-<a href="https://github.com/ptrkrysik/gr-gsm/issues/336">its underlying
-program grgsm_scanner</a>) do not work with the HackRF radio. It does
-work with RTL 8232 and other similar USB radio receivers you can get
-very cheaply
-(<a href="https://www.ebay.com/sch/items/?_nkw=rtl+2832">for example
-from ebay</a>), so for now the solution is to scan using the RTL radio
-and only use HackRF for fetching GSM data.</p>
-
-<p>As far as I can tell, a cell phone only show up on one of the
-frequencies at the time, so if you are going to track and count every
-cell phone around you, you need to listen to all the frequencies used.
-To listen to several frequencies, use the --numrecv argument to
-scan-and-livemon to use several receivers. Further, I am not sure if
-phones using 3G or 4G will show as talking GSM to base stations, so
-this approach might not see all phones around you. I typically see
-0-400 IMSI numbers an hour when looking around where I live.</p>
-
-<p>I've tried to run the scanner on a
-<a href="https://wiki.debian.org/RaspberryPi">Raspberry Pi 2 and 3
-running Debian Buster</a>, but the grgsm_livemon_headless process seem
-to be too CPU intensive to keep up. When GNU Radio print 'O' to
-stdout, I am told there it is caused by a buffer overflow between the
-radio and GNU Radio, caused by the program being unable to read the
-GSM data fast enough. If you see a stream of 'O's from the terminal
-where you started scan-and-livemon, you need a give the process more
-CPU power. Perhaps someone are able to optimize the code to a point
-where it become possible to set up RPi3 based GSM sniffers? I tried
-using Raspbian instead of Debian, but there seem to be something wrong
-with GNU Radio on raspbian, causing glibc to abort().</p>
+ <title>Valutakrambod - A python and bitcoin love story</title>
+ <link>http://people.skolelinux.org/pere/blog/Valutakrambod___A_python_and_bitcoin_love_story.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Valutakrambod___A_python_and_bitcoin_love_story.html</guid>
+ <pubDate>Sat, 29 Sep 2018 22:20:00 +0200</pubDate>
+ <description><p>It would come as no surprise to anyone that I am interested in
+bitcoins and virtual currencies. I've been keeping an eye on virtual
+currencies for many years, and it is part of the reason a few months
+ago, I started writing a python library for collecting currency
+exchange rates and trade on virtual currency exchanges. I decided to
+name the end result valutakrambod, which perhaps can be translated to
+small currency shop.</p>
+
+<p>The library uses the tornado python library to handle HTTP and
+websocket connections, and provide a asynchronous system for
+connecting to and tracking several services. The code is available
+from
+<a href="http://github.com/petterreinholdtsen/valutakrambod">github</a>.</p>
+
+</p>There are two example clients of the library. One is very simple and
+list every updated buy/sell price received from the various services.
+This code is started by running bin/btc-rates and call the client code
+in valutakrambod/client.py. The simple client look like this:</p>
+
+<p><blockquote><pre>
+import functools
+import tornado.ioloop
+import valutakrambod
+class SimpleClient(object):
+ def __init__(self):
+ self.services = []
+ self.streams = []
+ pass
+ def newdata(self, service, pair, changed):
+ print("%-15s %s-%s: %8.3f %8.3f" % (
+ service.servicename(),
+ pair[0],
+ pair[1],
+ service.rates[pair]['ask'],
+ service.rates[pair]['bid'])
+ )
+ async def refresh(self, service):
+ await service.fetchRates(service.wantedpairs)
+ def run(self):
+ self.ioloop = tornado.ioloop.IOLoop.current()
+ self.services = valutakrambod.service.knownServices()
+ for e in self.services:
+ service = e()
+ service.subscribe(self.newdata)
+ stream = service.websocket()
+ if stream:
+ self.streams.append(stream)
+ else:
+ # Fetch information from non-streaming services immediately
+ self.ioloop.call_later(len(self.services),
+ functools.partial(self.refresh, service))
+ # as well as regularly
+ service.periodicUpdate(60)
+ for stream in self.streams:
+ stream.connect()
+ try:
+ self.ioloop.start()
+ except KeyboardInterrupt:
+ print("Interrupted by keyboard, closing all connections.")
+ pass
+ for stream in self.streams:
+ stream.close()
+</pre></blockquote></p>
+
+<p>The library client loops over all known "public" services,
+initialises it, subscribes to any updates from the service, checks and
+activates websocket streaming if the service provide it, and if no
+streaming is supported, fetches information from the service and sets
+up a periodic update every 60 seconds. The output from this client
+can look like this:</p>
+
+<p><blockquote><pre>
+Bl3p BTC-EUR: 5687.110 5653.690
+Bl3p BTC-EUR: 5687.110 5653.690
+Bl3p BTC-EUR: 5687.110 5653.690
+Hitbtc BTC-USD: 6594.560 6593.690
+Hitbtc BTC-USD: 6594.560 6593.690
+Bl3p BTC-EUR: 5687.110 5653.690
+Hitbtc BTC-USD: 6594.570 6593.690
+Bitstamp EUR-USD: 1.159 1.154
+Hitbtc BTC-USD: 6594.570 6593.690
+Hitbtc BTC-USD: 6594.580 6593.690
+Hitbtc BTC-USD: 6594.580 6593.690
+Hitbtc BTC-USD: 6594.580 6593.690
+Bl3p BTC-EUR: 5687.110 5653.690
+Paymium BTC-EUR: 5680.000 5620.240
+</pre></blockquote></p>
+
+<p>The exchange order book is tracked in addition to the best buy/sell
+price, for those that need to know the details.</p>
+
+<p>The other example client is focusing on providing a curses view
+with updated buy/sell prices as soon as they are received from the
+services. This code is located in bin/btc-rates-curses and activated
+by using the '-c' argument. Without the argument the "curses" output
+is printed without using curses, which is useful for debugging. The
+curses view look like this:</p>
+
+<p><blockquote><pre>
+ Name Pair Bid Ask Spr Ftcd Age
+ BitcoinsNorway BTCEUR 5591.8400 5711.0800 2.1% 16 nan 60
+ Bitfinex BTCEUR 5671.0000 5671.2000 0.0% 16 22 59
+ Bitmynt BTCEUR 5580.8000 5807.5200 3.9% 16 41 60
+ Bitpay BTCEUR 5663.2700 nan nan% 15 nan 60
+ Bitstamp BTCEUR 5664.8400 5676.5300 0.2% 0 1 1
+ Bl3p BTCEUR 5653.6900 5684.9400 0.5% 0 nan 19
+ Coinbase BTCEUR 5600.8200 5714.9000 2.0% 15 nan nan
+ Kraken BTCEUR 5670.1000 5670.2000 0.0% 14 17 60
+ Paymium BTCEUR 5620.0600 5680.0000 1.1% 1 7515 nan
+ BitcoinsNorway BTCNOK 52898.9700 54034.6100 2.1% 16 nan 60
+ Bitmynt BTCNOK 52960.3200 54031.1900 2.0% 16 41 60
+ Bitpay BTCNOK 53477.7833 nan nan% 16 nan 60
+ Coinbase BTCNOK 52990.3500 54063.0600 2.0% 15 nan nan
+ MiraiEx BTCNOK 52856.5300 54100.6000 2.3% 16 nan nan
+ BitcoinsNorway BTCUSD 6495.5300 6631.5400 2.1% 16 nan 60
+ Bitfinex BTCUSD 6590.6000 6590.7000 0.0% 16 23 57
+ Bitpay BTCUSD 6564.1300 nan nan% 15 nan 60
+ Bitstamp BTCUSD 6561.1400 6565.6200 0.1% 0 2 1
+ Coinbase BTCUSD 6504.0600 6635.9700 2.0% 14 nan 117
+ Gemini BTCUSD 6567.1300 6573.0700 0.1% 16 89 nan
+ Hitbtc+BTCUSD 6592.6200 6594.2100 0.0% 0 0 0
+ Kraken BTCUSD 6565.2000 6570.9000 0.1% 15 17 58
+ Exchangerates EURNOK 9.4665 9.4665 0.0% 16 107789 nan
+ Norgesbank EURNOK 9.4665 9.4665 0.0% 16 107789 nan
+ Bitstamp EURUSD 1.1537 1.1593 0.5% 4 5 1
+ Exchangerates EURUSD 1.1576 1.1576 0.0% 16 107789 nan
+ BitcoinsNorway LTCEUR 1.0000 49.0000 98.0% 16 nan nan
+ BitcoinsNorway LTCNOK 492.4800 503.7500 2.2% 16 nan 60
+ BitcoinsNorway LTCUSD 1.0221 49.0000 97.9% 15 nan nan
+ Norgesbank USDNOK 8.1777 8.1777 0.0% 16 107789 nan
+</pre></blockquote></p>
+
+<p>The code for this client is too complex for a simple blog post, so
+you will have to check out the git repository to figure out how it
+work. What I can tell is how the three last numbers on each line
+should be interpreted. The first is how many seconds ago information
+was received from the service. The second is how long ago, according
+to the service, the provided information was updated. The last is an
+estimate on how often the buy/sell values change.</p>
+
+<p>If you find this library useful, or would like to improve it, I
+would love to hear from you. Note that for some of the services I've
+implemented a trading API. It might be the topic of a future blog
+post.</p>
+
+<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">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
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