The document discusses the development of BitcoinJS, an open-source Bitcoin library for Node.js. It describes how the developer started working on BitcoinJS after becoming interested in Bitcoin as an evangelist. Details are provided about implementing the library, challenges faced around memory leaks and platform compatibility, and future plans to build a graphical user interface and wallet.

1. Stefan Thomas • WeUseCoins.com
$
BitcoinJS
A divorce and new beginnings
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2. $ login
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3. $ login
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4. $ login
- Web developer
13 years
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5. $ login
- Web developer
13 years
- Bitcoin evangelist
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6. $ login
- Web developer
13 years
- Bitcoin evangelist
6 months
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7. $ login
- Web developer
13 years
- Bitcoin evangelist
6 months
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8. $ login
- Web developer
13 years
- Bitcoin evangelist
6 months
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9. $ ls
- What’s Bitcoin? (1 slide version)
- Things that are... sub-optimal
- Node.js to the rescue!
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10. $ man bitcoin
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11. $ man bitcoin
- Limited set of tokens
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12. $ man bitcoin
- Limited set of tokens
- Decentralized
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13. $ man bitcoin
- Limited set of tokens
- Decentralized
- Open-Source
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14. $ man bitcoin
- Limited set of tokens
- Decentralized
- Open-Source
= Internet Money
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15. $ wget blk*.dat
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16. $ wget blk*.dat
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17. $ wget blk*.dat
x 140000
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18. $ wget blk*.dat
x 140000
= 620 MB
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19. $ wget blk*.dat
x 140000
= 620 MB => 6-24 hours
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20. $ wget blk*.dat
x 140000
= 620 MB => 6-24 hours
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21. $ rm wallet.dat
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22. $ rm wallet.dat
VirtualBox Dropbox Ironkey
+
Truecrypt
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23. $ rm wallet.dat
VirtualBox Dropbox Ironkey
+
Truecrypt
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24. $ rm wallet.dat
VirtualBox Dropbox Ironkey
+
Truecrypt
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25. $ rm wallet.dat
VirtualBox Dropbox Ironkey
+
Truecrypt
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26. $ rm wallet.dat
VirtualBox Dropbox Ironkey
+
Truecrypt
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27. $ rm wallet.dat
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28. $ rm wallet.dat
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29. $ scp wallet.dat
Metasploit 4.0
These additions include nine new SCADA exploits, improved 64-
bit Linux payloads, exploits for Firefox and Internet Explorer,
full-HTTPS and HTTP Meterpreter stagers, and post-exploitation
modules for dumping passwords from Outlook, WSFTP,
CoreFTP, SmartFTP, TotalCommander, BitCoin and many other
applications.
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30. $ scp wallet.dat
Metasploit 4.0
These additions include nine new SCADA exploits, improved 64-
bit Linux payloads, exploits for Firefox and Internet Explorer,
full-HTTPS and HTTP Meterpreter stagers, and post-exploitation
modules for dumping passwords from Outlook, WSFTP,
CoreFTP, SmartFTP, TotalCommander, BitCoin and many other
applications.
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31. $ scp wallet.dat
Metasploit 4.0
blah new post exploitation modules
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32. $ scp wallet.dat
Metasploit 4.0
blah new post exploitation modules
blah blah for dumping passwords blah
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33. $ scp wallet.dat
Metasploit 4.0
blah new post exploitation modules
blah blah for dumping passwords blah
Blah, BitCoin, Blah, …
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34. $ scp wallet.dat
Metasploit 4.0
blah new post exploitation modules
blah blah for dumping passwords blah
Blah, BitCoin, Blah, …
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35. $ cat cmn_sense.txt
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36. $ cat cmn_sense.txt
Block chain
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37. $ uml blockchain
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38. $ cat cmn_sense.txt
Block chain
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39. $ cat cmn_sense.txt
Block chain UI
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40. $ cat cmn_sense.txt
Block chain UI Wallet
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41. $ cat cmn_sense.txt
Block chain UI Wallet
• HUGE!!
• Global
• Public
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42. $ cat cmn_sense.txt
Block chain UI Wallet
• HUGE!!
• Global
• Public
-> Server
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43. $ cat cmn_sense.txt
Block chain UI Wallet
• HUGE!! • Complex
• Global • Personal
• Public • Private
-> Server
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44. $ cat cmn_sense.txt
Block chain UI Wallet
• HUGE!! • Complex
• Global • Personal
• Public • Private
-> Server -> Client
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45. $ cat cmn_sense.txt
Block chain UI Wallet
• HUGE!! • Complex • Simple
• Global • Personal • Personal
• Public • Private • Secret!!
-> Server -> Client
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46. $ cat cmn_sense.txt
Block chain UI Wallet
• HUGE!! • Complex • Simple
• Global • Personal • Personal
• Public • Private • Secret!!
(ideally)
-> Server -> Client -> Hardware
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47. $ find platform
Block chain server
• Peer-to-peer node
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48. $ find platform
Block chain server
• Peer-to-peer node
• Realtime
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49. $ find platform
Block chain server
• Peer-to-peer node
• Realtime
• JSON-RPC
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50. $ find platform
Block chain server
• Peer-to-peer node
• Realtime
• JSON-RPC
• Lots of concurrent users
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51. $ find platform
Block chain server
• Peer-to-peer node
• Realtime
• JSON-RPC
• Lots of concurrent users
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52. $ find platform
Block chain server
• Peer-to-peer node
• Realtime
• JSON-RPC
• Lots of concurrent users
+
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53. $ d8 server.js
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54. $ d8 server.js
Memory leaks! Example: MongooseJS
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55. $ d8 server.js
Memory leaks! Example: MongooseJS
Collection.prototype.addQueue = function (name, args) {
this.queue.push([name, args]);
return this;
};
Collection.prototype.doQueue = function () {
for (var i = 0, l = this.queue.length; i < l; i++){
this[this.queue[i][0]].apply(this, this.queue[i][1]);
}
return this;
};
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56. $ d8 server.js
Memory leaks! Example: MongooseJS
Collection.prototype.addQueue = function (name, args) {
this.queue.push([name, args]);
return this;
};
Collection.prototype.doQueue = function () {
for (var i = 0, l = this.queue.length; i < l; i++){
this[this.queue[i][0]].apply(this, this.queue[i][1]);
}
+ this.queue = [];
return this;
};
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57. $ d8 server.js
Memory leaks! Example: node-binary
saw.chain = function () {
var ch = Traverse(saw.handlers).map(function (node) {
// ...
if (typeof node === 'function') {
this.update(function () {
saw.actions.push({
path : ps,
args : [].slice.call(arguments)
});
return ch;
});
}
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58. $ d8 server.js
Lesson
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59. $ d8 server.js
Lesson
Node.js libraries
can be strange
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60. $ d8 server.js
Lesson
Node.js libraries
can be strange
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61. $ d8 server.js
Lesson
Node.js libraries
can be strange
But overall it’s
not that bad!
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62. $ d8 server.js
Lesson Also:
Node.js libraries V8’s GC is very good!
can be strange
But overall it’s
not that bad!
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63. $ d8 server.js
Debugging Tip: “LiveObjectList”
Getting set up
# Compile V8 with LiveObjectList support
scons liveobjectlist=on ...
# Run your program with debugging
node --debug my_leaky_program.js
# Connect to your program with D8
d8 --remote_debugger
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64. $ d8 server.js
Debugging Tip: “LiveObjectList”
Usage
lol c Capture a heap snapshot
lol Show heap snapshots
lol list List objects in a snapshot
lol diff [s1] [s2] Show differences between snapshots
lol path [obj_id] Show retaining paths for an object
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65. $ d8 server.js
moon@clymene:~/opt/node$ deps/v8/d8 --remote_debugger
> Type: connect
V8-Version: 3.1.8.26
Protocol-Version: 1
Embedding-Host: node v0.4.10
stopped
dbg> lol c
Captured live object list 1: count 156079 size 8129300
dbg> c
(running)
>
stopped
dbg> lol c
Captured live object list 2: count 173343 size 8374416
dbg>
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66. $ d8 server.js
dbg> gc
GC 7809868 => 6710536 (7.4M => 6.4M)
dbg> lol diff 1 2 v t Array 1000
objects:
[ 1] @222138: size 16, 0xb39bd329 <JSArray> len 0
[ 2] @222139: size 16, 0xb39bd339 <JSArray> len 0
[ 3] @222143: size 16, 0xb39bd3a1 <JSArray> len 0
[ 4] @222144: size 16, 0xb39bd3b1 <JSArray> len 0
[ 5] @222145: size 16, 0xb39bd3c1 <JSArray> len 0
[ 6] @222365: size 16, 0xb39bede5 <JSArray> len 0
[ 7] @222498: size 16, 0xb39bfea5 <JSArray> len 0
[ 8] @222615: size 16, 0xb39c0d55 <JSArray> len 3
...
dbg> lol path @222138
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67. $ d8 server.js
|
|
V
[274] @79332 0xb4422699: size 20 : HeapObject DescriptorArray FixedArray
0xb4422699: [FixedArray]
- length: 3
[0]: 0xb77b3efd <FixedArray[53]>
[1]: 0xb577404d <undefined>
[2]: 0xb41eddd9 <JS array[0]>
|
|
V
[275] @215108 0xb41eddd9: size 16 : HeapObject JSObject JSArray
0xb41eddd9: [JSObject]
- map = 0xb5754861
- prototype = 0xb77b4f49
{
#length: 0xb577e581 <Proxy> (callback)
#_cast: (null descriptor)
}
=====================================
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68. $ uname -a
Another thing… 32 bit 64 bit
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69. $ uname -a
Another thing… 32 bit 64 bit
- V8 heap limit 1 GB 1.9 GB
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70. $ uname -a
Another thing… 32 bit 64 bit
- V8 heap limit 1 GB 1.9 GB
- MongoDB database 2.5 GB
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71. $ bitcoinjs run
Now STOP!
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72. $ bitcoinjs run
Now STOP!
Demo time!
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73. $ forecast
Lots more to be done!
- GUI
- Wallet
- Shopping Cart Interface
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74. $ git clone bitcoinjs-gui
A matching client!
- JS-based crypto (fun stuff!)
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75. $ git clone bitcoinjs-gui
A matching client!
- JS-based crypto (fun stuff!)
- HTML5 LocalStorage
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76. $ git clone bitcoinjs-gui
A matching client!
- JS-based crypto (fun stuff!)
- HTML5 LocalStorage
- Socket.IO
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77. $ git clone bitcoinjs-gui
A matching client!
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78. $ git clone bitcoinjs-gui
A matching client!
- Beta August 2011
- Screencast:
http:/
/www.youtube.com/watch?v=KTmFwnIRG9c
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79. $ wallet 2.0
Ideas for a more secure wallet
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80. $ wallet 2.0
Ideas for a more secure wallet
- Deterministic Wallet
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81. $ wallet 2.0
Ideas for a more secure wallet
- Deterministic Wallet
- Distributed Key Generation
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82. $ wallet 2.0
Ideas for a more secure wallet
- Deterministic Wallet
- Distributed Key Generation
- Hardware Device
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83. $ exit
Thank you
And good night!
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84. $ tail -f
github.com/bitcoinjs
@bitcoinjs
Meetup this Saturday!
Oliver Twist Pub 16:30
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