ProjectTox: Free as in freedom Skype replacement

OSDC.tw 2014
Speaker: Wei-Ning Huang (http://azhuang.me)

http://osdc.tw/schedule.html

Transcript

1. ProjectTox Free as in freedom Skype replacement Wei-Ning Huang (AZ)
2. About the Speaker • 正在水深火熱中的碩二學生 • 熱愛Python及Open Source • Involved open source projects: o Gummi LaTeX Editor o cppman o PyTox o ProjectTox-Core o Toxic o jToxcore o … • More info: http://azhuang.me
3. Outline • What is Tox? • Functionality • Architecture and Design • Pitfalls and Solutions • In Progress Features • Client and Bindings • Live Demo
4. What is anyway?
5. What is anyway? • FOSS messaging network, supports A/V (GPLv3)
6. What is anyway? • FOSS messaging network, supports A/V (GPLv3) • Decentralized architecture
7. What is anyway? • FOSS messaging network, supports A/V (GPLv3) • Decentralized architecture • End-to-end encryption
8. What is anyway? • FOSS messaging network, supports A/V (GPLv3) • Decentralized architecture • End-to-end encryption • Configuration free (does not require registration)
9. What is anyway? • FOSS messaging network, supports A/V (GPLv3) • Decentralized architecture • End-to-end encryption • Configuration free (does not require registration) • Secure and easy to use
10. What is anyway? • FOSS messaging network, supports A/V (GPLv3) • Decentralized architecture • End-to-end encryption • Configuration free (does not require registration) • Secure and easy to use • A Skype replacement
11. Why are we doing this?
12. Why are we doing this?
13. Why are we doing this?
14. Why are we doing this? 4chan/g/
15. Why are we doing this? 4chan/g/
16. Why are we doing this?
17. Why are we doing this?
18. Why are we doing this? 馬卡茸表示：如果沒做錯事，就不用怕監聽! 圖片來自插畫家謝立聖
19. Why are we doing this? 馬卡茸表示：如果沒做錯事，就不用怕監聽! 圖片來自插畫家謝立聖 ???
20. Why are we doing this? 馬卡茸表示：如果沒做錯事，就不用怕監聽! 圖片來自插畫家謝立聖 ???
21. Why are we doing this? 馬卡茸表示：如果沒做錯事，就不用怕監聽! 圖片來自插畫家謝立聖 憲法第十二條：「人民有祕密通訊之自由」 ???
22. Why are we doing this?
23. Why are we doing this? • We want a free(as in Freedom) and secure alternative for , since it is “Microsofted”....
24. Why are we doing this? • We want a free(as in Freedom) and secure alternative for , since it is “Microsofted”.... • "We don't want to be the next secure chatting program, we want to be the next secure chatting program that people actually use." - Someone on IRC
25. Why are we doing this? • We want a free(as in Freedom) and secure alternative for , since it is “Microsofted”.... • "We don't want to be the next secure chatting program, we want to be the next secure chatting program that people actually use." - Someone on IRC • Current secure chat programs aren't easy to use, at least not for our parents and grandparents normal people
26. Who started this?
27. Who started this? • irungentoo o Real identity is a mystery :P o Most of the code is implemented by him
28. Who started this? • irungentoo o Real identity is a mystery :P o Most of the code is implemented by him • Project started up Jun 23, 2013
29. Who started this? • irungentoo o Real identity is a mystery :P o Most of the code is implemented by him • Project started up Jun 23, 2013 • There are currently about 10 active tox.im developers, including me.
30. Architecture and Design
31. Architecture and Design • Separated core and client, Tox is a library.
32. Architecture and Design • Separated core and client, Tox is a library. • Current implemented features in core:
33. Architecture and Design • Separated core and client, Tox is a library. • Current implemented features in core: o Text messages • Read receipt • Typing status
34. Architecture and Design • Separated core and client, Tox is a library. • Current implemented features in core: o Text messages • Read receipt • Typing status o File transfer (way faster than Skype)
35. Architecture and Design • Separated core and client, Tox is a library. • Current implemented features in core: o Text messages • Read receipt • Typing status o File transfer (way faster than Skype) o Group chat (IRC-like, currently invitation only)
36. Architecture and Design • Separated core and client, Tox is a library. • Current implemented features in core: o Text messages • Read receipt • Typing status o File transfer (way faster than Skype) o Group chat (IRC-like, currently invitation only) o Audio / Video call support • Currently only 1-to-1 call supported • 1-to-many and many-to-many support on the way!
37. Architecture and Design • Separated core and client, Tox is a library. • Current implemented features in core: o Text messages • Read receipt • Typing status o File transfer (way faster than Skype) o Group chat (IRC-like, currently invitation only) o Audio / Video call support • Currently only 1-to-1 call supported • 1-to-many and many-to-many support on the way! o All communication between clients are encrypted.
38. DHT
39. DHT • Distributed Hash Table similar to BitTorrent
40. DHT • Distributed Hash Table similar to BitTorrent • Hash table contains ID to IP-Port mapping
41. DHT • Distributed Hash Table similar to BitTorrent • Hash table contains ID to IP-Port mapping Bootstrap Server Client NAT Client Client LAN Discovery Client Client Boostrap Hole punching NAT
42. Friend Requests
43. Friend Requests • Friend requests are routed between clients
44. Friend Requests • Friend requests are routed between clients • Client list or a list of clients whose ID are mathematically (XOR) closest to us
45. Friend Requests • Friend requests are routed between clients • Client list or a list of clients whose ID are mathematically (XOR) closest to us Alice Jack Lucy Bob Request Request Got Alice’s IP_Port
46. Using the UDP Protocal • Using UDP, easier for hole punching
47. Using the UDP Protocal • Using UDP, easier for hole punching • A Lossless UDP protocol on top of UDP
48. Using the UDP Protocal • Using UDP, easier for hole punching • A Lossless UDP protocol on top of UDP • Allow packet drop for A/V data packet
49. Using the UDP Protocal • Using UDP, easier for hole punching • A Lossless UDP protocol on top of UDP • Allow packet drop for A/V data packet • NAT Traversal: Most NAT works, but symmetric NAT are problematic for now
50. Encryption • Using Elliptic Curve Cryptography o Short key length, but still secure
51. Encryption • Using Elliptic Curve Cryptography o Short key length, but still secure • Using NaCl (Networking and Cryptography library)
52. Encryption • Using Elliptic Curve Cryptography o Short key length, but still secure • Using NaCl (Networking and Cryptography library) o libsodium is prefered
53. Encryption • Using Elliptic Curve Cryptography o Short key length, but still secure • Using NaCl (Networking and Cryptography library) o libsodium is prefered o crypto_box: curve25519xsalsa20poly1305 • curve25519 for Key exchange • xsalsa20 for encryption • poly1305 for message authentication
54. Encryption • Using Elliptic Curve Cryptography o Short key length, but still secure • Using NaCl (Networking and Cryptography library) o libsodium is prefered o crypto_box: curve25519xsalsa20poly1305 • curve25519 for Key exchange • xsalsa20 for encryption • poly1305 for message authentication • ID == Public Key o Example ID: 4E9D1B82DEE3BD3D4DDA62190873EA40737251A4 3445E4D517E66230BC4507233533EDD01F24
55. Pitfalls and Solutions
56. Pitfalls and Solutions • Attack against DHT o Sybil attacks: attacker with large resource (e.g. governments) can create a large number of pseudo nodes that does nothing or disrupt network.
57. Pitfalls and Solutions • Attack against DHT o Sybil attacks: attacker with large resource (e.g. governments) can create a large number of pseudo nodes that does nothing or disrupt network. • Metadata Leaking o When routing friend requests, nodes leaks information about the request’s ID and IP mapping. o Possible to identify a users’s real identity with IP
58. Pitfalls and Solutions • Attack against DHT o Sybil attacks: attacker with large resource (e.g. governments) can create a large number of pseudo nodes that does nothing or disrupt network. • Metadata Leaking o When routing friend requests, nodes leaks information about the request’s ID and IP mapping. o Possible to identify a users’s real identity with IP • How do we safely exchange ID (Public Key) o Key being swap by a MITM?
59. Solutions • Attack against DHT o Periodically check all client’s behavior to see if it’s a bad node. o The criteria of a good node is strict.
60. Solutions • Attack against DHT o Periodically check all client’s behavior to see if it’s a bad node. o The criteria of a good node is strict. • Metadata Leaking o Don’t use their long term keypair in DHT, generate a temporary one when sending friend requests. o Onion routing for friend requests
61. Solutions • Attack against DHT o Periodically check all client’s behavior to see if it’s a bad node. o The criteria of a good node is strict. • Metadata Leaking o Don’t use their long term keypair in DHT, generate a temporary one when sending friend requests. o Onion routing for friend requests • How do we safely exchange ID (Public Key) o DNS lookup!
62. DNS User Discovery
63. DNS User Discovery • Use DNS TXT record to store the ID, for example: o tox://tox1@azhuang.me will be mapped to at TXT record ‘tox1._tox.azhuang.me’
64. DNS User Discovery • Use DNS TXT record to store the ID, for example: o tox://tox1@azhuang.me will be mapped to at TXT record ‘tox1._tox.azhuang.me’ o ‘v=tox1;id=4E9D1B82DEE3BD3D4DDA62190873EA40 737251A43445E4D517E66230BC4507233533EDD01F2 4’
65. DNS User Discovery • Use DNS TXT record to store the ID, for example: o tox://tox1@azhuang.me will be mapped to at TXT record ‘tox1._tox.azhuang.me’ o ‘v=tox1;id=4E9D1B82DEE3BD3D4DDA62190873EA40 737251A43445E4D517E66230BC4507233533EDD01F2 4’ • To prevent DNS poisoning or MITM, use the tox2 protocol (requires a extra pin): o 'v=tox2;pub=4E9D1B82DEE3BD3D4DDA62190873EA407372 51A43445E4D517E66230BC450723;check=1F24‘
66. DNS User Discovery • Use DNS TXT record to store the ID, for example: o tox://tox1@azhuang.me will be mapped to at TXT record ‘tox1._tox.azhuang.me’ o ‘v=tox1;id=4E9D1B82DEE3BD3D4DDA62190873EA40 737251A43445E4D517E66230BC4507233533EDD01F2 4’ • To prevent DNS poisoning or MITM, use the tox2 protocol (requires a extra pin): o 'v=tox2;pub=4E9D1B82DEE3BD3D4DDA62190873EA407372 51A43445E4D517E66230BC450723;check=1F24‘ • tox.se will be available for the public 
67. In Progress Features
68. In Progress Features • DHT Hardening o Research for more attach patterns
69. In Progress Features • DHT Hardening o Research for more attach patterns • TCP Server o Route traffic for clients behind symmetric NAT or enterprise firewalls o Act like a “Super node” in the Skype network
70. In Progress Features • DHT Hardening o Research for more attach patterns • TCP Server o Route traffic for clients behind symmetric NAT or enterprise firewalls o Act like a “Super node” in the Skype network • A/V improvements o Congestion control and variable bitrate support o A/V synchronization
71. Clients and Bindings
72. Clients and Bindings
73. Clients and Bindings • Support most platforms
74. Clients and Bindings • Support most platforms o Windows, Linux, Mac • Toxic (Ncurses CLI), has audio call support • Venom (Vala with GTK+) • Poison (MacOS only)
75. Clients and Bindings • Support most platforms o Windows, Linux, Mac • Toxic (Ncurses CLI), has audio call support • Venom (Vala with GTK+) • Poison (MacOS only) o Mobile • AnTox (Android), supports QR code scanning • Toxicity (iOS)
76. Clients and Bindings • Support most platforms o Windows, Linux, Mac • Toxic (Ncurses CLI), has audio call support • Venom (Vala with GTK+) • Poison (MacOS only) o Mobile • AnTox (Android), supports QR code scanning • Toxicity (iOS) • Language bindings: o Python: PyTox (full A/V support) o jTorecore: used in Antox
77. How to use? • Just launch any client, and it will generate a public/private key pair for you
78. How to use? • Just launch any client, and it will generate a public/private key pair for you • No login required
79. How to use? • Just launch any client, and it will generate a public/private key pair for you • No login required • Send your public key to you friends
80. How to use? • Just launch any client, and it will generate a public/private key pair for you • No login required • Send your public key to you friends • Add you friends with their public key
81. How to use? • Just launch any client, and it will generate a public/private key pair for you • No login required • Send your public key to you friends • Add you friends with their public key • Start chatting!
82. PyTox
83. PyTox • CDD (Conference Driven Developemnt)
84. PyTox • CDD (Conference Driven Developemnt) • No A/V support 2 days ago… o The video implementation in core even has some critical bugs
85. PyTox • CDD (Conference Driven Developemnt) • No A/V support 2 days ago… o The video implementation in core even has some critical bugs • Full A/V support implemented before OSDC.tw!
86. PyTox • CDD (Conference Driven Developemnt) • No A/V support 2 days ago… o The video implementation in core even has some critical bugs • Full A/V support implemented before OSDC.tw! • Leverage the power of Python o An EchoBot can be implement in less than 50 lines of Python code o SyncBot: a PoC of PyTox, syncing messages between Tox groupchat and freenode #tox-ontopic
87. PyTox
88. Live Demo
89. Join Us! • Wiki: o http://wiki.tox.im/ • Github: o ProjectTox-Core: https://github.com/irungentoo/ProjectTox-Core o PyTox: https://github.com/aitjcize/PyTox • Freenode IRC o #tox, #tox-dev, #tox-ontopic