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2FA, WTF? (FullStackCon 2015)

Phil Nash
October 26, 2015

2FA, WTF? (FullStackCon 2015)

Everyone is hacking everything. Everything is vulnerable. Your site, your users, even you. Are you worried about this? You should be! Don't worry, Phil is not trying to scare you (that much). You have plenty of safeguards against attempts on your applications' user data. We all (hopefully) recognise Two Factor Auth as one of those safeguards, but what actually goes on under the hood of 2FA?

You will discover how to generate one-time passwords and implement 2FA in your applications, and hear the only real-life compelling use case for QR codes. Together, we'll make the web a more secure place.

Phil Nash

October 26, 2015
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  1. T W O F A C T O R A

    U T H E N T I C A T I O N
  2. Two Factor Authen ca on 2FA is a security process

    in which a user provides two different forms of iden fica on in order to authen cate themself with a system. The two forms must come from different categories. Normally something you know and something you have.
  3. Mat Honan's Hackers' Timeline 1.  Found Gmail address on his

    personal site 2.  Entered address in Gmail and found his @me.com back up email 3.  Called Amazon to add a credit card to file 4.  Called Amazon again to reset password and got access 5.  4:33pm: called Apple to reset password 6.  4:50pm: reset AppleID password and gained access to email
  4. Mat Honan's Hackers' Timeline 7.  4:52pm: reset Gmail account password

    8.  5:01pm: wiped iPhone 9.  5:02pm: reset Twi er password 10.  5:05pm: wiped MacBook and deleted Google account 11.  5:12pm: posted to Twi er taking credit for the hack
  5. Ashley Madison Top 10 Passwords 1.  123456 2.  12345 3.

     password 4.  DEFAULT 5.  123456789 6.  qwerty 7.  12345678 8.  abc123 9.  NSFW 10.  1234567
  6. Ashley Madison Top 10 Passwords 1.  123456 ‐ 120,511 users

    2.  12345 ‐ 48,452 users 3.  password ‐ 39,448 users 4.  DEFAULT ‐ 34,275 users 5.  123456789 ‐ 26,620 users 6.  qwerty ‐ 20,778 users 7.  12345678 ‐ 14,172 users 8.  abc123 ‐ 10,869 users 9.  NSFW ‐ 10,683 users 10.  1234567 ‐ 9,468 users Source: h p:/ /qz.com/501073/the‐top‐100‐passwords‐on‐ashley‐madison/
  7. User Registra on Flow 1.  Visit registra on page 2.

     Sign up with username and password 3.  User is logged in
  8. User Log In Flow 1.  Visit login page 2.  Enter

    username and password 3.  System verifies details 4.  User is logged in
  9. User Registra on Flow 1.  Visit registra on page 2.

     Sign up with username, password and phone nunber 3.  User is logged in
  10. User Log In Flow 1.  Visit login page 2.  Enter

    username and password 3.  System verifies details 4.  Verifica on code sent to user by SMS 5.  User enters verifica on code 6.  System verifies code 7.  User is logged in
  11. User Registra on Flow 1.  Visit registra on page 2.

     Sign up with username, password 3.  Generate a secret for the user 4.  Share the secret somehow 5.  User is logged in
  12. User Log In Flow 1.  Visit login page 2.  Enter

    username and password 3.  System verifies details 4.  User opens auth app 5.  User finds app verifica on code and enters on site 6.  System verifies code 7.  User is logged in
  13. HOTP H O T P ( K , C )

    = T r u n c a t e ( H M A C ( K , C ) ) & 0 x 7 F F F F F F F H O T P - V a l u e = H O T P ( K , C ) m o d 1 0 d
  14. h o t p = f u n c t

    i o n ( k e y , c o u n t e r ) { / / C r e a t e t h e b y t e a r r a y v a r b = n e w B u f f e r ( i n t T o B y t e s ( c o u n t e r ) ) ; v a r h m a c = c r y p t o . c r e a t e H m a c ( ' s h a 1 ' , n e w B u f f e r ( k e y ) ) ; / / U p d a t e t h e H M A C w i t h t h e b y t e a r r a y v a r d i g e s t = h m a c . u p d a t e ( b ) . d i g e s t ( ' h e x ' ) ;
  15. / / G e t b y t e a

    r r a y v a r h = h e x T o B y t e s ( d i g e s t ) ; / / T r u n c a t e v a r o f f s e t = h [ 1 9 ] & 0 x f ; v a r v = ( h [ o f f s e t ] & 0 x 7 f ) < < 2 4 | ( h [ o f f s e t + 1 ] & 0 x f f ) < < 1 6 | ( h [ o f f s e t + 2 ] & 0 x f f ) < < 8 | ( h [ o f f s e t + 3 ] & 0 x f f ) ;
  16. v = ( v % 1 0 0 0 0

    0 0 ) + ' ' ; r e t u r n A r r a y ( 7 - v . l e n g t h ) . j o i n ( ' 0 ' ) + v ; } ; h ps:/ /github.com/guyht/notp
  17. F R I E N D S D O N

    ' T L E T F R I E N D S W R I T E T H E I R O W N A U T H E N T I C A T I O N F R A M E W O R K S
  18. F R I E N D S D O N

    ' T L E T F R I E N D S W R I T E T H E I R O W N T W O F A C T O R A U T H E N T I C A T I O N F R A M E W O R K S
  19. User Registra on Flow 1.  Visit registra on page 2.

     Sign up with username, password and phone nunber 3.  System registers User with Authy 4.  User is logged in
  20. User Log In Flow 1.  Visit login page 2.  Enter

    username and password 3.  System verifies details 4.  Authy prompts user 5.  User finds app verifica on code and enters on site 6.  System verifies code with Authy 7.  User is logged in
  21. U S E R S A R E B A

    D W I T H P A S S W O R D S
  22. O T H E R W E B S I

    T E S A R E B A D W I T H P A S S W O R D S
  23. 2 F A C A N B E P U

    S H , T O K E N O R S M S
  24. 2 F A I S F O R Y O

    U R U S E R S
  25. Help me! On a scale of 0 to 10, how

    likely is it that you would recommend this talk to a friend or colleague? 0203 322 5761
  26. Thanks! @philnash h p:/ /philna.sh [email protected] On a scale of

    0 to 10, how likely is it that you would recommend this talk to a friend or colleague? 0203 322 5761