The first few milliseconds of HTTPS - loadays

Transcript

1. The first 200 milliseconds of HTTPS
   1
   Joshua Thijssen
   jaytaph
   

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2. 2
   Joshua Thijssen
   Freelance consultant, developer and
   trainer @ NoxLogic
   Founder of the Dutch Web Alliance
   Development in PHP, Python, C, Java.
   Lead developer of Saffire.
   Blog: http://adayinthelifeof.nl
   Email: jthijssen@noxlogic.nl
   Twitter: @jaytaph
   

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4. ➡ What’s happening in the first 200+
   milliseconds on a HTTPS connection.
   3
   

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5. ➡ What’s happening in the first 200+
   milliseconds on a HTTPS connection.
   ➡ Give tips and hints on hardening your setup.
   3
   

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6. ➡ What’s happening in the first 200+
   milliseconds on a HTTPS connection.
   ➡ Give tips and hints on hardening your setup.
   ➡ Give you insights in new and upcoming
   technologies.
   3
   

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7. ➡ What’s happening in the first 200+
   milliseconds on a HTTPS connection.
   ➡ Give tips and hints on hardening your setup.
   ➡ Give you insights in new and upcoming
   technologies.
   ➡ Show you things to you (probably) didn’t
   knew.
   3
   

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8. This talk is inspired by
   a blogpost from Jeff Moser
   http://www.moserware.com/2009/06/first-few-milliseconds-of-https.html
   Unknown fact!
   4
   

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9. Secure Socket Layer
   (SSL)
   5
   A short and scary history
   

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10. then
    now
    6
    

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11. then
    now
    SSL 1.0
    Vaporware
    1994
    6
    

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12. then
    now
    feb
    1995
    SSL 2.0
    Not-so-secure-socket-layer
    SSL 1.0
    Vaporware
    1994
    6
    

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13. then
    now
    feb
    1995
    SSL 2.0
    Not-so-secure-socket-layer
    jun
    1996
    SSL 3.0
    Something stable!
    SSL 1.0
    Vaporware
    1994
    6
    

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14. then
    now
    feb
    1995
    SSL 2.0
    Not-so-secure-socket-layer
    jun
    1996
    SSL 3.0
    Something stable!
    jan
    1999
    TLS 1.0
    SSL 3.1
    SSL 1.0
    Vaporware
    1994
    6
    

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15. then
    now
    feb
    1995
    SSL 2.0
    Not-so-secure-socket-layer
    jun
    1996
    SSL 3.0
    Something stable!
    jan
    1999
    TLS 1.0
    SSL 3.1
    apr
    2006
    TLS 1.1
    SSL 1.0
    Vaporware
    1994
    6
    

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16. then
    now
    feb
    1995
    SSL 2.0
    Not-so-secure-socket-layer
    jun
    1996
    SSL 3.0
    Something stable!
    jan
    1999
    TLS 1.0
    SSL 3.1
    apr
    2006
    TLS 1.1
    TLS 1.2
    aug
    2008
    SSL 1.0
    Vaporware
    1994
    6
    

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17. https://www.trustworthyinternet.org/ssl-pulse/
    25,7%
    99,6% 99,3%
    18,2% 20,7%
    SSL 2.0 TLS 1.0 TLS 1.2
    7
    November 2013
    

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18. https://www.trustworthyinternet.org/ssl-pulse/
    25,7%
    99,6% 99,3%
    18,2% 20,7%
    SSL 2.0 TLS 1.0 TLS 1.2
    7
    November 2013
    

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19. https://www.trustworthyinternet.org/ssl-pulse/
    25,7%
    99,6% 99,3%
    18,2% 20,7%
    SSL 2.0 TLS 1.0 TLS 1.2
    7
    23,7%
    99,4% 97,7%
    27,6% 30,2%
    SSL 2.0 TLS 1.0 TLS 1.2
    November 2013 March 2014
    

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20. RFC 5246
    (TLS v1.2)
    8
    

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21. 9
    * We can with openssl
    

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22. ➡ Binary protocol - so no quick
    telnet-to-see-if-it-works*
    9
    * We can with openssl
    

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23. ➡ Binary protocol - so no quick
    telnet-to-see-if-it-works*
    ➡ Different records
    9
    * We can with openssl
    

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24. ➡ Binary protocol - so no quick
    telnet-to-see-if-it-works*
    ➡ Different records
    ➡ Handshake protocol
    9
    * We can with openssl
    

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25. ➡ Binary protocol - so no quick
    telnet-to-see-if-it-works*
    ➡ Different records
    ➡ Handshake protocol
    ➡ Alert protocol
    9
    * We can with openssl
    

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26. ➡ Binary protocol - so no quick
    telnet-to-see-if-it-works*
    ➡ Different records
    ➡ Handshake protocol
    ➡ Alert protocol
    ➡ ChangeCipherSpec protocol
    9
    * We can with openssl
    

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27. ➡ Binary protocol - so no quick
    telnet-to-see-if-it-works*
    ➡ Different records
    ➡ Handshake protocol
    ➡ Alert protocol
    ➡ ChangeCipherSpec protocol
    ➡ Application protocol
    9
    * We can with openssl
    

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28. 10
    https://github.com/vincentbernat/rfc5077/blob/master/ssl-handshake.svg
    

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29. Attention:
    (live)
    wiresharking
    up ahead
    11
    

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32. Generating
    randomness is HARD
    14
    

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33. entropy
    (uncertainty)
    15
    

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34. TIME is NOT random
    thus not a very good
    entropy source
    16
    

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35. PHP is bad
    when it comes to
    entropy
    17
    Unknown fact!
    

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36. srand(microtime())
    18
    Unknown fact!
    

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37. rand()
    mt_rand()
    uniqid()
    19
    

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38. openssl_pseudo_random_bytes()
    read from /dev/(u)random
    Use a HRNG
    “A million random digits”
    https://github.com/ircmaxell/RandomLib
    20
    

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40. TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
    22
    

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41. TLS
    ECDHE_ECDSA
    WITH
    AES_128_GCM
    SHA256
    23
    

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42. TLS
    ECDHE_ECDSA
    WITH
    AES_128_GCM
    SHA256
    Used for exchanging
    key information
    23
    

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43. TLS
    ECDHE_ECDSA
    WITH
    AES_128_GCM
    SHA256
    Used for exchanging
    key information
    Used for authenticating
    key information
    23
    

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44. TLS
    ECDHE_ECDSA
    WITH
    AES_128_GCM
    SHA256
    Used for exchanging
    key information
    Used for authenticating
    key information
    Actual cipher (and
    length) used for
    communication
    23
    

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45. TLS
    ECDHE_ECDSA
    WITH
    AES_128_GCM
    SHA256
    Used for exchanging
    key information
    Used for authenticating
    key information
    Actual cipher (and
    length) used for
    communication
    Block cipher mode
    23
    

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46. TLS
    ECDHE_ECDSA
    WITH
    AES_128_GCM
    SHA256
    Used for exchanging
    key information
    Used for authenticating
    key information
    Used for message
    authenticating
    Actual cipher (and
    length) used for
    communication
    Block cipher mode
    23
    

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47. TLS_RSA_WITH_AES_256_CBC_SHA256
    24
    

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48. TLS_NULL_WITH_NULL_NULL
    25
    

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49. Client gives cipher options,
    Server ultimately decides on cipher!
    26
    

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50. THIS IS WHY YOU SHOULD ALWAYS
    CONFIGURE YOUR CIPHERS
    ON YOUR WEB SERVER!
    27
    Unknown fact!
    

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51. SSLProtocol all -SSLv2 -SSLv3
    SSLHonorCipherOrder on
    SSLCipherSuite "EECDH+ECDSA+AESGCM EECDH+aRSA+AESGCM EECDH+ECDSA+SHA384 \
    EECDH+ECDSA+SHA256 EECDH+aRSA+SHA384 EECDH+aRSA+SHA256 EECDH+aRSA+RC4 \
    EECDH EDH+aRSA RC4 !aNULL !eNULL !LOW !3DES !MD5 !EXP !PSK !SRP !DSS"
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    ssl_prefer_server_ciphers on;
    ssl_ciphers "EECDH+ECDSA+AESGCM EECDH+aRSA+AESGCM EECDH+ECDSA+SHA384 \
    EECDH+ECDSA+SHA256 EECDH+aRSA+SHA384 EECDH+aRSA+SHA256 EECDH+aRSA+RC4 \
    EECDH EDH+aRSA RC4 !aNULL !eNULL !LOW !3DES !MD5 !EXP !PSK !SRP !DSS";
    Apache
    Nginx
    28
    https://community.qualys.com/blogs/securitylabs/2013/08/05/configuring-apache-nginx-and-openssl-for-forward-secrecy
    

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52. https://www.ssllabs.com/ssltest/
    29
    

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53. View Slide

54. 31
    ➡ SNI (Server Name Indication)
    ➡ Extension 0x0000
    ➡ Pretty much every decent browser /
    server.
    ➡ IE6, Win XP, Blackberry, Android 2.x
    ➡ So no worries!
    

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55. View Slide

56. View Slide

57. What an SSL certificate is NOT:
    34
    ➡ SSL certificate (but a X.509 certificate)
    ➡ Automatically secure
    ➡ Automatically trustworthy
    ➡ In any way better self-signed certificates
    ➡ Cheap
    

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58. What an SSL certificate is:
    35
    ➡ The best way (but not perfect) to prove authenticity
    ➡ A way to bootstrap encrypted communication
    ➡ Misleading
    ➡ (Too) Expensive
    

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59. View Slide

60. View Slide

61. 37
    ➡ X.509 Certificate
    

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62. 37
    ➡ X.509 Certificate
    ➡ Owner info (who is this owner)
    

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63. 37
    ➡ X.509 Certificate
    ➡ Owner info (who is this owner)
    ➡ Domain info (for which domain(s) is
    this certificate valid)
    

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64. 37
    ➡ X.509 Certificate
    ➡ Owner info (who is this owner)
    ➡ Domain info (for which domain(s) is
    this certificate valid)
    ➡ Expiry info (from when to when is this
    certificate valid)
    

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66. 39
    yourdomain.com
    

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67. 39
    yourdomain.com
    Intermediate
    CA
    

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68. 39
    yourdomain.com
    Intermediate
    CA
    

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69. 39
    yourdomain.com
    Root
    CA
    Intermediate
    CA
    

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70. 39
    yourdomain.com
    Root
    CA
    Intermediate
    CA
    

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71. 39
    yourdomain.com
    Root
    CA
    Intermediate
    CA
    

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72. 40
    IMPLIED TRU$T
    

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73. ➡ (Root) Certificate Authorities
    ➡ They are built into your browser / OS
    and you will automatically trust them.
    41
    

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74. 42
    wget http://mxr.mozilla.org/mozilla-central/source/security/nss/lib/ckfw/builtins/certdata.txt\?raw\=1 -O - -q | grep Issuer | sort | uniq | wc -l
    

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75. 42
    wget http://mxr.mozilla.org/mozilla-central/source/security/nss/lib/ckfw/builtins/certdata.txt\?raw\=1 -O - -q | grep Issuer | sort | uniq | wc -l
    174
    

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77. 43
    ➡ X.509 certificates are used to authenticate
    the server.
    

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78. 43
    ➡ X.509 certificates are used to authenticate
    the server.
    ➡ Servers can ask clients to authenticate
    themselves as well.
    

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79. 43
    ➡ X.509 certificates are used to authenticate
    the server.
    ➡ Servers can ask clients to authenticate
    themselves as well.
    ➡ APIs
    

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82. 46
    Generating secrets:
    

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83. 46
    pre master secret server rand
    client rand
    Generating secrets:
    + +
    

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84. 46
    pre master secret server rand
    client rand
    master secret
    Generating secrets:
    + +
    

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85. 46
    pre master secret server rand
    client rand
    master secret
    master secret server rand client rand
    Generating secrets:
    + +
    +
    +
    

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86. 46
    pre master secret server rand
    client rand
    master secret
    master secret server rand client rand
    key buffer
    Generating secrets:
    + +
    +
    +
    

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87. 46
    pre master secret server rand
    client rand
    master secret
    client MAC client KEY client IV server MAC server KEY server IV
    master secret server rand client rand
    key buffer
    Generating secrets:
    + +
    +
    +
    

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88. https://github.com/jaytaph/TLS-decoder
    47
    http://www.adayinthelifeof.nl/2013/12/30/decoding-tls-with-php/
    Try it yourself, php style:
    

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93. 52
    Wireshark CAN decrypt your HTTPS traffic
    Unknown fact!
    SSLKEYLOGFILE
    https://isc.sans.edu/forums/diary/Psst+Your+Browser+Knows+All+Your+Secrets+/16415
    

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94. 53
    launchctl setenv SSLKEYLOGFILE /tmp/keylog.secret
    on a mac:
    

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96. ➡ TLS has overhead in computation and
    transfers. But definitely worth it.
    ➡ Some ciphersuites are better, but slower
    ➡ Speed / Security compromise
    ➡ (try: “openssl speed”)
    55
    

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97. Are we safe yet?
    56
    

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98. euh,.. no :/
    57
    

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99. 58
    PRE MASTER
    SECRET
    

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100. What if somebody*
     got hold of the site
     private key?
     59
     

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103. View Slide

104. 63
     Playing the waiting game...
     

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105. 63
     Playing the waiting game...
     

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106. View Slide

107. View Slide

108. (PERFECT)
     FORWARDING
     SECRECY
     66
     

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109. Compromising the
     pre-master secret does
     not compromise our
     communication.
     67
     

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110. PFS:
     Can’t compromise
     other keys with a
     compromised key.
     68
     

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111. Unfortunately..
     69
     

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112. 70
     PFS needs server
     AND browser support
     

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113. 71
     http://news.netcraft.com/archives/2013/06/25/ssl-intercepted-today-decrypted-tomorrow.html
     

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114. 72
     http://news.netcraft.com/archives/2013/06/25/ssl-intercepted-today-decrypted-tomorrow.html
     

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115. Update your cipher
     suite list and place
     PFS ciphers at the top
     73
     

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116. But beware:
     heavy computations
     74
     

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117. 75
     SSL Test
     https://www.ssllabs.com/ssltest/
     

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118. -ETOOMUCHINFO
     76
     

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119. 77
     https://www.ssllabs.com/projects/best-practices/index.html
     

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120. http://farm1.static.flickr.com/73/163450213_18478d3aa6_d.jpg 78
     

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121. 79
     Find me on twitter: @jaytaph
     Find me for development and training: www.noxlogic.nl
     Find me on email: jthijssen@noxlogic.nl
     Find me for blogs: www.adayinthelifeof.nl
     

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