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Cryptography With PHP - ZendCon 2017 Workshop

The IT security landscape is littered with events where cryptography was not properly used, leading to leaked sensitive data and major problems for organizations. Learn how to encrypt and hash data using cryptography features in PHP, including password hashing, libsodium, mcrypt, OpenSSL, CrackLib, and CSPRNG. Refresh on current industry standards and review cryptographic algorithms. Come ready to hash passwords, experiment with algorithm costs, and crack weak encryption using attacks from timing, brute force, and rainbow tables.

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Cryptography With PHP - ZendCon 2017 Workshop

  1. 1. CRYPTOGRAPHY WITH PHP MARK NIEBERGALL ZendCon 2017 Workshop https://joind.in/talk/7b305
  2. 2. CRYPTOGRAPHY WITH PHP ABOUT MARK NIEBERGALL ▸ PHP since 2005 ▸ Masters degree in MIS ▸ Senior Software Engineer ▸ Drug screening project ▸ UPHPU President ▸ SSCP, CSSLP Certified and SME ▸ Drones, fishing, skiing, father, husband
  3. 3. CRYPTOGRAPHY WITH PHP ABOUT MARK NIEBERGALL
  4. 4. CRYPTOGRAPHY WITH PHP ABOUT MARK NIEBERGALL
  5. 5. CRYPTOGRAPHY WITH PHP ABOUT MARK NIEBERGALL
  6. 6. CRYPTOGRAPHY WITH PHP OBJECTIVES ▸ Time on the keyboard ▸ Learn about and use PHP cryptography and hashing libraries ▸ Security considerations with implementation
  7. 7. CRYPTOGRAPHY WITH PHP OBJECTIVES ▸ Coding time! ▸ Various modules ▸ Estimated time (5, 10, or 15 minutes) ▸ Cryptography games will apply what was covered
  8. 8. CRYPTOGRAPHY WITH PHP SCHEDULE ▸ 9:00-9:30 Setup and covering slides that including terminology and cryptography ▸ 9:30-9:50 PHP hash, password hashing ▸ 9:50-10:00 Break, lock picking ▸ 10:00-10:50 CSPRNG, OpenSSL ▸ 10:50-11:00 Break, more lock picking ▸ 11:00-11:15 libsodium ▸ 11:15-11:55 Cryptography Games ▸ 11:55-12:00 Regroup and conclusion
  9. 9. CRYPTOGRAPHY WITH PHP OVERVIEW ▸ Environment Setup ▸ Why Cryptography ▸ Definitions ▸ Role of Cryptography ▸ Algorithms ▸ Encryption with PHP ▸ Considerations ▸ Cryptography Games
  10. 10. CRYPTOGRAPHY WITH PHP ENVIRONMENT SETUP
  11. 11. CRYPTOGRAPHY WITH PHP ENVIRONMENT SETUP ▸ PHP 5.5+, best is 7.0+ ▸ Ideally have libsodium PECL extension (see https:// paragonie.com/book/pecl-libsodium/read/00- intro.md#installing-libsodium) or 7.2 (RC) ▸ Once you are up and running, please help others ▸ Worse case, use https://3v4l.org/
  12. 12. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY
  13. 13. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY
  14. 14. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY
  15. 15. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY
  16. 16. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY ▸ Over 100,000 incidents in 2016 with 3,141 confirmed breaches ▸ Attacks largely for financial gain ▸ Many going after sensitive data
  17. 17. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY ▸ Review Verizon 2017 Data Breach Investigations Report ▸ Yearly report ▸ Cybersecurity investigations report ▸ Pulls from many sources ▸ Lots of informative charts
  18. 18. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY
  19. 19. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY Incidents by industry
  20. 20. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY
  21. 21. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY
  22. 22. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY
  23. 23. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY
  24. 24. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY
  25. 25. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY ▸ No organization is immune ▸ Cryptography significantly reduces breach cost ▸ Cryptography can prevent leak of actual sensitive data
  26. 26. CRYPTOGRAPHY WITH PHP WHY CRYPTOGRAPHY ▸ Attack Countermeasures ▸ Good password policy ▸ Encrypt sensitive data ▸ Encrypt computer disks and devices ▸ Keep current with patches
  27. 27. CRYPTOGRAPHY WITH PHP DEFINITIONS
  28. 28. CRYPTOGRAPHY WITH PHP DEFINITIONS ▸ Cryptography ▸ The process of writing or reading secret messages or codes ▸ Classical cryptography started thousands of years ago ▸ Advanced during wars of 20th century ▸ The science or study of secret communications
  29. 29. CRYPTOGRAPHY WITH PHP DEFINITIONS ▸ Encryption ▸ To change information from one form to another especially to hide its meaning ▸ En: to make ▸ Crypto: secret or hidden ▸ The actual changing of a communication
  30. 30. CRYPTOGRAPHY WITH PHP DEFINITIONS ▸ Algorithm ▸ A set of steps that are followed in order to solve a mathematical problem or to complete a computer process
  31. 31. CRYPTOGRAPHY WITH PHP DEFINITIONS ▸ Cipher ▸ A way of changing a message to keep it secret ▸ An algorithm used to encrypt or decrypt ▸ Classically included substitution and transposition ▸ A becomes 1 ▸ A becomes Z ▸ Abc123 becomes 123Abc ▸ Backwards
  32. 32. CRYPTOGRAPHY WITH PHP DEFINITIONS ▸ Hash ▸ To chop into small pieces ▸ Maps data to a string ▸ One-way hash functions ▸ Schneier “workhorses of modern cryptography” ▸ Input is the message, output is the digest
  33. 33. CRYPTOGRAPHY WITH PHP ROLE OF CRYPTOGRAPHY
  34. 34. CRYPTOGRAPHY WITH PHP ROLE OF CRYPTOGRAPHY ▸ World War II ▸ Enigma Machine used by Nazi Germany ▸ Code breaking by Allies, including Alan Turing
  35. 35. CRYPTOGRAPHY WITH PHP ROLE OF CRYPTOGRAPHY ▸ Secure communications from third parties ▸ Confidentiality of communications
  36. 36. CRYPTOGRAPHY WITH PHP ROLE OF CRYPTOGRAPHY ▸ Secure data at rest ▸ Secure data in transit
  37. 37. CRYPTOGRAPHY WITH PHP ROLE OF CRYPTOGRAPHY ▸ First 2 A’s in the AAA Framework ▸ Authentication: credentials ▸ Authorization: encrypt and decrypt data ▸ Accounting
  38. 38. CRYPTOGRAPHY WITH PHP ALGORITHMS
  39. 39. CRYPTOGRAPHY WITH PHP ALGORITHMS ▸ One Way Hash
  40. 40. CRYPTOGRAPHY WITH PHP ALGORITHMS ▸ One Way Hash ▸ Data is hashed ▸ Cannot go backwards ▸ Integrity checks ▸ Password checks ▸ Identifiers; ex: Git and Mercurial
  41. 41. CRYPTOGRAPHY WITH PHP ALGORITHMS ▸ One Way Hash ▸ MD5 ▸ SHA-1, SHA-2, SHA-3
  42. 42. CRYPTOGRAPHY WITH PHP ALGORITHMS ▸ Symmetric-Key
  43. 43. CRYPTOGRAPHY WITH PHP ALGORITHMS ▸ Symmetric-Key ▸ Same key to encrypt and decrypt ▸ Shared secret key ▸ Susceptible to plaintext attacks (known and chosen) and cryptanalysis (differential and linear)
  44. 44. CRYPTOGRAPHY WITH PHP ALGORITHMS ▸ Symmetric-Key ▸ DES ▸ Triple DES ▸ AES
  45. 45. CRYPTOGRAPHY WITH PHP ALGORITHMS ▸ Symmetric-Key ▸ Blowfish ▸ Twofish ▸ Threefish
  46. 46. CRYPTOGRAPHY WITH PHP ALGORITHMS ▸ Asymmetric-Key
  47. 47. CRYPTOGRAPHY WITH PHP ALGORITHMS ▸ Asymmetric-Key ▸ Heavily used in cryptography ▸ Public and private keys ▸ Public key is publicly available ▸ Private key is kept secret
  48. 48. CRYPTOGRAPHY WITH PHP ALGORITHMS ▸ Asymmetric-Key
  49. 49. CRYPTOGRAPHY WITH PHP ALGORITHMS ▸ Asymmetric-Key ▸ Public key used to authenticate messages from owner of the private key ▸ Public key used to encrypt message to send to owner of the private key ▸ Private key used to decrypt inbound messages ▸ Private key used to encrypt outbound messages
  50. 50. CRYPTOGRAPHY WITH PHP ALGORITHMS ▸ Asymmetric-Key (Public-Key) ▸ RSA ▸ DSA
  51. 51. CRYPTOGRAPHY WITH PHP ALGORITHMS ▸ Broken ▸ DES ▸ MD2, MD4, MD5 ▸ SHA-1 ▸ GOST ▸ Panama ▸ RC4
  52. 52. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  53. 53. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ String functions just don’t cut it ▸ bin2hex ▸ strrev ▸ base64_encode ▸ dechex ▸ ord and chr (ASCII) ▸ str_replace
  54. 54. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ Hash ▸ Password hashing ▸ mcrypt ▸ CSPRNG ▸ openssl ▸ libsodium ▸ StupidPass
  55. 55. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ Hash ▸ hash_algos for array of options ▸ hash($algorithm, $message, $raw = false); ▸ hash_file for file contents hash ▸ hash_equals for comparing hashed values
  56. 56. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ Hash - Coding time! ▸ 5 minutes ▸ hash_algos for array of algorithms ▸ Output available algorithms
 
 <?php
 print_r(hash_algos()); ▸ See https://en.wikipedia.org/wiki/ Comparison_of_cryptographic_hash_functions
  57. 57. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ Hash - Coding time! ▸ 10 minutes ▸ hash($algorithm, $message, $raw = false); ▸ foreach hash_algos generate hash ▸ Review output content, including characters, length ▸ Does different message or message length impact hash length?
  58. 58. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ Hash - Coding time! ▸ 5 minutes ▸ hash_file for file contents hash ▸ make a text file with some text in it ▸ compare with hash of plain text
  59. 59. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ Hash ▸ == and === are not timing safe comparisons ▸ Nuances with PHP == returning true
 var_dump(md5('240610708') == md5(‘QNKCDZO'));
 var_dump(md5('aabg7XSs') == md5('aabC9RqS'));
 var_dump(sha1('aaroZmOk') == sha1('aaK1STfY'));
 var_dump(sha1('aaO8zKZF') == sha1('aa3OFF9m'));
 var_dump('0010e2' == '1e3');
 var_dump('0x1234Ab' == '1193131');
 var_dump('0xABCdef' == ' 0xABCdef');
  60. 60. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ Hash - Coding time! ▸ 15 minutes ▸ hash_equals as a timing safe hash comparison ▸ run thousands of iterations, look for patterns with averages ▸ $timeStart = microtime(true); … $timeEnd = mircotime(true); ▸ array_multisort($timing, SORT_NUMERIC);
  61. 61. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  62. 62. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  63. 63. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  64. 64. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ 10 minute break ▸ Lock picking
  65. 65. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ CSPRNG
  66. 66. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ CSPRNG ▸ Cryptographically Secure Pseudo-Random Number Generator (CSPRNG) ▸ Part of PHP 7 core ▸ For PHP < 7:
 composer require paragonie/random_compat
  67. 67. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ CSPRNG - Coding time! ▸ 10 minutes ▸ random_bytes($length) ▸ bin2hex($randomBytes) for human readable version ▸ random_int($min, $max) ▸ PHP_INT_MIN and PHP_INT_MAX
  68. 68. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  69. 69. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  70. 70. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  71. 71. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  72. 72. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ Password hashing
  73. 73. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ Password hashing ▸ $insecure = md5($password); ▸ Too fast ▸ Brute force ▸ 5f4dcc3b5aa765d61d8327deb882cf99
  74. 74. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ Password hashing ▸ Anthony Ferrara RFC in 2012 to simplify password hashing ▸ Use password_hash and password_verfiy (PHP 5.5+) ▸ $current = password_hash($password, PASSWORD_DEFAULT); ▸ PASSWORD_DEFAULT can change over time, currently is blowfish, max password length of 72 ▸ $isValid = password_verify($password, $current);
  75. 75. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ Password hashing ▸ Salt generated automatically ▸ Deprecated as option in PHP 7 ▸ Option ‘cost’, target time it takes ▸ password_hash($password, PASSWORD_DEFAULT, [‘cost’ => 10]);
  76. 76. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ Password hashing - Coding time! ▸ 10 minutes ▸ password_hash($password, PASSWORD_DEFAULT, [‘cost’ => 10]); ▸ notice output pattern, repeat for same password, try variations, different costs ▸ $2y$10$i49TRWieyhYtQ6P.76R5aOwRisUIqnQJxS6tszUobVkGG8bP9/XsW ▸ $2y$ for algorithm ▸ 10 for cost ▸ 22 character salt, varies by algorithm ▸ Hash as the rest
  77. 77. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ Password hashing - Coding time! ▸ 10 minutes ▸ password_verify($plaintext, $hash); ▸ password_needs_rehash($hash, PASSWORD_DEFAULT, $options) ▸ Timing safe check
  78. 78. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  79. 79. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  80. 80. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  81. 81. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ mcrypt
  82. 82. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ mcrypt ▸ Encrypt and decrypt ▸ Uses libmcrypt, which hasn’t been updated since 2007 ▸ Bug fixes and patches ▸ Use libsodium or OpenSSL instead!
  83. 83. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ openssl
  84. 84. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ openssl ▸ Generate and verify signatures ▸ Certificate Signing Requests (CSR) ▸ Encrypt and decrypt data ▸ Actively supported
  85. 85. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ openssl ▸ Private key generation ▸ openssl_pkey_new([$configs]); ▸ openssl_pkey_export_to_file($privateKey, $fileName); ▸ openssl_free_key($privateKey);
  86. 86. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ openssl ▸ Configuration defaults to openssl.conf ▸ digest_alg: Digest method to use ▸ x509_extensions: Extensions to use for x509 cert ▸ req_extensions: Extensions to use for CSR ▸ private_key_bits: Bits for private key generation ▸ private_key_type: Type of key ▸ encrypt_key: Export key with passphrase ▸ encrypt_key_cipher: Cipher for key
  87. 87. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ openssl - Coding time! ▸ 5 minutes ▸ Private key generation ▸ $config = [‘private_key_bits’ => 2048, 'private_key_type' => OPENSSL_KEYTYPE_RSA]; ▸ openssl_pkey_new([$configs]); ▸ openssl_pkey_export_to_file($privateKey, $fileName); ▸ openssl_free_key($privateKey);
  88. 88. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  89. 89. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  90. 90. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ openssl - Coding time! ▸ 5 minutes ▸ Public key generation ▸ Continue on from private key generation ▸ openssl_pkey_get_details($privateKey); ▸ file_put_contents(‘public.pem’, $details[‘key’]); ▸ Array with keys ‘bits’, ‘key’ (public key), ‘rsa’, ‘type’
  91. 91. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  92. 92. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP
  93. 93. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ openssl - Coding time! ▸ 5 minutes ▸ Encrypting data with the public key, decrypt with private ▸ $isEncrypted = openssl_public_encrypt($message, $encrypted, file_get_contents(‘public.pem’)); ▸ $isDecrypted = openssl_private_decrypt($encrypted, $decrypted, file_get_contents(‘private.pem’);
  94. 94. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ openssl - Coding time! ▸ 5 minutes ▸ Encrypting data with the private key, decrypt with public ▸ $isEncrypted = openssl_private_encrypt($message, $encrypted, file_get_contents(‘private.pem’)); ▸ $isDecrypted = openssl_public_decrypt($encrypted, $decrypted, file_get_contents(‘public.pem’);
  95. 95. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ cracklib
  96. 96. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ cracklib ▸ PECL extension, must be installed ▸ Checks complexity of passwords ▸ Still experimental
  97. 97. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ cracklib ▸ crack_opendict(‘/path/to/dictionary’) ▸ crack_check($dictionary, $password) ▸ crack_getlastmessage() ▸ crack_closedict($dictionary)
  98. 98. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ cracklib ▸ it's WAY too short ▸ it is too short ▸ it does not contain enough DIFFERENT characters ▸ it is all whitespace ▸ it is too simplistic/systematic ▸ it looks like a National Insurance number. ▸ it is based on a dictionary word ▸ it is based on a (reversed) dictionary word ▸ strong password
  99. 99. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ 10 minute break ▸ Find group of up to 4 for games
  100. 100. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ libsodium
  101. 101. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ libsodium ▸ PECL extension ▸ PHP 7.2 core ▸ modern cryptography library ▸ namespaced as Sodiumfunction_name
  102. 102. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ libsodium - Coding time! ▸ 10 minutes ▸ Cryptographically secure randomness ▸ Sodiumrandombytes_buf($numberBytes) with each byte being a random value between 0 and 255 (bin2hex for readability) ▸ Sodiumrandombytes_random16() for random integer between 0 and 65535 ▸ Sodiumrandombytes_uniform($maxPlusOne) for uniformly distributed random integers between 0 and max
  103. 103. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ libsodium - Coding time! ▸ 10 minutes ▸ Secret-key encryption and decryption ▸ $key = Sodiumrandombytes_buf(SodiumCRYPTO_SECRETBOX_KEYBYTES); ▸ $nonce = Sodiumrandombytes_buf(SodiumCRYPTO_SECRETBOX_NONCEBYTES); ▸ $ciphertext = Sodiumcrypto_secretbox('test', $nonce, $key); ▸ $plaintext = Sodiumcrypto_secretbox_open($ciphertext, $nonce, $key);
  104. 104. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ libsodium ▸ Public-key encryption and decryption ▸ Sodiumcrypto_box_* functions
  105. 105. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ libsodium ▸ Much more functionality ▸ Password hashing and checking ▸ Key signing ▸ Message Authentication Code (MAC) ▸ Hashing
  106. 106. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ StupidPass
  107. 107. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ StupidPass ▸ composer require northox/stupid-password ▸ $stupidPass = new StupidPass; ▸ $isValid = $stupidPass->validate($password); ▸ $stupidPass->getErrors(); ▸ new StupidPass($maxLength, $environmental, $pathToDictionary, $errorText, $options);
  108. 108. CRYPTOGRAPHY WITH PHP ENCRYPTION WITH PHP ▸ StupidPass - Coding time! ▸ 10 minutes ▸ install composer, StupidPass ▸ Try out common passwords, custom dictionary, see the errors ▸ composer require northox/stupid-password ▸ $stupidPass = new StupidPass; ▸ $isValid = $stupidPass->validate($password); ▸ $stupidPass->getErrors(); ▸ new StupidPass($maxLength, $environmental, $pathToDictionary, $errorText, $options);
  109. 109. CRYPTOGRAPHY WITH PHP CONSIDERATIONS
  110. 110. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Salts ▸ Algorithm costs ▸ Timing attacks ▸ Brute force attacks ▸ Rainbow tables ▸ Max message length
  111. 111. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Salts ▸ Increased security for digest if done correctly ▸ Ex: $salt . $password ▸ Pepper debate ▸ Let password_hash generate the salt for you ▸ Different salt per password or message
  112. 112. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Algorithm Costs ▸ Default cost for password_hash is 10 ▸ Higher cost leads to more processing time ▸ 8-12 is generally a good baseline ▸ Might change depending on hardware available
  113. 113. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Timing Attacks ▸ Analyzing timing for algorithms ▸ Time variation for hashing, encrypting, decrypting ▸ Ex: Username not found, no password check attempted ▸ Ex: String comparisons stop after first mismatch ▸ Timing safety built into functions, take same time for positive or negative match
  114. 114. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Brute Force Attacks ▸ Timing attack used to brute force list of usernames ▸ Dictionary attack using dictionary and common passwords ▸ Take time ▸ Advanced Persistent Threat (APT)
  115. 115. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Brute Force Attacks ▸ Countermeasures ▸ Lock accounts, but causes Denial of Service ▸ Add time to each login ▸ Lock by IP address ▸ Vary failed login attempt behavior (Ex: HTTP status, redirect)
  116. 116. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Brute Force Attacks ▸ Countermeasures ▸ Key words in HTML comments (invalid login, bad username or password) ▸ Security questions ▸ CAPTCHA ▸ Add another factor (multi-factor authentication)
  117. 117. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Rainbow Tables ▸ Table with hashes already figured out ▸ Used for hashing that always generates same hash for an input ▸ Counter with modern algorithms, salts ▸ Common for MD5, SHA1, and other older algorithms
  118. 118. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Rainbow Tables ▸ Internet search for the hash ▸ Online hash cracking sites
  119. 119. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Max Message Length ▸ Only X characters considered when generating hash ▸ Ex: MD5 max is 128 characters in, 32 hex out ▸ Ex: password_hash max is 72 characters
  120. 120. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Identify sensitive data ▸ Determine appropriate encryption ▸ Use cryptography to keep data safe
  121. 121. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Cryptography can help minimize damage ▸ Electronic data breaches ▸ Stolen electronic devices ▸ Data transmission
  122. 122. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Cryptography cannot help minimize damage ▸ Phishing attacks ▸ Credential theft ▸ Escalation of privileges ▸ DoS/DDoS ▸ Social engineering
  123. 123. CRYPTOGRAPHY WITH PHP CONSIDERATIONS ▸ Security education ▸ Verizon Data Breach Investigation Report ▸ SANS Institution, email digest ▸ Krebs on Security blog ▸ OWASP ▸ BrightTALK
  124. 124. CRYPTOGRAPHY WITH PHP CRYPTOGRAPHY GAMES
  125. 125. CRYPTOGRAPHY WITH PHP CRYPTOGRAPHY GAMES ▸ Groups of up to 4 ▸ 11:15-11:20 Instructions and rules, get in groups ▸ 11:20-11:45 Coding time! ▸ 11:45-11:55 Review answers ▸ 11:55-12:00 Closing
  126. 126. CRYPTOGRAPHY WITH PHP CRYPTOGRAPHY GAMES ▸ Get into your groups of up to 4
  127. 127. CRYPTOGRAPHY WITH PHP CRYPTOGRAPHY GAMES ▸ Instructions and rules ▸ Use PHP ▸ Decrypt the data ▸ Record how you decrypted the message ▸ Record plain text answer ▸ Winning team is team with most correct answers
  128. 128. CRYPTOGRAPHY WITH PHP CRYPTOGRAPHY GAMES ▸ Time is up!
  129. 129. CRYPTOGRAPHY WITH PHP CRYPTOGRAPHY GAMES ▸ Answers
  130. 130. CRYPTOGRAPHY WITH PHP CRYPTOGRAPHY GAMES ▸ Conclusion ▸ Leverage PHP cryptography and hashing features ▸ Use modern libraries ▸ Encrypt sensitive information ▸ Hash passwords correctly
  131. 131. CRYPTOGRAPHY WITH PHP QUESTIONS? ▸ Rate on joind.in ▸ https://joind.in/talk/7b305
  132. 132. CRYPTOGRAPHY WITH PHP SOURCES ▸ Merriam-Webster Dictionary online ▸ PHP.net documentation ▸ Virendra Chandak https://www.virendrachandak.com ▸ OWASP ▸ Verizon 2017 Data Breach Investigations Report ▸ https://paragonie.com/book/pecl-libsodium/read/00-intro.md ▸ https://www.cryptologie.net/article/268/how-to-compare-password-hashes- in-php/ ▸ http://blog.ircmaxell.com/2014/11/its-all-about-time.html

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