CRYPTOGRAPHY WITH PHP
MARK NIEBERGALL
https://joind.in/talk/53c3d

CRYPTOGRAPHY WITH PHP
ABOUT MARK NIEBERGALL
▸ PHP since 2005
▸ Masters degree in MIS
▸ Senior Software Engineer
▸ Team Lead
▸ Drug screening project
▸ President of Utah PHP User Group (UPHPU)
▸ SSCP, CSSLP Certified and SME for (ISC)2
▸ PHP, databases, JavaScript
▸ Drones, fishing, skiing, father, husband

CRYPTOGRAPHY WITH PHP
ABOUT MARK NIEBERGALL

CRYPTOGRAPHY WITH PHP
UPHPU
▸ Third Thursday of each month at 7pm
▸ Venue is Vivint in Lehi (3401 Ashton Blvd)
▸ Variety of PHP related topics
▸ Mostly local speakers, occasional traveling speaker
▸ Networking with other developers, companies
▸ Professional development
▸ uphpu.org

CRYPTOGRAPHY WITH PHP
OVERVIEW
▸ Why Cryptography
▸ Definitions
▸ Role of Cryptography
▸ Algorithms
▸ Encryption with PHP
▸ Considerations

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY
▸ Over 100,000 security incidents in 2015
▸ Attacks largely for financial gain
▸ Many going after sensitive data

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY
▸ Review Verizon 2016 Data Breach Investigations Report
▸ Yearly report
▸ Cybersecurity investigations report
▸ Pulls from many sources
▸ Lots of informative charts

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY
Countries represented in report

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY
Incidents by industry

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY
Incidents with data loss

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY
▸ No organization is immune
▸ Cryptography significantly reduces breach cost
▸ Cryptography can prevent leak of actual sensitive data

CRYPTOGRAPHY WITH PHP
WHY CRYPTOGRAPHY
▸ Attack Countermeasures
▸ Good password policy
▸ Encrypt sensitive data
▸ Encrypt computer disks and devices

CRYPTOGRAPHY WITH PHP
DEFINITIONS

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

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

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

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

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

CRYPTOGRAPHY WITH PHP
ROLE OF CRYPTOGRAPHY

CRYPTOGRAPHY WITH PHP
ROLE OF CRYPTOGRAPHY
▸ World War II
▸ Enigma Machine used by Nazi Germany
▸ Code breaking by Allies, including Alan Turing

CRYPTOGRAPHY WITH PHP
ROLE OF CRYPTOGRAPHY
▸ Secure communications from third parties
▸ Confidentiality of communications

CRYPTOGRAPHY WITH PHP
ROLE OF CRYPTOGRAPHY
▸ Secure data at rest
▸ Secure data in transit

CRYPTOGRAPHY WITH PHP
ROLE OF CRYPTOGRAPHY
▸ First 2 A’s in the AAA Framework
▸ Authentication: credentials
▸ Authorization: encrypt and decrypt data
▸ Accounting

CRYPTOGRAPHY WITH PHP
ALGORITHMS

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ One Way Hash

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ One Way Hash
▸ Data is hashed
▸ Cannot go backwards
▸ Integrity checks
▸ Password checks
▸ Identifiers; ex: Git and Mercurial

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ One Way Hash
▸ MD5
▸ SHA-1, SHA-2, SHA-3

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Symmetric-Key

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Symmetric-Key
▸ Same key to encrypt and decrypt
▸ Shared secret key
▸ Stream 1 character at a time
▸ Blocks of X bits
▸ Susceptible to plaintext attacks (known and chosen) and
cryptanalysis (differential and linear)

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Symmetric-Key
▸ DES
▸ Triple DES
▸ AES

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Symmetric-Key
▸ Blowfish
▸ Twofish
▸ Threefish

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Asymmetric-Key

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Asymmetric-Key
▸ Heavily used in cryptography
▸ Public and private keys
▸ Public key is publicly available
▸ Private key is kept secret

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Asymmetric-Key

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

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Asymmetric-Key (Public-Key)
▸ RSA
▸ DSA

CRYPTOGRAPHY WITH PHP
ALGORITHMS
▸ Broken
▸ DES
▸ MD2, MD4, MD5
▸ SHA-1
▸ GOST
▸ Panama
▸ RC4

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Hash
▸ Password hashing
▸ mcrypt
▸ openssl
▸ cracklib
▸ CSPRNG

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Hash
▸ hash($algorithm, $message, $raw = false);
▸ hash_algos for array of options
▸ hash_file for file contents hash
▸ hash_update for larger data sets

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

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ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Password hashing

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Password hashing
▸ $insecure = md5($password);
▸ Too fast
▸ Brute force
▸ 5f4dcc3b5aa765d61d8327deb882cf99

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Password hashing
▸ Use password_hash and password_verfiy
▸ $current = password_hash($password,
PASSWORD_DEFAULT);
▸ PASSWORD_DEFAULT can change over time,
currently is blowfish, max password length of 72
▸ $verify = password_verify($password, $current);

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ Password hashing
▸ Salt generated automatically
▸ Deprecated as option in PHP 7
▸ Option ‘cost’
▸ password_hash($password, PASSWORD_DEFAULT,
[‘cost’ => 10]);

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

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ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ mcrypt

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ mcrypt
▸ Generally use openssl instead
▸ Supports many ciphers
▸ Encrypt and decrypt
▸ Uses libmcrypt, which hasn’t been updated since 2007
▸ Bug fixes and patches

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ mcrypt
▸ $digest = hash($algorithm, $data, $raw = false);
▸ Ex: hash(‘sha256’, ‘Some data!’, true);
▸ mcrypt_encrypt($cipher, $key, $data, $mode, $iv = null);
▸ Ex: mcrypt_encrypt(MCRYPT_TRIPLEDES,

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ mcrypt
▸ mcrypt_generic
▸ mcrypt_decrypt
▸ mcrypt_create_iv
▸ Initialization vector
▸ Alternative seed to encryption routines

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl
▸ Generate and verify signatures
▸ Certificate Signing Requests (CSR)
▸ Encrypt and decrypt data
▸ Actively supported

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);

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

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl
▸ Public key generation
▸ openssl_pkey_get_details($privateKey)
▸ Array with keys bits, key (public key), rsa, type

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl
▸ Encrypting data
▸ Encrypt in chunks smaller than key bit size
▸ openssl_public_encrypt

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl
▸ Decrypting data
▸ openssl_pkey_get_private($privateKey)
▸ openssl_private_decrypt($chunk, $decrypted,
$privateKey)

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ openssl
▸ openssl_encrypt($data, $cipher, $password, $options,
$iv)
▸ openssl_encrypt(‘Password123!@#’, ‘AES256’,
$publicKeyString, 0, $largeRandomNumber)

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ cracklib

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ cracklib
▸ PECL extension, must be installed
▸ Checks complexity of passwords
▸ Still experimental

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ cracklib
▸ crack_opendict(‘/ptah/to/dictionary’)
▸ crack_check($dictionary, $password)
▸ crack_getlastmessage()
▸ crack_closedict($dictionary)

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

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ CSPRNG

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ CSPRNG
▸ Part of PHP 7 core
▸ Cryptographically Secure Pseudo-Random Number
Generator (CSPRNG)

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP
▸ CSPRNG
▸ random_bytes($length)
▸ random_int($min, $max)

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

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ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
ENCRYPTION WITH PHP

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Salts
▸ Algorithm costs
▸ Timing attacks
▸ Brute force attacks
▸ Rainbow tables
▸ Max message length

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

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

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

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)

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)

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)

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, LM

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Rainbow Tables
▸ Internet search for the hash
▸ Online hash cracking sites

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Max Message Length
▸ Only X characters considered when generating hash
▸ Ex: MD5 max is 128 characters in, 32 hex out

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Identify sensitive data
▸ Determine appropriate encryption
▸ Use cryptography to keep data safe

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Cryptography can help minimize damage
▸ Electronic data breaches
▸ Stolen electronic devices
▸ Data transmission

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Cryptography cannot help minimize damage
▸ Phishing attacks
▸ Credential theft
▸ Escalation of privileges
▸ DoS/DDoS
▸ Social engineering

CRYPTOGRAPHY WITH PHP
CONSIDERATIONS
▸ Security education
▸ Verizon Data Breach Investigation Report
▸ SANS Institution, email digest
▸ Krebs on Security blog
▸ OWASP
▸ BrightTALK

CRYPTOGRAPHY WITH PHP
QUESTIONS?
▸ https://joind.in/talk/53c3d

CRYPTOGRAPHY WITH PHP
SOURCES
▸ Merriam-Webster Dictionary online
▸ PHP.net documentation
▸ Virendra Chandak https://www.virendrachandak.com
▸ OWASP
▸ Verizon 2016 Data Breach Investigations Report