Hash, Cryptography, and PHP

Slide link

Outline

About me
Why?
Hash
Encrypt
Decrypt
My Experiences

About me

Peter
GitHub
Active open source contributor
A Back-end developer
3+ years for PHP development
PHP 5.3 → PHP 7+
No framework→Slim→Laravel
Working for ITRI currently
Smart Grid technology

Why?

It's about a story....

PM

Resigned Engineer

Me

vacation engineer

senior developer

One Day...

PM
- one will take pregnant vacation
- one will resign this job
PM：You need to take over XXX
Me: Okay...

PM

Me

senior developer

One Day...

Demand Response system

Ubuntu 14.04
Laravel 5.2
PHP-5.5.9
No README
It only has codes!
It's part of smart grid system

Storing Password approach

ag "md5" ./app/Http/

$sql='update `dispatchAdmin` set pw = md5(?),...';

if($objs[0]->pw==md5($password)){
    $newPw = md5($pwd);
......

Something went wrong?

Finally, I got a summary

The password storing approach

Receive a password from client
Using MD5 hash to hash passwords and store in database

MD5 Risky

hash value databases

MD5 Hash

md5('werty')

"3f931c18b44ac93ac5b4b6c653f7c0b0"

md5('werty')

"3f931c18b44ac93ac5b4b6c653f7c0b0"

mysql> 
mysql> select md5('werty');
+----------------------------------+
| md5('werty')                     |
+----------------------------------+
| 3f931c18b44ac93ac5b4b6c653f7c0b0 |
+----------------------------------+
1 row in set (0.00 sec)

Tricky PHP MD5 Hash Equal

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');


md5('240610708') // 0e462097431906509019562988736854
md5('QNKCDZO')  //  0e830400451993494058024219903391

MD5 Decryption

Critical risky.....

MD5 collision

Magic hashes – PHP hash "collisions"

https://www.mscs.dal.ca/~selinger/md5collision/

Don't do MD5 hash to store passwords

I don't use MD5 hash.

Can I use SHA-1 hash?

SHA-1 risky

https://shattered.io

Attack proof

SHA-1 Decryption

mysql> 
mysql> select sha1('werty');
+------------------------------------------+
| sha1('werty')                            |
+------------------------------------------+
| 80a56aa9b9f2116798d51cc86586f309e54c1870 |
+------------------------------------------+

SHA-1 Hash Approach


sha1('werty')
"80a56aa9b9f2116798d51cc86586f309e54c1870"

Improvement Approach

~~Salt~~
===

$salt = 'this_is_salt';

md5($salt . 'password')
"2a413b9d39a34c49a036a08416e3a2b2"

sha1($salt . 'password')
"9588eb8d0bc9c24ee23cadb34296e16e53c19b39"

SHA-256

SHA-384

SHA-512
SHA3-256
SHA3-384
SHA3-512

don't find effective way to crack

SHA-2 decrypt?

Hash Database

Collecting hash results
Just like data dictionary files
Cannot avoid Brute Force Attack

What kinds of hash should be proper?

Take look at references on php.net

MD5 & SHA-1 function references

MD5 function

PHP
The Right Way

How to Safely Store Your Users' Passwords in 2016

Let me organize recommendations

Hash algorithms

BCrypt
Argon2 (recommended)
- Password Hashing Competition

password_hash function

PHP >= 5.5.9
~~PHP < 5.5.9~~
- ~~password_compat~~

$passwordHash = password_hash('secret-password',
    PASSWORD_DEFAULT);

if (password_verify('bad-password', $passwordHash)) {
    // Correct password
} else {
    // Wrong password
}

// password_hash ( 
//    string $password,
//    int $algo
//    [, array $options ] ) : string

password_hash function usage

Password hash algorithms

PASSWORD_DEFAULT
- Use BCRYPT (default as of PHP 5.5.0)
- To change over time as new and stronger algorithms
PASSWORD_BCRYPT
- BCRYPT_BLOWFISH
- salt option
- cost option (default is 10)

Password hash algorithms

PASSWORD_ARGON2I
PASSWORD_ARGON2ID
- memory_cost (KB)
- time_cost
- threads

password_hash('123456', PASSWORD_ARGON2I)
"$argon2i$v=19$m=65536,t=4,p=1$cERERktQb0xWUG5NNkIvTQ$SP/1Lx36WCO6yhaNgiw0EJXizMmddhrCDLpEc6LyvsY"

password_hash('123456', PASSWORD_ARGON2I, 
    [
        'time_cost' => 10,
        'memory_cost' => 60000,
        'threads' => 2,
    ]
)
"$argon2i$v=19$m=60000,t=10,p=2$Rk0vWWd2MVBEQjZTaWtmWA$YKRjIJk2qXuLutbtSC7zf1ikOkLlXhx2AS7h1/WlbRk"

Argon2I password hash

password_hash('123456', PASSWORD_ARGON2ID, 
    [
        'time_cost' => 10,
        'memory_cost' => 60000,
        'threads' => 2,
    ]
)
"$argon2id$v=19$m=60000,t=10,p=2$T3NlUDFLY0MyVFpxdURkVQ$k6jLfAHP/yIK1QhVL4rKjPky73HRdalDB3xxfMLXH0Q"

Argon2ID password hash

Laravel framework

Hashing

use Illuminate\Support\Facades\Hash;

$hashed = Hash::make('password', [
    'rounds' => 12
]);


$hashed = Hash::make('password', [
    'memory' => 1024,
    'time' => 2,
    'threads' => 2,
]);

Encryption/Decryption

Cryptography

Mcrypt

Don't use this.

2015-secure-php-data-encryption

if-you-re-typing-word-mcrypt-into-your-code-you-re-doing-it-wrong

The real reason

OpenSSL

AES Cipher Encryption Mode

ECB, Electronic codebook
CBC, Cipher-block chaining
GCM, Calois / Counter Mode

ECB

A plain text block
Using AES to encrypt them
Need to group the plain texts
- When cipher texts are loss or tampered
- Plain text will be wrong after encryption
- It cannot provide complete cipher validation
- It's not recommended in any situation

ECB

CBC, Cipher Block Chaining

Each plain text block should XOR with previous cipher block
Every cipher block depends on previous all plain text blocks
To guarantee every message is unique, the first block should use initialized vector

CBC

CTR (Counter mode)

Message authentication code

GMAC

Galois message authentication code mode

GCM mode

GMAC + CTR
Providing completed encrypted message validation
Some message should not be confidential
- Letting receiver can validate message
- IP，port number，target IP，IV
- These messages will be added on MAC value calculation

GCM mode

OpenSSL encrypt (PHP 5.6+)

$plaintext = "message to be encrypted";

$key = "your-secret-key";

$ivlen = openssl_cipher_iv_length($cipher="AES-128-CBC");

$iv = openssl_random_pseudo_bytes($ivlen);

$ciphertext_raw = openssl_encrypt(
    $plaintext,
    $cipher,
    $key,
    $options=OPENSSL_RAW_DATA,
    $iv
);

OpenSSL encrypt (PHP 5.6+)

$hmac = hash_hmac(
    'sha256',
    $ciphertext_raw,
    $key,
    $as_binary=true
);

$ciphertext = base64_encode(
    $iv . $hmac . $ciphertext_raw
);

OpenSSL decrypt (PHP 5.6+)

$c = base64_decode($ciphertext);

$ivlen = openssl_cipher_iv_length(
    $cipher="AES-128-CBC"
);

$iv = substr($c, 0, $ivlen);

$hmac = substr($c, $ivlen, $sha2len=32);

$ciphertext_raw = substr($c, $ivlen+$sha2len);

OpenSSL decrypt (PHP 5.6+)

$original_plaintext = openssl_decrypt(
    $ciphertext_raw,
    $cipher,
    $key,
    $options=OPENSSL_RAW_DATA,
    $iv
);

$calcmac = hash_hmac('sha256',
    $ciphertext_raw,
    $key,
    $as_binary=true
);

OpenSSL decrypt (PHP 5.6+)


if (hash_equals($hmac, $calcmac))
{
    //PHP 5.6+ timing attack safe comparison
    echo $original_plaintext."\n";
}

OpenSSL encrypt (PHP 7.1+)

$key = "your-secret-key";

$plaintext = "message to be encrypted";

$cipher = "aes-128-gcm";

if (in_array($cipher, openssl_get_cipher_methods()))
{
    $ivlen = openssl_cipher_iv_length($cipher);
    $iv = openssl_random_pseudo_bytes($ivlen);
    
    $ciphertext = openssl_encrypt(
        $plaintext,
        $cipher,
        $key,
        $options=0,
        $iv,
        $tag = 'tag');

OpenSSL encrypt (PHP 7.1+)


    //store $cipher, $iv, and $tag for decryption later
    $original_plaintext = openssl_decrypt(
        $ciphertext,
        $cipher,
        $key,
        $options=0,
        $iv,
        $tag
    );

    echo $original_plaintext."\n";
}

Sodium

Modern cryptography

NaCl: Networking and Cryptography library

THE SODIUM CRYPTO LIBRARY OF PHP 7.2

Sodium details

Curve25519 (ECC)
Salsa20 and ChaCha20
Poly1305
Ed25519
Argon2 and Scrypt
AES-GCM

Sodium details

Avoid side channel attacks
PHP 7.2+ supports
PHP 7.0, PHP 7.1 via PECL

Sodium use cases

Encrypt/Authenticate with a shared key
- Salsa20
Sending secret messages
- XSalsa20 to encrypt
- Poly1305 for MAC, and XS25519 for key exchange
Digital signature
- Elliptic Curve algorithm, Ed25519.
Authenticated encryption with AES-GCM
Store passwords safely, Argon2i
Derive a key from a user’s password, Argon2i

Encrypt/Authenticate with a shared key

$msg = 'This is a super secret message!';

// Generating an encryption key and a nonce
$key   = random_bytes(
    SODIUM_CRYPTO_SECRETBOX_KEYBYTES
); // 256 bit

$nonce = random_bytes(
    SODIUM_CRYPTO_SECRETBOX_NONCEBYTES
); // 24 bytes
 
// Encrypt
$ciphertext = sodium_crypto_secretbox(
    $msg, $nonce, $key
);

// Decrypt
$plaintext = sodium_crypto_secretbox_open(
    $ciphertext, $nonce, $key
);
 
echo $plaintext === $msg ? 'Success' : 'Error';

Sending secret messages

Generating their public/private keys

$bob_key_pair = sodium_crypto_box_keypair();
$bob_public_key = sodium_crypto_box_publickey(
    $bob_key_pair
);
$bob_private_key = sodium_crypto_box_secretkey(
    $bob_key_pair
);

$alice_key_pair = sodium_crypto_box_keypair();
$alice_public_key = sodium_crypto_box_publickey(
    $alice_key_pair
);
$alice_private_key = sodium_crypto_box_secretkey(
    $alice_key_pair
);

Bob sends encrtyped secret message to Alice

$secret_message = 'secret-message';

$throw_off_bytes = random_bytes(
    SODIUM_CRYPTO_BOX_NONCEBYTES
);

$encryption_key = 
sodium_crypto_box_keypair_from_secretkey_and_publickey(
    $bob_private_key,
    $alice_public_key
);

$encrypted = sodium_crypto_box(
    $secret_message,
    $throw_off_bytes,
    $encryption_key
);

echo base64_encode($encrypted);

Alice receives encrypted secret message

$throw_off_bytes = random_bytes(
    SODIUM_CRYPTO_BOX_NONCEBYTES
);

$decryption_key = 
sodium_crypto_box_keypair_from_secretkey_and_publickey(
    $alice_private_key,
    $bob_public_key
);

$decrypted = sodium_crypto_box_open(
    $encrypted,
    $throw_off_bytes,
    $decryption_key
);

echo $decrypted;

Digital signature

$key_pair = sodium_crypto_sign_keypair();

$public_key = sodium_crypto_sign_publickey(
    $key_pair
);
$secret_key = sodium_crypto_sign_secretkey(
    $key_pair
);

$message = 'message';

$signed_message = sodium_crypto_sign(
    $message,
    $secret_key
);
$signature = sodium_crypto_sign_detached(
    $message,
    $secret_key
);

Digital signature

$original = sodium_crypto_sign_open(
    $signed_message,
    $public_key
);

echo $original === $message ? 'ok' : 'error';

echo sodium_crypto_sign_verify_detached(
    $signature,
    $message,
    $public_key
) ? 'Signed is ok' : 'Error signature';

Authenticated encryption with AES-GCM

if (!sodium_crypto_aead_aes256gcm_is_available()) {
    exit(1);
}

$message = 'secret message';
$key = random_bytes(
    SODIUM_CRYPTO_AEAD_AES256GCM_KEYBYTES
);

$nonce = random_bytes(
    SODIUM_CRYPTO_AEAD_AES256GCM_NPUBBYTES
);

$ad = 'additional public data';

$cipher_text = sodium_crypto_aead_aes256gcm_encrypt(
    $message,
    $ad,
    $nonce,
    $key
);

Authenticated encryption with AES-GCM

echo base64_encode($cipher_text);

$decrypted = 
sodium_crypto_aead_aes256gcm_decrypt(
    $cipher_text,
    $ad,
    $nonce,
    $key
);

Store passwords safely, Argon2i

$password = 'password';

$hash = sodium_crypto_pwhash_str(
    $password,
    SODIUM_CRYPTO_PWHASH_OPSLIMIT_INTERACTIVE,
    SODIUM_CRYPTO_PWHASH_MEMLIMIT_INTERACTIVE
);

echo sodium_crypto_pwhash_str_verify(
    $hash,
    $password
) ? 'Ok' : 'Error';

$password_hash = password_hash(
    $password,
    PASSWORD_ARGON2I
);
echo password_verify(
    $password,
    $password_hash
) ? 'Ok' : 'Error';

ARGON2I hash comparison

Comparison hash

// 97
"$argon2id$v=19$m=65536,t=2,p=1$IOiuZanSOlw6Sn8C0AX9GA$QWjVw9IEfbY5a5hMu/NJcxBRaAYFS6ApmR5T62nClqc"

// 96
"$argon2i$v=19$m=65536,t=4,p=1$eW9lSDQzL1hMWnF0RXAzSw$yRKvmnPj1k/bb4U5Y55eZFvga7JNr1WAQC2xnFlJkeg"

Argon2I hash compatibility

// since php-7.3+ has the PASSWORD_ARGON2ID

echo sodium_crypto_pwhash_str_verify(
    $hash,
    $password
) ? 'Ok' : 'Error';

$password_hash = password_hash(
    $password,
    PASSWORD_ARGON2ID
);
echo password_verify(
    $password,
    $password_hash
) ? 'Ok' : 'Error';

Argon2I hash compatibility

// 97
"$argon2id$v=19$m=65536,t=2,p=1$IOiuZanSOlw6Sn8C0AX9GA$QWjVw9IEfbY5a5hMu/NJcxBRaAYFS6ApmR5T62nClqc"

// 97
"$argon2id$v=19$m=65536,t=4,p=1$NDY1Q1hVWFlYc3JNQ1hNRw$Gz4h4yb5yf4jtKLnKcnjQgEds+Bd4AlXn1K/JSXNoZI"

Argon2I hash compatibility check

$password = 'password';

$sodium_hash = sodium_crypto_pwhash_str(
    $password,
    SODIUM_CRYPTO_PWHASH_OPSLIMIT_INTERACTIVE,
    SODIUM_CRYPTO_PWHASH_MEMLIMIT_INTERACTIVE
);

$password_hash = password_hash(
    $password,
    PASSWORD_ARGON2ID
);

Argon2I hash compatibility check

echo sodium_crypto_pwhash_str_verify(
    $password_hash,
    $password
) ? 'Ok' : 'Error';

echo password_verify(
    $password,
    $sodium_hash
) ? 'Ok' : 'Error';

Derive a key from a user’s password, Argon2i

Generating binary key of 32 bytes

$password = 'password';

$salt = random_bytes(
    SODIUM_CRYPTO_PWHASH_SALTBYTES
);

$key = sodium_crypto_pwhash(
    32,
    $password,
    $salt,
    SODIUM_CRYPTO_PWHASH_OPSLIMIT_INTERACTIVE,
    SODIUM_CRYPTO_PWHASH_MEMLIMIT_INTERACTIVE,
    SODIUM_CRYPTO_PWHASH_ALG_DEFAULT
);

Sodium utility

sodium_memzero($sensitive_data);

sodium_hex2bin(
    string $hex 
    [, string $ignore ]
) : string

sodium_bin2hex(
    string $bin
) : string

Sodium utility

sodium_bin2base64(
    string $bin,
    int $id
) : string

sodium_base642bin(
    string $b64,
    int $id
    [, string $ignore ]
) : string

PHP cryptography package

Sodium wrapper

OpenSSL wrapper

sodium_compat

Sodium wrapper

Sodium has been released since 2018
Let's do open source contributions!

OpenSSL wrapper

OpenSSL has been released for whiles
They've completed wrapper ecosystem

My Experiences

Hash Migration

Demand Response system

Hash Migration Approach

Reset user passwords with Bcrypt
Forcing user to reset all passwords

Encrypt/Decrypt

Application

CIM Model Application

Follow IEC-61970 standard
- Formatting Power Plant Bid Data
Follow IEC-62325 standard
- Follow message transmission rule
- Receiving Bid Data Results
- AES encryption

Summary

Migrating to PHP 7+ (recommended PHP 7.2+)
Don't use Mcrypt
- Using OpenSSL or Sodium instead
Don't use MD5 hash
- Using password_hash function instead
Docker Demo enviroment

Any questions?

Hash, Cryptography, and PHP

By peter279k

Hash, Cryptography, and PHP

PHPConf Japan 2019

2,889

Hash, Cryptography, and PHP

Slide link

Outline

About me

Why?

Hash

Encrypt

Decrypt

My Experiences

About me

Why?

It's about a story....

PM

Resigned Engineer

Me

vacation engineer

senior developer

One Day...

PM

one will take pregnant vacation

one will resign this job

PM：You need to take over XXX

Me: Okay...

PM

Me

senior developer

One Day...

Demand Response system

Ubuntu 14.04

Laravel 5.2

PHP-5.5.9

No README

It only has codes!

It's part of smart grid system

Storing Password approach

Something went wrong?

Finally, I got a summary

The password storing approach

Receive a password from client

Using MD5 hash to hash passwords and store in database

MD5 Risky

hash value databases

MD5 Hash

Tricky PHP MD5 Hash Equal

MD5 Decryption

Critical risky.....

MD5 collision

Don't do MD5 hash to store passwords

I don't use MD5 hash.

Can I use SHA-1 hash?

SHA-1 risky

Attack proof

SHA-1 Decryption

SHA-1 Hash Approach

Improvement Approach

Salt

===

SHA-256

SHA-384

SHA-512 SHA3-256 SHA3-384 SHA3-512

don't find effective way to crack

SHA-2 decrypt?

Hash Database

Collecting hash results

Just like data dictionary files

Cannot avoid Brute Force Attack

What kinds of hash should be proper?

Take look at references on php.net

MD5 & SHA-1 function references

MD5 function

Let me organize recommendations

Hash algorithms

BCrypt

Argon2 (recommended)

password_hash function

PHP >= 5.5.9

PHP < 5.5.9

password_hash function usage

Password hash algorithms

PASSWORD_DEFAULT

SHA-512
SHA3-256
SHA3-384
SHA3-512

PASSWORD_ARGON2I
PASSWORD_ARGON2ID