Crypto Module

examples/Time.php

@@ -3,10 +3,12 @@
 require_once __DIR__ . '/../vendor/autoload.php';
 
 use PubNub\Models\Consumer\PNTimeResult;
+use PubNub\Crypto\Cryptor;
 
 $pnconfig = \PubNub\PNConfiguration::demoKeys();
 $pubnub = new \PubNub\PubNub($pnconfig);
 
 $result = $pubnub->time()->sync();
 
 printf("Server Time is: %s", date("Y-m-d H:i:s", $result->getTimetoken()));
+

src/PubNub/Crypto/AesCbcCryptor.php

@@ -0,0 +1,62 @@
+<?php
+
+namespace PubNub\Crypto;
+
+use PubNub\Crypto\Payload as CryptoPayload;
+use PubNub\Crypto\PaddingTrait;
+
+class AesCbcCryptor extends Cryptor
+{
+    use PaddingTrait;
+
+    public const CRYPTOR_ID = 'ACRH';
+    public const IV_LENGTH = 16;
+    public const BLOCK_SIZE = 16;
+    public const CIPHER_ALGO = 'aes-256-cbc';
+
+    protected string $cipherKey;
+
+    public function __construct(string $cipherKey)
+    {
+        $this->cipherKey = $cipherKey;
+    }
+
+    public function getIV(): string
+    {
+        return random_bytes(self::IV_LENGTH);
+    }
+
+    public function getCipherKey(): string
+    {
+        return $this->cipherKey;
+    }
+
+    protected function getSecret($cipherKey): string
+    {
+        $key = !is_null($cipherKey) ? $cipherKey : $this->cipherKey;
+        return hash("sha256", $key, true);
+    }
+
+    public function encrypt(string $text, ?string $cipherKey = null): CryptoPayload
+    {
+        $secret = $this->getSecret($cipherKey);
+        $iv = $this->getIV();
+        $encrypted = openssl_encrypt($text, self::CIPHER_ALGO, $secret, OPENSSL_RAW_DATA, $iv);
+        return new CryptoPayload($encrypted, $iv, self::CRYPTOR_ID);
+    }
+
+    public function decrypt(CryptoPayload $payload, ?string $cipherKey = null)
+    {
+        $text = $payload->getData();
+        $secret = $this->getSecret($cipherKey);
+        $iv = $payload->getCryptorData();
+        $decrypted = openssl_decrypt($text, self::CIPHER_ALGO, $secret, OPENSSL_RAW_DATA, $iv);
+        $result = json_decode($decrypted);
+
+        if ($result === null) {
+            return $decrypted;
+        } else {
+            return $result;
+        }
+    }
+}

src/PubNub/Crypto/Cryptor.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace PubNub\Crypto;
+
+use PubNub\Crypto\Payload as CryptoPayload;
+
+abstract class Cryptor
+{
+    public const CRYPTOR_ID = null;
+
+    abstract public function encrypt(string $text, ?string $cipherKey = null): CryptoPayload;
+    abstract public function decrypt(CryptoPayload $payload, ?string $cipherKey = null);
+}

src/PubNub/Crypto/Header.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace PubNub\Crypto;
+
+class Header
+{
+    public const HEADER_VERSION = 1;
+    private string $sentinel;
+    private string $cryptorId;
+    private string $cryptorData;
+    private int $length;
+
+    public function __construct(
+        string $sentinel,
+        string $cryptorId,
+        string $cryptorData,
+        int $length
+    ) {
+        $this->sentinel = $sentinel;
+        $this->cryptorId = $cryptorId;
+        $this->cryptorData = $cryptorData;
+        $this->length = $length;
+    }
+
+    public function getSentinel(): string
+    {
+        return $this->sentinel;
+    }
+
+    public function getCryptorId(): string
+    {
+        return $this->cryptorId;
+    }
+
+    public function getCryptorData(): string
+    {
+        return $this->cryptorData;
+    }
+
+    public function getLength(): int
+    {
+        return $this->length;
+    }
+}

src/PubNub/Crypto/LegacyCryptor.php

@@ -0,0 +1,101 @@
+<?php
+
+namespace PubNub\Crypto;
+
+use PubNub\Crypto\Cryptor;
+use PubNub\Exceptions\PubNubResponseParsingException;
+use PubNub\Crypto\PaddingTrait;
+
+class LegacyCryptor extends Cryptor
+{
+    use PaddingTrait;
+
+    public const CRYPTOR_ID = '0000';
+    public const IV_LENGTH = 16;
+    public const BLOCK_SIZE = 16;
+    public const CIPHER_ALGO = 'aes-256-cbc';
+    protected const STATIC_IV = '0123456789012345';
+
+    protected string $cipherKey;
+    protected bool $useRandomIV;
+
+    public function __construct(string $key, bool $useRandomIV)
+    {
+        $this->cipherKey = $key;
+        $this->useRandomIV = $useRandomIV;
+    }
+
+    public function getIV(): string
+    {
+        if (!$this->useRandomIV) {
+            return self::STATIC_IV;
+        }
+        return random_bytes(static::IV_LENGTH);
+    }
+
+    public function getCipherKey(): string
+    {
+        return $this->cipherKey;
+    }
+
+    public function encrypt(string $text, ?string $cipherKey = null): Payload
+    {
+        $iv = $this->getIV();
+        $shaCipherKey = substr(hash("sha256", $this->cipherKey), 0, 32);
+        $padded = $this->pad($text, self::BLOCK_SIZE);
+        $encrypted = openssl_encrypt($text, self::CIPHER_ALGO, $shaCipherKey, OPENSSL_RAW_DATA, $iv);
+        if ($this->useRandomIV) {
+            $encryptedWithIV = $iv . $encrypted;
+        } else {
+            $encryptedWithIV = $encrypted;
+        }
+        return new Payload($encryptedWithIV, '', self::CRYPTOR_ID);
+    }
+
+    public function decrypt(Payload $payload, ?string $cipherKey = null)
+    {
+        $text = $payload->getData();
+        if (strlen($text) === 0) {
+            throw new PubNubResponseParsingException("Decryption error: message is empty");
+        }
+
+        if (is_array($text)) {
+            if (array_key_exists("pn_other", $text)) {
+                $text = $text["pn_other"];
+            } else {
+                if (is_array($text)) {
+                    throw new PubNubResponseParsingException("Decryption error: message is not a string");
+                } else {
+                    throw new PubNubResponseParsingException("Decryption error: pn_other object key missing");
+                }
+            }
+        } elseif (!is_string($text)) {
+            throw new PubNubResponseParsingException("Decryption error: message is not a string or object");
+        }
+
+        $shaCipherKey = substr(hash("sha256", $this->cipherKey), 0, 32);
+
+        if ($this->useRandomIV) {
+            $iv = substr($text, 0, 16);
+            $data = substr($text, 16);
+        } else {
+            $iv = self::STATIC_IV;
+            $data = $text;
+        }
+        $decrypted = openssl_decrypt($data, 'aes-256-cbc', $shaCipherKey, OPENSSL_RAW_DATA, $iv);
+
+        if ($decrypted === false) {
+            throw new PubNubResponseParsingException("Decryption error: " . openssl_error_string());
+        }
+
+        $unPadded = $this->depad($decrypted, self::BLOCK_SIZE);
+
+        $result = json_decode($unPadded);
+
+        if ($result === null) {
+            return $unPadded;
+        } else {
+            return $result;
+        }
+    }
+}

src/PubNub/Crypto/PaddingTrait.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace PubNub\Crypto;
+
+trait PaddingTrait
+{
+    /**
+     * Pad $text to multiple of $blockSize lenght using PKCS5Padding schema
+     *
+     * @param string $text
+     * @param int $blockSize
+     * @return string
+     */
+    public function pad(string $text, int $blockSize)
+    {
+        $pad = $blockSize - (strlen($text) % $blockSize);
+        return $text . str_repeat(chr($pad), $pad);
+    }
+
+    /**
+     * Remove padding from $text using PKCS5Padding schema
+     *
+     * @param string $text
+     * @param int $blockSize
+     * @return string
+     */
+    public function depad($data, $blockSize)
+    {
+        $length = strlen($data);
+        if ($length == 0) {
+            return $data;
+        }
+
+        $padLength = substr($data, -1);
+
+        if (ord($padLength) <= $blockSize) {
+            for ($i = $length - 2; $i > 0; $i--) {
+                if (ord($data [$i] != $padLength)) {
+                    break;
+                }
+            }
+            return substr($data, 0, $i + 1);
+        }
+        return $data;
+    }
+}

src/PubNub/Crypto/Payload.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace PubNub\Crypto;
+
+class Payload
+{
+    private string $data;
+    private ?string $cryptorData;
+    private ?string $cryptorId;
+
+    public function __construct(string $data, ?string $cryptorData = null, ?string $cryptorId = null)
+    {
+        $this->data = $data;
+        $this->cryptorData = $cryptorData;
+        $this->cryptorId = $cryptorId;
+    }
+
+    public function getData(): string
+    {
+        return $this->data;
+    }
+
+    public function getCryptorData(): ?string
+    {
+        return $this->cryptorData;
+    }
+
+    public function getCryptorId(): ?string
+    {
+        return $this->cryptorId;
+    }
+}