Added: encryption support

README.md

@@ -26,12 +26,15 @@ Here is a simple example of how to send a message using the client:
 require 'vendor/autoload.php';
 
 use AndroidSmsGateway\Client;
+use AndroidSmsGateway\EncryptedClient;
 use AndroidSmsGateway\Domain\Message;
 
 $login = 'your_login';
 $password = 'your_password';
 
 $client = new Client($login, $password);
+// or
+// $client = new EncryptedClient('your_passphrase', $login, $password);
 
 $message = new Message('Your message text here.', ['+1234567890']);
 
@@ -50,9 +53,16 @@ try {
 }
 ```
 
-## Methods
+## Clients
 
-The `Client` class provides the following methods:
+There are two clients available:
+
+- `Client` is used for sending SMS messages in plain text.
+- `EncryptedClient` is used for sending AES encrypted SMS messages. You need to provide the same passphrase in Android app.
+
+### Methods
+
+Each client has the following methods:
 
 * `Send(Message $message)`: Send a new SMS message.
 * `GetState(string $id)`: Retrieve the state of a previously sent message by its ID.

src/Domain/Message.php

@@ -2,6 +2,7 @@
 
 namespace AndroidSmsGateway\Domain;
 
+use AndroidSmsGateway\Encryptor;
 use AndroidSmsGateway\Interfaces\SerializableInterface;
 
 /**
@@ -30,6 +31,10 @@ class Message implements SerializableInterface {
      * Request delivery report, `true` by default
      */
     private bool $withDeliveryReport;
+    /**
+     * Is message and phones encrypted, `false` by default
+     */
+    private bool $isEncrypted = false;
     /**
      * Phone numbers in E164 format
      * @var array<string>
@@ -39,13 +44,35 @@ class Message implements SerializableInterface {
     /**
      * @param array<string> $phoneNumbers
      */
-    public function __construct(string $message, array $phoneNumbers, ?string $id = null, ?int $ttl = null, ?int $simNumber = null, bool $withDeliveryReport = true) {
+    public function __construct(
+        string $message,
+        array $phoneNumbers,
+        ?string $id = null,
+        ?int $ttl = null,
+        ?int $simNumber = null,
+        bool $withDeliveryReport = true
+    ) {
         $this->id = $id;
         $this->message = $message;
         $this->ttl = $ttl;
         $this->simNumber = $simNumber;
         $this->withDeliveryReport = $withDeliveryReport;
         $this->phoneNumbers = $phoneNumbers;
+        $this->isEncrypted = false;
+    }
+
+    public function Encrypt(Encryptor $encryptor): self {
+        if ($this->isEncrypted) {
+            return $this;
+        }
+
+        $this->isEncrypted = true;
+        $this->message = $encryptor->Encrypt($this->message);
+        $this->phoneNumbers = array_map(
+            fn(string $phoneNumber) => $encryptor->Encrypt($phoneNumber),
+            $this->phoneNumbers
+        );
+        return $this;
     }
 
     public function ToObject(): object {
@@ -55,6 +82,7 @@ public function ToObject(): object {
             'ttl' => $this->ttl,
             'simNumber' => $this->simNumber,
             'withDeliveryReport' => $this->withDeliveryReport,
+            'isEncrypted' => $this->isEncrypted,
             'phoneNumbers' => $this->phoneNumbers
         ];
     }

src/Domain/MessageState.php

@@ -2,6 +2,7 @@
 
 namespace AndroidSmsGateway\Domain;
 
+use AndroidSmsGateway\Encryptor;
 use AndroidSmsGateway\Enums\ProcessState;
 
 /**
@@ -24,13 +25,25 @@ class MessageState {
      */
     private array $recipients;
 
+    /**
+     * Is message and phones encrypted
+     * @var bool
+     */
+    private bool $isEncrypted;
+
     /**
      * @param array<RecipientState> $recipients
      */
-    public function __construct(string $id, ProcessState $state, array $recipients) {
+    public function __construct(
+        string $id,
+        ProcessState $state,
+        array $recipients,
+        bool $isEncrypted = false
+    ) {
         $this->id = $id;
         $this->state = $state;
         $this->recipients = $recipients;
+        $this->isEncrypted = $isEncrypted;
     }
 
     public function ID(): string {
@@ -48,14 +61,28 @@ public function Recipients(): array {
         return $this->recipients;
     }
 
+    public function Decrypt(Encryptor $encryptor): self {
+        if (!$this->isEncrypted) {
+            return $this;
+        }
+
+        $this->recipients = array_map(
+            static fn(RecipientState $recipient) => $recipient->Decrypt($encryptor),
+            $this->recipients
+        );
+
+        return $this;
+    }
+
     public static function FromObject(object $obj): self {
         return new self(
             $obj->id,
             ProcessState::FromValue($obj->state),
             array_map(
                 static fn($obj) => RecipientState::FromObject($obj),
                 $obj->recipients
-            )
+            ),
+            $obj->isEncrypted ?? false
         );
     }
 }

src/Domain/RecipientState.php

@@ -2,6 +2,7 @@
 
 namespace AndroidSmsGateway\Domain;
 
+use AndroidSmsGateway\Encryptor;
 use AndroidSmsGateway\Enums\ProcessState;
 
 /**
@@ -39,6 +40,12 @@ public function Error(): ?string {
         return $this->error;
     }
 
+    public function Decrypt(Encryptor $encryptor): self {
+        $this->phoneNumber = $encryptor->Decrypt($this->phoneNumber);
+
+        return $this;
+    }
+
     public static function FromObject(object $obj): self {
         return new self(
             $obj->phoneNumber,

src/EncryptedClient.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace AndroidSmsGateway;
+
+use AndroidSmsGateway\Domain\Message;
+use AndroidSmsGateway\Domain\MessageState;
+use Http\Client\HttpClient;
+
+class EncryptedClient extends Client {
+    protected Encryptor $encryptor;
+
+    public function __construct(
+        string $passphrase,
+        string $login,
+        string $password,
+        string $serverUrl = self::DEFAULT_URL,
+        ?HttpClient $client = null
+    ) {
+        parent::__construct($login, $password, $serverUrl, $client);
+
+        $this->encryptor = new Encryptor($passphrase);
+    }
+
+    public function Send(Message $message): MessageState {
+        $message = $message->Encrypt($this->encryptor);
+        return parent::Send($message)->Decrypt($this->encryptor);
+    }
+
+    public function GetState(string $id): MessageState {
+        return parent::GetState($id)->Decrypt($this->encryptor);
+    }
+}

src/Encryptor.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace AndroidSmsGateway;
+
+class Encryptor {
+    protected string $passphrase;
+
+    public function __construct(
+        string $passphrase
+    ) {
+        $this->passphrase = $passphrase;
+    }
+
+    public function Encrypt(string $data): string {
+        $salt = $this->generateSalt();
+        $secretKey = $this->generateSecretKeyFromPassphrase($this->passphrase, $salt);
+
+        return base64_encode($salt) . '.' . openssl_encrypt($data, 'aes-256-cbc', $secretKey, 0, $salt);
+    }
+
+    public function Decrypt(string $data): string {
+        list($saltBase64, $encryptedBase64) = explode('.', $data, 2);
+
+        $salt = base64_decode($saltBase64);
+        $secretKey = $this->generateSecretKeyFromPassphrase($this->passphrase, $salt);
+
+        return openssl_decrypt($encryptedBase64, 'aes-256-cbc', $secretKey, 0, $salt);
+    }
+
+    protected function generateSalt(int $size = 16): string {
+        return random_bytes($size);
+    }
+
+    protected function generateSecretKeyFromPassphrase(
+        string $passphrase,
+        string $salt,
+        int $keyLength = 32,
+        int $iterationCount = 10000
+    ): string {
+        return hash_pbkdf2('sha1', $passphrase, $salt, $iterationCount, $keyLength, true);
+    }
+}

tests/Domain/MessageTest.php

@@ -34,6 +34,7 @@ public function testCanSerializeToObject(): void {
             'ttl' => $ttl,
             'simNumber' => $simNumber,
             'withDeliveryReport' => $withDeliveryReport,
+            'isEncrypted' => false,
             'phoneNumbers' => $phoneNumbers
         ];