Add encryption functionality

Author: codedmonkey

tests/UnitTests/Encryption/EncryptionTest.php

@@ -120,6 +120,31 @@ public function testCreateFromFiles(): void
         $this->validateEncryption($encryption);
     }
 
+    public function testValidate(): void
+    {
+        $this->expectNotToPerformAssertions();
+
+        $privateKey = sodium_crypto_box_keypair();
+        $publicKey = sodium_crypto_box_publickey($privateKey);
+
+        $encryption = new Encryption($privateKey, $publicKey, []);
+
+        $encryption->validate();
+    }
+
+    public function testValidateFailsWithInvalidPublicKey(): void
+    {
+        $privateKey = sodium_crypto_box_keypair();
+        $publicKey = sodium_crypto_box_publickey(sodium_crypto_box_keypair());
+
+        $this->expectException(EncryptionException::class);
+        $this->expectExceptionMessage('The encryption key is not valid.');
+
+        $encryption = new Encryption($privateKey, $publicKey, []);
+
+        $encryption->validate();
+    }
+
     private function validateEncryption(Encryption $encryption): void
     {
         $data = $encryption->reveal($encryption->seal(self::DATA));