change resource key type from resource to mixed to support both resource and OpenSSLAsymmetricKey

Author: miladrahimi

src/Cryptography/Keys/EcdsaPrivateKey.php

@@ -9,7 +9,7 @@
 class EcdsaPrivateKey
 {
     /**
-     * @var resource Key resource handler
+     * @var mixed Key resource handler
      */
     protected $resource;
 
@@ -35,7 +35,7 @@ public function __construct(string $key, string $passphrase = '', ?string $id =
     }
 
     /**
-     * @return resource
+     * @return mixed
      */
     public function getResource()
     {

src/Cryptography/Keys/EcdsaPublicKey.php

@@ -9,7 +9,7 @@
 class EcdsaPublicKey
 {
     /**
-     * @var resource Key resource handler
+     * @var mixed Key resource handler
      */
     protected $resource;
 
@@ -34,7 +34,7 @@ public function __construct(string $key, ?string $id = null)
     }
 
     /**
-     * @return resource
+     * @return mixed
      */
     public function getResource()
     {

src/Cryptography/Keys/RsaPrivateKey.php

@@ -9,7 +9,7 @@
 class RsaPrivateKey
 {
     /**
-     * @var resource Key resource handler
+     * @var mixed Key resource handler
      */
     protected $resource;
 
@@ -35,7 +35,7 @@ public function __construct(string $key, string $passphrase = '', ?string $id =
     }
 
     /**
-     * @return resource
+     * @return mixed
      */
     public function getResource()
     {

src/Cryptography/Keys/RsaPublicKey.php

@@ -9,7 +9,7 @@
 class RsaPublicKey
 {
     /**
-     * @var resource Key resource handler
+     * @var mixed Key resource handler
      */
     protected $resource;
 
@@ -34,7 +34,7 @@ public function __construct(string $key, ?string $id = null)
     }
 
     /**
-     * @return resource
+     * @return mixed
      */
     public function getResource()
     {