Adds token abstraction

src/Abstraction/TokenAbstraction.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace SlashId\Php\Abstraction;
+
+use SlashId\Php\Exception\MalformedTokenException;
+
+class TokenAbstraction extends AbstractionBase
+{
+    public function validateToken(string $token): bool
+    {
+        return $this->sdk->post('/token/validate', ['token' => $token])['valid'] ?? false;
+    }
+
+    public function getSubFromToken(string $token): string
+    {
+        if (!str_contains($token, '.')) {
+            throw new MalformedTokenException('The token is malformed.');
+        }
+
+        $tokenParts = explode('.', $token);
+
+        if (count($tokenParts) !== 3) {
+            throw new MalformedTokenException('The token is malformed.');
+        }
+
+        [, $userDataTokenPart] = $tokenParts;
+        $userData = json_decode(base64_decode($userDataTokenPart), true);
+        return $userData['sub'];
+    }
+}

src/Exception/MalformedTokenException.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace SlashId\Php\Exception;
+
+/**
+ * Exception thrown when an invalid token is informed.
+ */
+class MalformedTokenException extends \Exception {}