feat: add FetchEntityStatementEndpoint

lib/Federation/FetchEntityStatementEndpoint.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace SPID_CIE_OIDC_PHP\Federation;
+
+use SPID_CIE_OIDC_PHP\Core\Util;
+use SPID_CIE_OIDC_PHP\Core\JWT;
+use SPID_CIE_OIDC_PHP\OIDC\RP\Database;
+use SPID_CIE_OIDC_PHP\Federation\EntityStatement;
+
+const DEFAULT_EXPIRATION_TIME = 30;
+
+class FetchEntityStatementEndpoint
+{
+
+    private $sa_config;
+    private $rp_config;
+    private $rps_config;    // all rp configurations
+
+    /**
+     *  creates a new FetchEntityStatementEndpoint instance
+     *
+     * @param array $sa_config      sa configuration
+     * @param array $rp_config      relying parties configurations
+     * @throws Exception
+     * @return FetchEntityStatementEndpoint
+     */
+    public function __construct(array $sa_config, array $rps_config)
+    {
+        $this->sa_config = $sa_config;
+        $this->rp_config = null;
+        $this->rps_config = $rps_config;
+    }
+
+    // TODO merge into lib/federation/EntityStatement
+    public function process()
+    {
+        try {
+            $iss = $_GET['iss'] ?? null;
+            $sub = $_GET['sub'] ?? null;
+            $output = $_GET['output'] ?? null;
+
+            if($iss!=null && $iss!=$this->sa_config['client_id']) {
+                throw new \Exception('iss MUST be equal to: ' . $this->iss);
+            }
+
+            if($sub==null) {
+                $this->rp_config = $this->sa_config;
+
+            } else {
+                foreach($this->rps_config as $rp_config) {
+                    if($rp_config['client_id'] == $sub) {
+                        $this->rp_config = $rp_config;
+                        break;
+                    }
+                }
+
+                if($this->rp_config==null) throw new \Exception("sub not found");
+            }
+
+            $entity_statement = EntityStatement::makeRPEntityStatementFromConfig($this->sa_config, $this->rp_config, $output=='json'); 
+
+            $mediaType = $output=='json'? 'application/json' : 'application/entity-statement+jwt';
+            header('Content-Type: ' . $mediaType);
+            echo $entity_statement;
+
+        } catch(\Exception $e) {
+            // API error
+            http_response_code(400);
+            echo "ERROR: " . $e->getMessage();
+        }
+    }
+}