1 files changed, 66 insertions, 0 deletions
diff --git a/src/OAuthMiddleware.php b/src/OAuthMiddleware.php
new file mode 100644
index 0000000..aeb28c7
--- /dev/null
+++ b/src/OAuthMiddleware.php
@@ -0,0 +1,66 @@
+<?php
+
+namespace CardmarketApi;
+
+use Psr\Http\Message\RequestInterface;
+
+class OAuthMiddleware
+{
+    public function __invoke(callable $handler): callable
+    {
+        return function (RequestInterface $request, array $options) use ($handler) {
+            $cardMarketConfig = $options['cardmarket'];
+            $oAuthParams = [
+                'oauth_consumer_key' => $cardMarketConfig['app_token'],
+                'oauth_token' => $cardMarketConfig['access_token'],
+                'oauth_nonce' => uniqid(),
+                'oauth_timestamp' => time(),
+                'oauth_signature_method' => 'HMAC-SHA1',
+                'oauth_version' => '1.0',
+            ];
+
+            $oAuthHeaderParams = $oAuthParams + [
+                'realm' => $request->getUri(),
+                'oauth_signature' => $this->getOAuthSignature($request->getMethod(), $request->getUri(), $options, $oAuthParams)
+            ];
+            $oAuthHeader = 'OAuth ' .
+                implode(',', array_map(
+                    fn ($key, $value) => "$key=\"$value\"",
+                    array_keys($oAuthHeaderParams),
+                    $oAuthHeaderParams
+                ));
+
+            $request = $request->withHeader('Authorization', $oAuthHeader);
+
+            return $handler($request, $options);
+        };
+    }
+
+    /**
+     * Generates the OAuthSignature
+     * @see https://api.cardmarket.com/ws/documentation/API:Auth_libcurl
+     *
+     * @param string $method
+     * @param string $uri
+     * @param array  $options
+     * @param array  $oAuthParams
+     *
+     * @return string
+     */
+    private function getOAuthSignature(string $method, string $uri, array $options, array $oAuthParams): string
+    {
+        $cardMarketConfig = $options['cardmarket'];
+
+        ksort($oAuthParams);
+        $baseStringParams = [
+            strtoupper($method),
+            rawurlencode($uri),
+            rawurlencode(http_build_query($oAuthParams)),
+        ];
+        $baseString = implode('&', $baseStringParams);
+        $signatureKey = rawurlencode($cardMarketConfig['app_secret']) . '&' . rawurlencode($cardMarketConfig['access_token_secret']);
+        $rawSignature = hash_hmac('sha1', $baseString, $signatureKey, true);
+
+        return base64_encode($rawSignature);
+    }
+}