fix: Signing and presigning s3-object-lambda requests fail

When signing and presigning s3-object-lambda requests we get an invalid signature error, due to that the signature provider was not resolving the right signature class implementation, which handle s3-object-lambda requests; The name for that class is S3SignatureV4 and the reason why was not resolved is that the s3-object-lambda service name was not in the s3-v4-signed-services-list "$s3v4SignedServices", so that to fix this behavior I added the desired services in that array. This fix also add a special handling in the presigning proccess that validates if the service is s3-object-lambda, then that is the service used for the signature, otherwise the default signing service is used.

src/S3/S3Client.php

@@ -460,17 +460,19 @@ public function createPresignedRequest(CommandInterface $command, $expires, arra
     {
         $command = clone $command;
         $command->getHandlerList()->remove('signer');
+        $request = \Aws\serialize($command);
+        $signing_name = $this->getSigningName($request->getUri()->getHost());
 
         /** @var \Aws\Signature\SignatureInterface $signer */
         $signer = call_user_func(
             $this->getSignatureProvider(),
             $this->getConfig('signature_version'),
-            $this->getConfig('signing_name'),
+            $signing_name,
             $this->getConfig('signing_region')
         );
 
         return $signer->presign(
-            \Aws\serialize($command),
+            $request,
             $this->getCredentials()->wait(),
             $expires,
             $options
@@ -638,6 +640,22 @@ private function getEncodingTypeMiddleware()
         };
     }
 
+    /**
+     * Special handling for when the service name is s3-object-lambda.
+     * So, if the host contains s3-object-lambda, then the service name
+     * returned is s3-object-lambda, otherwise the default signing service is returned.
+     * @param string $host The host to validate if is a s3-object-lambda URL.
+     * @return string returns the signing service name to be used
+     */
+    private function getSigningName($host)
+    {
+        if (strpos( $host, 's3-object-lambda')) {
+            return 's3-object-lambda';
+        }
+
+        return $this->getConfig('signing_name');
+    }
+
     /** @internal */
     public static function _applyRetryConfig($value, $args, HandlerList $list)
     {

src/Signature/SignatureProvider.php

@@ -43,6 +43,7 @@ class SignatureProvider
     private static $s3v4SignedServices = [
         's3' => true,
         's3control' => true,
+        's3-object-lambda' => true,
     ];
 
     /**