use FileBodyDecoder if the format is specified as binary

Author: dbarrosop

openapi3filter/req_resp_decoder.go

@@ -1246,8 +1246,17 @@ func decodeBody(body io.Reader, header http.Header, schema *openapi3.SchemaRef,
 			contentType = "text/plain"
 		}
 	}
+
 	mediaType := parseMediaType(contentType)
-	decoder, ok := bodyDecoders[mediaType]
+	var decoder BodyDecoder
+	var ok bool
+	if schema.Value.Format == "binary" {
+		ok = true
+		decoder = FileBodyDecoder
+	} else {
+		decoder, ok = bodyDecoders[mediaType]
+	}
+
 	if !ok {
 		return "", nil, &ParseError{
 			Kind:   KindUnsupportedFormat,