| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| |
| package oauth2 |
| |
| import ( |
| "encoding/base64" |
| "errors" |
| "regexp" |
| ) |
| |
| var errDataURLInvalid = errors.New("invalid data URL") |
| |
| // https://datatracker.ietf.org/doc/html/rfc2397 |
| var dataURLRegex = regexp.MustCompile("^data:(?P<mimetype>[^;,]+)?(;(?P<charset>charset=[^;,]+))?" + |
| "(;(?P<base64>base64))?,(?P<data>.+)") |
| |
| type dataURL struct { |
| url string |
| Mimetype string |
| Data []byte |
| } |
| |
| func newDataURL(url string) (*dataURL, error) { |
| if !dataURLRegex.Match([]byte(url)) { |
| return nil, errDataURLInvalid |
| } |
| |
| match := dataURLRegex.FindStringSubmatch(url) |
| if len(match) != 7 { |
| return nil, errDataURLInvalid |
| } |
| |
| dataURL := &dataURL{ |
| url: url, |
| } |
| |
| mimetype := match[dataURLRegex.SubexpIndex("mimetype")] |
| if mimetype == "" { |
| mimetype = "text/plain" |
| } |
| dataURL.Mimetype = mimetype |
| |
| data := match[dataURLRegex.SubexpIndex("data")] |
| if match[dataURLRegex.SubexpIndex("base64")] == "" { |
| dataURL.Data = []byte(data) |
| } else { |
| data, err := base64.StdEncoding.DecodeString(data) |
| if err != nil { |
| return nil, err |
| } |
| dataURL.Data = data |
| } |
| |
| return dataURL, nil |
| } |