forked from greenpau/go-authcrunch
/
parsers.go
51 lines (48 loc) · 1.46 KB
/
parsers.go
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// Copyright 2022 Paul Greenberg greenpau@outlook.com
//
// Licensed 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 kms
import (
"encoding/base64"
"encoding/json"
"fmt"
"strings"
)
// ParsePayloadFromToken extracts payload from a token.
func ParsePayloadFromToken(s string) (map[string]interface{}, error) {
m := make(map[string]interface{})
arr := strings.SplitN(s, ".", 3)
if len(arr) != 3 {
return nil, fmt.Errorf("malformed token")
}
payload := arr[1]
if i := len(payload) % 4; i != 0 {
payload += strings.Repeat("=", 4-i)
}
var decodedStr []byte
var err error
if strings.ContainsAny(payload, "/+") {
// This decoding works with + and / signs. (legacy)
decodedStr, err = base64.StdEncoding.DecodeString(payload)
} else {
// This decoding works with - and _ signs.
decodedStr, err = base64.URLEncoding.DecodeString(payload)
}
if err != nil {
return nil, err
}
if err := json.Unmarshal(decodedStr, &m); err != nil {
return nil, err
}
return m, nil
}