woodpecker/shared/token/token.go
2021-11-24 01:31:11 +01:00

157 lines
3.8 KiB
Go

// Copyright 2018 Drone.IO Inc.
//
// 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 token
import (
"fmt"
"net/http"
"github.com/golang-jwt/jwt/v4"
"github.com/rs/zerolog/log"
)
type SecretFunc func(*Token) (string, error)
const (
UserToken = "user"
SessToken = "sess"
HookToken = "hook"
CsrfToken = "csrf"
AgentToken = "agent"
)
// SignerAlgo id default algorithm used to sign JWT tokens.
const SignerAlgo = "HS256"
type Token struct {
Kind string
Text string
}
func parse(raw string, fn SecretFunc) (*Token, error) {
token := &Token{}
parsed, err := jwt.Parse(raw, keyFunc(token, fn))
if err != nil {
return nil, err
} else if !parsed.Valid {
return nil, jwt.ValidationError{}
}
return token, nil
}
func ParseRequest(r *http.Request, fn SecretFunc) (*Token, error) {
token := r.Header.Get("Authorization")
// first we attempt to get the token from the
// authorization header.
if len(token) != 0 {
log.Trace().Msgf("token.ParseRequest: found token in header: %s", token)
bearer := token
if _, err := fmt.Sscanf(token, "Bearer %s", &bearer); err != nil {
return nil, err
}
return parse(bearer, fn)
}
// then we attempt to get the token from the
// access_token url query parameter
token = r.FormValue("access_token")
if len(token) != 0 {
return parse(token, fn)
}
// and finally we attempt to get the token from
// the user session cookie
cookie, err := r.Cookie("user_sess")
if err != nil {
return nil, err
}
return parse(cookie.Value, fn)
}
func CheckCsrf(r *http.Request, fn SecretFunc) error {
// get and options requests are always
// enabled, without CSRF checks.
switch r.Method {
case "GET", "OPTIONS":
return nil
}
// parse the raw CSRF token value and validate
raw := r.Header.Get("X-CSRF-TOKEN")
_, err := parse(raw, fn)
return err
}
func New(kind, text string) *Token {
return &Token{Kind: kind, Text: text}
}
// Sign signs the token using the given secret hash
// and returns the string value.
func (t *Token) Sign(secret string) (string, error) {
return t.SignExpires(secret, 0)
}
// Sign signs the token using the given secret hash
// with an expiration date.
func (t *Token) SignExpires(secret string, exp int64) (string, error) {
token := jwt.New(jwt.SigningMethodHS256)
claims, ok := token.Claims.(jwt.MapClaims)
if !ok {
return "", fmt.Errorf("token claim is not a MapClaims")
}
claims["type"] = t.Kind
claims["text"] = t.Text
if exp > 0 {
claims["exp"] = float64(exp)
}
return token.SignedString([]byte(secret))
}
func keyFunc(token *Token, fn SecretFunc) jwt.Keyfunc {
return func(t *jwt.Token) (interface{}, error) {
claims, ok := t.Claims.(jwt.MapClaims)
if !ok {
return nil, fmt.Errorf("token claim is not a MapClaims")
}
// validate the correct algorithm is being used
if t.Method.Alg() != SignerAlgo {
return nil, jwt.ErrSignatureInvalid
}
// extract the token kind and cast to
// the expected type.
kindv, ok := claims["type"]
if !ok {
return nil, jwt.ValidationError{}
}
token.Kind, _ = kindv.(string)
// extract the token value and cast to
// expected type.
textv, ok := claims["text"]
if !ok {
return nil, jwt.ValidationError{}
}
token.Text, _ = textv.(string)
// invoke the callback function to retrieve
// the secret key used to verify
secret, err := fn(token)
return []byte(secret), err
}
}