pki/vendor/github.com/labstack/echo/v4/middleware/jwt.go
Paul Lecuq d5159b447a
All checks were successful
continuous-integration/drone/push Build is passing
updated dependencies
2021-08-30 20:04:15 +02:00

348 lines
10 KiB
Go

// +build go1.15
package middleware
import (
"errors"
"fmt"
"net/http"
"reflect"
"strings"
"github.com/golang-jwt/jwt"
"github.com/labstack/echo/v4"
)
type (
// JWTConfig defines the config for JWT middleware.
JWTConfig struct {
// Skipper defines a function to skip middleware.
Skipper Skipper
// BeforeFunc defines a function which is executed just before the middleware.
BeforeFunc BeforeFunc
// SuccessHandler defines a function which is executed for a valid token.
SuccessHandler JWTSuccessHandler
// ErrorHandler defines a function which is executed for an invalid token.
// It may be used to define a custom JWT error.
ErrorHandler JWTErrorHandler
// ErrorHandlerWithContext is almost identical to ErrorHandler, but it's passed the current context.
ErrorHandlerWithContext JWTErrorHandlerWithContext
// Signing key to validate token.
// This is one of the three options to provide a token validation key.
// The order of precedence is a user-defined KeyFunc, SigningKeys and SigningKey.
// Required if neither user-defined KeyFunc nor SigningKeys is provided.
SigningKey interface{}
// Map of signing keys to validate token with kid field usage.
// This is one of the three options to provide a token validation key.
// The order of precedence is a user-defined KeyFunc, SigningKeys and SigningKey.
// Required if neither user-defined KeyFunc nor SigningKey is provided.
SigningKeys map[string]interface{}
// Signing method used to check the token's signing algorithm.
// Optional. Default value HS256.
SigningMethod string
// Context key to store user information from the token into context.
// Optional. Default value "user".
ContextKey string
// Claims are extendable claims data defining token content. Used by default ParseTokenFunc implementation.
// Not used if custom ParseTokenFunc is set.
// Optional. Default value jwt.MapClaims
Claims jwt.Claims
// TokenLookup is a string in the form of "<source>:<name>" or "<source>:<name>,<source>:<name>" that is used
// to extract token from the request.
// Optional. Default value "header:Authorization".
// Possible values:
// - "header:<name>"
// - "query:<name>"
// - "param:<name>"
// - "cookie:<name>"
// - "form:<name>"
// Multiply sources example:
// - "header: Authorization,cookie: myowncookie"
TokenLookup string
// AuthScheme to be used in the Authorization header.
// Optional. Default value "Bearer".
AuthScheme string
// KeyFunc defines a user-defined function that supplies the public key for a token validation.
// The function shall take care of verifying the signing algorithm and selecting the proper key.
// A user-defined KeyFunc can be useful if tokens are issued by an external party.
// Used by default ParseTokenFunc implementation.
//
// When a user-defined KeyFunc is provided, SigningKey, SigningKeys, and SigningMethod are ignored.
// This is one of the three options to provide a token validation key.
// The order of precedence is a user-defined KeyFunc, SigningKeys and SigningKey.
// Required if neither SigningKeys nor SigningKey is provided.
// Not used if custom ParseTokenFunc is set.
// Default to an internal implementation verifying the signing algorithm and selecting the proper key.
KeyFunc jwt.Keyfunc
// ParseTokenFunc defines a user-defined function that parses token from given auth. Returns an error when token
// parsing fails or parsed token is invalid.
// Defaults to implementation using `github.com/golang-jwt/jwt` as JWT implementation library
ParseTokenFunc func(auth string, c echo.Context) (interface{}, error)
}
// JWTSuccessHandler defines a function which is executed for a valid token.
JWTSuccessHandler func(echo.Context)
// JWTErrorHandler defines a function which is executed for an invalid token.
JWTErrorHandler func(error) error
// JWTErrorHandlerWithContext is almost identical to JWTErrorHandler, but it's passed the current context.
JWTErrorHandlerWithContext func(error, echo.Context) error
jwtExtractor func(echo.Context) (string, error)
)
// Algorithms
const (
AlgorithmHS256 = "HS256"
)
// Errors
var (
ErrJWTMissing = echo.NewHTTPError(http.StatusBadRequest, "missing or malformed jwt")
ErrJWTInvalid = echo.NewHTTPError(http.StatusUnauthorized, "invalid or expired jwt")
)
var (
// DefaultJWTConfig is the default JWT auth middleware config.
DefaultJWTConfig = JWTConfig{
Skipper: DefaultSkipper,
SigningMethod: AlgorithmHS256,
ContextKey: "user",
TokenLookup: "header:" + echo.HeaderAuthorization,
AuthScheme: "Bearer",
Claims: jwt.MapClaims{},
KeyFunc: nil,
}
)
// JWT returns a JSON Web Token (JWT) auth middleware.
//
// For valid token, it sets the user in context and calls next handler.
// For invalid token, it returns "401 - Unauthorized" error.
// For missing token, it returns "400 - Bad Request" error.
//
// See: https://jwt.io/introduction
// See `JWTConfig.TokenLookup`
func JWT(key interface{}) echo.MiddlewareFunc {
c := DefaultJWTConfig
c.SigningKey = key
return JWTWithConfig(c)
}
// JWTWithConfig returns a JWT auth middleware with config.
// See: `JWT()`.
func JWTWithConfig(config JWTConfig) echo.MiddlewareFunc {
// Defaults
if config.Skipper == nil {
config.Skipper = DefaultJWTConfig.Skipper
}
if config.SigningKey == nil && len(config.SigningKeys) == 0 && config.KeyFunc == nil && config.ParseTokenFunc == nil {
panic("echo: jwt middleware requires signing key")
}
if config.SigningMethod == "" {
config.SigningMethod = DefaultJWTConfig.SigningMethod
}
if config.ContextKey == "" {
config.ContextKey = DefaultJWTConfig.ContextKey
}
if config.Claims == nil {
config.Claims = DefaultJWTConfig.Claims
}
if config.TokenLookup == "" {
config.TokenLookup = DefaultJWTConfig.TokenLookup
}
if config.AuthScheme == "" {
config.AuthScheme = DefaultJWTConfig.AuthScheme
}
if config.KeyFunc == nil {
config.KeyFunc = config.defaultKeyFunc
}
if config.ParseTokenFunc == nil {
config.ParseTokenFunc = config.defaultParseToken
}
// Initialize
// Split sources
sources := strings.Split(config.TokenLookup, ",")
var extractors []jwtExtractor
for _, source := range sources {
parts := strings.Split(source, ":")
switch parts[0] {
case "query":
extractors = append(extractors, jwtFromQuery(parts[1]))
case "param":
extractors = append(extractors, jwtFromParam(parts[1]))
case "cookie":
extractors = append(extractors, jwtFromCookie(parts[1]))
case "form":
extractors = append(extractors, jwtFromForm(parts[1]))
case "header":
extractors = append(extractors, jwtFromHeader(parts[1], config.AuthScheme))
}
}
return func(next echo.HandlerFunc) echo.HandlerFunc {
return func(c echo.Context) error {
if config.Skipper(c) {
return next(c)
}
if config.BeforeFunc != nil {
config.BeforeFunc(c)
}
var auth string
var err error
for _, extractor := range extractors {
// Extract token from extractor, if it's not fail break the loop and
// set auth
auth, err = extractor(c)
if err == nil {
break
}
}
// If none of extractor has a token, handle error
if err != nil {
if config.ErrorHandler != nil {
return config.ErrorHandler(err)
}
if config.ErrorHandlerWithContext != nil {
return config.ErrorHandlerWithContext(err, c)
}
return err
}
token, err := config.ParseTokenFunc(auth, c)
if err == nil {
// Store user information from token into context.
c.Set(config.ContextKey, token)
if config.SuccessHandler != nil {
config.SuccessHandler(c)
}
return next(c)
}
if config.ErrorHandler != nil {
return config.ErrorHandler(err)
}
if config.ErrorHandlerWithContext != nil {
return config.ErrorHandlerWithContext(err, c)
}
return &echo.HTTPError{
Code: ErrJWTInvalid.Code,
Message: ErrJWTInvalid.Message,
Internal: err,
}
}
}
}
func (config *JWTConfig) defaultParseToken(auth string, c echo.Context) (interface{}, error) {
token := new(jwt.Token)
var err error
// Issue #647, #656
if _, ok := config.Claims.(jwt.MapClaims); ok {
token, err = jwt.Parse(auth, config.KeyFunc)
} else {
t := reflect.ValueOf(config.Claims).Type().Elem()
claims := reflect.New(t).Interface().(jwt.Claims)
token, err = jwt.ParseWithClaims(auth, claims, config.KeyFunc)
}
if err != nil {
return nil, err
}
if !token.Valid {
return nil, errors.New("invalid token")
}
return token, nil
}
// defaultKeyFunc returns a signing key of the given token.
func (config *JWTConfig) defaultKeyFunc(t *jwt.Token) (interface{}, error) {
// Check the signing method
if t.Method.Alg() != config.SigningMethod {
return nil, fmt.Errorf("unexpected jwt signing method=%v", t.Header["alg"])
}
if len(config.SigningKeys) > 0 {
if kid, ok := t.Header["kid"].(string); ok {
if key, ok := config.SigningKeys[kid]; ok {
return key, nil
}
}
return nil, fmt.Errorf("unexpected jwt key id=%v", t.Header["kid"])
}
return config.SigningKey, nil
}
// jwtFromHeader returns a `jwtExtractor` that extracts token from the request header.
func jwtFromHeader(header string, authScheme string) jwtExtractor {
return func(c echo.Context) (string, error) {
auth := c.Request().Header.Get(header)
l := len(authScheme)
if len(auth) > l+1 && auth[:l] == authScheme {
return auth[l+1:], nil
}
return "", ErrJWTMissing
}
}
// jwtFromQuery returns a `jwtExtractor` that extracts token from the query string.
func jwtFromQuery(param string) jwtExtractor {
return func(c echo.Context) (string, error) {
token := c.QueryParam(param)
if token == "" {
return "", ErrJWTMissing
}
return token, nil
}
}
// jwtFromParam returns a `jwtExtractor` that extracts token from the url param string.
func jwtFromParam(param string) jwtExtractor {
return func(c echo.Context) (string, error) {
token := c.Param(param)
if token == "" {
return "", ErrJWTMissing
}
return token, nil
}
}
// jwtFromCookie returns a `jwtExtractor` that extracts token from the named cookie.
func jwtFromCookie(name string) jwtExtractor {
return func(c echo.Context) (string, error) {
cookie, err := c.Cookie(name)
if err != nil {
return "", ErrJWTMissing
}
return cookie.Value, nil
}
}
// jwtFromForm returns a `jwtExtractor` that extracts token from the form field.
func jwtFromForm(name string) jwtExtractor {
return func(c echo.Context) (string, error) {
field := c.FormValue(name)
if field == "" {
return "", ErrJWTMissing
}
return field, nil
}
}