jwt/request/extractor.go

76 lines
1.8 KiB
Go

package request
import (
"errors"
"net/http"
)
// Errors
var (
ErrNoTokenInRequest = errors.New("no token present in request")
)
// Interface for extracting a token from an HTTP request
type Extractor interface {
ExtractToken(*http.Request) (string, error)
}
// Extract token from headers
type HeaderExtractor []string
func (e HeaderExtractor) ExtractToken(req *http.Request) (string, error) {
// loop over header names and return the first one that contains data
for _, header := range e {
if ah := req.Header.Get(header); ah != "" {
return ah, nil
}
}
return "", ErrNoTokenInRequest
}
// Extract token from request args
type ArgumentExtractor []string
func (e ArgumentExtractor) ExtractToken(req *http.Request) (string, error) {
// Make sure form is parsed
req.ParseMultipartForm(10e6)
// loop over arg names and return the first one that contains data
for _, arg := range e {
if ah := req.Form.Get(arg); ah != "" {
return ah, nil
}
}
return "", ErrNoTokenInRequest
}
// Tries extractors in order until one works or an error occurs
type MultiExtractor []Extractor
func (e MultiExtractor) ExtractToken(req *http.Request) (string, error) {
// loop over header names and return the first one that contains data
for _, extractor := range e {
if tok, err := extractor.ExtractToken(req); tok != "" {
return tok, nil
} else if err != ErrNoTokenInRequest {
return "", err
}
}
return "", ErrNoTokenInRequest
}
// Wrap an Extractor in this to post-process the value before it's handed off
type PostExtractionFilter struct {
Extractor
Filter func(string) (string, error)
}
func (e *PostExtractionFilter) ExtractToken(req *http.Request) (string, error) {
if tok, err := e.Extractor.ExtractToken(req); tok != "" {
return e.Filter(tok)
} else {
return "", err
}
}