linx-server/auth/apikeys/apikeys.go

155 lines
3.1 KiB
Go

package apikeys
import (
"bufio"
"encoding/base64"
"fmt"
"log"
"net/http"
"os"
"golang.org/x/crypto/scrypt"
"github.com/zenazn/goji/web"
)
const (
scryptSalt = "linx-server"
scryptN = 16384
scryptr = 8
scryptp = 1
scryptKeyLen = 32
)
type AuthOptions struct {
AuthFile string
UnauthMethods []string
BasicAuth bool
SiteName string
SitePath string
}
type ApiKeysMiddleware struct {
successHandler http.Handler
authKeys []string
o AuthOptions
}
func ReadAuthKeys(authFile string) []string {
var authKeys []string
f, err := os.Open(authFile)
if err != nil {
log.Fatal("Failed to open authfile: ", err)
}
defer f.Close()
scanner := bufio.NewScanner(f)
for scanner.Scan() {
authKeys = append(authKeys, scanner.Text())
}
err = scanner.Err()
if err != nil {
log.Fatal("Scanner error while reading authfile: ", err)
}
return authKeys
}
func CheckAuth(authKeys []string, key string) (result bool, err error) {
checkKey, err := scrypt.Key([]byte(key), []byte(scryptSalt), scryptN, scryptr, scryptp, scryptKeyLen)
if err != nil {
return
}
encodedKey := base64.StdEncoding.EncodeToString(checkKey)
for _, v := range authKeys {
if encodedKey == v {
result = true
return
}
}
result = false
return
}
func (a ApiKeysMiddleware) getSitePrefix() string {
prefix := a.o.SitePath
if len(prefix) <= 0 || prefix[0] != '/' {
prefix = "/" + prefix
}
return prefix
}
func (a ApiKeysMiddleware) goodAuthorizationHandler(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Location", a.getSitePrefix())
w.WriteHeader(http.StatusFound)
}
func (a ApiKeysMiddleware) badAuthorizationHandler(w http.ResponseWriter, r *http.Request) {
if a.o.BasicAuth {
rs := ""
if a.o.SiteName != "" {
rs = fmt.Sprintf(` realm="%s"`, a.o.SiteName)
}
w.Header().Set("WWW-Authenticate", `Basic`+rs)
}
http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
}
func (a ApiKeysMiddleware) ServeHTTP(w http.ResponseWriter, r *http.Request) {
var successHandler http.Handler
prefix := a.getSitePrefix()
if r.URL.Path == prefix+"auth" {
successHandler = http.HandlerFunc(a.goodAuthorizationHandler)
} else {
successHandler = a.successHandler
}
if sliceContains(a.o.UnauthMethods, r.Method) && r.URL.Path != prefix+"auth" {
// allow unauthenticated methods
successHandler.ServeHTTP(w, r)
return
}
key := r.Header.Get("Linx-Api-Key")
if key == "" && a.o.BasicAuth {
_, password, ok := r.BasicAuth()
if ok {
key = password
}
}
result, err := CheckAuth(a.authKeys, key)
if err != nil || !result {
http.HandlerFunc(a.badAuthorizationHandler).ServeHTTP(w, r)
return
}
successHandler.ServeHTTP(w, r)
}
func NewApiKeysMiddleware(o AuthOptions) func(*web.C, http.Handler) http.Handler {
fn := func(c *web.C, h http.Handler) http.Handler {
return ApiKeysMiddleware{
successHandler: h,
authKeys: ReadAuthKeys(o.AuthFile),
o: o,
}
}
return fn
}
func sliceContains(slice []string, s string) bool {
for _, v := range slice {
if s == v {
return true
}
}
return false
}