zitadel/internal/api/http/middleware/security_headers.go
2020-12-07 09:00:31 +01:00

101 lines
2.4 KiB
Go

package middleware
import (
"context"
"crypto/rand"
"encoding/base64"
"net/http"
http_utils "github.com/caos/zitadel/internal/api/http"
)
type securityKey int
const (
nonceKey securityKey = 0
DefaultNonceLength = uint(32)
)
func SecurityHeaders(csp *CSP, errorHandler func(error) http.Handler, nonceLength ...uint) func(http.Handler) http.Handler {
return func(handler http.Handler) http.Handler {
if csp == nil {
csp = &DefaultSCP
}
length := DefaultNonceLength
if len(nonceLength) > 0 {
length = nonceLength[0]
}
return &headers{
csp: csp,
handler: handler,
errorHandler: errorHandler,
nonceLength: length,
}
}
}
type headers struct {
csp *CSP
handler http.Handler
errorHandler func(err error) http.Handler
nonceLength uint
}
func (h *headers) ServeHTTP(w http.ResponseWriter, r *http.Request) {
nonce := GetNonce(r)
if nonce == "" {
var err error
nonce, err = generateNonce(h.nonceLength)
if err != nil {
errorHandler := h.errorHandler
if errorHandler == nil {
errorHandler = func(err error) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
})
}
}
errorHandler(err).ServeHTTP(w, r)
return
}
r = saveContext(r, nonceKey, nonce)
}
headers := w.Header()
headers.Set(http_utils.ContentSecurityPolicy, h.csp.Value(nonce))
headers.Set(http_utils.XXSSProtection, "1; mode=block")
headers.Set(http_utils.StrictTransportSecurity, "max-age=31536000; includeSubDomains")
headers.Set(http_utils.XFrameOptions, "DENY")
headers.Set(http_utils.XContentTypeOptions, "nosniff")
headers.Set(http_utils.ReferrerPolicy, "same-origin")
headers.Set(http_utils.FeaturePolicy, "payment 'none'")
headers.Set(http_utils.PermissionsPolicy, "payment=()")
//PLANNED: add expect-ct
h.handler.ServeHTTP(w, r)
}
func GetNonce(r *http.Request) string {
nonce, _ := getContext(r, nonceKey).(string)
return nonce
}
func generateNonce(length uint) (string, error) {
b := make([]byte, length)
_, err := rand.Read(b)
if err != nil {
return "", err
}
return base64.StdEncoding.EncodeToString(b), nil
}
func saveContext(r *http.Request, key, value interface{}) *http.Request {
ctx := context.WithValue(r.Context(), key, value)
return r.WithContext(ctx)
}
func getContext(r *http.Request, key interface{}) interface{} {
return r.Context().Value(key)
}