// WithAuthentication creates an http handler that tries to authenticate the given request as a user, and then
// stores any such user found onto the provided context for the request. If authentication fails or returns an error
// the failed handler is used. On success, "Authorization" header is removed from the request and handler
// is invoked to serve the request.
func WithAuthentication(handler http.Handler, mapper genericapirequest.RequestContextMapper, auth authenticator.Request, failed http.Handler) http.Handler {
if auth == nil {
glog.Warningf("Authentication is disabled")
return handler
}
return genericapirequest.WithRequestContext(
http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
user, ok, err := auth.AuthenticateRequest(req)
if err != nil || !ok {
if err != nil {
glog.Errorf("Unable to authenticate the request due to an error: %v", err)
}
failed.ServeHTTP(w, req)
return
}
// authorization header is not required anymore in case of a successful authentication.
req.Header.Del("Authorization")
if ctx, ok := mapper.Get(req); ok {
mapper.Update(req, genericapirequest.WithUser(ctx, user))
}
authenticatedUserCounter.WithLabelValues(compressUsername(user.GetName())).Inc()
handler.ServeHTTP(w, req)
}),
mapper,
)
}
// WithRequestInfo attaches a RequestInfo to the context.
func WithRequestInfo(handler http.Handler, resolver *request.RequestInfoFactory, requestContextMapper request.RequestContextMapper) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
ctx, ok := requestContextMapper.Get(req)
if !ok {
responsewriters.InternalError(w, req, errors.New("no context found for request"))
return
}
info, err := resolver.NewRequestInfo(req)
if err != nil {
responsewriters.InternalError(w, req, fmt.Errorf("failed to create RequestInfo: %v", err))
return
}
requestContextMapper.Update(req, request.WithRequestInfo(ctx, info))
handler.ServeHTTP(w, req)
})
}
// WithImpersonation is a filter that will inspect and check requests that attempt to change the user.Info for their requests
func WithImpersonation(handler http.Handler, requestContextMapper request.RequestContextMapper, a authorizer.Authorizer) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
impersonationRequests, err := buildImpersonationRequests(req.Header)
if err != nil {
glog.V(4).Infof("%v", err)
responsewriters.InternalError(w, req, err)
return
}
if len(impersonationRequests) == 0 {
handler.ServeHTTP(w, req)
return
}
ctx, exists := requestContextMapper.Get(req)
if !exists {
responsewriters.InternalError(w, req, errors.New("no context found for request"))
return
}
requestor, exists := request.UserFrom(ctx)
if !exists {
responsewriters.InternalError(w, req, errors.New("no user found for request"))
return
}
// if groups are not specified, then we need to look them up differently depending on the type of user
// if they are specified, then they are the authority
groupsSpecified := len(req.Header[authenticationapi.ImpersonateGroupHeader]) > 0
// make sure we're allowed to impersonate each thing we're requesting. While we're iterating through, start building username
// and group information
username := ""
groups := []string{}
userExtra := map[string][]string{}
for _, impersonationRequest := range impersonationRequests {
actingAsAttributes := &authorizer.AttributesRecord{
User: requestor,
Verb: "impersonate",
APIGroup: impersonationRequest.GetObjectKind().GroupVersionKind().Group,
Namespace: impersonationRequest.Namespace,
Name: impersonationRequest.Name,
ResourceRequest: true,
}
switch impersonationRequest.GetObjectKind().GroupVersionKind().GroupKind() {
case api.Kind("ServiceAccount"):
actingAsAttributes.Resource = "serviceaccounts"
username = serviceaccount.MakeUsername(impersonationRequest.Namespace, impersonationRequest.Name)
if !groupsSpecified {
// if groups aren't specified for a service account, we know the groups because its a fixed mapping. Add them
groups = serviceaccount.MakeGroupNames(impersonationRequest.Namespace, impersonationRequest.Name)
}
case api.Kind("User"):
actingAsAttributes.Resource = "users"
username = impersonationRequest.Name
case api.Kind("Group"):
actingAsAttributes.Resource = "groups"
groups = append(groups, impersonationRequest.Name)
case authenticationapi.Kind("UserExtra"):
extraKey := impersonationRequest.FieldPath
extraValue := impersonationRequest.Name
actingAsAttributes.Resource = "userextras"
actingAsAttributes.Subresource = extraKey
userExtra[extraKey] = append(userExtra[extraKey], extraValue)
default:
glog.V(4).Infof("unknown impersonation request type: %v", impersonationRequest)
responsewriters.Forbidden(actingAsAttributes, w, req, fmt.Sprintf("unknown impersonation request type: %v", impersonationRequest))
return
}
allowed, reason, err := a.Authorize(actingAsAttributes)
if err != nil || !allowed {
glog.V(4).Infof("Forbidden: %#v, Reason: %s, Error: %v", req.RequestURI, reason, err)
responsewriters.Forbidden(actingAsAttributes, w, req, reason)
return
}
}
newUser := &user.DefaultInfo{
Name: username,
Groups: groups,
Extra: userExtra,
}
requestContextMapper.Update(req, request.WithUser(ctx, newUser))
oldUser, _ := request.UserFrom(ctx)
httplog.LogOf(req, w).Addf("%v is acting as %v", oldUser, newUser)
// clear all the impersonation headers from the request
req.Header.Del(authenticationapi.ImpersonateUserHeader)
req.Header.Del(authenticationapi.ImpersonateGroupHeader)
for headerName := range req.Header {
if strings.HasPrefix(headerName, authenticationapi.ImpersonateUserExtraHeaderPrefix) {
req.Header.Del(headerName)
}
}
handler.ServeHTTP(w, req)
})
}