Add Cache-Control: private, no-store HTTP header to server endpoints that respond with sensitive info.

Fixes smallstep#793

Author: km274

acme/api/account.go

@@ -162,6 +162,7 @@ func NewAccount(w http.ResponseWriter, r *http.Request) {
 	linker.LinkAccount(ctx, acc)
 
 	w.Header().Set("Location", getAccountLocationPath(ctx, linker, acc.ID))
+	w.Header().Set("Cache-Control", "private, no-store")
 	render.JSONStatus(w, acc, httpStatus)
 }
 
@@ -212,6 +213,7 @@ func GetOrUpdateAccount(w http.ResponseWriter, r *http.Request) {
 	linker.LinkAccount(ctx, acc)
 
 	w.Header().Set("Location", linker.GetLink(ctx, acme.AccountLinkType, acc.ID))
+	w.Header().Set("Cache-Control", "private, no-store")
 	render.JSON(w, acc)
 }
 

acme/api/handler.go

@@ -306,6 +306,7 @@ func GetAuthorization(w http.ResponseWriter, r *http.Request) {
 	linker.LinkAuthorization(ctx, az)
 
 	w.Header().Set("Location", linker.GetLink(ctx, acme.AuthzLinkType, az.ID))
+	w.Header().Set("Cache-Control", "private, no-store")
 	render.JSON(w, az)
 }
 
@@ -359,6 +360,7 @@ func GetChallenge(w http.ResponseWriter, r *http.Request) {
 
 	w.Header().Add("Link", link(linker.GetLink(ctx, acme.AuthzLinkType, azID), "up"))
 	w.Header().Set("Location", linker.GetLink(ctx, acme.ChallengeLinkType, azID, ch.ID))
+	w.Header().Set("Cache-Control", "private, no-store")
 	render.JSON(w, ch)
 }
 

authority/admin/api/provisioner.go

@@ -55,6 +55,8 @@ func GetProvisioner(w http.ResponseWriter, r *http.Request) {
 		render.Error(w, err)
 		return
 	}
+
+	w.Header().Set("Cache-Control", "private, no-store")
 	render.ProtoJSON(w, prov)
 }
 
@@ -72,6 +74,7 @@ func GetProvisioners(w http.ResponseWriter, r *http.Request) {
 		render.Error(w, errs.InternalServerErr(err))
 		return
 	}
+
 	render.JSON(w, &GetProvisionersResponse{
 		Provisioners: p,
 		NextCursor:   next,
@@ -102,6 +105,8 @@ func CreateProvisioner(w http.ResponseWriter, r *http.Request) {
 		render.Error(w, admin.WrapErrorISE(err, "error storing provisioner %s", prov.Name))
 		return
 	}
+
+	w.Header().Set("Cache-Control", "private, no-store")
 	render.ProtoJSONStatus(w, prov, http.StatusCreated)
 }
 
@@ -198,6 +203,8 @@ func UpdateProvisioner(w http.ResponseWriter, r *http.Request) {
 		render.Error(w, err)
 		return
 	}
+
+	w.Header().Set("Cache-Control", "private, no-store")
 	render.ProtoJSON(w, nu)
 }
 

authority/admin/api/webhook.go

@@ -127,6 +127,7 @@ func (war *webhookAdminResponder) CreateProvisionerWebhook(w http.ResponseWriter
 		return
 	}
 
+	w.Header().Set("Cache-Control", "private, no-store")
 	render.ProtoJSONStatus(w, newWebhook, http.StatusCreated)
 }
 
@@ -231,5 +232,7 @@ func (war *webhookAdminResponder) UpdateProvisionerWebhook(w http.ResponseWriter
 		Auth:                 newWebhook.Auth,
 		DisableTlsClientAuth: newWebhook.DisableTlsClientAuth,
 	}
+
+	w.Header().Set("Cache-Control", "private, no-store")
 	render.ProtoJSONStatus(w, whResponse, http.StatusCreated)
 }

scep/api/api.go

@@ -359,6 +359,7 @@ func writeResponse(w http.ResponseWriter, res Response) {
 	}
 
 	w.Header().Set("Content-Type", contentHeader(res))
+	w.Header().Set("Cache-Control", "private, no-store")
 	_, _ = w.Write(res.Data)
 }