Initial commit

internal/server/delete.go

@@ -0,0 +1,79 @@
+package server
+
+import (
+	"net/http"
+	"strings"
+
+	"send/internal/auth"
+	"send/internal/store"
+)
+
+// handleDelete removes an object early. Three credentials are accepted: the
+// delete token handed to the uploader, the token that owns the object, and any
+// admin token.
+//
+// There is only one delete route, and it is a POST, so the success page's plain
+// form works with scripting disabled and no second code path is needed.
+func (s *Server) handleDelete(w http.ResponseWriter, r *http.Request) {
+	id, err := store.CleanID(r.PathValue("id"))
+	if err != nil {
+		s.fail(w, r, http.StatusNotFound, "No such file.")
+		return
+	}
+	m, err := s.store.Get(id, s.now())
+	if err != nil {
+		s.fail(w, r, http.StatusNotFound, "No such file.")
+		return
+	}
+
+	secret := bearer(r)
+	if secret == "" {
+		// A small form post; the 4 KiB cap keeps this from being a way to
+		// stream a body into memory.
+		r.Body = http.MaxBytesReader(w, r.Body, maxFieldBytes)
+		if err := r.ParseForm(); err == nil {
+			secret = strings.TrimSpace(r.PostFormValue("token"))
+		}
+	}
+	if secret == "" {
+		s.fail(w, r, http.StatusUnauthorized, "A delete token or an owning token is required.")
+		return
+	}
+
+	if !s.mayDelete(m, secret) {
+		s.fail(w, r, http.StatusForbidden, "That token cannot delete this file.")
+		return
+	}
+	if err := s.store.Delete(id); err != nil {
+		s.log.Error("deleting object", "id", id, "err", err)
+		s.fail(w, r, http.StatusInternalServerError, "Could not delete the file.")
+		return
+	}
+	s.log.Info("deleted", "id", id, "ip", clientIP(r, s.cfg))
+
+	if wantsJSON(r) {
+		writeJSON(w, http.StatusOK, map[string]string{"status": "deleted", "id": id})
+		return
+	}
+	s.render(w, http.StatusOK, "error.html", errorPage{
+		page:    s.page("Deleted", false),
+		Status:  "Deleted",
+		Message: "The file is gone.",
+	})
+}
+
+// mayDelete checks the presented secret against the object's delete token
+// first, then against the token file.
+func (s *Server) mayDelete(m *store.Meta, secret string) bool {
+	if auth.EqualHash(m.DeleteHash, auth.HashSecret(secret)) {
+		return true
+	}
+	if err := s.tokens.MaybeReload(); err != nil {
+		s.log.Error("reloading token file", "err", err)
+	}
+	t := s.tokens.Lookup(secret)
+	if t == nil {
+		return false
+	}
+	return t.Admin || (m.Owner != "" && t.Name == m.Owner)
+}