release: 0.1.0: Phases 0-11: panel, Postfix/DKIM, milter, backup, Docker image

Initial feature-complete implementation of the v1.0 specification (phases 0-11 of `docs/implementation-plan.md`).
Added:
  - Panel (Go, single static binary) with SQLite persistence, one-time
  - Domain management with per-domain DKIM (RSA-2048, generated in pure Go) and
  - Application (sender identity) management: SASL credentials via `sasldb2`,
  - Full Postfix relay config generated from env at container start: SMTPS 465,
  - Journal milter (pure Go, `go-milter`) recording every send to `send_log`;
  … (6 more in CHANGELOG)

Full detail: CHANGELOG.md (0.1.0).

internal/web/handlers_account.go

@@ -0,0 +1,168 @@
+package web
+
+import (
+	"errors"
+	"net/http"
+	"strings"
+
+	"codeberg.org/mix/selfpost/internal/store"
+	"golang.org/x/crypto/bcrypt"
+)
+
+// handleAccount serves the administrator's own account settings: the username
+// and password chosen during setup are the only panel credentials (spec 7.6.1),
+// and until now they could be changed only by recreating the state. Changing
+// them here never touches application SASL logins, which are a separate
+// identity system (spec 5.1).
+func (s *Server) handleAccount(w http.ResponseWriter, r *http.Request) {
+	switch r.Method {
+	case http.MethodGet:
+		s.renderAccount(w, r, http.StatusOK, "", currentUser(r))
+	case http.MethodPost:
+		s.submitAccount(w, r)
+	default:
+		w.Header().Set("Allow", "GET, POST")
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+	}
+}
+
+// renderAccount draws the settings form. formUsername repopulates the username
+// field after a rejected submission; the password fields are never repopulated.
+func (s *Server) renderAccount(w http.ResponseWriter, r *http.Request, status int, formErr, formUsername string) {
+	s.render(w, status, "account", map[string]any{
+		"Title":        "SelfPost — account",
+		"User":         currentUser(r),
+		"Active":       "account",
+		"FormUsername": formUsername,
+		"Error":        formErr,
+		"Flash":        accountFlash(r),
+	})
+}
+
+// accountFlash maps a fixed redirect flag to a fixed message, so status text
+// after a redirect is never attacker-influenced.
+func accountFlash(r *http.Request) string {
+	switch r.URL.Query().Get("updated") {
+	case "username":
+		return "Username changed."
+	case "password":
+		return "Password changed. Any other signed-in sessions were signed out."
+	case "both":
+		return "Username and password changed. Any other signed-in sessions were signed out."
+	default:
+		return ""
+	}
+}
+
+// submitAccount applies a username and/or password change. The current password
+// is always required, so a stolen session alone cannot lock the administrator
+// out of their own panel, and the attempt is throttled on the same limiter as
+// the login form so this route cannot be used to brute-force the password past
+// that limit (spec 7.6.5).
+func (s *Server) submitAccount(w http.ResponseWriter, r *http.Request) {
+	if !s.loginLimiter.Allow(clientIP(r, s.trustedProxies)) {
+		s.renderAccount(w, r, http.StatusTooManyRequests,
+			"Too many attempts. Please wait and try again.", currentUser(r))
+		return
+	}
+	if err := r.ParseForm(); err != nil {
+		s.renderAccount(w, r, http.StatusBadRequest, "Invalid form submission.", currentUser(r))
+		return
+	}
+
+	username := strings.TrimSpace(r.PostFormValue("username"))
+	current := r.PostFormValue("current_password")
+	password := r.PostFormValue("new_password")
+	confirm := r.PostFormValue("new_password_confirm")
+
+	admin, err := s.store.GetAdmin()
+	if err != nil {
+		logf("panel: account: get admin failed: %v", err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+	if username == "" {
+		username = admin.Username
+	}
+
+	if err := bcrypt.CompareHashAndPassword([]byte(admin.PasswordHash), []byte(current)); err != nil {
+		s.renderAccount(w, r, http.StatusUnauthorized, "Current password is incorrect.", username)
+		return
+	}
+
+	renaming := username != admin.Username
+	if renaming {
+		if err := validateUsername(username); err != nil {
+			s.renderAccount(w, r, http.StatusBadRequest, err.Error(), username)
+			return
+		}
+	}
+
+	// An empty pair of new-password fields means "leave the password alone", so
+	// the username can be changed on its own.
+	repassword := password != "" || confirm != ""
+	if repassword {
+		if password != confirm {
+			s.renderAccount(w, r, http.StatusBadRequest, "New passwords do not match.", username)
+			return
+		}
+		if err := validateAdminPassword(password); err != nil {
+			s.renderAccount(w, r, http.StatusBadRequest, err.Error(), username)
+			return
+		}
+	}
+	if !renaming && !repassword {
+		s.renderAccount(w, r, http.StatusBadRequest,
+			"Nothing to change: enter a new username, a new password, or both.", username)
+		return
+	}
+
+	hash := admin.PasswordHash
+	if repassword {
+		newHash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+		if err != nil {
+			logf("panel: account: hashing password failed: %v", err)
+			s.renderAccount(w, r, http.StatusInternalServerError,
+				"Internal error. Please try again.", username)
+			return
+		}
+		hash = string(newHash)
+	}
+
+	if err := s.store.UpdateAdmin(username, hash); err != nil {
+		logf("panel: account: update admin failed: %v", err)
+		msg := "Could not save the changes. Please check the logs and try again."
+		if errors.Is(err, store.ErrNoAdmin) {
+			msg = "There is no administrator account to update."
+		}
+		s.renderAccount(w, r, http.StatusInternalServerError, msg, username)
+		return
+	}
+
+	// Keep this session usable under the new name, and — when the password
+	// changed — drop every other session so a cookie captured under the old
+	// password stops working.
+	if token, ok := s.sessionToken(r); ok {
+		if renaming {
+			s.sessions.Rename(token, username)
+		}
+		if repassword {
+			s.sessions.DestroyOthers(token)
+		}
+	}
+
+	logf("panel: administrator account updated (username changed: %t, password changed: %t)", renaming, repassword)
+	http.Redirect(w, r, "/account?updated="+updatedFlag(renaming, repassword), http.StatusSeeOther)
+}
+
+// updatedFlag names what changed, for the fixed post-redirect flash message.
+func updatedFlag(renamed, repassword bool) string {
+	switch {
+	case renamed && repassword:
+		return "both"
+	case renamed:
+		return "username"
+	default:
+		return "password"
+	}
+}