access-list: Hash basic-auth passwords and redact API reads (#18)

Closes #17.

- bcrypt-hash access-list item passwords on create/update
- redact password fields on API reads
- legacy plaintext still authenticates until re-saved
- gofmt api.go and engine.go

cmd/helix-proxy/api.go

@@ -5,6 +5,7 @@ import (
 	"log/slog"
 	"net/http"
 	"strconv"
+	"strings"
 
 	"helix-proxy/internal/auth"
 	"helix-proxy/internal/certificate"
@@ -107,7 +108,7 @@ func mountAPI(r chi.Router, st store.Store, eng *proxy.Engine, cm *certificate.M
 			}
 			_ = claims
 			w.Header().Set("Content-Type", "application/json")
-			_ = json.NewEncoder(w).Encode(st.GetAccessLists())
+			_ = json.NewEncoder(w).Encode(redactAccessLists(st.GetAccessLists()))
 		})
 		r.Post("/access-lists", func(w http.ResponseWriter, r *http.Request) {
 			claims, ok := auth.RequireAuth(w, r)
@@ -122,13 +123,17 @@ func mountAPI(r chi.Router, st store.Store, eng *proxy.Engine, cm *certificate.M
 			if payload.OwnerUserID == 0 {
 				payload.OwnerUserID = claims.UserID
 			}
+			if err := hashAccessListPasswords(&payload); err != nil {
+				http.Error(w, "password hash failed", 500)
+				return
+			}
 			created, err := st.CreateAccessList(payload)
 			if err != nil {
 				http.Error(w, err.Error(), 500)
 				return
 			}
 			w.WriteHeader(http.StatusCreated)
-			_ = json.NewEncoder(w).Encode(created)
+			_ = json.NewEncoder(w).Encode(redactAccessList(created))
 			eng.ReloadFromStore()
 			_, _ = st.AddAuditLog(store.AuditLog{
 				UserID:     claims.UserID,
@@ -153,7 +158,7 @@ func mountAPI(r chi.Router, st store.Store, eng *proxy.Engine, cm *certificate.M
 				return
 			}
 			if al, ok := st.GetAccessList(id); ok {
-				_ = json.NewEncoder(w).Encode(al)
+				_ = json.NewEncoder(w).Encode(redactAccessList(al))
 				return
 			}
 			http.Error(w, "not found", 404)
@@ -187,13 +192,29 @@ func mountAPI(r chi.Router, st store.Store, eng *proxy.Engine, cm *certificate.M
 			payload.OwnerUserID = existing.OwnerUserID
 			// preserve CreatedOn on update (server-set on create; do not lose on edit)
 			payload.CreatedOn = existing.CreatedOn
+			// Empty password on an item means "keep existing" when username matches.
+			for i := range payload.Items {
+				if payload.Items[i].Password != "" {
+					continue
+				}
+				for _, prev := range existing.Items {
+					if prev.Username == payload.Items[i].Username && prev.Password != "" {
+						payload.Items[i].Password = prev.Password
+						break
+					}
+				}
+			}
+			if err := hashAccessListPasswords(&payload); err != nil {
+				http.Error(w, "password hash failed", 500)
+				return
+			}
 			updated, err := st.UpdateAccessList(payload)
 			if err != nil {
 				http.Error(w, err.Error(), 500)
 				return
 			}
 			eng.ReloadFromStore()
-			_ = json.NewEncoder(w).Encode(updated)
+			_ = json.NewEncoder(w).Encode(redactAccessList(updated))
 			_, _ = st.AddAuditLog(store.AuditLog{
 				UserID:     claims.UserID,
 				ObjectType: "access-list",
@@ -1281,3 +1302,41 @@ func mountAPI(r chi.Router, st store.Store, eng *proxy.Engine, cm *certificate.M
 		})
 	})
 }
+
+func hashAccessListPasswords(al *store.AccessList) error {
+	for i := range al.Items {
+		pw := al.Items[i].Password
+		if pw == "" {
+			continue
+		}
+		if strings.HasPrefix(pw, "$2a$") || strings.HasPrefix(pw, "$2b$") || strings.HasPrefix(pw, "$2y$") {
+			continue
+		}
+		h, err := bcrypt.GenerateFromPassword([]byte(pw), bcrypt.DefaultCost)
+		if err != nil {
+			return err
+		}
+		al.Items[i].Password = string(h)
+	}
+	return nil
+}
+
+func redactAccessList(al store.AccessList) store.AccessList {
+	out := al
+	out.Items = make([]store.AccessItem, len(al.Items))
+	copy(out.Items, al.Items)
+	for i := range out.Items {
+		if out.Items[i].Password != "" {
+			out.Items[i].Password = ""
+		}
+	}
+	return out
+}
+
+func redactAccessLists(list []store.AccessList) []store.AccessList {
+	out := make([]store.AccessList, len(list))
+	for i, al := range list {
+		out[i] = redactAccessList(al)
+	}
+	return out
+}

internal/proxy/engine.go

@@ -5,6 +5,7 @@ import (
 	"crypto/tls"
 	"encoding/base64"
 	"fmt"
+	"golang.org/x/crypto/bcrypt"
 	"io"
 	"log/slog"
 	"net"
@@ -349,7 +350,7 @@ func (e *Engine) Handler() http.Handler {
 			user, pass := creds[0], creds[1]
 			authed := false
 			for _, item := range hcfg.AccessItems {
-				if item.Username == user && item.Password == pass { // demo: plain compare; real would hash
+				if item.Username == user && accessListPasswordOK(item.Password, pass) {
 					authed = true
 					break
 				}
@@ -1250,3 +1251,14 @@ func parseAdvancedConfig(adv string) (reqSets map[string]string, respAdds map[st
 	}
 	return
 }
+
+func accessListPasswordOK(stored, provided string) bool {
+	if stored == "" {
+		return false
+	}
+	if strings.HasPrefix(stored, "$2a$") || strings.HasPrefix(stored, "$2b$") || strings.HasPrefix(stored, "$2y$") {
+		return bcrypt.CompareHashAndPassword([]byte(stored), []byte(provided)) == nil
+	}
+	// Legacy plaintext rows until re-saved via admin API.
+	return stored == provided
+}