Server keys in etc/, bind in docker compose

- bin/gen-server-keys.sh: generate Ed25519 keypair to etc/server-service.{pub,key,env}
- main.go: read keys from file (ADMIN_PUBLIC_KEY_FILE) when env empty
- docker-compose: env_file etc/server-service.env, mount etc/
- bin/up.sh: auto-run gen-server-keys if etc/server-service.env missing
- ErrRegistrationNotConfigured for clearer 503 when keys not set
- etc/README.md, etc/.gitignore
- bin/gen-admin-key.sh for one-off key gen
- .env.example

Made-with: Cursor

.env.example

@@ -0,0 +1,6 @@
+# Required for registration-by-signature and bootstrap admin.
+# Generate with: ./bin/gen-admin-key.sh
+ADMIN_PUBLIC_KEY=
+
+# Optional: override service key for registration (defaults to ADMIN_PUBLIC_KEY)
+# SERVICE_PUBLIC_KEY=

AGENTS.md

@@ -13,6 +13,7 @@ This file gives future coding agents a fast path map for this repository.
 - TypeScript API client: `libs/geo-api-client/`
 - CI workflow: `.gitea/workflows/ci.yml`
 - Architecture/planning docs: `docs/`
+- Server keys: `etc/` (generated by `./bin/gen-server-keys.sh`)
 
 ## Most common commands
 
@@ -21,7 +22,8 @@ From repo root:
 ```bash
 go test ./...
 go run ./cmd/api
-docker compose up --build -d
+./bin/gen-server-keys.sh   # before first docker up (creates etc/server-service.*)
+./bin/up.sh                # or: docker compose up --build -d
 docker compose down
 docker compose --profile test run --rm test   # run tests as root (avoids var/ permission issues)
 ```

README.md

@@ -33,17 +33,22 @@ Local default (for development): `http://localhost:8122`.
 Optional environment variables:
 
 - `ADDR` (default `:8122`)
-- `ADMIN_PUBLIC_KEY` (bootstrap initial inviter/admin user)
+- `ADMIN_PUBLIC_KEY` — **required for registration**: bootstrap admin + service key for `register-by-signature`. Generate with `./bin/gen-admin-key.sh`
 - `SERVICE_PUBLIC_KEY` (public key users sign to register; defaults to `ADMIN_PUBLIC_KEY`)
 
+**Deployment:** Set `ADMIN_PUBLIC_KEY` before starting. Without it, `/v1/service-key` returns 503 and registration is disabled.
+
 ## Docker Compose
 
-Build and run the backend service:
+Generate server keys (creates `etc/server-service.*`), then build and run:
 
 ```bash
+./bin/gen-server-keys.sh
 COMPOSE_BAKE=true docker compose up --build -d
 ```
 
+Or use `./bin/up.sh` which runs the key generation if needed.
+
 This starts:
 
 - `db` (`postgis/postgis`) on `5432`

bin/gen-admin-key.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+# Generate Ed25519 keypair for ADMIN_PUBLIC_KEY (one-off, prints to stdout).
+# For etc/ + docker compose, use ./bin/gen-server-keys.sh instead.
+set -e
+cd "$(dirname "$0")/.."
+(cd libs/geo-api-client && bun run build 2>/dev/null) || true
+cd libs/geo-api-client
+bun -e "
+import { generateKeyPair } from './dist/index.js';
+const k = await generateKeyPair();
+console.log('ADMIN_PUBLIC_KEY=' + k.publicKey);
+console.log('# Private key (keep secret, bootstrap only): ' + k.privateKey);
+"

bin/gen-server-keys.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+# Generate server-service Ed25519 keypair. Output in etc/ for docker compose.
+# Clients download the public key via GET /v1/service-key.
+set -e
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+mkdir -p "$ROOT/etc"
+(cd "$ROOT/libs/geo-api-client" && bun run build 2>/dev/null) || true
+cd "$ROOT/libs/geo-api-client"
+OUT=$(bun -e "
+import { generateKeyPair } from './dist/index.js';
+const k = await generateKeyPair();
+console.log(k.publicKey);
+console.log(k.privateKey);
+")
+PUB=$(echo "$OUT" | head -1)
+PRIV=$(echo "$OUT" | tail -1)
+echo "$PUB" > "$ROOT/etc/server-service.pub"
+echo "$PRIV" > "$ROOT/etc/server-service.key"
+echo "ADMIN_PUBLIC_KEY=$PUB" > "$ROOT/etc/server-service.env"
+echo "SERVICE_PUBLIC_KEY=$PUB" >> "$ROOT/etc/server-service.env"
+chmod 600 "$ROOT/etc/server-service.key" "$ROOT/etc/server-service.env" 2>/dev/null || true
+echo "Wrote etc/server-service.pub, etc/server-service.key, etc/server-service.env"

bin/up.sh

@@ -1,4 +1,8 @@
 #!/bin/bash
 set -e
 cd "$(dirname "$0")/.."
+if [ ! -f etc/server-service.env ]; then
+  echo "Generating server keys (etc/server-service.env)..."
+  ./bin/gen-server-keys.sh
+fi
 docker compose up --build -d

cmd/api/main.go

@@ -4,6 +4,7 @@ import (
 	"log"
 	"net/http"
 	"os"
+	"strings"
 	"time"
 
 	"momswap/backend/internal/app"
@@ -16,6 +17,16 @@ func main() {
 	adminPublicKey := os.Getenv("ADMIN_PUBLIC_KEY")
 	servicePublicKey := getEnv("SERVICE_PUBLIC_KEY", adminPublicKey)
 
+	if adminPublicKey == "" {
+		adminPublicKey = readKeyFile(getEnv("ADMIN_PUBLIC_KEY_FILE", "etc/server-service.pub"))
+	}
+	if servicePublicKey == "" {
+		servicePublicKey = readKeyFile(getEnv("SERVICE_PUBLIC_KEY_FILE", "etc/server-service.pub"))
+	}
+	if servicePublicKey == "" {
+		servicePublicKey = adminPublicKey
+	}
+
 	memory := store.NewMemoryStore()
 	service := app.NewService(memory, app.Config{
 		ChallengeTTL: 5 * time.Minute,
@@ -37,3 +48,11 @@ func getEnv(key, fallback string) string {
 	}
 	return v
 }
+
+func readKeyFile(path string) string {
+	b, err := os.ReadFile(path)
+	if err != nil {
+		return ""
+	}
+	return strings.TrimSpace(string(b))
+}

docker-compose.yml

@@ -23,10 +23,14 @@ services:
       target: runtime
     image: momswap-backend:latest
     container_name: momswap-backend-api
+    env_file:
+      - etc/server-service.env
     environment:
       ADDR: ":8122"
       ADMIN_PUBLIC_KEY: "${ADMIN_PUBLIC_KEY:-}"
       DATABASE_URL: "postgres://${POSTGRES_USER:-momswap}:${POSTGRES_PASSWORD:-momswap}@db:5432/${POSTGRES_DB:-momswap}?sslmode=disable"
+    volumes:
+      - ./etc:/app/etc:ro
     depends_on:
       db:
         condition: service_healthy
@@ -42,10 +46,14 @@ services:
       target: dev
     image: momswap-backend:dev
     container_name: momswap-backend-api-dev
+    env_file:
+      - etc/server-service.env
     environment:
       ADDR: ":8122"
       ADMIN_PUBLIC_KEY: "${ADMIN_PUBLIC_KEY:-}"
       DATABASE_URL: "postgres://${POSTGRES_USER:-momswap}:${POSTGRES_PASSWORD:-momswap}@db:5432/${POSTGRES_DB:-momswap}?sslmode=disable"
+    volumes:
+      - ./etc:/src/etc:ro
     depends_on:
       db:
         condition: service_healthy

docs/typescript-frontend-integration.md

@@ -68,10 +68,12 @@ Key methods:
 
 When `SERVICE_PUBLIC_KEY` (or `ADMIN_PUBLIC_KEY`) is set, users can register without an invitation:
 
-1. `GET /v1/service-key` — fetch the API public key to sign.
+1. `GET /v1/service-key` — fetch the server public key (clients use this for registration and further signed communication).
 2. Sign that key with your private key.
 3. `POST /v1/auth/register-by-signature` with `{ publicKey, signature }`.
 
+Server keys are generated with `./bin/gen-server-keys.sh` and stored in `etc/`.
+
 ## Example (TypeScript app)
 
 ```ts

etc/.gitignore

@@ -0,0 +1,3 @@
+server-service.pub
+server-service.key
+server-service.env

etc/README.md

@@ -0,0 +1,26 @@
+# Server Service Keys
+
+Server Ed25519 keypair for client authentication and registration.
+
+## Generate
+
+```bash
+./bin/gen-server-keys.sh
+```
+
+Creates:
+
+- `server-service.pub` — public key; clients download via `GET /v1/service-key`
+- `server-service.key` — private key (keep secret)
+- `server-service.env` — env vars for docker compose (`ADMIN_PUBLIC_KEY`, `SERVICE_PUBLIC_KEY`)
+
+## Client Usage
+
+Clients fetch the server public key and use it to:
+
+1. **Register** — sign the server pubkey, post to `POST /v1/auth/register-by-signature`
+2. **Verify server identity** — for future signed responses or request validation
+
+## Docker Compose
+
+The api service uses `env_file: etc/server-service.env` and mounts `./etc` so keys are available. Run `./bin/gen-server-keys.sh` before first `docker compose up`.

internal/app/service.go

@@ -15,6 +15,7 @@ var (
 	ErrUnauthorized              = errors.New("unauthorized")
 	ErrForbidden                 = errors.New("forbidden")
 	ErrBadRequest                = errors.New("bad request")
+	ErrRegistrationNotConfigured = errors.New("registration by signature not configured; set ADMIN_PUBLIC_KEY")
 	ErrInviteInvalid             = errors.New("invite invalid")
 	ErrInviteExpired             = errors.New("invite expired")
 	ErrInviteExhaust             = errors.New("invite exhausted")
@@ -62,7 +63,7 @@ func (s *Service) ServicePublicKey() string {
 
 func (s *Service) RegisterBySignature(publicKey, signature string) error {
 	if s.servicePublicKey == "" {
-		return fmt.Errorf("%w: registration by signature not configured", ErrBadRequest)
+		return ErrRegistrationNotConfigured
 	}
 	if publicKey == "" {
 		return fmt.Errorf("%w: missing public key", ErrBadRequest)

internal/http/handlers.go

@@ -88,6 +88,8 @@ func statusFromErr(err error) int {
 		return http.StatusBadRequest
 	case errors.Is(err, app.ErrAlreadyUser):
 		return http.StatusConflict
+	case errors.Is(err, app.ErrRegistrationNotConfigured):
+		return http.StatusServiceUnavailable
 	case errors.Is(err, app.ErrInviteInvalid),
 		errors.Is(err, app.ErrInviteExpired),
 		errors.Is(err, app.ErrInviteExhaust):
@@ -165,7 +167,7 @@ func (a *API) login(w http.ResponseWriter, r *http.Request) {
 func (a *API) getServiceKey(w http.ResponseWriter, _ *http.Request) {
 	pk := a.service.ServicePublicKey()
 	if pk == "" {
-		writeErr(w, app.ErrBadRequest)
+		writeErr(w, app.ErrRegistrationNotConfigured)
 		return
 	}
 	writeJSON(w, http.StatusOK, map[string]string{"publicKey": pk})

web/app.js

@@ -47,7 +47,7 @@ createApp({
         try {
           await client.registerBySigningServiceKey(state.publicKey, state.privateKey);
         } catch (err) {
-          if (!err.message.includes("already registered") && !err.message.includes("not configured")) {
+          if (!err.message.includes("already registered") && !err.message.includes("not configured") && !err.message.includes("ADMIN_PUBLIC_KEY")) {
             throw err;
           }
           // Proceed to login: already registered or registration disabled (invitation flow)