First Commit

internal/api/http.go

@@ -0,0 +1,458 @@
+package api
+
+import (
+	"crypto/hmac"
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/tls"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"greencoast/internal/index"
+	"greencoast/internal/storage"
+)
+
+// ----------- Auth Providers & config (SSO / 2FA stubs) ------------
+
+type DiscordProvider struct {
+	Enabled      bool
+	ClientID     string
+	ClientSecret string
+	RedirectURI  string
+}
+
+type AuthProviders struct {
+	SigningSecretHex string
+	Discord          DiscordProvider
+	GoogleEnabled    bool // placeholder
+	FacebookEnabled  bool // placeholder
+	WebAuthnEnabled  bool // placeholder
+	TOTPEnabled      bool // placeholder
+}
+
+// ----------- SSE hub (live index) ------------
+
+type sseEvent struct {
+	Event string      `json:"event"` // "put" | "delete"
+	Data  interface{} `json:"data"`
+}
+
+type hub struct {
+	mu   sync.Mutex
+	subs map[chan []byte]struct{}
+}
+
+func newHub() *hub { return &hub{subs: make(map[chan []byte]struct{})} }
+
+func (h *hub) subscribe() (ch chan []byte, cancel func()) {
+	ch = make(chan []byte, 16)
+	h.mu.Lock(); h.subs[ch] = struct{}{}; h.mu.Unlock()
+	cancel = func() { h.mu.Lock(); if _, ok := h.subs[ch]; ok { delete(h.subs, ch); close(ch) }; h.mu.Unlock() }
+	return ch, cancel
+}
+func (h *hub) broadcast(ev sseEvent) {
+	b, _ := json.Marshal(ev)
+	line := append([]byte("data: "), b...)
+	line = append(line, '\n', '\n')
+	h.mu.Lock()
+	for ch := range h.subs {
+		select { case ch <- line: default: }
+	}
+	h.mu.Unlock()
+}
+
+// ----------- Server ------------
+
+type Server struct {
+	mux       *http.ServeMux
+	store     *storage.FSStore
+	idx       *index.Index
+	coarseTS  bool
+	zeroTrust bool
+
+	signingSecret []byte
+	discord       DiscordProvider
+
+	devAllow bool
+	devToken string
+
+	live *hub
+}
+
+func New(store *storage.FSStore, idx *index.Index, coarseTimestamps bool, zeroTrust bool, auth AuthProviders) *Server {
+	devAllow := strings.ToLower(os.Getenv("GC_DEV_ALLOW_UNAUTH")) == "true"
+	devToken := os.Getenv("GC_DEV_BEARER")
+	if devToken == "" { devToken = "dev-local-token" }
+
+	sec := make([]byte, 0)
+	if auth.SigningSecretHex != "" {
+		if b, err := hex.DecodeString(auth.SigningSecretHex); err == nil { sec = b }
+	}
+
+	s := &Server{
+		mux:           http.NewServeMux(),
+		store:         store,
+		idx:           idx,
+		coarseTS:      coarseTimestamps,
+		zeroTrust:     zeroTrust,
+		signingSecret: sec,
+		discord:       auth.Discord,
+		devAllow:      devAllow,
+		devToken:      devToken,
+		live:          newHub(),
+	}
+	s.routes()
+	return s
+}
+
+// ---------- middleware helpers (privacy, CORS, auth) ----------
+
+func (s *Server) secureHeaders(w http.ResponseWriter) {
+	// Anti-fingerprinting posture: do not echo request details; set strict policies.
+	w.Header().Set("Referrer-Policy", "no-referrer")
+	w.Header().Set("Permissions-Policy", "camera=(), microphone=(), geolocation=(), interest-cohort=(), browsing-topics=()")
+	w.Header().Set("X-Content-Type-Options", "nosniff")
+	w.Header().Set("X-Frame-Options", "DENY")
+	w.Header().Set("Cross-Origin-Opener-Policy", "same-origin")
+	w.Header().Set("Cross-Origin-Resource-Policy", "same-site")
+	// CORS: allow simple cross-origin usage without credentials (we do not use cookies).
+	w.Header().Set("Access-Control-Allow-Origin", "*")
+	w.Header().Set("Access-Control-Allow-Headers", "Authorization, Content-Type, X-GC-Private, X-GC-3P-Assent")
+	w.Header().Set("Access-Control-Allow-Methods", "GET, PUT, DELETE, OPTIONS")
+	// No-store by default (content blobs may be large but not user-identifying)
+	w.Header().Set("Cache-Control", "no-store")
+	// HSTS is meaningful over HTTPS; harmless otherwise.
+	w.Header().Set("Strict-Transport-Security", "max-age=15552000; includeSubDomains; preload")
+}
+
+func (s *Server) with(w http.ResponseWriter, r *http.Request, handler func(http.ResponseWriter, *http.Request)) {
+	s.secureHeaders(w)
+	// Handle CORS preflight
+	if r.Method == http.MethodOptions {
+		w.WriteHeader(http.StatusNoContent)
+		return
+	}
+	handler(w, r)
+}
+
+func (s *Server) auth(next http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		s.secureHeaders(w)
+		if !s.zeroTrust {
+			next.ServeHTTP(w, r); return
+		}
+		authz := r.Header.Get("Authorization")
+
+		// Dev bypass if explicitly enabled
+		if s.devAllow {
+			if authz == "" || authz == "Bearer "+s.devToken {
+				next.ServeHTTP(w, r); return
+			}
+		}
+		if !strings.HasPrefix(authz, "Bearer ") {
+			http.Error(w, "unauthorized", http.StatusUnauthorized); return
+		}
+		if len(s.signingSecret) == 0 {
+			// If no signing secret configured, accept presence only (dev posture).
+			next.ServeHTTP(w, r); return
+		}
+		token := strings.TrimPrefix(authz, "Bearer ")
+		if ok := s.verifyShardToken(token); !ok {
+			http.Error(w, "unauthorized", http.StatusUnauthorized); return
+		}
+		next.ServeHTTP(w, r)
+	}
+}
+
+// ---------- shard token (HMAC, short-lived) ----------
+
+// Format: gc|prov|sub|expEpoch|hex(hmacSHA256(secret, prov+'|'+sub+'|'+exp))
+func (s *Server) signShardToken(provider, subject string, exp time.Time) (string, error) {
+	if len(s.signingSecret) == 0 {
+		return "", errors.New("signing disabled (missing auth.signing_secret)")
+	}
+	msg := provider + "|" + subject + "|" + fmt.Sprint(exp.Unix())
+	mac := hmac.New(sha256.New, s.signingSecret)
+	_, _ = mac.Write([]byte(msg))
+	sig := hex.EncodeToString(mac.Sum(nil))
+	return "gc|" + msg + "|" + sig, nil
+}
+func (s *Server) verifyShardToken(tok string) bool {
+	parts := strings.Split(tok, "|")
+	if len(parts) != 5 || parts[0] != "gc" { return false }
+	prov, sub, expStr, sig := parts[1], parts[2], parts[3], parts[4]
+	msg := prov + "|" + sub + "|" + expStr
+	mac := hmac.New(sha256.New, s.signingSecret)
+	_, _ = mac.Write([]byte(msg))
+	want := hex.EncodeToString(mac.Sum(nil))
+	if !hmac.Equal([]byte(want), []byte(sig)) { return false }
+	// expiry
+	secs, err := time.ParseDuration(expStr + "s")
+	if err != nil {
+		// expStr is epoch; parse manually
+		epoch, e2 := time.ParseDuration("0s"); _ = epoch; _ = e2
+	}
+	// treat expStr as epoch seconds
+	var expUnix int64
+	fmt.Sscan(expStr, &expUnix)
+	return time.Now().UTC().Unix() < expUnix
+}
+
+// ---------- routes ----------
+
+func (s *Server) routes() {
+	s.mux.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
+		s.with(w, r, func(w http.ResponseWriter, _ *http.Request) {
+			w.WriteHeader(http.StatusOK)
+			_, _ = w.Write([]byte("ok"))
+		})
+	})
+
+	// PUT object (opaque). Client may flag privacy in index via X-GC-Private: 1.
+	s.mux.HandleFunc("/v1/object", s.auth(func(w http.ResponseWriter, r *http.Request) {
+		s.with(w, r, func(w http.ResponseWriter, r *http.Request) {
+			if r.Method != http.MethodPut {
+				http.Error(w, "method not allowed", http.StatusMethodNotAllowed); return
+			}
+			isPrivate := strings.TrimSpace(r.Header.Get("X-GC-Private")) == "1"
+			hash, n, err := s.store.Put(r.Body)
+			if err != nil { http.Error(w, err.Error(), http.StatusBadRequest); return }
+			ts := s.nowCoarse()
+			_ = s.idx.AppendPut(index.Entry{
+				Hash: hash, Bytes: n, StoredAt: s.parseRFC3339(ts), Private: isPrivate,
+			})
+			s.live.broadcast(sseEvent{Event: "put", Data: map[string]any{
+				"hash": hash, "bytes": n, "stored_at": ts, "private": isPrivate,
+			}})
+			w.Header().Set("Content-Type", "application/json")
+			fmt.Fprintf(w, `{"ok":true,"hash":"%s","bytes":%d,"stored_at":"%s"}`, hash, n, ts)
+		})
+	}))
+
+	// GET/DELETE object by hash
+	s.mux.HandleFunc("/v1/object/", s.auth(func(w http.ResponseWriter, r *http.Request) {
+		s.with(w, r, func(w http.ResponseWriter, r *http.Request) {
+			switch r.Method {
+			case http.MethodGet:
+				hash := strings.TrimPrefix(r.URL.Path, "/v1/object/")
+				p, err := s.store.Get(hash)
+				if err != nil { http.NotFound(w, r); return }
+				f, err := os.Open(p)
+				if err != nil { http.Error(w, "open error", http.StatusInternalServerError); return }
+				defer f.Close()
+				w.Header().Set("Content-Type", "application/octet-stream")
+				_, _ = io.Copy(w, f)
+			case http.MethodDelete:
+				hash := strings.TrimPrefix(r.URL.Path, "/v1/object/")
+				if err := s.store.Delete(hash); err != nil { http.NotFound(w, r); return }
+				_ = s.idx.AppendDelete(hash)
+				s.live.broadcast(sseEvent{Event: "delete", Data: map[string]any{"hash": hash}})
+				w.Header().Set("Content-Type", "application/json")
+				_, _ = w.Write([]byte(`{"ok":true,"deleted":true}`))
+			default:
+				http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			}
+		})
+	}))
+
+	// Index snapshot
+	s.mux.HandleFunc("/v1/index", s.auth(func(w http.ResponseWriter, r *http.Request) {
+		s.with(w, r, func(w http.ResponseWriter, r *http.Request) {
+			if r.Method != http.MethodGet { http.Error(w, "method not allowed", http.StatusMethodNotAllowed); return }
+			entries, err := s.idx.Snapshot()
+			if err != nil { http.Error(w, err.Error(), 500); return }
+			sort.Slice(entries, func(i, j int) bool { return entries[i].StoredAt.After(entries[j].StoredAt) })
+			w.Header().Set("Content-Type", "application/json")
+			_ = json.NewEncoder(w).Encode(entries)
+		})
+	}))
+
+	// Index live (SSE)
+	s.mux.HandleFunc("/v1/index/stream", s.auth(func(w http.ResponseWriter, r *http.Request) {
+		s.secureHeaders(w)
+		flusher, ok := w.(http.Flusher)
+		if !ok { http.Error(w, "stream unsupported", http.StatusInternalServerError); return }
+		w.Header().Set("Content-Type", "text/event-stream")
+		w.Header().Set("Cache-Control", "no-store")
+		w.Header().Set("Connection", "keep-alive")
+
+		ch, cancel := s.live.subscribe()
+		defer cancel()
+
+		_, _ = w.Write([]byte(": ok\n\n")); flusher.Flush()
+		ticker := time.NewTicker(25 * time.Second); defer ticker.Stop()
+		notify := r.Context().Done()
+		for {
+			select {
+			case <-notify: return
+			case <-ticker.C:
+				_, _ = w.Write([]byte(": ping\n\n")); flusher.Flush()
+			case msg, ok := <-ch:
+				if !ok { return }
+				_, _ = w.Write(msg); flusher.Flush()
+			}
+		}
+	}))
+
+	// GDPR policy + Third-party disclaimer
+	s.mux.HandleFunc("/v1/gdpr/policy", func(w http.ResponseWriter, r *http.Request) {
+		s.with(w, r, func(w http.ResponseWriter, _ *http.Request) {
+			w.Header().Set("Content-Type", "application/json")
+			_ = json.NewEncoder(w).Encode(map[string]any{
+				"collect_ip":        false,
+				"collect_useragent": false,
+				"timestamp_policy":  s.ternary(s.coarseTS, "coarse-hour", "exact"),
+				"stores_pii":        false,
+				"erasure":           "DELETE /v1/object/{hash}",
+				"portability":       "GET /v1/object/{hash}",
+				"third_party_auth":  "Using external SSO providers is optional. We cannot vouch for their security; proceed only if you trust the provider.",
+			})
+		})
+	})
+
+	// ---------- Discord SSO (first provider) ----------
+
+	// Start: returns authorization URL. Requires explicit assent.
+	s.mux.HandleFunc("/v1/auth/discord/start", func(w http.ResponseWriter, r *http.Request) {
+		s.with(w, r, func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Content-Type", "application/json")
+			if !s.discord.Enabled {
+				http.Error(w, "discord SSO disabled", http.StatusNotImplemented); return
+			}
+			if !assented(r) {
+				http.Error(w, "third-party assent required (set header X-GC-3P-Assent: 1)", http.StatusPreconditionFailed); return
+			}
+			state := randHex(24)
+			url := "https://discord.com/api/oauth2/authorize" +
+				"?response_type=code" +
+				"&client_id=" + urlq(s.discord.ClientID) +
+				"&scope=" + urlq("identify") +
+				"&redirect_uri=" + urlq(s.discord.RedirectURI) +
+				"&prompt=consent" +
+				"&state=" + urlq(state)
+			_ = state // stateless; client returns same state to callback; you can verify in client
+			_ = json.NewEncoder(w).Encode(map[string]any{"url": url, "note": "We cannot vouch for external IdP security."})
+		})
+	})
+
+	// Callback: exchanges code for Discord access_token, fetches @me to get subject id
+	// then issues a short-lived shard token (HMAC). No data persisted.
+	s.mux.HandleFunc("/v1/auth/discord/callback", func(w http.ResponseWriter, r *http.Request) {
+		s.with(w, r, func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Content-Type", "application/json")
+			if !s.discord.Enabled {
+				http.Error(w, "discord SSO disabled", http.StatusNotImplemented); return
+			}
+			if !assented(r) {
+				http.Error(w, "third-party assent required (set header X-GC-3P-Assent: 1)", http.StatusPreconditionFailed); return
+			}
+			code := r.URL.Query().Get("code")
+			if code == "" { http.Error(w, "missing code", 400); return }
+
+			// Exchange code -> access_token
+			form := "client_id=" + urlq(s.discord.ClientID) +
+				"&client_secret=" + urlq(s.discord.ClientSecret) +
+				"&grant_type=authorization_code" +
+				"&code=" + urlq(code) +
+				"&redirect_uri=" + urlq(s.discord.RedirectURI)
+			req, _ := http.NewRequest(http.MethodPost, "https://discord.com/api/oauth2/token", strings.NewReader(form))
+			req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+			resp, err := http.DefaultClient.Do(req)
+			if err != nil { http.Error(w, "token exchange failed", 502); return }
+			defer resp.Body.Close()
+			var tok struct{ AccessToken, TokenType string `json:"access_token","token_type"` }
+			if err := json.NewDecoder(resp.Body).Decode(&tok); err != nil || tok.AccessToken == "" {
+				http.Error(w, "invalid token response", 502); return
+			}
+
+			// Fetch user id (PII seen in transit only; not stored)
+			uReq, _ := http.NewRequest(http.MethodGet, "https://discord.com/api/users/@me", nil)
+			uReq.Header.Set("Authorization", tok.TokenType+" "+tok.AccessToken)
+			uResp, err := http.DefaultClient.Do(uReq)
+			if err != nil { http.Error(w, "userinfo failed", 502); return }
+			defer uResp.Body.Close()
+			var me struct{ ID string `json:"id"` }
+			if err := json.NewDecoder(uResp.Body).Decode(&me); err != nil || me.ID == "" {
+				http.Error(w, "userinfo parse failed", 502); return
+			}
+
+			// Issue shard token
+			exp := time.Now().UTC().Add(30 * time.Minute)
+			gcTok, err := s.signShardToken("discord", me.ID, exp)
+			if err != nil { http.Error(w, err.Error(), 500); return }
+
+			_ = json.NewEncoder(w).Encode(map[string]any{
+				"ok": true,
+				"token": gcTok,
+				"expires_at": exp.Format(time.RFC3339),
+				"disclaimer": "This token is issued after authenticating with a third-party provider (Discord). We cannot vouch for third-party security.",
+			})
+		})
+	})
+}
+
+// ---------- helpers ----------
+
+func (s *Server) nowCoarse() string {
+	ts := time.Now().UTC()
+	if s.coarseTS { ts = ts.Truncate(time.Hour) }
+	return ts.Format(time.RFC3339)
+}
+func (s *Server) parseRFC3339(v string) time.Time { t, _ := time.Parse(time.RFC3339, v); return t }
+
+func (s *Server) ternary[T any](cond bool, a, b T) T { if cond { return a }; return b }
+
+func assented(r *http.Request) bool {
+	if r.Header.Get("X-GC-3P-Assent") == "1" { return true }
+	if r.URL.Query().Get("assent") == "1" { return true }
+	return false
+}
+
+func randHex(n int) string {
+	b := make([]byte, n)
+	if _, err := rand.Read(b); err != nil {
+		// very unlikely; fall back to timestamp bytes
+		ts := time.Now().UnixNano()
+		for i := 0; i < n; i++ { b[i] = byte(ts >> (8 * (i % 8))) }
+	}
+	return hex.EncodeToString(b)
+}
+
+// randReader uses crypto/rand without importing directly to keep imports tidy here.
+type randReader struct{}
+func (randReader) Read(p []byte) (int, error) { return io.ReadFull(os.OpenFile("/dev/urandom", os.O_RDONLY, 0), p) } // fallback if needed (linux-only)
+
+// ----- listeners -----
+
+func (s *Server) ListenHTTP(addr string) error {
+	log.Printf("http listening on %s", addr)
+	server := &http.Server{ Addr: addr, Handler: s.mux, ReadHeaderTimeout: 5 * time.Second }
+	ln, err := net.Listen("tcp", addr)
+	if err != nil { return err }
+	return server.Serve(ln)
+}
+
+func (s *Server) ListenHTTPS(addr, certFile, keyFile string) error {
+	log.Printf("https listening on %s", addr)
+	server := &http.Server{ Addr: addr, Handler: s.mux, ReadHeaderTimeout: 5 * time.Second }
+	return server.ListenAndServeTLS(certFile, keyFile)
+}
+
+func (s *Server) ListenMTLS(addr string, tlsCfg *tls.Config) error {
+	log.Printf("federation mTLS listening on %s", addr)
+	server := &http.Server{ Addr: addr, Handler: s.mux, ReadHeaderTimeout: 5 * time.Second, TLSConfig: tlsCfg }
+	ln, err := tls.Listen("tcp", addr, tlsCfg)
+	if err != nil { return err }
+	return server.Serve(ln)
+}

internal/api/static.go

@@ -0,0 +1,54 @@
+package api
+
+import (
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// MountStatic serves files from dir under baseURL. If baseURL == "/", it serves root.
+// Directory listings are disabled. Unknown paths fall back to index.html (SPA).
+func (s *Server) MountStatic(dir string, baseURL string) {
+	if dir == "" {
+		return
+	}
+	if baseURL == "" {
+		baseURL = "/"
+	}
+	fs := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		s.secureHeaders(w)
+		// normalize path inside dir
+		up := strings.TrimPrefix(r.URL.Path, baseURL)
+		if up == "" || strings.HasSuffix(r.URL.Path, "/") {
+			up = "index.html"
+		}
+		full := filepath.Join(dir, filepath.FromSlash(up))
+		// prevent path escape
+		if !strings.HasPrefix(filepath.Clean(full), filepath.Clean(dir)) {
+			http.NotFound(w, r)
+			return
+		}
+		// serve if exists, else SPA fallback
+		if st, err := os.Stat(full); err == nil && !st.IsDir() {
+			http.ServeFile(w, r, full)
+			return
+		}
+		fallback := filepath.Join(dir, "index.html")
+		if _, err := os.Stat(fallback); err == nil {
+			http.ServeFile(w, r, fallback)
+			return
+		}
+		http.NotFound(w, r)
+	})
+	// Root or subpath
+	if baseURL == "/" {
+		s.mux.Handle("/", fs)
+	} else {
+		if !strings.HasSuffix(baseURL, "/") {
+			baseURL += "/"
+		}
+		s.mux.Handle(baseURL, fs)
+		s.mux.Handle(baseURL+"", fs) // ensure exact mount works
+	}
+}

internal/config/config.go

@@ -0,0 +1,88 @@
+package config
+
+import (
+	"os"
+
+	"gopkg.in/yaml.v3"
+)
+
+type Config struct {
+	ShardID string `yaml:"shard_id"`
+	Listen  struct {
+		HTTP  string `yaml:"http"`
+		HTTPS string `yaml:"https"`
+		WS    string `yaml:"ws"`
+	} `yaml:"listen"`
+	TLS struct {
+		Enable   bool   `yaml:"enable"`
+		CertFile string `yaml:"cert_file"`
+		KeyFile  string `yaml:"key_file"`
+	} `yaml:"tls"`
+	Federation struct {
+		MTLSEnable   bool   `yaml:"mtls_enable"`
+		Listen       string `yaml:"listen"`
+		CertFile     string `yaml:"cert_file"`
+		KeyFile      string `yaml:"key_file"`
+		ClientCAFile string `yaml:"client_ca_file"`
+	} `yaml:"federation"`
+	UI struct {
+		Enable  bool   `yaml:"enable"`
+		Path    string `yaml:"path"`
+		BaseURL string `yaml:"base_url"`
+	} `yaml:"ui"`
+	Storage struct {
+		Backend     string `yaml:"backend"`
+		Path        string `yaml:"path"`
+		MaxObjectKB int    `yaml:"max_object_kb"`
+	} `yaml:"storage"`
+	Security struct {
+		ZeroTrust                bool   `yaml:"zero_trust"`
+		RequireMTLSForFederation bool   `yaml:"require_mtls_for_federation"`
+		AcceptClientSignedTokens bool   `yaml:"accept_client_signed_tokens"`
+		LogLevel                 string `yaml:"log_level"`
+	} `yaml:"security"`
+	Privacy struct {
+		RetainIP         string `yaml:"retain_ip"`
+		RetainUserAgent  string `yaml:"retain_user_agent"`
+		RetainTimestamps string `yaml:"retain_timestamps"`
+	} `yaml:"privacy"`
+	Auth struct {
+		SigningSecret string `yaml:"signing_secret"`
+		SSO           struct {
+			Discord struct {
+				Enabled      bool   `yaml:"enabled"`
+				ClientID     string `yaml:"client_id"`
+				ClientSecret string `yaml:"client_secret"`
+				RedirectURI  string `yaml:"redirect_uri"`
+			} `yaml:"discord"`
+			Google struct {
+				Enabled      bool   `yaml:"enabled"`
+				ClientID     string `yaml:"client_id"`
+				ClientSecret string `yaml:"client_secret"`
+				RedirectURI  string `yaml:"redirect_uri"`
+			} `yaml:"google"`
+			Facebook struct {
+				Enabled      bool   `yaml:"enabled"`
+				ClientID     string `yaml:"client_id"`
+				ClientSecret string `yaml:"client_secret"`
+				RedirectURI  string `yaml:"redirect_uri"`
+			} `yaml:"facebook"`
+		} `yaml:"sso"`
+		TwoFactor struct {
+			WebAuthnEnabled bool `yaml:"webauthn_enabled"`
+			TOTPEnabled     bool `yaml:"totp_enabled"`
+		} `yaml:"two_factor"`
+	} `yaml:"auth"`
+}
+
+func Load(path string) (*Config, error) {
+	b, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	var c Config
+	if err := yaml.Unmarshal(b, &c); err != nil {
+		return nil, err
+	}
+	return &c, nil
+}

internal/federation/tls.go

@@ -0,0 +1,32 @@
+package federation
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"os"
+)
+
+func ServerTLSConfig(certFile, keyFile, clientCAFile string) (*tls.Config, error) {
+	// Load server cert
+	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
+	if err != nil {
+		return nil, err
+	}
+
+	// Load client CA for mTLS
+	caPEM, err := os.ReadFile(clientCAFile)
+	if err != nil {
+		return nil, err
+	}
+	clientCAs := x509.NewCertPool()
+	if ok := clientCAs.AppendCertsFromPEM(caPEM); !ok {
+		return nil, err
+	}
+
+	return &tls.Config{
+		MinVersion:   tls.VersionTLS13,
+		Certificates: []tls.Certificate{cert},
+		ClientAuth:   tls.RequireAndVerifyClientCert,
+		ClientCAs:    clientCAs,
+	}, nil
+}

internal/index/index.go

@@ -0,0 +1,123 @@
+package index
+
+import (
+	"bufio"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"sort"
+	"sync"
+	"time"
+)
+
+type opType string
+
+const (
+	OpPut opType = "put"
+	OpDel opType = "del"
+)
+
+type record struct {
+	Op       opType    `json:"op"`
+	Hash     string    `json:"hash"`
+	Bytes    int64     `json:"bytes,omitempty"`
+	StoredAt time.Time `json:"stored_at,omitempty"`
+	Private  bool      `json:"private,omitempty"`
+}
+
+type Entry struct {
+	Hash     string    `json:"hash"`
+	Bytes    int64     `json:"bytes"`
+	StoredAt time.Time `json:"stored_at"`
+	Private  bool      `json:"private"`
+}
+
+type Index struct {
+	path string
+	mu   sync.Mutex
+}
+
+func New(baseDir string) *Index {
+	return &Index{path: filepath.Join(baseDir, "index.jsonl")}
+}
+
+func (i *Index) AppendPut(e Entry) error {
+	i.mu.Lock()
+	defer i.mu.Unlock()
+	return appendRec(i.path, record{
+		Op:       OpPut,
+		Hash:     e.Hash,
+		Bytes:    e.Bytes,
+		StoredAt: e.StoredAt,
+		Private:  e.Private,
+	})
+}
+
+func (i *Index) AppendDelete(hash string) error {
+	i.mu.Lock()
+	defer i.mu.Unlock()
+	return appendRec(i.path, record{Op: OpDel, Hash: hash})
+}
+
+func appendRec(path string, r record) error {
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		return err
+	}
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0o644)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	enc := json.NewEncoder(f)
+	return enc.Encode(r)
+}
+
+func (i *Index) Snapshot() ([]Entry, error) {
+	i.mu.Lock()
+	defer i.mu.Unlock()
+
+	f, err := os.Open(i.path)
+	if os.IsNotExist(err) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	sc := bufio.NewScanner(f)
+	sc.Buffer(make([]byte, 0, 64*1024), 4*1024*1024)
+
+	type state struct {
+		Entry   Entry
+		Deleted bool
+	}
+	m := make(map[string]state)
+	for sc.Scan() {
+		var rec record
+		if err := json.Unmarshal(sc.Bytes(), &rec); err != nil {
+			continue
+		}
+		switch rec.Op {
+		case OpPut:
+			m[rec.Hash] = state{Entry: Entry{
+				Hash: rec.Hash, Bytes: rec.Bytes, StoredAt: rec.StoredAt, Private: rec.Private,
+			}}
+		case OpDel:
+			s := m[rec.Hash]
+			s.Deleted = true
+			m[rec.Hash] = s
+		}
+	}
+	if err := sc.Err(); err != nil {
+		return nil, err
+	}
+	var out []Entry
+	for _, s := range m {
+		if !s.Deleted && s.Entry.Hash != "" {
+			out = append(out, s.Entry)
+		}
+	}
+	sort.Slice(out, func(i, j int) bool { return out[i].StoredAt.After(out[j].StoredAt) })
+	return out, nil
+}

internal/storage/fsstore.go

@@ -0,0 +1,83 @@
+package config
+
+import (
+	"os"
+
+	"gopkg.in/yaml.v3"
+)
+
+type Config struct {
+	ShardID string `yaml:"shard_id"`
+	Listen  struct {
+		HTTP  string `yaml:"http"`
+		HTTPS string `yaml:"https"`
+		WS    string `yaml:"ws"`
+	} `yaml:"listen"`
+	TLS struct {
+		Enable   bool   `yaml:"enable"`
+		CertFile string `yaml:"cert_file"`
+		KeyFile  string `yaml:"key_file"`
+	} `yaml:"tls"`
+	Federation struct {
+		MTLSEnable   bool   `yaml:"mtls_enable"`
+		Listen       string `yaml:"listen"`
+		CertFile     string `yaml:"cert_file"`
+		KeyFile      string `yaml:"key_file"`
+		ClientCAFile string `yaml:"client_ca_file"`
+	} `yaml:"federation"`
+	Storage struct {
+		Backend     string `yaml:"backend"`
+		Path        string `yaml:"path"`
+		MaxObjectKB int    `yaml:"max_object_kb"`
+	} `yaml:"storage"`
+	Security struct {
+		ZeroTrust                bool   `yaml:"zero_trust"`
+		RequireMTLSForFederation bool   `yaml:"require_mtls_for_federation"`
+		AcceptClientSignedTokens bool   `yaml:"accept_client_signed_tokens"`
+		LogLevel                 string `yaml:"log_level"`
+	} `yaml:"security"`
+	Privacy struct {
+		RetainIP         string `yaml:"retain_ip"`
+		RetainUserAgent  string `yaml:"retain_user_agent"`
+		RetainTimestamps string `yaml:"retain_timestamps"`
+	} `yaml:"privacy"`
+	Auth struct {
+		SigningSecret string `yaml:"signing_secret"`
+		SSO           struct {
+			Discord struct {
+				Enabled      bool   `yaml:"enabled"`
+				ClientID     string `yaml:"client_id"`
+				ClientSecret string `yaml:"client_secret"`
+				RedirectURI  string `yaml:"redirect_uri"`
+			} `yaml:"discord"`
+			Google struct {
+				Enabled      bool   `yaml:"enabled"`
+				ClientID     string `yaml:"client_id"`
+				ClientSecret string `yaml:"client_secret"`
+				RedirectURI  string `yaml:"redirect_uri"`
+			} `yaml:"google"`
+			Facebook struct {
+				Enabled      bool   `yaml:"enabled"`
+				ClientID     string `yaml:"client_id"`
+				ClientSecret string `yaml:"client_secret"`
+				RedirectURI  string `yaml:"redirect_uri"`
+			} `yaml:"facebook"`
+		} `yaml:"sso"`
+		TwoFactor struct {
+			WebAuthnEnabled bool `yaml:"webauthn_enabled"`
+			TOTPEnabled     bool `yaml:"totp_enabled"`
+		} `yaml:"two_factor"`
+	} `yaml:"auth"`
+}
+
+func Load(path string) (*Config, error) {
+	b, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	var c Config
+	if err := yaml.Unmarshal(b, &c); err != nil {
+		return nil, err
+	}
+	return &c, nil
+}