Files
Artifacto/internal/auth/admin.go
dtoro c7d7ee287c initial commit: Artifacto v0.1
Self-hosted HTML artifact publisher. Single Go binary, SQLite metadata,
HTML on disk. Features: password-protected artifacts, per-artifact expiration,
admin dashboard with view metrics (privacy-preserving daily-salt visitor hash,
sparklines, 30-day SVG chart, top referrers), rate-limited unlock endpoint.

Packaged as a Docker image (two-stage, CGO_ENABLED=0, pure-Go SQLite).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-22 15:45:57 +02:00

134 lines
3.0 KiB
Go

package auth
import (
"context"
"crypto/hmac"
"crypto/sha256"
"encoding/base64"
"errors"
"net/http"
"strconv"
"strings"
"time"
"golang.org/x/crypto/bcrypt"
)
const (
AdminCookie = "artifacto_admin"
adminLifetime = 30 * 24 * time.Hour
)
type ctxKey int
const ctxAdmin ctxKey = 1
type Admin struct {
passwordHash []byte
secret []byte
secure bool
}
func NewAdmin(password, secretHex string, secure bool) (*Admin, error) {
if password == "" {
return nil, errors.New("ADMIN_PASSWORD required")
}
if len(secretHex) < 32 {
return nil, errors.New("SESSION_SECRET must be >= 32 chars")
}
h, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
if err != nil {
return nil, err
}
return &Admin{passwordHash: h, secret: []byte(secretHex), secure: secure}, nil
}
func (a *Admin) VerifyPassword(p string) bool {
return bcrypt.CompareHashAndPassword(a.passwordHash, []byte(p)) == nil
}
// Issue returns a signed cookie value "issued_at.sig".
func (a *Admin) Issue() string {
issued := strconv.FormatInt(time.Now().Unix(), 10)
return issued + "." + a.sign("admin|"+issued)
}
func (a *Admin) Verify(raw string) bool {
parts := strings.SplitN(raw, ".", 2)
if len(parts) != 2 {
return false
}
issued, err := strconv.ParseInt(parts[0], 10, 64)
if err != nil {
return false
}
if time.Since(time.Unix(issued, 0)) > adminLifetime {
return false
}
expected := a.sign("admin|" + parts[0])
return hmac.Equal([]byte(expected), []byte(parts[1]))
}
func (a *Admin) sign(s string) string {
m := hmac.New(sha256.New, a.secret)
m.Write([]byte(s))
return base64.RawURLEncoding.EncodeToString(m.Sum(nil))
}
func (a *Admin) SetCookie(w http.ResponseWriter) {
http.SetCookie(w, &http.Cookie{
Name: AdminCookie,
Value: a.Issue(),
Path: "/",
HttpOnly: true,
Secure: a.secure,
SameSite: http.SameSiteLaxMode,
Expires: time.Now().Add(adminLifetime),
})
}
func (a *Admin) ClearCookie(w http.ResponseWriter) {
http.SetCookie(w, &http.Cookie{
Name: AdminCookie,
Value: "",
Path: "/",
HttpOnly: true,
Secure: a.secure,
SameSite: http.SameSiteLaxMode,
MaxAge: -1,
})
}
// Middleware allows the request through if the admin cookie is valid; otherwise
// redirects to /login (for HTML nav) or returns 401 (for API/HTMX).
func (a *Admin) Middleware(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
c, err := r.Cookie(AdminCookie)
if err != nil || !a.Verify(c.Value) {
if isAPI(r) {
http.Error(w, "unauthorized", http.StatusUnauthorized)
return
}
http.Redirect(w, r, "/login?next="+r.URL.RequestURI(), http.StatusSeeOther)
return
}
ctx := context.WithValue(r.Context(), ctxAdmin, true)
next.ServeHTTP(w, r.WithContext(ctx))
})
}
func isAPI(r *http.Request) bool {
if strings.HasPrefix(r.URL.Path, "/api/") {
return true
}
if r.Header.Get("HX-Request") == "true" {
return true
}
return false
}
func IsAdmin(ctx context.Context) bool {
v, _ := ctx.Value(ctxAdmin).(bool)
return v
}