| 1 | package admin |
| 2 | |
| 3 | import ( |
| 4 | "crypto/subtle" |
| 5 | "html/template" |
| 6 | "net/http" |
| 7 | "strings" |
| 8 | |
| 9 | "go.bigb.es/curator/internal/oidcauth" |
| 10 | ) |
| 11 | |
| 12 | // AuthMiddleware protects admin routes with admin token and/or OIDC. |
| 13 | // Supports Bearer token in Authorization header, cookie-based sessions, |
| 14 | // and OIDC session cookies. |
| 15 | func AuthMiddleware(adminToken string, oidcProvider *oidcauth.Provider, next http.Handler) http.Handler { |
| 16 | return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| 17 | if adminToken == "" && oidcProvider == nil { |
| 18 | http.Error(w, "admin access not configured", http.StatusForbidden) |
| 19 | return |
| 20 | } |
| 21 | |
| 22 | // Check Authorization: Bearer header (admin token). |
| 23 | if adminToken != "" { |
| 24 | if auth := r.Header.Get("Authorization"); auth != "" { |
| 25 | if token, ok := strings.CutPrefix(auth, "Bearer "); ok { |
| 26 | if subtle.ConstantTimeCompare([]byte(token), []byte(adminToken)) == 1 { |
| 27 | next.ServeHTTP(w, r) |
| 28 | return |
| 29 | } |
| 30 | } |
| 31 | } |
| 32 | } |
| 33 | |
| 34 | // Check curator_admin cookie (admin token session). |
| 35 | if adminToken != "" { |
| 36 | if cookie, err := r.Cookie("curator_admin"); err == nil { |
| 37 | if subtle.ConstantTimeCompare([]byte(cookie.Value), []byte(adminToken)) == 1 { |
| 38 | next.ServeHTTP(w, r) |
| 39 | return |
| 40 | } |
| 41 | } |
| 42 | } |
| 43 | |
| 44 | // Check curator_session cookie (OIDC session). |
| 45 | if oidcProvider != nil { |
| 46 | if cookie, err := r.Cookie("curator_session"); err == nil { |
| 47 | if email := oidcProvider.ValidateSession(cookie.Value); email != "" { |
| 48 | next.ServeHTTP(w, r) |
| 49 | return |
| 50 | } |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | // Handle login page. |
| 55 | if r.URL.Path == "/-/admin/login" { |
| 56 | // If only OIDC is configured (no admin_token), redirect straight to OIDC. |
| 57 | if adminToken == "" && oidcProvider != nil { |
| 58 | http.Redirect(w, r, "/-/oidc/login", http.StatusSeeOther) |
| 59 | return |
| 60 | } |
| 61 | |
| 62 | returnURL := r.URL.Query().Get("return") |
| 63 | |
| 64 | if adminToken != "" && r.Method == http.MethodPost { |
| 65 | token := r.FormValue("token") |
| 66 | // Return URL from hidden form field (POST doesn't carry query params). |
| 67 | if ret := r.FormValue("return"); ret != "" { |
| 68 | returnURL = ret |
| 69 | } |
| 70 | if subtle.ConstantTimeCompare([]byte(token), []byte(adminToken)) == 1 { |
| 71 | http.SetCookie(w, &http.Cookie{ |
| 72 | Name: "curator_admin", |
| 73 | Value: adminToken, |
| 74 | Path: "/-/", |
| 75 | HttpOnly: true, |
| 76 | SameSite: http.SameSiteStrictMode, |
| 77 | }) |
| 78 | http.SetCookie(w, &http.Cookie{ |
| 79 | Name: "curator_auth", |
| 80 | Value: adminToken, |
| 81 | Path: "/", |
| 82 | HttpOnly: true, |
| 83 | SameSite: http.SameSiteStrictMode, |
| 84 | }) |
| 85 | if returnURL == "" || !strings.HasPrefix(returnURL, "/") { |
| 86 | returnURL = "/-/admin/" |
| 87 | } |
| 88 | http.Redirect(w, r, returnURL, http.StatusSeeOther) |
| 89 | return |
| 90 | } |
| 91 | w.WriteHeader(http.StatusUnauthorized) |
| 92 | renderLogin(w, "Invalid token", oidcProvider != nil, returnURL) |
| 93 | return |
| 94 | } |
| 95 | |
| 96 | renderLogin(w, "", oidcProvider != nil, returnURL) |
| 97 | return |
| 98 | } |
| 99 | |
| 100 | // Redirect to login for browser requests. |
| 101 | if strings.HasPrefix(r.URL.Path, "/-/admin/") { |
| 102 | // If only OIDC configured, go straight to OIDC. |
| 103 | if adminToken == "" && oidcProvider != nil { |
| 104 | http.Redirect(w, r, "/-/oidc/login", http.StatusSeeOther) |
| 105 | return |
| 106 | } |
| 107 | http.Redirect(w, r, "/-/admin/login", http.StatusSeeOther) |
| 108 | return |
| 109 | } |
| 110 | |
| 111 | // API requests get 401. |
| 112 | w.Header().Set("WWW-Authenticate", `Bearer realm="curator admin"`) |
| 113 | http.Error(w, "unauthorized", http.StatusUnauthorized) |
| 114 | }) |
| 115 | } |
| 116 | |
| 117 | func renderLogin(w http.ResponseWriter, errMsg string, hasOIDC bool, returnURL string) { |
| 118 | w.Header().Set("Content-Type", "text/html; charset=utf-8") |
| 119 | page := `<!DOCTYPE html> |
| 120 | <html><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1"> |
| 121 | <title>Curator Login</title> |
| 122 | <style> |
| 123 | :root{--bg:#fff;--text:#202124;--border:#dadce0;--accent:#1a73e8;--err:#d93025} |
| 124 | @media(prefers-color-scheme:dark){:root{--bg:#1e1e1e;--text:#d4d4d4;--border:#404040;--accent:#6cb6ff;--err:#f28b82}} |
| 125 | *{box-sizing:border-box;margin:0;padding:0} |
| 126 | body{font-family:system-ui,sans-serif;background:var(--bg);color:var(--text);display:flex;justify-content:center;align-items:center;min-height:100vh} |
| 127 | .login{border:1px solid var(--border);border-radius:8px;padding:32px;max-width:360px;width:100%} |
| 128 | h1{font-size:20px;margin-bottom:16px} |
| 129 | input[type=password]{display:block;width:100%;padding:10px 12px;border:1px solid var(--border);border-radius:4px;font-size:14px;margin-bottom:16px;background:var(--bg);color:var(--text)} |
| 130 | button{background:var(--accent);color:#fff;border:none;padding:10px 24px;border-radius:4px;font-size:14px;cursor:pointer;width:100%} |
| 131 | button:hover{opacity:0.9} |
| 132 | .err{color:var(--err);font-size:13px;margin-bottom:12px} |
| 133 | .divider{text-align:center;color:var(--border);margin:16px 0;font-size:13px} |
| 134 | .sso-btn{background:transparent;color:var(--accent);border:1px solid var(--accent);margin-top:0} |
| 135 | .sso-btn:hover{background:var(--accent);color:#fff} |
| 136 | </style></head><body> |
| 137 | <div class="login"><h1>Curator</h1>` |
| 138 | |
| 139 | if errMsg != "" { |
| 140 | page += `<p class="err">` + errMsg + `</p>` |
| 141 | } |
| 142 | |
| 143 | page += `<form method="POST" action="/-/admin/login"> |
| 144 | <input type="hidden" name="return" value="` + template.HTMLEscapeString(returnURL) + `"> |
| 145 | <input type="password" name="token" placeholder="Token" autofocus required> |
| 146 | <button type="submit">Login</button> |
| 147 | </form>` |
| 148 | |
| 149 | if hasOIDC { |
| 150 | page += `<div class="divider">— or —</div> |
| 151 | <a href="/-/oidc/login"><button type="button" class="sso-btn">Login with SSO</button></a>` |
| 152 | } |
| 153 | |
| 154 | page += `</div></body></html>` |
| 155 | w.Write([]byte(page)) |
| 156 | } |
| 157 | |