*/
disorder_client *dcgi_client;
+/** @brief Return true if @p a is better than @p b
+ *
+ * NB. We don't bother checking if the path is right, we merely check for the
+ * longest path. This isn't a security hole: if the browser wants to send us
+ * bad cookies it's quite capable of sending just the right path anyway. The
+ * point of choosing the longest path is to avoid using a cookie set by another
+ * CGI script which shares a path prefix with us, which would allow it to
+ * maliciously log users out.
+ *
+ * Such a script could still "maliciously" log someone in, if it had acquired a
+ * suitable cookie. But it could just log in directly if it had that, so there
+ * is no obvious vulnerability here either.
+ */
+static int better_cookie(const struct cookie *a, const struct cookie *b) {
+ if(a->path && b->path)
+ /* If both have a path then the one with the longest path is best */
+ return strlen(a->path) > strlen(b->path);
+ else if(a->path)
+ /* If only @p a has a path then it is better */
+ return 1;
+ else
+ /* If neither have a path, or if only @p b has a path, then @p b is
+ * better */
+ return 0;
+}
+
/** @brief Login cookie */
char *dcgi_cookie;
+/** @brief Set @ref login_cookie */
+void dcgi_get_cookie(void) {
+ const char *cookie_env;
+ int n, best_cookie;
+ struct cookiedata cd;
+
+ /* See if there's a cookie */
+ cookie_env = getenv("HTTP_COOKIE");
+ if(cookie_env) {
+ /* This will be an HTTP header */
+ if(!parse_cookie(cookie_env, &cd)) {
+ /* Pick the best available cookie from all those offered */
+ best_cookie = -1;
+ for(n = 0; n < cd.ncookies; ++n) {
+ /* Is this the right cookie? */
+ if(strcmp(cd.cookies[n].name, "disorder"))
+ continue;
+ /* Is it better than anything we've seen so far? */
+ if(best_cookie < 0
+ || better_cookie(&cd.cookies[n], &cd.cookies[best_cookie]))
+ best_cookie = n;
+ }
+ if(best_cookie != -1)
+ dcgi_cookie = cd.cookies[best_cookie].value;
+ } else
+ error(0, "could not parse cookie field '%s'", cookie_env);
+ }
+}
+
/** @brief Return a Cookie: header */
char *dcgi_cookie_header(void) {
struct dynstr d[1];
dcgi_client = disorder_new(0);
/* Reconnect */
if(disorder_connect_cookie(dcgi_client, dcgi_cookie)) {
- dcgi_error("Cannot connect to server");
+ dcgi_error("connect");
exit(0);
}
/* If there was a cookie but it went bad, we forget it */