sudo-baron-samedit-12.cpp

//sudo-1.8.30/plugins/sudoers/sudoers.c
//Note: sudo_1.8.30-1.ph3 does not have sources for it
int
sudoers_policy_main(int argc, char * const argv[], int pwflag, char *env_add[],
    bool verbose, void *closure)
{
    ...

    /* Find command in path and apply per-command Defaults. */
[A] cmnd_status = set_cmnd();
    if (cmnd_status == NOT_FOUND_ERROR)
        goto done;

    /* Check for -C overriding def_closefrom. */
    if (user_closefrom >= 0 && user_closefrom != def_closefrom) {
        if (!def_closefrom_override) {
            /* XXX - audit? */
[D]         sudo_warnx(U_("you are not permitted to use the -C option"));
            goto bad;
        }
        def_closefrom = user_closefrom;
    }

    /*
     * Check sudoers sources, using the locale specified in sudoers.
     */
    sudoers_setlocale(SUDOERS_LOCALE_SUDOERS, &oldlocale);
[E] validated = sudoers_lookup(snl, sudo_user.pw, FLAG_NO_USER | FLAG_NO_HOST,
        pwflag);

[B] [... lots of code here ...]

    /* Require a password if sudoers says so.  */
[C] switch (check_user(validated, sudo_mode)) {
    case true:
        /* user authenticated successfully. */
        break;