sasl.c

/* -*- show-trailing-whitespace: t; indent-tabs: t -*-
 *
 * Copyright (c) 2006 David Lichteblau
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <curses.h>
#include <signal.h>
#include <term.h>
#include "config.h"
#ifdef HAVE_SASL
#include <sasl/sasl.h>
#endif
#include "common.h"

tsasl_defaults *
sasl_defaults_new(bind_options *bind_options)
{
      struct sasl_defaults *result = xalloc(sizeof(tsasl_defaults));
      result->bind_options = bind_options;
      result->scratch = g_ptr_array_new();
      result->fd = -1;
      return result;
}

void
sasl_defaults_free(tsasl_defaults *sd)
{
      GPtrArray *scratch = sd->scratch;
      int i;

      for (i = 0; i < scratch->len; i++)
            free(g_ptr_array_index(scratch, i));
      g_ptr_array_free(sd->scratch, 1);
      free(sd);
}

void
init_sasl_redirection(tsasl_defaults *defaults, char *pathname)
{
      int fd = open(pathname, O_RDWR | O_CREAT | O_TRUNC, 0600);
      if (fd == -1) syserr();
      fflush(stdout);
      defaults->out = dup(1);
      defaults->err = dup(2);
      defaults->fd = fd;
      defaults->pathname = pathname;
      dup2(defaults->fd, 1);
      dup2(defaults->fd, 2);
}

void
finish_sasl_redirection(tsasl_defaults *defaults)
{
      dup2(defaults->out, 1);
      dup2(defaults->err, 2);
      close(defaults->out);
      close(defaults->err);
      if (lseek(defaults->fd, 0, SEEK_SET) != 0) syserr();
      fdcp(defaults->fd, 2);
      close(defaults->fd);
      defaults->fd = -1;
}

#ifndef HAVE_SASL

#warning SASL support disabled

int
ldapvi_sasl_interact(LDAP *ld, unsigned flags, void *de, void *in)
{
      fputs("Error: ldapvi compiled without SASL support.\n", stderr);
        return LDAP_OTHER;
}

#else

static int
process_default(sasl_interact_t *interact, tsasl_defaults *defaults)
{
      char *result;

      switch (interact->id) {
      case SASL_CB_GETREALM:
            result = defaults->bind_options->sasl_realm;
            break;
      case SASL_CB_AUTHNAME:
            result = defaults->bind_options->sasl_authcid;
            break;
      case SASL_CB_PASS:
            result = defaults->bind_options->password;
            break;
      case SASL_CB_USER:
            result = defaults->bind_options->sasl_authzid;
            break;
      default:
            result = (char *) interact->defresult;
            break;
      }

      if (result && *result) {
            interact->result = result;
            interact->len = strlen(result);
            return 1;
      } else {
            interact->result = "";
            return interact->id == SASL_CB_USER;
      }
}

static int
process_result(int id, char *result, tsasl_defaults *defaults)
{
      switch (id) {
      case SASL_CB_GETREALM:
            defaults->bind_options->sasl_realm = result;
            break;
      case SASL_CB_AUTHNAME:
            defaults->bind_options->sasl_authcid = result;
            break;
      case SASL_CB_PASS:
            defaults->bind_options->password = result;
            break;
      case SASL_CB_USER:
            defaults->bind_options->sasl_authzid = result;
            break;
      default:
            g_ptr_array_add(defaults->scratch, result);
      }
}

static int
challengep(int id)
{
      return id == SASL_CB_ECHOPROMPT || id == SASL_CB_NOECHOPROMPT;
}

static int
interact_mode(int id)
{
      if (id == SASL_CB_PASS || id == SASL_CB_NOECHOPROMPT)
            return DIALOG_PASSWORD;
      return DIALOG_DEFAULT;
}

int
ldapvi_sasl_interact(LDAP *ld, unsigned flags, void *de, void *in)
{
      tsasl_defaults *defaults = de;
      sasl_interact_t *interact = in;
      tdialog *d;
      int redirected = defaults->fd != -1;
      int force_interactive = 0;
      int i, j, start;
      int n = 0, m = 0;

      while (interact[n].id != SASL_CB_LIST_END) {
            n++;
            if (challengep(interact[n].id))
                  m++;
      }

      for (i = 0; i < n; i++)
            if (!process_default(&interact[i], defaults))
                  force_interactive = 1;

      if (force_interactive) {
            if (flags == LDAP_SASL_QUIET)
                  return LDAP_OTHER;
      } else
            if (flags != LDAP_SASL_INTERACTIVE)
                  return LDAP_SUCCESS;

      if (redirected)
            finish_sasl_redirection(defaults);

      d = xalloc(sizeof(tdialog) * (n + m));
      start = -1; /* authcid if unset, else password if any, else first */
      j = 0;
      for (i = 0; i < n; i++) {
            char *value = (char *) interact[i].result;
            char *prompt = (char *) interact[i].prompt;
            if (!strncmp(prompt, "Please enter your ", 18))
                  prompt += 18;
            if (challengep(interact[i].id))
                  init_dialog(&d[j++],
                            DIALOG_CHALLENGE,
                            "Challenge",
                            (char *) interact[i].challenge);
            switch (interact[i].id) {
            case SASL_CB_AUTHNAME: if (!value || !*value) start = j; break;
            case SASL_CB_PASS: if (start == -1) start = j; break;
            }
            init_dialog(&d[j++],
                      interact_mode(interact[i].id),
                      prompt,
                      value);
      }

      dialog("--- SASL login", d, n + m, start == -1 ? 0 : start);
      j = 0;
      for (i = 0; i < n; i++) {
            char *value;

            while (d[j].mode == DIALOG_CHALLENGE) j++;
            if ( (value = d[j++].value))
                  process_result(interact[i].id, value, defaults);
            else
                  value = "";
            interact[i].result = value;
            interact[i].len = strlen(value);
      }
      free(d);

      if (redirected)
            init_sasl_redirection(defaults, defaults->pathname);
      return LDAP_SUCCESS;
}

#endif