Beispiel #1
0
int sftp_auth_password(struct ssh2_packet *pkt, cmd_rec *pass_cmd,
                       const char *orig_user, const char *user, const char *service,
                       unsigned char **buf, uint32_t *buflen, int *send_userauth_fail) {
    const char *cipher_algo, *mac_algo;
    char *passwd;
    int have_new_passwd, res;
    struct passwd *pw;

    cipher_algo = sftp_cipher_get_read_algo();
    mac_algo = sftp_mac_get_read_algo();

    if (strncmp(cipher_algo, "none", 5) == 0 ||
            strncmp(mac_algo, "none", 5) == 0) {

        if (sftp_opts & SFTP_OPT_ALLOW_INSECURE_LOGIN) {
            (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
                                    "WARNING: cipher algorithm '%s' or MAC algorithm '%s' INSECURE for "
                                    "password authentication (SFTPOption AllowInsecureLogin in effect)",
                                    cipher_algo, mac_algo);

        } else {
            (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
                                    "cipher algorithm '%s' or MAC algorithm '%s' unacceptable for "
                                    "password authentication, denying password authentication request",
                                    cipher_algo, mac_algo);
            *send_userauth_fail = TRUE;
            errno = EPERM;
            return 0;
        }
    }

    /* XXX We currently don't do anything with this. */
    have_new_passwd = sftp_msg_read_bool(pkt->pool, buf, buflen);
    if (have_new_passwd) {
        (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION, "%s",
                                "client says they have provided a new password; this functionality "
                                "is not currently supported");
    }

    passwd = sftp_msg_read_string(pkt->pool, buf, buflen);
    passwd = sftp_utf8_decode_str(pkt->pool, passwd);

    pass_cmd->arg = passwd;

    if (pr_cmd_dispatch_phase(pass_cmd, PRE_CMD, 0) < 0) {
        (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
                                "authentication request for user '%s' blocked by '%s' handler",
                                orig_user, (char *) pass_cmd->argv[0]);

        pr_cmd_dispatch_phase(pass_cmd, POST_CMD_ERR, 0);
        pr_cmd_dispatch_phase(pass_cmd, LOG_CMD_ERR, 0);

        pr_memscrub(passwd, strlen(passwd));

        *send_userauth_fail = TRUE;
        errno = EPERM;
        return 0;
    }

    pw = pr_auth_getpwnam(pkt->pool, user);
    if (pw == NULL) {
        (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
                                "no account for user '%s' found", user);

        pr_log_auth(PR_LOG_NOTICE,
                    "USER %s: no such user found from %s [%s] to %s:%d", user,
                    session.c->remote_name, pr_netaddr_get_ipstr(session.c->remote_addr),
                    pr_netaddr_get_ipstr(session.c->local_addr), session.c->local_port);

        pr_memscrub(passwd, strlen(passwd));

        *send_userauth_fail = TRUE;
        errno = ENOENT;
        return 0;
    }

    res = pr_auth_authenticate(pkt->pool, user, passwd);
    pr_memscrub(passwd, strlen(passwd));

    switch (res) {
    case PR_AUTH_OK:
        break;

    case PR_AUTH_NOPWD:
        (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
                                "password authentication for user '%s' failed: No such user", user);
        pr_log_auth(PR_LOG_NOTICE, "USER %s (Login failed): No such user found",
                    user);
        *send_userauth_fail = TRUE;
        errno = ENOENT;
        return 0;

    case PR_AUTH_BADPWD:
        (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
                                "password authentication for user '%s' failed: Incorrect password",
                                user);
        pr_log_auth(PR_LOG_NOTICE, "USER %s (Login failed): Incorrect password",
                    user);
        *send_userauth_fail = TRUE;
        errno = EINVAL;
        return 0;

    case PR_AUTH_AGEPWD:
        (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
                                "password authentication for user '%s' failed: Password expired",
                                user);
        pr_log_auth(PR_LOG_NOTICE, "USER %s (Login failed): Password expired",
                    user);
        *send_userauth_fail = TRUE;
        errno = EINVAL;
        return 0;

    case PR_AUTH_DISABLEDPWD:
        (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
                                "password authentication for user '%s' failed: Account disabled",
                                user);
        pr_log_auth(PR_LOG_NOTICE, "USER %s (Login failed): Account disabled",
                    user);
        *send_userauth_fail = TRUE;
        errno = EINVAL;
        return 0;

    default:
        (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
                                "unknown authentication value (%d), returning error", res);
        *send_userauth_fail = TRUE;
        errno = EINVAL;
        return 0;
    }

    return 1;
}
Beispiel #2
0
int sftp_auth_kbdint(struct ssh2_packet *pkt, cmd_rec *pass_cmd,
    const char *orig_user, const char *user, const char *service,
    unsigned char **buf, uint32_t *buflen, int *send_userauth_fail) {
  const char *cipher_algo, *mac_algo;
  struct passwd *pw;
  char *submethods;
  sftp_kbdint_driver_t *driver;
  int res = -1;

  if (sftp_kbdint_have_drivers() == 0) {
    (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
      "no 'keyboard-interactive' drivers currently registered, unable to "
      "authenticate user '%s' via 'keyboard-interactive' method", user);

    pr_log_auth(PR_LOG_NOTICE,
      "USER %s (Login failed): keyboard-interactive authentication disabled",
      user);

    *send_userauth_fail = TRUE;
    errno = EPERM;
    return 0;
  }

  if (pr_cmd_dispatch_phase(pass_cmd, PRE_CMD, 0) < 0) {
    (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
      "authentication request for user '%s' blocked by '%s' handler",
      orig_user, (char *) pass_cmd->argv[0]);

    pr_log_auth(PR_LOG_NOTICE,
      "USER %s (Login failed): blocked by '%s' handler", orig_user,
      (char *) pass_cmd->argv[0]);

    pr_cmd_dispatch_phase(pass_cmd, POST_CMD_ERR, 0);
    pr_cmd_dispatch_phase(pass_cmd, LOG_CMD_ERR, 0);

    *send_userauth_fail = TRUE;
    errno = EPERM;
    return 0;
  }

  pw = pr_auth_getpwnam(pkt->pool, user);
  if (pw == NULL) {
    (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
      "no account for user '%s' found", user);

    pr_log_auth(PR_LOG_NOTICE,
      "USER %s: no such user found from %s [%s] to %s:%d", user,
      session.c->remote_name, pr_netaddr_get_ipstr(session.c->remote_addr),
      pr_netaddr_get_ipstr(session.c->local_addr), session.c->local_port);

    *send_userauth_fail = TRUE;
    errno = ENOENT;
    return 0;
  }

  cipher_algo = sftp_cipher_get_read_algo();
  mac_algo = sftp_mac_get_read_algo();

  /* XXX Is this too strict?  For PAM authentication, no -- but for S/Key or
   * one-time password authencation, maybe yes.
   */
  if (strncmp(cipher_algo, "none", 5) == 0 ||
      strncmp(mac_algo, "none", 5) == 0) {

    if (sftp_opts & SFTP_OPT_ALLOW_INSECURE_LOGIN) {
      (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
        "WARNING: cipher algorithm '%s' or MAC algorithm '%s' INSECURE for "
        "keyboard-interactive authentication "
        "(SFTPOption AllowInsecureLogin in effect)", cipher_algo, mac_algo);

    } else {
      (void) pr_log_writefile(sftp_logfd, MOD_SFTP_VERSION,
        "cipher algorithm '%s' or MAC algorithm '%s' unacceptable for "
        "keyboard-interactive authentication, denying authentication request",
        cipher_algo, mac_algo);

      pr_log_auth(PR_LOG_NOTICE,
        "USER %s (Login failed): cipher algorithm '%s' or MAC algorithm '%s' "
        "unsupported for keyboard-interactive authentication", user,
        cipher_algo, mac_algo);

      *send_userauth_fail = TRUE;
      errno = EPERM;
      return 0;
    }
  }

  /* XXX Read off the deprecated language string. */
  sftp_msg_read_string(pkt->pool, buf, buflen);

  submethods = sftp_msg_read_string(pkt->pool, buf, buflen);

  if (strlen(submethods) > 0) {
    pr_trace_msg(trace_channel, 8, "client suggested 'keyboard-interactive' "
      "methods: %s", submethods);
  }

  /* XXX get our own get_shared_name() function (see kex.c), to see if
   * any of the "hints" sent by the client match any of the registered
   * kbdint drivers.
   */

  driver = sftp_kbdint_first_driver();
  while (driver != NULL) {
    register unsigned int i;
    int skip_driver = FALSE;

    pr_signals_handle();

    /* If this driver has already successfully handled this user, skip it. */
    for (i = 0; i < kbdint_drivers->nelts; i++) {
      char *dri;

      dri = ((char **) kbdint_drivers->elts)[i];
      if (strcmp(driver->driver_name, dri) == 0) {
        skip_driver = TRUE;
        break;
      }
    }

    if (skip_driver) {
      pr_trace_msg(trace_channel, 9,
        "skipping already-used kbdint driver '%s' for user '%s'",
        driver->driver_name, user);
      driver = sftp_kbdint_next_driver();
      continue;
    }

    pr_trace_msg(trace_channel, 3, "trying kbdint driver '%s' for user '%s'",
      driver->driver_name, user);

    res = driver->open(driver, user);
    if (res < 0) {
      driver = sftp_kbdint_next_driver();
      continue;
    }

    res = driver->authenticate(driver, user);
    driver->close(driver);

    if (res == 0) {
      /* Store the driver name for future checking. */
      *((char **) push_array(kbdint_drivers)) = pstrdup(sftp_pool,
        driver->driver_name);
      break; 
    }

    driver = sftp_kbdint_next_driver();
  }

  if (res < 0) {
    *send_userauth_fail = TRUE;

    /* We explicitly want to use an errno value other than EPERM here, so
     * that the calling code allows the connecting client to make other
     * login attempts, rather than failing this authentication method
     * after a single failure (Bug#3921).
     */
    errno = EACCES;
    return 0;
  }

  return 1;
}