/* 

   Unix SMB/CIFS implementation.

   Winbind authentication mechanism

   Copyright (C) Tim Potter 2000

   Copyright (C) Andrew Bartlett 2001 - 2002

   Copyright (C) Stefan Metzmacher 2005

   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 3 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, see <http://www.gnu.org/licenses/>.

*/

#include "includes.h"

#include <tevent.h>

#include "../lib/util/tevent_ntstatus.h"

#include "auth/auth.h"

#include "auth/ntlm/auth_proto.h"

#include "librpc/gen_ndr/ndr_winbind_c.h"

#include "lib/messaging/irpc.h"

#include "param/param.h"

#include "nsswitch/libwbclient/wbclient.h"

#include "auth/auth_sam_reply.h"

#include "libcli/security/security.h"

#include "dsdb/samdb/samdb.h"

#include "auth/auth_sam.h"

#undef DBGC_CLASS

#define DBGC_CLASS DBGC_AUTH

_PUBLIC_ NTSTATUS auth4_winbind_init(TALLOC_CTX *);

static NTSTATUS winbind_want_check(struct auth_method_context *ctx,

           TALLOC_CTX *mem_ctx,

           const struct auth_usersupplied_info *user_info)

{

  if (!user_info->mapped.account_name || !*user_info->mapped.account_name) {

    return NT_STATUS_NOT_IMPLEMENTED;

  }

  /* TODO: maybe limit the user scope to remote users only */

  return NT_STATUS_OK;

}

struct winbind_check_password_state {

  struct auth_method_context *ctx;

  const struct auth_usersupplied_info *user_info;

  struct winbind_SamLogon req;

  struct auth_user_info_dc *user_info_dc;

  bool authoritative;

};

static void winbind_check_password_done(struct tevent_req *subreq);

/*

 Authenticate a user with a challenge/response

 using IRPC to the winbind task

*/

static struct tevent_req *winbind_check_password_send(TALLOC_CTX *mem_ctx,

        struct tevent_context *ev,

        struct auth_method_context *ctx,

        const struct auth_usersupplied_info *user_info)

{

  struct tevent_req *req = NULL;

  struct winbind_check_password_state *state = NULL;

  NTSTATUS status;

  struct dcerpc_binding_handle *irpc_handle;

  const struct auth_usersupplied_info *user_info_new;

  struct netr_IdentityInfo *identity_info;

  struct imessaging_context *msg_ctx;

  struct tevent_req *subreq = NULL;

  req = tevent_req_create(mem_ctx, &state,

        struct winbind_check_password_state);

  if (req == NULL) {

    return NULL;

  }

  state->ctx = ctx;

  state->user_info = user_info;

  state->authoritative = true;

  if (ctx->auth_ctx->for_netlogon) {

    state->req.in.internal_flags |= WB_SAMLOGON_FOR_NETLOGON;

  }

  msg_ctx = imessaging_client_init(state, ctx->auth_ctx->lp_ctx, ev);

  if (msg_ctx == NULL) {

    DEBUG(1, ("imessaging_init failed\n"));

    tevent_req_nterror(req, NT_STATUS_INVALID_SERVER_STATE);

    return tevent_req_post(req, ev);

  }

  irpc_handle = irpc_binding_handle_by_name(state, msg_ctx,

              "winbind_server",

              &ndr_table_winbind);

  if (irpc_handle == NULL) {

    DEBUG(0, ("Winbind authentication for [%s]\\[%s] failed, " 

        "no winbind_server running!\n",

        user_info->client.domain_name, user_info->client.account_name));

    tevent_req_nterror(req, NT_STATUS_NO_LOGON_SERVERS);

    return tevent_req_post(req, ev);

  }

  /*

   * 120 seconds should be enough even for trusted domains.

   *

   * Currently winbindd has a much lower limit.

   * And tests with Windows RODCs show that it

   * returns NO_LOGON_SERVERS after 90-100 seconds

   * if it can't reach any RWDC.

   */

  dcerpc_binding_handle_set_timeout(irpc_handle, 120);

  if (user_info->flags & USER_INFO_INTERACTIVE_LOGON) {

    struct netr_PasswordInfo *password_info;

    status = encrypt_user_info(state, ctx->auth_ctx, AUTH_PASSWORD_HASH,

             user_info, &user_info_new);

    if (tevent_req_nterror(req, status)) {

      return tevent_req_post(req, ev);

    }

    user_info = user_info_new;

    password_info = talloc_zero(state, struct netr_PasswordInfo);

    if (tevent_req_nomem(password_info, req)) {

      return tevent_req_post(req, ev);

    }

    password_info->lmpassword = *user_info->password.hash.lanman;

    password_info->ntpassword = *user_info->password.hash.nt;

    identity_info = &password_info->identity_info;

    state->req.in.logon_level = 1;

    state->req.in.logon.password= password_info;

  } else {

    struct netr_NetworkInfo *network_info;

    uint8_t chal[8];

    status = encrypt_user_info(state, ctx->auth_ctx, AUTH_PASSWORD_RESPONSE,

             user_info, &user_info_new);

    if (tevent_req_nterror(req, status)) {

      return tevent_req_post(req, ev);

    }

    user_info = user_info_new;

    network_info = talloc_zero(state, struct netr_NetworkInfo);

    if (tevent_req_nomem(network_info, req)) {

      return tevent_req_post(req, ev);

    }

    status = auth_get_challenge(ctx->auth_ctx, chal);

    if (tevent_req_nterror(req, status)) {

      return tevent_req_post(req, ev);

    }

    memcpy(network_info->challenge, chal, sizeof(network_info->challenge));

    network_info->nt.length = user_info->password.response.nt.length;

    network_info->nt.data = user_info->password.response.nt.data;

    network_info->lm.length = user_info->password.response.lanman.length;

    network_info->lm.data = user_info->password.response.lanman.data;

    identity_info = &network_info->identity_info;

    state->req.in.logon_level = 2;

    state->req.in.logon.network = network_info;

  }

  identity_info->domain_name.string = user_info->client.domain_name;

  identity_info->parameter_control  = user_info->logon_parameters; /* see MSV1_0_* */

  identity_info->logon_id     = user_info->logon_id;

  identity_info->account_name.string  = user_info->client.account_name;

  identity_info->workstation.string = user_info->workstation_name;

  state->req.in.validation_level = 6;

  subreq = dcerpc_winbind_SamLogon_r_send(state, ev, irpc_handle,

            &state->req);

  if (tevent_req_nomem(subreq, req)) {

    return tevent_req_post(req, ev);

  }

  tevent_req_set_callback(subreq,

        winbind_check_password_done,

        req);

  return req;

}

static void winbind_check_password_done(struct tevent_req *subreq)

{

  struct tevent_req *req =

    tevent_req_callback_data(subreq,

    struct tevent_req);

  struct winbind_check_password_state *state =

    tevent_req_data(req,

    struct winbind_check_password_state);

  struct auth_method_context *ctx = state->ctx;

  const struct auth_usersupplied_info *user_info = state->user_info;

  struct ldb_dn *domain_dn = NULL;

  const char *nt4_domain = NULL;

  const char *nt4_account = NULL;

  struct ldb_message *msg = NULL;

  NTSTATUS status;

  status = dcerpc_winbind_SamLogon_r_recv(subreq, state);

  if (NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT)) {

    status = NT_STATUS_NO_LOGON_SERVERS;

  }

  TALLOC_FREE(subreq);

  if (tevent_req_nterror(req, status)) {

    return;

  }

  status = state->req.out.result;

  if (!NT_STATUS_IS_OK(status)) {

    if (!state->req.out.authoritative) {

      state->authoritative = false;

    }

    tevent_req_nterror(req, status);

    return;

  }

  status = make_user_info_dc_netlogon_validation(state,

                  user_info->client.account_name,

                  state->req.in.validation_level,

                  &state->req.out.validation,

                  true, /* This user was authenticated */

                  &state->user_info_dc);

  if (tevent_req_nterror(req, status)) {

    return;

  }

  nt4_domain = state->user_info_dc->info->domain_name;

  nt4_account = state->user_info_dc->info->account_name;

  if (lpcfg_is_mydomain(ctx->auth_ctx->lp_ctx, nt4_domain)) {

    domain_dn = ldb_get_default_basedn(ctx->auth_ctx->sam_ctx);

  }

  if (domain_dn != NULL) {

    /*

     * At best, reset the badPwdCount to 0 if the account exists.

     * This means that lockouts happen at a badPwdCount earlier than

     * normal, but makes it more fault tolerant.

     */

    status = authsam_search_account(state, ctx->auth_ctx->sam_ctx,

            nt4_account, domain_dn, &msg);

    if (NT_STATUS_IS_OK(status)) {

      status = authsam_logon_success_accounting(

        ctx->auth_ctx->sam_ctx, msg,

        domain_dn,

        user_info->flags & USER_INFO_INTERACTIVE_LOGON,

        NULL, NULL);

      if (tevent_req_nterror(req, status)) {

        return;

      }

    }

  }

  /*

   * We need to expand group memberships within our local domain,

   * as the token might be generated by a trusted domain, unless we're

   * an RODC.

   */

  status = authsam_update_user_info_dc(state->user_info_dc,

               ctx->auth_ctx->sam_ctx,

               state->user_info_dc);

  if (tevent_req_nterror(req, status)) {

    return;

  }

  tevent_req_done(req);

}

static NTSTATUS winbind_check_password_recv(struct tevent_req *req,

              TALLOC_CTX *mem_ctx,

              struct auth_user_info_dc **user_info_dc,

              const struct authn_audit_info **client_audit_info,

              const struct authn_audit_info **server_audit_info,

              bool *pauthoritative)

{

  struct winbind_check_password_state *state =

    tevent_req_data(req,

    struct winbind_check_password_state);

  NTSTATUS status = NT_STATUS_OK;

  *pauthoritative = state->authoritative;

  *client_audit_info = NULL;

  *server_audit_info = NULL;

  if (tevent_req_is_nterror(req, &status)) {

    tevent_req_received(req);

    return status;

  }

  *user_info_dc = talloc_move(mem_ctx, &state->user_info_dc);

  tevent_req_received(req);

  return NT_STATUS_OK;

}

static const struct auth_operations winbind_ops = {

  .name     = "winbind",

  .want_check   = winbind_want_check,

  .check_password_send  = winbind_check_password_send,

  .check_password_recv  = winbind_check_password_recv

};

_PUBLIC_ NTSTATUS auth4_winbind_init(TALLOC_CTX *ctx)

{

  NTSTATUS ret;

  ret = auth_register(ctx, &winbind_ops);

  if (!NT_STATUS_IS_OK(ret)) {

    DEBUG(0,("Failed to register 'winbind' auth backend!\n"));

    return ret;

  }

  return NT_STATUS_OK;

}