/*

   Unix SMB/CIFS implementation.

   Password and authentication handling

   Copyright (C) Andrew Bartlett         2001-2002

   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 "auth.h"

#include "../lib/tsocket/tsocket.h"

#include "param/param.h"

#include "../lib/messaging/messaging.h"

#include "lib/global_contexts.h"

#undef DBGC_CLASS

#define DBGC_CLASS DBGC_AUTH

static_decl_auth;

static struct auth_init_function_entry *auth_backends = NULL;

static struct auth_init_function_entry *auth_find_backend_entry(const char *name);

NTSTATUS smb_register_auth(int version, const char *name, auth_init_function init)

{

  struct auth_init_function_entry *entry = NULL;

  if (version != AUTH_INTERFACE_VERSION) {

    DEBUG(0,("Can't register auth_method!\n"

       "You tried to register an auth module with AUTH_INTERFACE_VERSION %d, while this version of samba uses %d\n",

       version,AUTH_INTERFACE_VERSION));

    return NT_STATUS_OBJECT_TYPE_MISMATCH;

  }

  if (!name || !init) {

    return NT_STATUS_INVALID_PARAMETER;

  }

  DEBUG(5,("Attempting to register auth backend %s\n", name));

  if (auth_find_backend_entry(name)) {

    DEBUG(0,("There already is an auth method registered with the name %s!\n", name));

    return NT_STATUS_OBJECT_NAME_COLLISION;

  }

  entry = SMB_XMALLOC_P(struct auth_init_function_entry);

  entry->name = smb_xstrdup(name);

  entry->init = init;

  DLIST_ADD(auth_backends, entry);

  DEBUG(5,("Successfully added auth method '%s'\n", name));

  return NT_STATUS_OK;

}

static struct auth_init_function_entry *auth_find_backend_entry(const char *name)

{

  struct auth_init_function_entry *entry = auth_backends;

  while(entry) {

    if (strcmp(entry->name, name)==0) return entry;

    entry = entry->next;

  }

  return NULL;

}

/****************************************************************************

 Try to get a challenge out of the various authentication modules.

 Returns a const char of length 8 bytes.

****************************************************************************/

NTSTATUS auth_get_ntlm_challenge(struct auth_context *auth_context,

         uint8_t chal[8])

{

  if (auth_context->challenge.length) {

    DBG_INFO("get_ntlm_challenge (auth subsystem): returning "

       "previous challenge by module %s (normal)\n",

        auth_context->challenge_set_by);

    memcpy(chal, auth_context->challenge.data, 8);

    return NT_STATUS_OK;

  }

  auth_context->challenge = data_blob_talloc(auth_context, NULL, 8);

  if (auth_context->challenge.data == NULL) {

    DBG_WARNING("data_blob_talloc failed\n");

    return NT_STATUS_NO_MEMORY;

  }

  generate_random_buffer(

    auth_context->challenge.data, auth_context->challenge.length);

  auth_context->challenge_set_by = "random";

  memcpy(chal, auth_context->challenge.data, 8);

  return NT_STATUS_OK;

}

/**

 * Check user is in correct domain (if required)

 *

 * @param user Only used to fill in the debug message

 *

 * @param domain The domain to be verified

 *

 * @return True if the user can connect with that domain,

 *         False otherwise.

**/

static bool check_domain_match(const char *user, const char *domain)

{

  /*

   * If we aren't serving to trusted domains, we must make sure that

   * the validation request comes from an account in the same domain

   * as the Samba server

   */

  if (!lp_allow_trusted_domains() &&

      !(strequal("", domain) ||

        strequal(lp_workgroup(), domain) ||

        is_myname(domain))) {

    DEBUG(1, ("check_domain_match: Attempt to connect as user %s from domain %s denied.\n", user, domain));

    return False;

  } else {

    return True;

  }

}

/**

 * Check a user's Plaintext, LM or NTLM password.

 *

 * Check a user's password, as given in the user_info struct and return various

 * interesting details in the server_info struct.

 *

 * This function does NOT need to be in a become_root()/unbecome_root() pair

 * as it makes the calls itself when needed.

 *

 * The return value takes precedence over the contents of the server_info

 * struct.  When the return is other than NT_STATUS_OK the contents

 * of that structure is undefined.

 *

 * @param user_info Contains the user supplied components, including the passwords.

 *                  Must be created with make_user_info() or one of its wrappers.

 *

 * @param auth_context Supplies the challenges and some other data.

 *                  Must be created with make_auth_context(), and the challenges should be

 *                  filled in, either at creation or by calling the challenge generation

 *                  function auth_get_challenge().

 *

 * @param pserver_info If successful, contains information about the authentication,

 *                     including a struct samu struct describing the user.

 *

 * @param pauthoritative Indicates if the result should be treated as final

 *                       result.

 *

 * @return An NTSTATUS with NT_STATUS_OK or an appropriate error.

 *

 **/

NTSTATUS auth_check_ntlm_password(TALLOC_CTX *mem_ctx,

          const struct auth_context *auth_context,

          const struct auth_usersupplied_info *user_info,

          struct auth_serversupplied_info **pserver_info,

          uint8_t *pauthoritative)

{

  TALLOC_CTX *frame;

  const char *auth_method_name = "";

  /* if all the modules say 'not for me' this is reasonable */

  NTSTATUS nt_status = NT_STATUS_NOT_IMPLEMENTED;

  const char *unix_username;

  struct auth_methods *auth_method;

  struct auth_serversupplied_info *server_info = NULL;

  struct dom_sid sid = {0};

  struct imessaging_context *msg_ctx = NULL;

  struct loadparm_context *lp_ctx = NULL;

  if (user_info == NULL || auth_context == NULL || pserver_info == NULL) {

    return NT_STATUS_LOGON_FAILURE;

  }

  frame = talloc_stackframe();

  if (lp_auth_event_notification()) {

    lp_ctx = loadparm_init_s3(frame, loadparm_s3_helpers());

    msg_ctx = imessaging_client_init(

        frame, lp_ctx, global_event_context());

  }

  *pauthoritative = 1;

  DBG_NOTICE("check_ntlm_password:  Checking password for unmapped user "

       "[%s]\\[%s]@[%s] with the new password interface\n",

       user_info->client.domain_name,

       user_info->client.account_name,

       user_info->workstation_name);

  DBG_NOTICE("check_ntlm_password:  mapped user is: [%s]\\[%s]@[%s]\n",

       user_info->mapped.domain_name,

       user_info->mapped.account_name,

       user_info->workstation_name);

  if (auth_context->challenge.length != 8) {

    DEBUG(0, ("check_ntlm_password:  Invalid challenge stored for this auth context - cannot continue\n"));

    nt_status = NT_STATUS_LOGON_FAILURE;

    goto fail;

  }

  if (auth_context->challenge_set_by)

    DEBUG(10, ("check_ntlm_password: auth_context challenge created by %s\n",

          auth_context->challenge_set_by));

  DEBUG(10, ("challenge is: \n"));

  dump_data(5, auth_context->challenge.data, auth_context->challenge.length);

#ifdef DEBUG_PASSWORD

  DEBUG(100, ("user_info has passwords of length %d and %d\n",

        (int)user_info->password.response.lanman.length, (int)user_info->password.response.nt.length));

  DEBUG(100, ("lm:\n"));

  dump_data(100, user_info->password.response.lanman.data, user_info->password.response.lanman.length);

  DEBUG(100, ("nt:\n"));

  dump_data(100, user_info->password.response.nt.data, user_info->password.response.nt.length);

#endif

  /* This needs to be sorted:  If it doesn't match, what should we do? */

  if (!check_domain_match(user_info->client.account_name,

        user_info->mapped.domain_name)) {

    nt_status = NT_STATUS_LOGON_FAILURE;

    goto fail;

  }

  for (auth_method = auth_context->auth_method_list;auth_method; auth_method = auth_method->next) {

    auth_method_name = auth_method->name;

    nt_status = auth_method->auth(auth_context,

                auth_method->private_data,

                talloc_tos(),

                user_info,

                &server_info);

    if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_NOT_IMPLEMENTED)) {

      break;

    }

    DBG_DEBUG("%s had nothing to say\n", auth_method->name);

  }

  if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NOT_IMPLEMENTED)) {

    *pauthoritative = 0;

    nt_status = NT_STATUS_NO_SUCH_USER;

  }

  if (!NT_STATUS_IS_OK(nt_status)) {

    DBG_INFO("%s authentication for user [%s] FAILED with "

       "error %s, authoritative=%u\n",

       auth_method_name,

       user_info->client.account_name,

       nt_errstr(nt_status),

       *pauthoritative);

    goto fail;

  }

  DBG_NOTICE("%s authentication for user [%s] succeeded\n",

       auth_method_name, user_info->client.account_name);

  unix_username = server_info->unix_name;

  /* We skip doing this step if the caller asked us not to */

  if (!(user_info->flags & USER_INFO_INFO3_AND_NO_AUTHZ)

      && !(server_info->guest)) {

    const char *rhost;

    if (tsocket_address_is_inet(user_info->remote_host, "ip")) {

      rhost = tsocket_address_inet_addr_string(

        user_info->remote_host, talloc_tos());

      if (rhost == NULL) {

        nt_status = NT_STATUS_NO_MEMORY;

        goto fail;

      }

    } else {

      rhost = "127.0.0.1";

    }

    /* We might not be root if we are an RPC call */

    become_root();

    nt_status = smb_pam_accountcheck(unix_username, rhost);

    unbecome_root();

    if (NT_STATUS_IS_OK(nt_status)) {

      DEBUG(5, ("check_ntlm_password:  PAM Account for user [%s] "

          "succeeded\n", unix_username));

    } else {

      DEBUG(3, ("check_ntlm_password:  PAM Account for user [%s] "

          "FAILED with error %s\n",

          unix_username, nt_errstr(nt_status)));

    }

  }

  if (!NT_STATUS_IS_OK(nt_status)) {

    goto fail;

  }

  nt_status = get_user_sid_info3_and_extra(server_info->info3,

             &server_info->extra,

             &sid);

  if (!NT_STATUS_IS_OK(nt_status)) {

    sid = (struct dom_sid) {0};

  }

  log_authentication_event(msg_ctx,

         lp_ctx,

         &auth_context->start_time,

         user_info,

         nt_status,

         server_info->info3->base.logon_domain.string,

         server_info->info3->base.account_name.string,

         &sid,

         NULL /* client_audit_info */,

         NULL /* server_audit_info */);

  DEBUG(server_info->guest ? 5 : 2,

        ("check_ntlm_password:  %sauthentication for user "

         "[%s] -> [%s] -> [%s] succeeded\n",

         server_info->guest ? "guest " : "",

         user_info->client.account_name,

         user_info->mapped.account_name,

         unix_username));

  *pserver_info = talloc_move(mem_ctx, &server_info);

  TALLOC_FREE(frame);

  return NT_STATUS_OK;

fail:

  /* failed authentication; check for guest lapping */

  /*

   * Please try not to change this string, it is probably in use

   * in audit logging tools

   */

  DEBUG(2, ("check_ntlm_password:  Authentication for user "

      "[%s] -> [%s] FAILED with error %s, authoritative=%u\n",

      user_info->client.account_name, user_info->mapped.account_name,

      nt_errstr(nt_status), *pauthoritative));

  log_authentication_event(msg_ctx,

         lp_ctx,

         &auth_context->start_time,

         user_info,

         nt_status,

         NULL,

         NULL,

         NULL,

         NULL /* client_audit_info */,

         NULL /* server_audit_info */);

  ZERO_STRUCTP(pserver_info);

  TALLOC_FREE(frame);

  return nt_status;

}

/***************************************************************************

 Clear out a auth_context, and destroy the attached TALLOC_CTX

***************************************************************************/

static int auth_context_destructor(void *ptr)

{

  struct auth_context *ctx = talloc_get_type(ptr, struct auth_context);

  struct auth_methods *am;

  /* Free private data of context's authentication methods */

  for (am = ctx->auth_method_list; am; am = am->next) {

    TALLOC_FREE(am->private_data);

  }

  return 0;

}

/***************************************************************************

 Make a auth_info struct

***************************************************************************/

static NTSTATUS make_auth_context(TALLOC_CTX *mem_ctx,

          struct auth_context **auth_context)

{

  struct auth_context *ctx;

  ctx = talloc_zero(mem_ctx, struct auth_context);

  if (!ctx) {

    DEBUG(0,("make_auth_context: talloc failed!\n"));

    return NT_STATUS_NO_MEMORY;

  }

  ctx->start_time = timeval_current();

  talloc_set_destructor((TALLOC_CTX *)ctx, auth_context_destructor);

  *auth_context = ctx;

  return NT_STATUS_OK;

}

static bool load_auth_module(

  struct auth_context *auth_context,

  const char *module,

  struct auth_methods **ret)

{

  static bool initialised_static_modules = False;

  struct auth_init_function_entry *entry;

  char *module_name = smb_xstrdup(module);

  char *module_params = NULL;

  char *p;

  bool good = False;

  /* Initialise static modules if not done so yet */

  if(!initialised_static_modules) {

    static_init_auth(NULL);

    initialised_static_modules = True;

  }

  DEBUG(5,("load_auth_module: Attempting to find an auth method to match %s\n",

     module));

  p = strchr(module_name, ':');

  if (p) {

    *p = 0;

    module_params = p+1;

    trim_char(module_params, ' ', ' ');

  }

  trim_char(module_name, ' ', ' ');

  entry = auth_find_backend_entry(module_name);

  if (entry == NULL) {

    if (NT_STATUS_IS_OK(smb_probe_module("auth", module_name))) {

      entry = auth_find_backend_entry(module_name);

    }

  }

  if (entry != NULL) {

    if (!NT_STATUS_IS_OK(entry->init(auth_context, module_params, ret))) {

      DEBUG(0,("load_auth_module: auth method %s did not correctly init\n",

         module_name));

    } else {

      DEBUG(5,("load_auth_module: auth method %s has a valid init\n",

         module_name));

      good = True;

    }

  } else {

    DEBUG(0,("load_auth_module: can't find auth method %s!\n", module_name));

  }

  SAFE_FREE(module_name);

  return good;

}

/***************************************************************************

 Make a auth_info struct for the auth subsystem

***************************************************************************/

static NTSTATUS make_auth_context_text_list(TALLOC_CTX *mem_ctx,

              struct auth_context **auth_context,

              char **text_list)

{

  struct auth_methods *list = NULL;

  struct auth_methods *t, *method = NULL;

  NTSTATUS nt_status;

  if (!text_list) {

    DEBUG(2,("make_auth_context_text_list: No auth method list!?\n"));

    return NT_STATUS_UNSUCCESSFUL;

  }

  nt_status = make_auth_context(mem_ctx, auth_context);

  if (!NT_STATUS_IS_OK(nt_status)) {

    return nt_status;

  }

  for (;*text_list; text_list++) {

    if (load_auth_module(*auth_context, *text_list, &t)) {

        DLIST_ADD_END(list, t);

    }

  }

  (*auth_context)->auth_method_list = list;

  /* Look for the first module to provide a prepare_gensec and

   * make_auth4_context hook, and set that if provided */

  for (method = (*auth_context)->auth_method_list; method; method = method->next) {

    if (method->prepare_gensec && method->make_auth4_context) {

      (*auth_context)->prepare_gensec = method->prepare_gensec;

      (*auth_context)->make_auth4_context = method->make_auth4_context;

      break;

    }

  }

  return NT_STATUS_OK;

}

static NTSTATUS make_auth_context_specific(TALLOC_CTX *mem_ctx,

             struct auth_context **auth_context,

             const char *methods)

{

  char **method_list;

  NTSTATUS status;

  method_list = str_list_make_v3(talloc_tos(), methods, NULL);

  if (method_list == NULL) {

    return NT_STATUS_NO_MEMORY;

  }

  status = make_auth_context_text_list(

    mem_ctx, auth_context, method_list);

  TALLOC_FREE(method_list);

  return status;

}

/***************************************************************************

 Make a auth_context struct for the auth subsystem

***************************************************************************/

NTSTATUS make_auth3_context_for_ntlm(TALLOC_CTX *mem_ctx,

             struct auth_context **auth_context)

{

  const char *methods = NULL;

  const char *role = NULL;

  switch (lp_server_role()) {

  case ROLE_ACTIVE_DIRECTORY_DC:

    role = "'active directory domain controller'";

    methods = "samba4";

    break;

  case ROLE_DOMAIN_MEMBER:

    role = "'domain member'";

    methods = "anonymous sam winbind sam_ignoredomain";

    break;

  case ROLE_DOMAIN_BDC:

  case ROLE_DOMAIN_PDC:

  case ROLE_IPA_DC:

    role = "'DC'";

    methods = "anonymous sam winbind sam_ignoredomain";

    break;

  case ROLE_STANDALONE:

    if (lp_encrypt_passwords()) {

      role = "'standalone server', encrypt passwords = yes";

      methods = "anonymous sam_ignoredomain";

    } else {

      role = "'standalone server', encrypt passwords = no";

      methods = "anonymous unix";

    }

    break;

  default:

    DEBUG(5,("Unknown auth method!\n"));

    return NT_STATUS_UNSUCCESSFUL;

  }

  DBG_INFO("Making default auth method list for server role = %s\n",

     role);

  return make_auth_context_specific(mem_ctx, auth_context, methods);

}

NTSTATUS make_auth3_context_for_netlogon(TALLOC_CTX *mem_ctx,

           struct auth_context **auth_context)

{

  const char *methods = NULL;

  NTSTATUS status;

  switch (lp_server_role()) {

  case ROLE_DOMAIN_BDC:

  case ROLE_DOMAIN_PDC:

  case ROLE_IPA_DC:

    methods = "sam_netlogon3 winbind";

    break;

  default:

    DBG_ERR("Invalid server role!\n");

    return NT_STATUS_INVALID_SERVER_STATE;

  }

  status = make_auth_context_specific(mem_ctx, auth_context, methods);

  if (!NT_STATUS_IS_OK(status)) {

    return status;

  }

  (*auth_context)->for_netlogon = true;

  return NT_STATUS_OK;

}

NTSTATUS make_auth3_context_for_winbind(TALLOC_CTX *mem_ctx,

                struct auth_context **auth_context)

{

  const char *methods = NULL;

  switch (lp_server_role()) {

  case ROLE_STANDALONE:

  case ROLE_DOMAIN_MEMBER:

  case ROLE_DOMAIN_BDC:

  case ROLE_DOMAIN_PDC:

  case ROLE_IPA_DC:

    methods = "sam";

    break;

  case ROLE_ACTIVE_DIRECTORY_DC:

    methods = "samba4:sam";

    break;

  default:

    DEBUG(5,("Unknown auth method!\n"));

    return NT_STATUS_UNSUCCESSFUL;

  }

  return make_auth_context_specific(mem_ctx, auth_context, methods);

}

bool auth3_context_set_challenge(

  struct auth_context *ctx,

  const uint8_t chal[8],

  const char *challenge_set_by)

{

  ctx->challenge = data_blob_talloc(ctx, chal, 8);

  if (ctx->challenge.data == NULL) {

    return false;

  }

  ctx->challenge_set_by = talloc_strdup(ctx, challenge_set_by);

  if (ctx->challenge_set_by == NULL) {

    return false;

  }

  return true;

}