s3-winbindd: Allow DNS resolution of trusted domains if DNS name is avaliable

[Samba/id10ts.git] / source3 / auth / auth.c

/* 
   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"

#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 = auth_backends;

        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])
{
        uchar tmp[8];


        if (auth_context->challenge.length) {
                DEBUG(5, ("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;
        }

        generate_random_buffer(tmp, sizeof(tmp));
        auth_context->challenge = data_blob_talloc(auth_context,
                                                   tmp, sizeof(tmp));

        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 geneation 
 *                  function auth_get_challenge().  
 *
 * @param server_info If successful, contains information about the authentication, 
 *                    including a struct samu struct describing the user.
 *
 * @return An NTSTATUS with NT_STATUS_OK or an appropriate error.
 *
 **/

NTSTATUS auth_check_ntlm_password(const struct auth_context *auth_context,
                                  const struct auth_usersupplied_info *user_info, 
                                  struct auth_serversupplied_info **server_info)
{
        /* if all the modules say 'not for me' this is reasonable */
        NTSTATUS nt_status = NT_STATUS_NO_SUCH_USER;
        const char *unix_username;
        auth_methods *auth_method;
        TALLOC_CTX *mem_ctx;

        if (!user_info || !auth_context || !server_info)
                return NT_STATUS_LOGON_FAILURE;

        DEBUG(3, ("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));

        DEBUG(3, ("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"));
                return NT_STATUS_LOGON_FAILURE;
        }

        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))
                return NT_STATUS_LOGON_FAILURE;

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

                mem_ctx = talloc_init("%s authentication for user %s\\%s", auth_method->name,
                                      user_info->mapped.domain_name, user_info->client.account_name);

                result = auth_method->auth(auth_context, auth_method->private_data, mem_ctx, user_info, server_info);

                /* check if the module did anything */
                if ( NT_STATUS_V(result) == NT_STATUS_V(NT_STATUS_NOT_IMPLEMENTED) ) {
                        DEBUG(10,("check_ntlm_password: %s had nothing to say\n", auth_method->name));
                        talloc_destroy(mem_ctx);
                        continue;
                }

                nt_status = result;

                if (NT_STATUS_IS_OK(nt_status)) {
                        DEBUG(3, ("check_ntlm_password: %s authentication for user [%s] succeeded\n", 
                                  auth_method->name, user_info->client.account_name));
                } else {
                        DEBUG(5, ("check_ntlm_password: %s authentication for user [%s] FAILED with error %s\n", 
                                  auth_method->name, user_info->client.account_name, nt_errstr(nt_status)));
                }

                talloc_destroy(mem_ctx);

                if ( NT_STATUS_IS_OK(nt_status))
                {
                                break;                  
                }
        }

        /* successful authentication */

        if (NT_STATUS_IS_OK(nt_status)) {
                unix_username = (*server_info)->unix_name;
                if (!(*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) {
                                        return NT_STATUS_NO_MEMORY;
                                }
                        } 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)) {
                        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));
                }

                return nt_status;
        }

        /* failed authentication; check for guest lapping */

        DEBUG(2, ("check_ntlm_password:  Authentication for user [%s] -> [%s] FAILED with error %s\n",
                  user_info->client.account_name, user_info->mapped.account_name,
                  nt_errstr(nt_status)));
        ZERO_STRUCTP(server_info);

        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;
        }

        talloc_set_destructor((TALLOC_CTX *)ctx, auth_context_destructor);

        *auth_context = ctx;
        return NT_STATUS_OK;
}

bool load_auth_module(struct auth_context *auth_context, 
                      const char *module, 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;
                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)
{
        auth_methods *list = NULL;
        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_methods *);
                }
        }

        (*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;
}

/***************************************************************************
 Make a auth_context struct for the auth subsystem
***************************************************************************/

NTSTATUS make_auth_context_subsystem(TALLOC_CTX *mem_ctx,
                                     struct auth_context **auth_context)
{
        char **auth_method_list = NULL; 
        NTSTATUS nt_status;

        if (lp_auth_methods()
            && !(auth_method_list = str_list_copy(talloc_tos(), 
                              lp_auth_methods()))) {
                return NT_STATUS_NO_MEMORY;
        }

        if (auth_method_list == NULL) {
                switch (lp_server_role()) 
                {
                case ROLE_DOMAIN_MEMBER:
                        DEBUG(5,("Making default auth method list for server role = 'domain member'\n"));
                        auth_method_list = str_list_make_v3(
                                talloc_tos(), "guest sam winbind:ntdomain",
                                NULL);
                        break;
                case ROLE_DOMAIN_BDC:
                case ROLE_DOMAIN_PDC:
                        DEBUG(5,("Making default auth method list for DC\n"));
                        auth_method_list = str_list_make_v3(
                                talloc_tos(),
                                "guest sam winbind:trustdomain",
                                NULL);
                        break;
                case ROLE_STANDALONE:
                        DEBUG(5,("Making default auth method list for server role = 'standalone server', encrypt passwords = yes\n"));
                        if (lp_encrypted_passwords()) {
                                auth_method_list = str_list_make_v3(
                                                talloc_tos(), "guest sam",
                                                NULL);
                        } else {
                                DEBUG(5,("Making default auth method list for server role = 'standalone server', encrypt passwords = no\n"));
                                auth_method_list = str_list_make_v3(
                                        talloc_tos(), "guest unix", NULL);
                        }
                        break;
                case ROLE_ACTIVE_DIRECTORY_DC:
                        DEBUG(5,("Making default auth method list for server role = 'active directory domain controller'\n"));
                        auth_method_list = str_list_make_v3(
                                talloc_tos(),
                                "samba4",
                                NULL);
                        break;
                default:
                        DEBUG(5,("Unknown auth method!\n"));
                        return NT_STATUS_UNSUCCESSFUL;
                }
        } else {
                DEBUG(5,("Using specified auth order\n"));
        }

        nt_status = make_auth_context_text_list(mem_ctx, auth_context,
                                                auth_method_list);

        TALLOC_FREE(auth_method_list);
        return nt_status;
}

/***************************************************************************
 Make a auth_info struct with a fixed challenge
***************************************************************************/

NTSTATUS make_auth_context_fixed(TALLOC_CTX *mem_ctx,
                                 struct auth_context **auth_context,
                                 uchar chal[8])
{
        NTSTATUS nt_status;
        nt_status = make_auth_context_subsystem(mem_ctx, auth_context);
        if (!NT_STATUS_IS_OK(nt_status)) {
                return nt_status;
        }

        (*auth_context)->challenge = data_blob_talloc(*auth_context, chal, 8);
        (*auth_context)->challenge_set_by = "fixed";
        return nt_status;
}