s3:auth_winbind: remove fallback to optional backend

[Samba.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 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;
        auth_methods *auth_method;
        struct auth_serversupplied_info *server_info = NULL;
        struct dom_sid sid = {0};

        if (user_info == NULL || auth_context == NULL || pserver_info == NULL) {
                return NT_STATUS_LOGON_FAILURE;
        }

        frame = talloc_stackframe();

        *pauthoritative = 1;

        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"));
                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(NULL, NULL,
                                 &auth_context->start_time,
                                 user_info,
                                 nt_status,
                                 server_info->info3->base.logon_domain.string,
                                 server_info->info3->base.account_name.string,
                                 unix_username, &sid);

        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(NULL,
                                 NULL,
                                 &auth_context->start_time,
                                 user_info,
                                 nt_status,
                                 NULL,
                                 NULL,
                                 NULL,
                                 NULL);

        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;
}

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(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)
{
        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_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;

        switch (lp_server_role()) {
        case ROLE_ACTIVE_DIRECTORY_DC:
                DEBUG(5,("Making default auth method list for server role = "
                         "'active directory domain controller'\n"));
                methods = "samba4";
                break;
        case ROLE_DOMAIN_MEMBER:
                DEBUG(5,("Making default auth method list for server role = 'domain member'\n"));
                methods = "anonymous sam winbind sam_ignoredomain";
                break;
        case ROLE_DOMAIN_BDC:
        case ROLE_DOMAIN_PDC:
                DEBUG(5,("Making default auth method list for DC\n"));
                methods = "anonymous sam winbind sam_ignoredomain";
                break;
        case ROLE_STANDALONE:
                DEBUG(5,("Making default auth method list for server role = 'standalone server', encrypt passwords = yes\n"));
                if (lp_encrypt_passwords()) {
                        methods = "anonymous sam_ignoredomain";
                } else {
                        DEBUG(5,("Making default auth method list for server role = 'standalone server', encrypt passwords = no\n"));
                        methods = "anonymous unix";
                }
                break;
        default:
                DEBUG(5,("Unknown auth method!\n"));
                return NT_STATUS_UNSUCCESSFUL;
        }

        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;

        switch (lp_server_role()) {
        case ROLE_DOMAIN_BDC:
        case ROLE_DOMAIN_PDC:
                methods = "sam_netlogon3 winbind";
                break;

        default:
                DBG_ERR("Invalid server role!\n");
                return NT_STATUS_INVALID_SERVER_STATE;
        }

        return make_auth_context_specific(mem_ctx, auth_context, methods);
}

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:
                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, 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;
}