dnsp: Parse TXT records

[Samba/gebeck_regimport.git] / source3 / smbd / password.c

/*
   Unix SMB/CIFS implementation.
   Password and authentication handling
   Copyright (C) Andrew Tridgell 1992-1998
   Copyright (C) Jeremy Allison 2007.

   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 "smbd/globals.h"
#include "../librpc/gen_ndr/netlogon.h"

/* Fix up prototypes for OSX 10.4, where they're missing */
#ifndef HAVE_SETNETGRENT_PROTOTYPE
extern int setnetgrent(const char* netgroup);
#endif
#ifndef HAVE_GETNETGRENT_PROTOTYPE
extern int getnetgrent(char **host, char **user, char **domain);
#endif
#ifndef HAVE_ENDNETGRENT_PROTOTYPE
extern void endnetgrent(void);
#endif

enum server_allocated_state { SERVER_ALLOCATED_REQUIRED_YES,
                                SERVER_ALLOCATED_REQUIRED_NO,
                                SERVER_ALLOCATED_REQUIRED_ANY};

static user_struct *get_valid_user_struct_internal(
                        struct smbd_server_connection *sconn,
                        uint16 vuid,
                        enum server_allocated_state server_allocated)
{
        user_struct *usp;
        int count=0;

        if (vuid == UID_FIELD_INVALID)
                return NULL;

        usp=sconn->smb1.sessions.validated_users;
        for (;usp;usp=usp->next,count++) {
                if (vuid == usp->vuid) {
                        switch (server_allocated) {
                                case SERVER_ALLOCATED_REQUIRED_YES:
                                        if (usp->server_info == NULL) {
                                                continue;
                                        }
                                        break;
                                case SERVER_ALLOCATED_REQUIRED_NO:
                                        if (usp->server_info != NULL) {
                                                continue;
                                        }
                                case SERVER_ALLOCATED_REQUIRED_ANY:
                                        break;
                        }
                        if (count > 10) {
                                DLIST_PROMOTE(sconn->smb1.sessions.validated_users,
                                              usp);
                        }
                        return usp;
                }
        }

        return NULL;
}

/****************************************************************************
 Check if a uid has been validated, and return an pointer to the user_struct
 if it has. NULL if not. vuid is biased by an offset. This allows us to
 tell random client vuid's (normally zero) from valid vuids.
****************************************************************************/

user_struct *get_valid_user_struct(struct smbd_server_connection *sconn,
                                   uint16 vuid)
{
        return get_valid_user_struct_internal(sconn, vuid,
                        SERVER_ALLOCATED_REQUIRED_YES);
}

bool is_partial_auth_vuid(struct smbd_server_connection *sconn, uint16 vuid)
{
        return (get_partial_auth_user_struct(sconn, vuid) != NULL);
}

/****************************************************************************
 Get the user struct of a partial NTLMSSP login
****************************************************************************/

user_struct *get_partial_auth_user_struct(struct smbd_server_connection *sconn,
                                          uint16 vuid)
{
        return get_valid_user_struct_internal(sconn, vuid,
                        SERVER_ALLOCATED_REQUIRED_NO);
}

/****************************************************************************
 Invalidate a uid.
****************************************************************************/

void invalidate_vuid(struct smbd_server_connection *sconn, uint16 vuid)
{
        user_struct *vuser = NULL;

        vuser = get_valid_user_struct_internal(sconn, vuid,
                        SERVER_ALLOCATED_REQUIRED_ANY);
        if (vuser == NULL) {
                return;
        }

        session_yield(vuser);

        if (vuser->auth_ntlmssp_state) {
                TALLOC_FREE(vuser->auth_ntlmssp_state);
        }

        DLIST_REMOVE(sconn->smb1.sessions.validated_users, vuser);

        /* clear the vuid from the 'cache' on each connection, and
           from the vuid 'owner' of connections */
        conn_clear_vuid_caches(sconn, vuid);

        TALLOC_FREE(vuser);
        sconn->smb1.sessions.num_validated_vuids--;
}

/****************************************************************************
 Invalidate all vuid entries for this process.
****************************************************************************/

void invalidate_all_vuids(struct smbd_server_connection *sconn)
{
        if (sconn->using_smb2) {
                return;
        }

        while (sconn->smb1.sessions.validated_users != NULL) {
                invalidate_vuid(sconn,
                                sconn->smb1.sessions.validated_users->vuid);
        }
}

static void increment_next_vuid(uint16_t *vuid)
{
        *vuid += 1;

        /* Check for vuid wrap. */
        if (*vuid == UID_FIELD_INVALID) {
                *vuid = VUID_OFFSET;
        }
}

/****************************************************
 Create a new partial auth user struct.
*****************************************************/

int register_initial_vuid(struct smbd_server_connection *sconn)
{
        user_struct *vuser;

        /* Paranoia check. */
        if(lp_security() == SEC_SHARE) {
                smb_panic("register_initial_vuid: "
                        "Tried to register uid in security=share");
        }

        /* Limit allowed vuids to 16bits - VUID_OFFSET. */
        if (sconn->smb1.sessions.num_validated_vuids >= 0xFFFF-VUID_OFFSET) {
                return UID_FIELD_INVALID;
        }

        if((vuser = talloc_zero(NULL, user_struct)) == NULL) {
                DEBUG(0,("register_initial_vuid: "
                                "Failed to talloc users struct!\n"));
                return UID_FIELD_INVALID;
        }

        /* Allocate a free vuid. Yes this is a linear search... */
        while( get_valid_user_struct_internal(sconn,
                        sconn->smb1.sessions.next_vuid,
                        SERVER_ALLOCATED_REQUIRED_ANY) != NULL ) {
                increment_next_vuid(&sconn->smb1.sessions.next_vuid);
        }

        DEBUG(10,("register_initial_vuid: allocated vuid = %u\n",
                (unsigned int)sconn->smb1.sessions.next_vuid ));

        vuser->vuid = sconn->smb1.sessions.next_vuid;

        /*
         * This happens in an unfinished NTLMSSP session setup. We
         * need to allocate a vuid between the first and second calls
         * to NTLMSSP.
         */
        increment_next_vuid(&sconn->smb1.sessions.next_vuid);
        sconn->smb1.sessions.num_validated_vuids++;

        DLIST_ADD(sconn->smb1.sessions.validated_users, vuser);
        return vuser->vuid;
}

int register_homes_share(const char *username)
{
        int result;
        struct passwd *pwd;

        result = lp_servicenumber(username);
        if (result != -1) {
                DEBUG(3, ("Using static (or previously created) service for "
                          "user '%s'; path = '%s'\n", username,
                          lp_pathname(result)));
                return result;
        }

        pwd = getpwnam_alloc(talloc_tos(), username);

        if ((pwd == NULL) || (pwd->pw_dir[0] == '\0')) {
                DEBUG(3, ("No home directory defined for user '%s'\n",
                          username));
                TALLOC_FREE(pwd);
                return -1;
        }

        DEBUG(3, ("Adding homes service for user '%s' using home directory: "
                  "'%s'\n", username, pwd->pw_dir));

        result = add_home_service(username, username, pwd->pw_dir);

        TALLOC_FREE(pwd);
        return result;
}

/**
 *  register that a valid login has been performed, establish 'session'.
 *  @param server_info The token returned from the authentication process.
 *   (now 'owned' by register_existing_vuid)
 *
 *  @param session_key The User session key for the login session (now also
 *  'owned' by register_existing_vuid)
 *
 *  @param respose_blob The NT challenge-response, if available.  (May be
 *  freed after this call)
 *
 *  @param smb_name The untranslated name of the user
 *
 *  @return Newly allocated vuid, biased by an offset. (This allows us to
 *   tell random client vuid's (normally zero) from valid vuids.)
 *
 */

int register_existing_vuid(struct smbd_server_connection *sconn,
                        uint16 vuid,
                        struct auth_serversupplied_info *server_info,
                        DATA_BLOB response_blob,
                        const char *smb_name)
{
        fstring tmp;
        user_struct *vuser;

        vuser = get_partial_auth_user_struct(sconn, vuid);
        if (!vuser) {
                goto fail;
        }

        /* Use this to keep tabs on all our info from the authentication */
        vuser->server_info = talloc_move(vuser, &server_info);

        /* This is a potentially untrusted username */
        alpha_strcpy(tmp, smb_name, ". _-$", sizeof(tmp));

        vuser->server_info->sanitized_username = talloc_strdup(
                vuser->server_info, tmp);

        DEBUG(10,("register_existing_vuid: (%u,%u) %s %s %s guest=%d\n",
                  (unsigned int)vuser->server_info->utok.uid,
                  (unsigned int)vuser->server_info->utok.gid,
                  vuser->server_info->unix_name,
                  vuser->server_info->sanitized_username,
                  vuser->server_info->info3->base.domain.string,
                  vuser->server_info->guest ));

        DEBUG(3, ("register_existing_vuid: User name: %s\t"
                  "Real name: %s\n", vuser->server_info->unix_name,
                  vuser->server_info->info3->base.full_name.string));

        if (!vuser->server_info->ptok) {
                DEBUG(1, ("register_existing_vuid: server_info does not "
                        "contain a user_token - cannot continue\n"));
                goto fail;
        }

        DEBUG(3,("register_existing_vuid: UNIX uid %d is UNIX user %s, "
                "and will be vuid %u\n", (int)vuser->server_info->utok.uid,
                 vuser->server_info->unix_name, vuser->vuid));

        if (!session_claim(sconn, vuser)) {
                DEBUG(1, ("register_existing_vuid: Failed to claim session "
                        "for vuid=%d\n",
                        vuser->vuid));
                goto fail;
        }

        /* Register a home dir service for this user if
        (a) This is not a guest connection,
        (b) we have a home directory defined
        (c) there s not an existing static share by that name
        If a share exists by this name (autoloaded or not) reuse it . */

        vuser->homes_snum = -1;

        if (!vuser->server_info->guest) {
                vuser->homes_snum = register_homes_share(
                        vuser->server_info->unix_name);
        }

        if (srv_is_signing_negotiated(sconn) &&
            !vuser->server_info->guest) {
                /* Try and turn on server signing on the first non-guest
                 * sessionsetup. */
                srv_set_signing(sconn,
                                vuser->server_info->user_session_key,
                                response_blob);
        }

        /* fill in the current_user_info struct */
        set_current_user_info(
                vuser->server_info->sanitized_username,
                vuser->server_info->unix_name,
                vuser->server_info->info3->base.domain.string);

        return vuser->vuid;

  fail:

        if (vuser) {
                invalidate_vuid(sconn, vuid);
        }
        return UID_FIELD_INVALID;
}

/****************************************************************************
 Add a name to the session users list.
****************************************************************************/

void add_session_user(struct smbd_server_connection *sconn,
                      const char *user)
{
        struct passwd *pw;
        char *tmp;

        pw = Get_Pwnam_alloc(talloc_tos(), user);

        if (pw == NULL) {
                return;
        }

        if (sconn->smb1.sessions.session_userlist == NULL) {
                sconn->smb1.sessions.session_userlist = SMB_STRDUP(pw->pw_name);
                goto done;
        }

        if (in_list(pw->pw_name,sconn->smb1.sessions.session_userlist,false)) {
                goto done;
        }

        if (strlen(sconn->smb1.sessions.session_userlist) > 128 * 1024) {
                DEBUG(3,("add_session_user: session userlist already "
                         "too large.\n"));
                goto done;
        }

        if (asprintf(&tmp, "%s %s",
                     sconn->smb1.sessions.session_userlist, pw->pw_name) == -1) {
                DEBUG(3, ("asprintf failed\n"));
                goto done;
        }

        SAFE_FREE(sconn->smb1.sessions.session_userlist);
        sconn->smb1.sessions.session_userlist = tmp;
 done:
        TALLOC_FREE(pw);
}

/****************************************************************************
 In security=share mode we need to store the client workgroup, as that's
  what Vista uses for the NTLMv2 calculation.
****************************************************************************/

void add_session_workgroup(struct smbd_server_connection *sconn,
                           const char *workgroup)
{
        if (sconn->smb1.sessions.session_workgroup) {
                SAFE_FREE(sconn->smb1.sessions.session_workgroup);
        }
        sconn->smb1.sessions.session_workgroup = smb_xstrdup(workgroup);
}

/****************************************************************************
 In security=share mode we need to return the client workgroup, as that's
  what Vista uses for the NTLMv2 calculation.
****************************************************************************/

const char *get_session_workgroup(struct smbd_server_connection *sconn)
{
        return sconn->smb1.sessions.session_workgroup;
}

/****************************************************************************
 Check if a username is valid.
****************************************************************************/

static bool user_ok(const char *user, int snum)
{
        bool ret;

        ret = True;

        if (lp_invalid_users(snum)) {
                char **invalid = str_list_copy(talloc_tos(),
                        lp_invalid_users(snum));
                if (invalid &&
                    str_list_substitute(invalid, "%S", lp_servicename(snum))) {

                        /* This is used in sec=share only, so no current user
                         * around to pass to str_list_sub_basic() */

                        if ( invalid && str_list_sub_basic(invalid, "", "") ) {
                                ret = !user_in_list(user,
                                                    (const char **)invalid);
                        }
                }
                TALLOC_FREE(invalid);
        }

        if (ret && lp_valid_users(snum)) {
                char **valid = str_list_copy(talloc_tos(),
                        lp_valid_users(snum));
                if ( valid &&
                     str_list_substitute(valid, "%S", lp_servicename(snum)) ) {

                        /* This is used in sec=share only, so no current user
                         * around to pass to str_list_sub_basic() */

                        if ( valid && str_list_sub_basic(valid, "", "") ) {
                                ret = user_in_list(user,
                                                   (const char **)valid);
                        }
                }
                TALLOC_FREE(valid);
        }

        if (ret && lp_onlyuser(snum)) {
                char **user_list = str_list_make_v3(
                        talloc_tos(), lp_username(snum), NULL);
                if (user_list &&
                    str_list_substitute(user_list, "%S",
                                        lp_servicename(snum))) {
                        ret = user_in_list(user,
                                           (const char **)user_list);
                }
                TALLOC_FREE(user_list);
        }

        return(ret);
}

/****************************************************************************
 Validate a group username entry. Return the username or NULL.
****************************************************************************/

static char *validate_group(struct smbd_server_connection *sconn,
                            char *group, DATA_BLOB password,int snum)
{
#ifdef HAVE_NETGROUP
        {
                char *host, *user, *domain;
                struct auth_context *actx = sconn->smb1.negprot.auth_context;
                bool enc = sconn->smb1.negprot.encrypted_passwords;
                setnetgrent(group);
                while (getnetgrent(&host, &user, &domain)) {
                        if (user) {
                                if (user_ok(user, snum) &&
                                    password_ok(actx, enc,
                                                get_session_workgroup(sconn),
                                                user,password)) {
                                        endnetgrent();
                                        return(user);
                                }
                        }
                }
                endnetgrent();
        }
#endif

#ifdef HAVE_GETGRENT
        {
                struct group *gptr;
                struct auth_context *actx = sconn->smb1.negprot.auth_context;
                bool enc = sconn->smb1.negprot.encrypted_passwords;

                setgrent();
                while ((gptr = (struct group *)getgrent())) {
                        if (strequal(gptr->gr_name,group))
                                break;
                }

                /*
                 * As user_ok can recurse doing a getgrent(), we must
                 * copy the member list onto the heap before
                 * use. Bug pointed out by leon@eatworms.swmed.edu.
                 */

                if (gptr) {
                        char *member_list = NULL;
                        size_t list_len = 0;
                        char *member;
                        int i;

                        for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
                                list_len += strlen(gptr->gr_mem[i])+1;
                        }
                        list_len++;

                        member_list = (char *)SMB_MALLOC(list_len);
                        if (!member_list) {
                                endgrent();
                                return NULL;
                        }

                        *member_list = '\0';
                        member = member_list;

                        for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
                                size_t member_len = strlen(gptr->gr_mem[i])+1;

                                DEBUG(10,("validate_group: = gr_mem = "
                                          "%s\n", gptr->gr_mem[i]));

                                safe_strcpy(member, gptr->gr_mem[i],
                                        list_len - (member-member_list));
                                member += member_len;
                        }

                        endgrent();

                        member = member_list;
                        while (*member) {
                                if (user_ok(member,snum) &&
                                    password_ok(actx, enc,
                                                get_session_workgroup(sconn),
                                                member,password)) {
                                        char *name = talloc_strdup(talloc_tos(),
                                                                member);
                                        SAFE_FREE(member_list);
                                        return name;
                                }

                                DEBUG(10,("validate_group = member = %s\n",
                                          member));

                                member += strlen(member) + 1;
                        }

                        SAFE_FREE(member_list);
                } else {
                        endgrent();
                        return NULL;
                }
        }
#endif
        return(NULL);
}

/****************************************************************************
 Check for authority to login to a service with a given username/password.
 Note this is *NOT* used when logging on using sessionsetup_and_X.
****************************************************************************/

bool authorise_login(struct smbd_server_connection *sconn,
                     int snum, fstring user, DATA_BLOB password,
                     bool *guest)
{
        bool ok = False;
        struct auth_context *actx = sconn->smb1.negprot.auth_context;
        bool enc = sconn->smb1.negprot.encrypted_passwords;

#ifdef DEBUG_PASSWORD
        DEBUG(100,("authorise_login: checking authorisation on "
                   "user=%s pass=%s\n", user,password.data));
#endif

        *guest = False;

        /* there are several possibilities:
                1) login as the given user with given password
                2) login as a previously registered username with the given
                   password
                3) login as a session list username with the given password
                4) login as a previously validated user/password pair
                5) login as the "user =" user with given password
                6) login as the "user =" user with no password
                   (guest connection)
                7) login as guest user with no password

                if the service is guest_only then steps 1 to 5 are skipped
        */

        /* now check the list of session users */
        if (!ok) {
                char *auser;
                char *user_list = NULL;
                char *saveptr;

                if (sconn->smb1.sessions.session_userlist)
                        user_list = SMB_STRDUP(sconn->smb1.sessions.session_userlist);
                else
                        user_list = SMB_STRDUP("");

                if (!user_list)
                        return(False);

                for (auser = strtok_r(user_list, LIST_SEP, &saveptr);
                     !ok && auser;
                     auser = strtok_r(NULL, LIST_SEP, &saveptr)) {
                        fstring user2;
                        fstrcpy(user2,auser);
                        if (!user_ok(user2,snum))
                                continue;

                        if (password_ok(actx, enc,
                                        get_session_workgroup(sconn),
                                        user2,password)) {
                                ok = True;
                                fstrcpy(user,user2);
                                DEBUG(3,("authorise_login: ACCEPTED: session "
                                         "list username (%s) and given "
                                         "password ok\n", user));
                        }
                }

                SAFE_FREE(user_list);
        }

        /* check the user= fields and the given password */
        if (!ok && lp_username(snum)) {
                TALLOC_CTX *ctx = talloc_tos();
                char *auser;
                char *user_list = talloc_strdup(ctx, lp_username(snum));
                char *saveptr;

                if (!user_list) {
                        goto check_guest;
                }

                user_list = talloc_string_sub(ctx,
                                user_list,
                                "%S",
                                lp_servicename(snum));

                if (!user_list) {
                        goto check_guest;
                }

                for (auser = strtok_r(user_list, LIST_SEP, &saveptr);
                     auser && !ok;
                     auser = strtok_r(NULL, LIST_SEP, &saveptr)) {
                        if (*auser == '@') {
                                auser = validate_group(sconn,auser+1,
                                                       password,snum);
                                if (auser) {
                                        ok = True;
                                        fstrcpy(user,auser);
                                        DEBUG(3,("authorise_login: ACCEPTED: "
                                                 "group username and given "
                                                 "password ok (%s)\n", user));
                                }
                        } else {
                                fstring user2;
                                fstrcpy(user2,auser);
                                if (user_ok(user2,snum) &&
                                    password_ok(actx, enc,
                                                get_session_workgroup(sconn),
                                                user2,password)) {
                                        ok = True;
                                        fstrcpy(user,user2);
                                        DEBUG(3,("authorise_login: ACCEPTED: "
                                                 "user list username and "
                                                 "given password ok (%s)\n",
                                                 user));
                                }
                        }
                }
        }

  check_guest:

        /* check for a normal guest connection */
        if (!ok && GUEST_OK(snum)) {
                struct passwd *guest_pw;
                fstring guestname;
                fstrcpy(guestname,lp_guestaccount());
                guest_pw = Get_Pwnam_alloc(talloc_tos(), guestname);
                if (guest_pw != NULL) {
                        fstrcpy(user,guestname);
                        ok = True;
                        DEBUG(3,("authorise_login: ACCEPTED: guest account "
                                 "and guest ok (%s)\n", user));
                } else {
                        DEBUG(0,("authorise_login: Invalid guest account "
                                 "%s??\n",guestname));
                }
                TALLOC_FREE(guest_pw);
                *guest = True;
        }

        if (ok && !user_ok(user, snum)) {
                DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
                ok = False;
        }

        return(ok);
}