/* 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" enum server_allocated_state { SERVER_ALLOCATED_REQUIRED_YES, SERVER_ALLOCATED_REQUIRED_NO, SERVER_ALLOCATED_REQUIRED_ANY}; static user_struct *get_valid_user_struct_internal(uint16 vuid, enum server_allocated_state server_allocated) { user_struct *usp; int count=0; if (vuid == UID_FIELD_INVALID) return NULL; for (usp=validated_users;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(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(uint16 vuid) { return get_valid_user_struct_internal(vuid, SERVER_ALLOCATED_REQUIRED_YES); } bool is_partial_auth_vuid(uint16 vuid) { return (get_partial_auth_user_struct(vuid) != NULL); } /**************************************************************************** Get the user struct of a partial NTLMSSP login ****************************************************************************/ user_struct *get_partial_auth_user_struct(uint16 vuid) { return get_valid_user_struct_internal(vuid, SERVER_ALLOCATED_REQUIRED_NO); } /**************************************************************************** Invalidate a uid. ****************************************************************************/ void invalidate_vuid(uint16 vuid) { user_struct *vuser = NULL; vuser = get_valid_user_struct_internal(vuid, SERVER_ALLOCATED_REQUIRED_ANY); if (vuser == NULL) { return; } session_yield(vuser); if (vuser->auth_ntlmssp_state) { auth_ntlmssp_end(&vuser->auth_ntlmssp_state); } DLIST_REMOVE(validated_users, vuser); /* clear the vuid from the 'cache' on each connection, and from the vuid 'owner' of connections */ conn_clear_vuid_caches(vuid); TALLOC_FREE(vuser); num_validated_vuids--; } /**************************************************************************** Invalidate all vuid entries for this process. ****************************************************************************/ void invalidate_all_vuids(void) { while (validated_users != NULL) { invalidate_vuid(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(void) { 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 (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(next_vuid, SERVER_ALLOCATED_REQUIRED_ANY) != NULL ) { increment_next_vuid(&next_vuid); } DEBUG(10,("register_initial_vuid: allocated vuid = %u\n", (unsigned int)next_vuid )); vuser->vuid = 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(&next_vuid); num_validated_vuids++; DLIST_ADD(validated_users, vuser); return vuser->vuid; } static 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(uint16 vuid, auth_serversupplied_info *server_info, DATA_BLOB response_blob, const char *smb_name) { fstring tmp; user_struct *vuser; vuser = get_partial_auth_user_struct(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, pdb_get_domain(vuser->server_info->sam_account), vuser->server_info->guest )); DEBUG(3, ("register_existing_vuid: User name: %s\t" "Real name: %s\n", vuser->server_info->unix_name, pdb_get_fullname(vuser->server_info->sam_account))); 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(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(smbd_server_conn) && !vuser->server_info->guest) { /* Try and turn on server signing on the first non-guest * sessionsetup. */ srv_set_signing(smbd_server_conn, 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, pdb_get_domain(vuser->server_info->sam_account)); return vuser->vuid; fail: if (vuser) { invalidate_vuid(vuid); } return UID_FIELD_INVALID; } /**************************************************************************** Add a name to the session users list. ****************************************************************************/ void add_session_user(const char *user) { struct passwd *pw; char *tmp; pw = Get_Pwnam_alloc(talloc_tos(), user); if (pw == NULL) { return; } if (session_userlist == NULL) { session_userlist = SMB_STRDUP(pw->pw_name); goto done; } if (in_list(pw->pw_name,session_userlist,False) ) { goto done; } if (strlen(session_userlist) > 128 * 1024) { DEBUG(3,("add_session_user: session userlist already " "too large.\n")); goto done; } if (asprintf(&tmp, "%s %s", session_userlist, pw->pw_name) == -1) { DEBUG(3, ("asprintf failed\n")); goto done; } SAFE_FREE(session_userlist); 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(const char *workgroup) { if (session_workgroup) { SAFE_FREE(session_workgroup); } 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(void) { return session_workgroup; } /**************************************************************************** Check if a user is in a netgroup user list. If at first we don't succeed, try lower case. ****************************************************************************/ bool user_in_netgroup(const char *user, const char *ngname) { #ifdef HAVE_NETGROUP fstring lowercase_user; if (my_yp_domain == NULL) yp_get_default_domain(&my_yp_domain); if(my_yp_domain == NULL) { DEBUG(5,("Unable to get default yp domain, " "let's try without specifying it\n")); } DEBUG(5,("looking for user %s of domain %s in netgroup %s\n", user, my_yp_domain?my_yp_domain:"(ANY)", ngname)); if (innetgr(ngname, NULL, user, my_yp_domain)) { DEBUG(5,("user_in_netgroup: Found\n")); return (True); } else { /* * Ok, innetgr is case sensitive. Try once more with lowercase * just in case. Attempt to fix #703. JRA. */ fstrcpy(lowercase_user, user); strlower_m(lowercase_user); DEBUG(5,("looking for user %s of domain %s in netgroup %s\n", lowercase_user, my_yp_domain?my_yp_domain:"(ANY)", ngname)); if (innetgr(ngname, NULL, lowercase_user, my_yp_domain)) { DEBUG(5,("user_in_netgroup: Found\n")); return (True); } } #endif /* HAVE_NETGROUP */ return False; } /**************************************************************************** Check if a user is in a user list - can check combinations of UNIX and netgroup lists. ****************************************************************************/ bool user_in_list(const char *user,const char **list) { if (!list || !*list) return False; DEBUG(10,("user_in_list: checking user %s in list\n", user)); while (*list) { DEBUG(10,("user_in_list: checking user |%s| against |%s|\n", user, *list)); /* * Check raw username. */ if (strequal(user, *list)) return(True); /* * Now check to see if any combination * of UNIX and netgroups has been specified. */ if(**list == '@') { /* * Old behaviour. Check netgroup list * followed by UNIX list. */ if(user_in_netgroup(user, *list +1)) return True; if(user_in_group(user, *list +1)) return True; } else if (**list == '+') { if((*(*list +1)) == '&') { /* * Search UNIX list followed by netgroup. */ if(user_in_group(user, *list +2)) return True; if(user_in_netgroup(user, *list +2)) return True; } else { /* * Just search UNIX list. */ if(user_in_group(user, *list +1)) return True; } } else if (**list == '&') { if(*(*list +1) == '+') { /* * Search netgroup list followed by UNIX list. */ if(user_in_netgroup(user, *list +2)) return True; if(user_in_group(user, *list +2)) return True; } else { /* * Just search netgroup list. */ if(user_in_netgroup(user, *list +1)) return True; } } list++; } return(False); } /**************************************************************************** Check if a username is valid. ****************************************************************************/ static bool user_ok(const char *user, int snum) { char **valid, **invalid; bool ret; valid = invalid = NULL; ret = True; if (lp_invalid_users(snum)) { 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)) { 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(char *group, DATA_BLOB password,int snum) { #ifdef HAVE_NETGROUP { char *host, *user, *domain; setnetgrent(group); while (getnetgrent(&host, &user, &domain)) { if (user) { if (user_ok(user, snum) && password_ok(user,password)) { endnetgrent(); return(user); } } } endnetgrent(); } #endif #ifdef HAVE_GETGRENT { struct group *gptr; 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(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(int snum, fstring user, DATA_BLOB password, bool *guest) { bool ok = False; #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 ( session_userlist ) user_list = SMB_STRDUP(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(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(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(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); }