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samba-mirror/source3/smbd/password.c
2007-10-10 11:38:32 -05:00

802 lines
20 KiB
C

/*
Unix SMB/CIFS implementation.
Password and authentication handling
Copyright (C) Andrew Tridgell 1992-1998
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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
/* users from session setup */
static char *session_userlist = NULL;
static int len_session_userlist = 0;
/* this holds info on user ids that are already validated for this VC */
static user_struct *validated_users;
static int next_vuid = VUID_OFFSET;
static int num_validated_vuids;
/****************************************************************************
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)
{
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 && usp->server_info) {
if (count > 10) {
DLIST_PROMOTE(validated_users, usp);
}
return usp;
}
}
return NULL;
}
/****************************************************************************
Get the user struct of a partial NTLMSSP login
****************************************************************************/
user_struct *get_partial_auth_user_struct(uint16 vuid)
{
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 && !usp->server_info) {
if (count > 10) {
DLIST_PROMOTE(validated_users, usp);
}
return usp;
}
}
return NULL;
}
/****************************************************************************
Invalidate a uid.
****************************************************************************/
void invalidate_vuid(uint16 vuid)
{
user_struct *vuser = get_valid_user_struct(vuid);
if (vuser == NULL)
return;
SAFE_FREE(vuser->homedir);
SAFE_FREE(vuser->unix_homedir);
SAFE_FREE(vuser->logon_script);
session_yield(vuser);
SAFE_FREE(vuser->session_keystr);
TALLOC_FREE(vuser->server_info);
data_blob_free(&vuser->session_key);
DLIST_REMOVE(validated_users, vuser);
/* clear the vuid from the 'cache' on each connection, and
from the vuid 'owner' of connections */
conn_clear_vuid_cache(vuid);
SAFE_FREE(vuser->groups);
TALLOC_FREE(vuser->nt_user_token);
SAFE_FREE(vuser);
num_validated_vuids--;
}
/****************************************************************************
Invalidate all vuid entries for this process.
****************************************************************************/
void invalidate_all_vuids(void)
{
user_struct *usp, *next=NULL;
for (usp=validated_users;usp;usp=next) {
next = usp->next;
invalidate_vuid(usp->vuid);
}
}
/**
* register that a valid login has been performed, establish 'session'.
* @param server_info The token returned from the authentication process.
* (now 'owned' by register_vuid)
*
* @param session_key The User session key for the login session (now also
* 'owned' by register_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_vuid(auth_serversupplied_info *server_info,
DATA_BLOB session_key, DATA_BLOB response_blob,
const char *smb_name)
{
user_struct *vuser = NULL;
/* Paranoia check. */
if(lp_security() == SEC_SHARE) {
smb_panic("Tried to register uid in security=share\n");
}
/* Limit allowed vuids to 16bits - VUID_OFFSET. */
if (num_validated_vuids >= 0xFFFF-VUID_OFFSET) {
data_blob_free(&session_key);
return UID_FIELD_INVALID;
}
if((vuser = SMB_MALLOC_P(user_struct)) == NULL) {
DEBUG(0,("Failed to malloc users struct!\n"));
data_blob_free(&session_key);
return UID_FIELD_INVALID;
}
ZERO_STRUCTP(vuser);
/* Allocate a free vuid. Yes this is a linear search... :-) */
while( get_valid_user_struct(next_vuid) != NULL ) {
next_vuid++;
/* Check for vuid wrap. */
if (next_vuid == UID_FIELD_INVALID)
next_vuid = VUID_OFFSET;
}
DEBUG(10,("register_vuid: allocated vuid = %u\n",
(unsigned int)next_vuid ));
vuser->vuid = next_vuid;
if (!server_info) {
/*
* This happens in an unfinished NTLMSSP session setup. We
* need to allocate a vuid between the first and second calls
* to NTLMSSP.
*/
next_vuid++;
num_validated_vuids++;
vuser->server_info = NULL;
DLIST_ADD(validated_users, vuser);
return vuser->vuid;
}
/* the next functions should be done by a SID mapping system (SMS) as
* the new real sam db won't have reference to unix uids or gids
*/
vuser->uid = server_info->uid;
vuser->gid = server_info->gid;
vuser->n_groups = server_info->n_groups;
if (vuser->n_groups) {
if (!(vuser->groups = (gid_t *)memdup(server_info->groups,
sizeof(gid_t) *
vuser->n_groups))) {
DEBUG(0,("register_vuid: failed to memdup "
"vuser->groups\n"));
data_blob_free(&session_key);
free(vuser);
TALLOC_FREE(server_info);
return UID_FIELD_INVALID;
}
}
vuser->guest = server_info->guest;
fstrcpy(vuser->user.unix_name, server_info->unix_name);
/* This is a potentially untrusted username */
alpha_strcpy(vuser->user.smb_name, smb_name, ". _-$",
sizeof(vuser->user.smb_name));
fstrcpy(vuser->user.domain, pdb_get_domain(server_info->sam_account));
fstrcpy(vuser->user.full_name,
pdb_get_fullname(server_info->sam_account));
{
/* Keep the homedir handy */
const char *homedir =
pdb_get_homedir(server_info->sam_account);
const char *logon_script =
pdb_get_logon_script(server_info->sam_account);
if (!IS_SAM_DEFAULT(server_info->sam_account,
PDB_UNIXHOMEDIR)) {
const char *unix_homedir =
pdb_get_unix_homedir(server_info->sam_account);
if (unix_homedir) {
vuser->unix_homedir =
smb_xstrdup(unix_homedir);
}
} else {
struct passwd *passwd =
getpwnam_alloc(NULL, vuser->user.unix_name);
if (passwd) {
vuser->unix_homedir =
smb_xstrdup(passwd->pw_dir);
TALLOC_FREE(passwd);
}
}
if (homedir) {
vuser->homedir = smb_xstrdup(homedir);
}
if (logon_script) {
vuser->logon_script = smb_xstrdup(logon_script);
}
}
vuser->session_key = session_key;
DEBUG(10,("register_vuid: (%u,%u) %s %s %s guest=%d\n",
(unsigned int)vuser->uid,
(unsigned int)vuser->gid,
vuser->user.unix_name, vuser->user.smb_name,
vuser->user.domain, vuser->guest ));
DEBUG(3, ("User name: %s\tReal name: %s\n", vuser->user.unix_name,
vuser->user.full_name));
if (server_info->ptok) {
vuser->nt_user_token = dup_nt_token(NULL, server_info->ptok);
} else {
DEBUG(1, ("server_info does not contain a user_token - "
"cannot continue\n"));
TALLOC_FREE(server_info);
data_blob_free(&session_key);
SAFE_FREE(vuser->homedir);
SAFE_FREE(vuser->unix_homedir);
SAFE_FREE(vuser->logon_script);
SAFE_FREE(vuser);
return UID_FIELD_INVALID;
}
/* use this to keep tabs on all our info from the authentication */
vuser->server_info = server_info;
DEBUG(3,("UNIX uid %d is UNIX user %s, and will be vuid %u\n",
(int)vuser->uid,vuser->user.unix_name, vuser->vuid));
next_vuid++;
num_validated_vuids++;
DLIST_ADD(validated_users, vuser);
if (!session_claim(vuser)) {
DEBUG(1, ("Failed to claim session for vuid=%d\n",
vuser->vuid));
invalidate_vuid(vuser->vuid);
return UID_FIELD_INVALID;
}
/* Register a home dir service for this user iff
(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->guest) && vuser->unix_homedir && *(vuser->unix_homedir))
{
int servicenumber = lp_servicenumber(vuser->user.unix_name);
if ( servicenumber == -1 ) {
DEBUG(3, ("Adding homes service for user '%s' using "
"home directory: '%s'\n",
vuser->user.unix_name, vuser->unix_homedir));
vuser->homes_snum =
add_home_service(vuser->user.unix_name,
vuser->user.unix_name,
vuser->unix_homedir);
} else {
DEBUG(3, ("Using static (or previously created) "
"service for user '%s'; path = '%s'\n",
vuser->user.unix_name,
lp_pathname(servicenumber) ));
vuser->homes_snum = servicenumber;
}
}
if (srv_is_signing_negotiated() && !vuser->guest &&
!srv_signing_started()) {
/* Try and turn on server signing on the first non-guest
* sessionsetup. */
srv_set_signing(vuser->session_key, response_blob);
}
/* fill in the current_user_info struct */
set_current_user_info( &vuser->user );
return vuser->vuid;
}
/****************************************************************************
Add a name to the session users list.
****************************************************************************/
void add_session_user(const char *user)
{
fstring suser;
struct passwd *passwd;
if (!(passwd = Get_Pwnam(user)))
return;
fstrcpy(suser,passwd->pw_name);
if(!*suser)
return;
if( session_userlist && in_list(suser,session_userlist,False) )
return;
if( !session_userlist ||
(strlen(suser) + strlen(session_userlist) + 2 >=
len_session_userlist) ) {
char *newlist;
if (len_session_userlist > 128 * PSTRING_LEN) {
DEBUG(3,("add_session_user: session userlist already "
"too large.\n"));
return;
}
newlist = (char *)SMB_REALLOC_KEEP_OLD_ON_ERROR(
session_userlist,
len_session_userlist + PSTRING_LEN );
if( newlist == NULL ) {
DEBUG(1,("Unable to resize session_userlist\n"));
return;
}
if (!session_userlist) {
*newlist = '\0';
}
session_userlist = newlist;
len_session_userlist += PSTRING_LEN;
}
safe_strcat(session_userlist," ",len_session_userlist-1);
safe_strcat(session_userlist,suser,len_session_userlist-1);
}
/****************************************************************************
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
static char *mydomain = NULL;
fstring lowercase_user;
if (mydomain == NULL)
yp_get_default_domain(&mydomain);
if(mydomain == 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, mydomain?mydomain:"(ANY)", ngname));
if (innetgr(ngname, NULL, user, mydomain)) {
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, mydomain?mydomain:"(ANY)", ngname));
if (innetgr(ngname, NULL, lowercase_user, mydomain)) {
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)) {
str_list_copy(&invalid, 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);
}
}
}
if (invalid)
str_list_free (&invalid);
if (ret && lp_valid_users(snum)) {
str_list_copy(&valid, 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);
}
}
}
if (valid)
str_list_free (&valid);
if (ret && lp_onlyuser(snum)) {
char **user_list = str_list_make (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);
}
if (user_list) str_list_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 into a pstring on the stack before
* use. Bug pointed out by leon@eatworms.swmed.edu.
*/
if (gptr) {
pstring member_list;
char *member;
size_t copied_len = 0;
int i;
*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;
if(copied_len+member_len < sizeof(pstring)) {
DEBUG(10,("validate_group: = gr_mem = "
"%s\n", gptr->gr_mem[i]));
safe_strcpy(member, gptr->gr_mem[i],
sizeof(pstring) -
copied_len - 1);
copied_len += member_len;
member += copied_len;
} else {
*member = '\0';
}
}
endgrent();
member = member_list;
while (*member) {
static fstring name;
fstrcpy(name,member);
if (user_ok(name,snum) &&
password_ok(name,password)) {
endgrent();
return(&name[0]);
}
DEBUG(10,("validate_group = member = %s\n",
member));
member += strlen(member) + 1;
}
} 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;
if ( session_userlist )
user_list = SMB_STRDUP(session_userlist);
else
user_list = SMB_STRDUP("");
if (!user_list)
return(False);
for (auser=strtok(user_list,LIST_SEP); !ok && auser;
auser = strtok(NULL,LIST_SEP)) {
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)) {
char *auser;
pstring user_list;
pstrcpy(user_list,lp_username(snum));
pstring_sub(user_list,"%S",lp_servicename(snum));
for (auser=strtok(user_list,LIST_SEP); auser && !ok;
auser = strtok(NULL,LIST_SEP)) {
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 for a normal guest connection */
if (!ok && GUEST_OK(snum)) {
fstring guestname;
fstrcpy(guestname,lp_guestaccount());
if (Get_Pwnam(guestname)) {
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));
}
*guest = True;
}
if (ok && !user_ok(user, snum)) {
DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
ok = False;
}
return(ok);
}