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mirror of https://github.com/samba-team/samba.git synced 2025-01-11 05:18:09 +03:00

Unify se_access_check with the S4 code. Will make

calculation of SEC_FLAG_MAXIMUM_ALLOWED much easier
for files.
Jeremy.
This commit is contained in:
Jeremy Allison 2008-10-31 10:51:45 -07:00
parent 161cb81911
commit 8344e94574
12 changed files with 172 additions and 277 deletions

View File

@ -1417,9 +1417,8 @@ WERROR registry_push_value(TALLOC_CTX *mem_ctx,
void se_map_generic(uint32 *access_mask, const struct generic_mapping *mapping);
void security_acl_map_generic(struct security_acl *sa, const struct generic_mapping *mapping);
void se_map_standard(uint32 *access_mask, struct standard_mapping *mapping);
bool se_access_check(const SEC_DESC *sd, const NT_USER_TOKEN *token,
uint32 acc_desired, uint32 *acc_granted,
NTSTATUS *status);
NTSTATUS se_access_check(const SEC_DESC *sd, const NT_USER_TOKEN *token,
uint32 acc_desired, uint32 *acc_granted);
NTSTATUS samr_make_sam_obj_sd(TALLOC_CTX *ctx, SEC_DESC **psd, size_t *sd_size);
/* The following definitions come from lib/util_sec.c */

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@ -287,11 +287,11 @@ bool share_access_check(const NT_USER_TOKEN *token, const char *sharename,
return True;
}
ret = se_access_check(psd, token, desired_access, &granted, &status);
status = se_access_check(psd, token, desired_access, &granted);
TALLOC_FREE(psd);
return ret;
return NT_STATUS_IS_OK(status);
}
/***************************************************************************

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@ -1,8 +1,10 @@
/*
Unix SMB/CIFS implementation.
Copyright (C) Luke Kenneth Casson Leighton 1996-2000.
Copyright (C) Tim Potter 2000.
Copyright (C) Re-written by Jeremy Allison 2000.
Copyright (C) Andrew Tridgell 2004
Copyright (C) Gerald Carter 2005
Copyright (C) Volker Lendecke 2007
Copyright (C) Jeremy Allison 2008
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
@ -22,125 +24,6 @@
extern NT_USER_TOKEN anonymous_token;
/*********************************************************************************
Check an ACE against a SID. We return the remaining needed permission
bits not yet granted. Zero means permission allowed (no more needed bits).
**********************************************************************************/
static uint32 check_ace(SEC_ACE *ace, const NT_USER_TOKEN *token, uint32 acc_desired,
NTSTATUS *status)
{
uint32_t mask = ace->access_mask;
/*
* Inherit only is ignored.
*/
if (ace->flags & SEC_ACE_FLAG_INHERIT_ONLY) {
return acc_desired;
}
/*
* If this ACE has no SID in common with the token,
* ignore it as it cannot be used to make an access
* determination.
*/
if (!token_sid_in_ace( token, ace))
return acc_desired;
switch (ace->type) {
case SEC_ACE_TYPE_ACCESS_ALLOWED:
/*
* This is explicitly allowed.
* Remove the bits from the remaining
* access required. Return the remaining
* bits needed.
*/
acc_desired &= ~mask;
break;
case SEC_ACE_TYPE_ACCESS_DENIED:
/*
* This is explicitly denied.
* If any bits match terminate here,
* we are denied.
*/
if (acc_desired & mask) {
*status = NT_STATUS_ACCESS_DENIED;
return 0xFFFFFFFF;
}
break;
case SEC_ACE_TYPE_SYSTEM_ALARM:
case SEC_ACE_TYPE_SYSTEM_AUDIT:
*status = NT_STATUS_NOT_IMPLEMENTED;
return 0xFFFFFFFF;
default:
*status = NT_STATUS_INVALID_PARAMETER;
return 0xFFFFFFFF;
}
return acc_desired;
}
/*********************************************************************************
Maximum access was requested. Calculate the max possible. Fail if it doesn't
include other bits requested.
**********************************************************************************/
static bool get_max_access( SEC_ACL *the_acl, const NT_USER_TOKEN *token, uint32 *granted,
uint32 desired,
NTSTATUS *status)
{
uint32 acc_denied = 0;
uint32 acc_granted = 0;
size_t i;
for ( i = 0 ; i < the_acl->num_aces; i++) {
SEC_ACE *ace = &the_acl->aces[i];
uint32 mask = ace->access_mask;
if (!token_sid_in_ace( token, ace))
continue;
switch (ace->type) {
case SEC_ACE_TYPE_ACCESS_ALLOWED:
acc_granted |= (mask & ~acc_denied);
break;
case SEC_ACE_TYPE_ACCESS_DENIED:
acc_denied |= (mask & ~acc_granted);
break;
case SEC_ACE_TYPE_SYSTEM_ALARM:
case SEC_ACE_TYPE_SYSTEM_AUDIT:
*status = NT_STATUS_NOT_IMPLEMENTED;
*granted = 0;
return False;
default:
*status = NT_STATUS_INVALID_PARAMETER;
*granted = 0;
return False;
}
}
/*
* If we were granted no access, or we desired bits that we
* didn't get, then deny.
*/
if ((acc_granted == 0) || ((acc_granted & desired) != desired)) {
*status = NT_STATUS_ACCESS_DENIED;
*granted = 0;
return False;
}
/*
* Return the access we did get.
*/
*granted = acc_granted;
*status = NT_STATUS_OK;
return True;
}
/* Map generic access rights to object specific rights. This technique is
used to give meaning to assigning read, write, execute and all access to
objects. Each type of object has its own mapping of generic to object
@ -203,13 +86,13 @@ void se_map_standard(uint32 *access_mask, struct standard_mapping *mapping)
{
uint32 old_mask = *access_mask;
if (*access_mask & READ_CONTROL_ACCESS) {
*access_mask &= ~READ_CONTROL_ACCESS;
if (*access_mask & SEC_STD_READ_CONTROL) {
*access_mask &= ~SEC_STD_READ_CONTROL;
*access_mask |= mapping->std_read;
}
if (*access_mask & (DELETE_ACCESS|WRITE_DAC_ACCESS|WRITE_OWNER_ACCESS|SYNCHRONIZE_ACCESS)) {
*access_mask &= ~(DELETE_ACCESS|WRITE_DAC_ACCESS|WRITE_OWNER_ACCESS|SYNCHRONIZE_ACCESS);
if (*access_mask & (SEC_STD_DELETE|SEC_STD_WRITE_DAC|SEC_STD_WRITE_OWNER|SEC_STD_SYNCHRONIZE)) {
*access_mask &= ~(SEC_STD_DELETE|SEC_STD_WRITE_DAC|SEC_STD_WRITE_OWNER|SEC_STD_SYNCHRONIZE);
*access_mask |= mapping->std_all;
}
@ -219,122 +102,140 @@ void se_map_standard(uint32 *access_mask, struct standard_mapping *mapping)
}
}
/*****************************************************************************
Check access rights of a user against a security descriptor. Look at
each ACE in the security descriptor until an access denied ACE denies
any of the desired rights to the user or any of the users groups, or one
or more ACEs explicitly grant all requested access rights. See
"Access-Checking" document in MSDN.
*****************************************************************************/
bool se_access_check(const SEC_DESC *sd, const NT_USER_TOKEN *token,
uint32 acc_desired, uint32 *acc_granted,
NTSTATUS *status)
/*
perform a SEC_FLAG_MAXIMUM_ALLOWED access check
*/
static uint32_t access_check_max_allowed(const struct security_descriptor *sd,
const NT_USER_TOKEN *token)
{
size_t i;
SEC_ACL *the_acl;
uint32 tmp_acc_desired = acc_desired;
if (!status || !acc_granted)
return False;
if (!token)
token = &anonymous_token;
*status = NT_STATUS_OK;
*acc_granted = 0;
DEBUG(10,("se_access_check: requested access 0x%08x, for NT token "
"with %u entries and first sid %s.\n",
(unsigned int)acc_desired, (unsigned int)token->num_sids,
sid_string_dbg(&token->user_sids[0])));
/*
* No security descriptor or security descriptor with no DACL
* present allows all access.
*/
/* ACL must have something in it */
if (!sd || (sd && (!(sd->type & SEC_DESC_DACL_PRESENT) || sd->dacl == NULL))) {
*status = NT_STATUS_OK;
*acc_granted = acc_desired;
DEBUG(5, ("se_access_check: no sd or blank DACL, access allowed\n"));
return True;
uint32_t denied = 0, granted = 0;
unsigned i;
if (is_sid_in_token(token, sd->owner_sid)) {
granted |= SEC_STD_WRITE_DAC | SEC_STD_READ_CONTROL | SEC_STD_DELETE;
} else if (user_has_privileges(token, &se_restore)) {
granted |= SEC_STD_DELETE;
}
/* The user sid is the first in the token */
if (DEBUGLVL(3)) {
DEBUG(3, ("se_access_check: user sid is %s\n",
sid_string_dbg(
&token->user_sids[PRIMARY_USER_SID_INDEX])));
for (i = 1; i < token->num_sids; i++) {
DEBUGADD(3, ("se_access_check: also %s\n",
sid_string_dbg(&token->user_sids[i])));
if (sd->dacl == NULL) {
return granted & ~denied;
}
for (i = 0;i<sd->dacl->num_aces; i++) {
struct security_ace *ace = &sd->dacl->aces[i];
if (ace->flags & SEC_ACE_FLAG_INHERIT_ONLY) {
continue;
}
if (!is_sid_in_token(token, &ace->trustee)) {
continue;
}
switch (ace->type) {
case SEC_ACE_TYPE_ACCESS_ALLOWED:
granted |= ace->access_mask;
break;
case SEC_ACE_TYPE_ACCESS_DENIED:
case SEC_ACE_TYPE_ACCESS_DENIED_OBJECT:
denied |= ace->access_mask;
break;
default: /* Other ACE types not handled/supported */
break;
}
}
/* Is the token the owner of the SID ? */
if (sd->owner_sid) {
for (i = 0; i < token->num_sids; i++) {
if (sid_equal(&token->user_sids[i], sd->owner_sid)) {
/*
* The owner always has SEC_RIGHTS_WRITE_DAC & READ_CONTROL.
*/
if (tmp_acc_desired & WRITE_DAC_ACCESS)
tmp_acc_desired &= ~WRITE_DAC_ACCESS;
if (tmp_acc_desired & READ_CONTROL_ACCESS)
tmp_acc_desired &= ~READ_CONTROL_ACCESS;
}
}
}
the_acl = sd->dacl;
if (tmp_acc_desired & MAXIMUM_ALLOWED_ACCESS) {
tmp_acc_desired &= ~MAXIMUM_ALLOWED_ACCESS;
return get_max_access( the_acl, token, acc_granted, tmp_acc_desired,
status);
}
for ( i = 0 ; i < the_acl->num_aces && tmp_acc_desired != 0; i++) {
SEC_ACE *ace = &the_acl->aces[i];
DEBUGADD(10,("se_access_check: ACE %u: type %d, flags = "
"0x%02x, SID = %s mask = %x, current desired "
"= %x\n", (unsigned int)i, ace->type, ace->flags,
sid_string_dbg(&ace->trustee),
(unsigned int) ace->access_mask,
(unsigned int)tmp_acc_desired ));
tmp_acc_desired = check_ace( ace, token, tmp_acc_desired, status);
if (NT_STATUS_V(*status)) {
*acc_granted = 0;
DEBUG(5,("se_access_check: ACE %u denied with status %s.\n", (unsigned int)i, nt_errstr(*status)));
return False;
}
}
/*
* If there are no more desired permissions left then
* access was allowed.
*/
if (tmp_acc_desired == 0) {
*acc_granted = acc_desired;
*status = NT_STATUS_OK;
DEBUG(5,("se_access_check: access (%x) granted.\n", (unsigned int)acc_desired ));
return True;
}
*acc_granted = 0;
*status = NT_STATUS_ACCESS_DENIED;
DEBUG(5,("se_access_check: access (%x) denied.\n", (unsigned int)acc_desired ));
return False;
return granted & ~denied;
}
/*
the main entry point for access checking.
*/
NTSTATUS se_access_check(const struct security_descriptor *sd,
const NT_USER_TOKEN *token,
uint32_t access_desired,
uint32_t *access_granted)
{
int i;
uint32_t bits_remaining;
*access_granted = access_desired;
bits_remaining = access_desired;
/* handle the maximum allowed flag */
if (access_desired & SEC_FLAG_MAXIMUM_ALLOWED) {
access_desired |= access_check_max_allowed(sd, token);
access_desired &= ~SEC_FLAG_MAXIMUM_ALLOWED;
*access_granted = access_desired;
bits_remaining = access_desired & ~SEC_STD_DELETE;
}
#if 0
/* We need to support SeSecurityPrivilege for this. */
if (access_desired & SEC_FLAG_SYSTEM_SECURITY) {
if (user_has_privileges(token, &sec_security)) {
bits_remaining &= ~SEC_FLAG_SYSTEM_SECURITY;
} else {
return NT_STATUS_PRIVILEGE_NOT_HELD;
}
}
#endif
/* a NULL dacl allows access */
if ((sd->type & SEC_DESC_DACL_PRESENT) && sd->dacl == NULL) {
*access_granted = access_desired;
return NT_STATUS_OK;
}
/* the owner always gets SEC_STD_WRITE_DAC, SEC_STD_READ_CONTROL and SEC_STD_DELETE */
if ((bits_remaining & (SEC_STD_WRITE_DAC|SEC_STD_READ_CONTROL|SEC_STD_DELETE)) &&
is_sid_in_token(token, sd->owner_sid)) {
bits_remaining &= ~(SEC_STD_WRITE_DAC|SEC_STD_READ_CONTROL|SEC_STD_DELETE);
}
if ((bits_remaining & SEC_STD_DELETE) &&
user_has_privileges(token, &se_restore)) {
bits_remaining &= ~SEC_STD_DELETE;
}
if (sd->dacl == NULL) {
goto done;
}
/* check each ace in turn. */
for (i=0; bits_remaining && i < sd->dacl->num_aces; i++) {
struct security_ace *ace = &sd->dacl->aces[i];
if (ace->flags & SEC_ACE_FLAG_INHERIT_ONLY) {
continue;
}
if (!is_sid_in_token(token, &ace->trustee)) {
continue;
}
switch (ace->type) {
case SEC_ACE_TYPE_ACCESS_ALLOWED:
bits_remaining &= ~ace->access_mask;
break;
case SEC_ACE_TYPE_ACCESS_DENIED:
case SEC_ACE_TYPE_ACCESS_DENIED_OBJECT:
if (bits_remaining & ace->access_mask) {
return NT_STATUS_ACCESS_DENIED;
}
break;
default: /* Other ACE types not handled/supported */
break;
}
}
done:
if (bits_remaining != 0) {
return NT_STATUS_ACCESS_DENIED;
}
return NT_STATUS_OK;
}
/*******************************************************************
samr_make_sam_obj_sd

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@ -376,11 +376,11 @@ static int open_acl_xattr(vfs_handle_struct *handle,
&pdesc);
if (NT_STATUS_IS_OK(status)) {
/* See if we can access it. */
if (!se_access_check(pdesc,
status = se_access_check(pdesc,
handle->conn->server_info->ptok,
fsp->access_mask,
&access_granted,
&status)) {
&access_granted);
if (!NT_STATUS_IS_OK(status)) {
errno = map_errno_from_nt_status(status);
return -1;
}

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@ -5825,10 +5825,10 @@ bool print_access_check(struct auth_serversupplied_info *server_info, int snum,
}
/* Check access */
result = se_access_check(secdesc->sd, server_info->ptok, access_type,
&access_granted, &status);
status = se_access_check(secdesc->sd, server_info->ptok, access_type,
&access_granted);
DEBUG(4, ("access check was %s\n", result ? "SUCCESS" : "FAILURE"));
DEBUG(4, ("access check was %s\n", NT_STATUS_IS_OK(status) ? "SUCCESS" : "FAILURE"));
/* see if we need to try the printer admin list */
@ -5842,11 +5842,11 @@ bool print_access_check(struct auth_serversupplied_info *server_info, int snum,
talloc_destroy(mem_ctx);
if (!result) {
if (!NT_STATUS_IS_OK(status)) {
errno = EACCES;
}
return result;
return NT_STATUS_IS_OK(status);
}
/****************************************************************************

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@ -170,7 +170,8 @@ bool regkey_access_check( REGISTRY_KEY *key, uint32 requested, uint32 *granted,
se_map_generic( &requested, &reg_generic_map );
if (!se_access_check(sec_desc, token, requested, granted, &status)) {
status =se_access_check(sec_desc, token, requested, granted);
if (!NT_STATUS_IS_OK(status)) {
TALLOC_FREE(mem_ctx);
return false;
}

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@ -71,8 +71,7 @@ static bool elog_check_access( EVENTLOG_INFO *info, NT_USER_TOKEN *token )
{
char *tdbname = elog_tdbname(talloc_tos(), info->logname );
SEC_DESC *sec_desc;
bool ret;
NTSTATUS ntstatus;
NTSTATUS status;
if ( !tdbname )
return False;
@ -97,15 +96,15 @@ static bool elog_check_access( EVENTLOG_INFO *info, NT_USER_TOKEN *token )
/* run the check, try for the max allowed */
ret = se_access_check( sec_desc, token, MAXIMUM_ALLOWED_ACCESS,
&info->access_granted, &ntstatus );
status = se_access_check( sec_desc, token, MAXIMUM_ALLOWED_ACCESS,
&info->access_granted);
if ( sec_desc )
TALLOC_FREE( sec_desc );
if ( !ret ) {
if (!NT_STATUS_IS_OK(status)) {
DEBUG(8,("elog_check_access: se_access_check() return %s\n",
nt_errstr( ntstatus)));
nt_errstr(status)));
return False;
}

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@ -381,7 +381,8 @@ NTSTATUS _lsa_OpenPolicy2(pipes_struct *p,
/* get the generic lsa policy SD until we store it */
lsa_get_generic_sd(p->mem_ctx, &psd, &sd_size);
if(!se_access_check(psd, p->pipe_user.nt_user_token, des_access, &acc_granted, &status)) {
status = se_access_check(psd, p->pipe_user.nt_user_token, des_access, &acc_granted);
if (!NT_STATUS_IS_OK(status)) {
if (p->pipe_user.ut.uid != sec_initial_uid()) {
return status;
}
@ -431,7 +432,8 @@ NTSTATUS _lsa_OpenPolicy(pipes_struct *p,
/* get the generic lsa policy SD until we store it */
lsa_get_generic_sd(p->mem_ctx, &psd, &sd_size);
if(!se_access_check(psd, p->pipe_user.nt_user_token, des_access, &acc_granted, &status)) {
status = se_access_check(psd, p->pipe_user.nt_user_token, des_access, &acc_granted);
if (!NT_STATUS_IS_OK(status)) {
if (p->pipe_user.ut.uid != sec_initial_uid()) {
return status;
}

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@ -186,8 +186,10 @@ static NTSTATUS access_check_samr_object( SEC_DESC *psd, NT_USER_TOKEN *token,
/* check the security descriptor first */
if ( se_access_check(psd, token, des_access, acc_granted, &status) )
status = se_access_check(psd, token, des_access, acc_granted);
if (NT_STATUS_IS_OK(status)) {
goto done;
}
/* give root a free pass */

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@ -123,16 +123,12 @@ static struct service_control_op* find_service_by_name( const char *name )
static NTSTATUS svcctl_access_check( SEC_DESC *sec_desc, NT_USER_TOKEN *token,
uint32 access_desired, uint32 *access_granted )
{
NTSTATUS result;
if ( geteuid() == sec_initial_uid() ) {
DEBUG(5,("svcctl_access_check: using root's token\n"));
token = get_root_nt_token();
}
se_access_check( sec_desc, token, access_desired, access_granted, &result );
return result;
return se_access_check( sec_desc, token, access_desired, access_granted);
}
/********************************************************************

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@ -30,7 +30,6 @@ bool can_access_file_acl(struct connection_struct *conn,
const char * fname,
uint32_t access_mask)
{
bool result;
NTSTATUS status;
uint32_t access_granted;
struct security_descriptor *secdesc = NULL;
@ -45,10 +44,10 @@ bool can_access_file_acl(struct connection_struct *conn,
return false;
}
result = se_access_check(secdesc, conn->server_info->ptok,
access_mask, &access_granted, &status);
status = se_access_check(secdesc, conn->server_info->ptok,
access_mask, &access_granted);
TALLOC_FREE(secdesc);
return result;
return NT_STATUS_IS_OK(status);
}
/****************************************************************************

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@ -4285,16 +4285,15 @@ static void show_userlist(struct rpc_pipe_client *pipe_hnd,
uint32 acc_granted;
if (share_sd != NULL) {
if (!se_access_check(share_sd, &tokens[i].token,
1, &acc_granted, &status)) {
status = se_access_check(share_sd, &tokens[i].token,
1, &acc_granted);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("Could not check share_sd for "
"user %s\n",
tokens[i].name));
continue;
}
if (!NT_STATUS_IS_OK(status))
continue;
}
if (root_sd == NULL) {
@ -4302,16 +4301,13 @@ static void show_userlist(struct rpc_pipe_client *pipe_hnd,
continue;
}
if (!se_access_check(root_sd, &tokens[i].token,
1, &acc_granted, &status)) {
status = se_access_check(root_sd, &tokens[i].token,
1, &acc_granted);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("Could not check root_sd for user %s\n",
tokens[i].name));
continue;
}
if (!NT_STATUS_IS_OK(status))
continue;
d_printf(" %s\n", tokens[i].name);
}