/*
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
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
{
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;
}
}
}
-/*****************************************************************************
- 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;
+ 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;
+ }
- if (!token)
- token = &anonymous_token;
+ if (sd->dacl == NULL) {
+ return granted & ~denied;
+ }
+
+ for (i = 0;i<sd->dacl->num_aces; i++) {
+ struct security_ace *ace = &sd->dacl->aces[i];
- *status = NT_STATUS_OK;
- *acc_granted = 0;
+ if (ace->flags & SEC_ACE_FLAG_INHERIT_ONLY) {
+ continue;
+ }
- 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])));
+ if (!is_sid_in_token(token, &ace->trustee)) {
+ continue;
+ }
- /*
- * No security descriptor or security descriptor with no DACL
- * present allows all access.
- */
+ 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;
+ }
+ }
- /* ACL must have something in it */
+ return granted & ~denied;
+}
- 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;
+/*
+ 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;
}
- /* 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 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
- /* 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;
- }
- }
+ /* a NULL dacl allows access */
+ if ((sd->type & SEC_DESC_DACL_PRESENT) && sd->dacl == NULL) {
+ *access_granted = access_desired;
+ return NT_STATUS_OK;
}
- the_acl = sd->dacl;
+ /* 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 (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);
+ if (sd->dacl == NULL) {
+ goto done;
}
- 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;
+ /* 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 there are no more desired permissions left then
- * access was allowed.
- */
+ if (!is_sid_in_token(token, &ace->trustee)) {
+ continue;
+ }
- 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;
+ 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;
+ }
}
-
- *acc_granted = 0;
- *status = NT_STATUS_ACCESS_DENIED;
- DEBUG(5,("se_access_check: access (%x) denied.\n", (unsigned int)acc_desired ));
- return False;
-}
+done:
+ if (bits_remaining != 0) {
+ return NT_STATUS_ACCESS_DENIED;
+ }
+
+ return NT_STATUS_OK;
+}
/*******************************************************************
samr_make_sam_obj_sd
git.samba.org / sfrench / samba-autobuild / .git / commitdiff