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* security.cc (get_attribute_from_acl): Always test "anti",

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just in case an access_denied ACE follows an access_allowed.
	Handle the case owner_sid == group_sid, with a FIXME.
	Remove unnecessary tests for non-NULL PSIDs.
	(alloc_sd): Use existing owner and group sids if {ug}id == -1.
	Handle case where owner_sid == group_sid.
	Do not call is_grp_member. Try to preserve canonical ACE order.
	Remove unnecessary tests for non-NULL PSIDs. Reorganize
	debug_printf's.
	(get_initgroups_sidlist): Put well_known_system_sid on left
	side of ==.
	(add_access_denied_ace): Only call GetAce if inherit != 0.
	(add_access_allowed_ace): Ditto. Use appropriate sizeof.
	* syscalls.cc (chown_worker): Pass {ug}id equal to -1 to
	alloc_sd, which removes the need to obtain old_{ug}id.
	(chmod): Remove call to get_file_attribute (), simply pass
	{ug}id equal to -1 to alloc_sd.
This commit is contained in:
Corinna Vinschen
2002-11-20 09:23:21 +00:00
parent 03b65245db
commit dbcb75780a
3 changed files with 107 additions and 96 deletions
Download Patch File Download Diff File Expand all files Collapse all files

152
winsup/cygwin/security.cc
View File

@@ -449,7 +449,7 @@ get_user_primary_group (WCHAR *wlogonserver, const char *user,
BOOL retval = FALSE;
UCHAR count = 0;
if (pusersid == well_known_system_sid)
if (well_known_system_sid == pusersid)
{
pgrpsid = well_known_system_sid;
return TRUE;
@@ -540,7 +540,7 @@ get_initgroups_sidlist (cygsidlist &grp_list,
{
grp_list += well_known_world_sid;
grp_list += well_known_authenticated_users_sid;
if (usersid == well_known_system_sid)
if (well_known_system_sid == usersid)
{
auth_pos = -1;
grp_list += well_known_admins_sid;
@@ -1238,19 +1238,17 @@ get_attribute_from_acl (int * attribute, PACL acl, PSID owner_sid,
if (ace_sid == well_known_world_sid)
{
if (ace->Mask & FILE_READ_DATA)
*flags |= S_IROTH
*flags |= ((!(*anti & S_IROTH)) ? S_IROTH : 0)
| ((!(*anti & S_IRGRP)) ? S_IRGRP : 0)
| ((!(*anti & S_IRUSR)) ? S_IRUSR : 0);
if (ace->Mask & FILE_WRITE_DATA)
*flags |= S_IWOTH
*flags |= ((!(*anti & S_IWOTH)) ? S_IWOTH : 0)
| ((!(*anti & S_IWGRP)) ? S_IWGRP : 0)
| ((!(*anti & S_IWUSR)) ? S_IWUSR : 0);
if (ace->Mask & FILE_EXECUTE)
{
*flags |= S_IXOTH
| ((!(*anti & S_IXGRP)) ? S_IXGRP : 0)
| ((!(*anti & S_IXUSR)) ? S_IXUSR : 0);
}
*flags |= ((!(*anti & S_IXOTH)) ? S_IXOTH : 0)
| ((!(*anti & S_IXGRP)) ? S_IXGRP : 0)
| ((!(*anti & S_IXUSR)) ? S_IXUSR : 0);
if ((*attribute & S_IFDIR) &&
(ace->Mask & (FILE_WRITE_DATA | FILE_EXECUTE | FILE_DELETE_CHILD))
== (FILE_WRITE_DATA | FILE_EXECUTE))
@@ -1266,31 +1264,39 @@ get_attribute_from_acl (int * attribute, PACL acl, PSID owner_sid,
if (ace->Mask & FILE_APPEND_DATA)
*flags |= S_ISUID;
}
else if (owner_sid && ace_sid == owner_sid)
else if (ace_sid == owner_sid)
{
if (ace->Mask & FILE_READ_DATA)
*flags |= S_IRUSR;
*flags |= ((!(*anti & S_IRUSR)) ? S_IRUSR : 0);
if (ace->Mask & FILE_WRITE_DATA)
*flags |= S_IWUSR;
*flags |= ((!(*anti & S_IWUSR)) ? S_IWUSR : 0);
if (ace->Mask & FILE_EXECUTE)
*flags |= S_IXUSR;
*flags |= ((!(*anti & S_IXUSR)) ? S_IXUSR : 0);
}
else if (group_sid && ace_sid == group_sid)
else if (ace_sid == group_sid)
{
if (ace->Mask & FILE_READ_DATA)
*flags |= S_IRGRP
*flags |= ((!(*anti & S_IRGRP)) ? S_IRGRP : 0)
| ((grp_member && !(*anti & S_IRUSR)) ? S_IRUSR : 0);
if (ace->Mask & FILE_WRITE_DATA)
*flags |= S_IWGRP
*flags |= ((!(*anti & S_IWGRP)) ? S_IWGRP : 0)
| ((grp_member && !(*anti & S_IWUSR)) ? S_IWUSR : 0);
if (ace->Mask & FILE_EXECUTE)
*flags |= S_IXGRP
*flags |= ((!(*anti & S_IXGRP)) ? S_IXGRP : 0)
| ((grp_member && !(*anti & S_IXUSR)) ? S_IXUSR : 0);
}
}
*attribute &= ~(S_IRWXU | S_IRWXG | S_IRWXO | S_ISVTX | S_ISGID | S_ISUID);
if (owner_sid && group_sid && EqualSid (owner_sid, group_sid)
/* FIXME: temporary exception for /var/empty */
&& well_known_system_sid != group_sid)
{
allow &= ~(S_IRGRP | S_IWGRP | S_IXGRP);
allow |= (((allow & S_IRUSR) ? S_IRGRP : 0)
| ((allow & S_IWUSR) ? S_IWGRP : 0)
| ((allow & S_IXUSR) ? S_IXGRP : 0));
}
*attribute |= allow;
*attribute &= ~deny;
return;
}
@@ -1494,9 +1500,9 @@ add_access_allowed_ace (PACL acl, int offset, DWORD attributes,
return FALSE;
}
ACCESS_ALLOWED_ACE *ace;
if (GetAce (acl, offset, (PVOID *) &ace))
if (inherit && GetAce (acl, offset, (PVOID *) &ace))
ace->Header.AceFlags |= inherit;
len_add += sizeof (ACCESS_DENIED_ACE) - sizeof (DWORD) + GetLengthSid (sid);
len_add += sizeof (ACCESS_ALLOWED_ACE) - sizeof (DWORD) + GetLengthSid (sid);
return TRUE;
}
@@ -1510,7 +1516,7 @@ add_access_denied_ace (PACL acl, int offset, DWORD attributes,
return FALSE;
}
ACCESS_DENIED_ACE *ace;
if (GetAce (acl, offset, (PVOID *) &ace))
if (inherit && GetAce (acl, offset, (PVOID *) &ace))
ace->Header.AceFlags |= inherit;
len_add += sizeof (ACCESS_DENIED_ACE) - sizeof (DWORD) + GetLengthSid (sid);
return TRUE;
@@ -1522,36 +1528,32 @@ alloc_sd (__uid32_t uid, __gid32_t gid, int attribute,
{
BOOL dummy;
if (!wincap.has_security ())
return NULL;
debug_printf("uid %d, gid %d, attribute %x", uid, gid, attribute);
if (!sd_ret || !sd_size_ret)
{
set_errno (EINVAL);
return NULL;
}
/* Get owner and group from current security descriptor. */
PSID cur_owner_sid = NULL;
PSID cur_group_sid = NULL;
if (!GetSecurityDescriptorOwner (sd_ret, &cur_owner_sid, &dummy))
debug_printf ("GetSecurityDescriptorOwner %E");
if (!GetSecurityDescriptorGroup (sd_ret, &cur_group_sid, &dummy))
debug_printf ("GetSecurityDescriptorGroup %E");
/* Get SID of owner. */
cygsid owner_sid (NO_SID);
/* Check for current user first */
if (uid == myself->uid)
owner_sid = cygheap->user.sid ();
else
else if (uid == ILLEGAL_UID)
owner_sid = cur_owner_sid;
else if (!owner_sid.getfrompw (getpwuid32 (uid)))
{
/* Otherwise retrieve user data from /etc/passwd */
struct passwd *pw = getpwuid32 (uid);
if (!pw)
{
debug_printf ("no /etc/passwd entry for %d", uid);
set_errno (EINVAL);
return NULL;
}
else if (!owner_sid.getfrompw (pw))
{
debug_printf ("no SID for user %d", uid);
set_errno (EINVAL);
return NULL;
}
set_errno (EINVAL);
return NULL;
}
owner_sid.debug_print ("alloc_sd: owner SID =");
@@ -1560,14 +1562,15 @@ alloc_sd (__uid32_t uid, __gid32_t gid, int attribute,
/* Check for current user first */
if (gid == myself->gid)
group_sid = cygheap->user.groups.pgsid;
else
{
struct __group32 *grp = getgrgid32 (gid);
if (!grp)
debug_printf ("no /etc/group entry for %d", gid);
else if (!group_sid.getfromgr (grp))
debug_printf ("no SID for group %d", gid);
}
else if (gid == ILLEGAL_GID)
group_sid = cur_group_sid;
else if (!group_sid.getfromgr (getgrgid32 (gid)))
{
set_errno (EINVAL);
return NULL;
}
group_sid.debug_print ("alloc_sd: group SID =");
/* Initialize local security descriptor. */
SECURITY_DESCRIPTOR sd;
PSECURITY_DESCRIPTOR psd = NULL;
@@ -1594,7 +1597,7 @@ alloc_sd (__uid32_t uid, __gid32_t gid, int attribute,
}
/* Create group for local security descriptor. */
if (group_sid && !SetSecurityDescriptorGroup (&sd, group_sid, FALSE))
if (!SetSecurityDescriptorGroup (&sd, group_sid, FALSE))
{
__seterrno ();
return NULL;
@@ -1665,17 +1668,24 @@ alloc_sd (__uid32_t uid, __gid32_t gid, int attribute,
null_allow |= FILE_READ_DATA;
}
/* Construct deny attributes for owner and group. */
DWORD owner_deny = 0;
if (is_grp_member (uid, gid))
owner_deny = ~owner_allow & (group_allow | other_allow);
/* Add owner and group permissions if SIDs are equal
and construct deny attributes for group and owner. */
DWORD group_deny;
if (owner_sid == group_sid)
{
owner_allow |= group_allow;
group_allow = group_deny = 0L;
}
else
owner_deny = ~owner_allow & other_allow;
{
group_deny = ~group_allow & other_allow;
group_deny &= ~(STANDARD_RIGHTS_READ
| FILE_READ_ATTRIBUTES | FILE_READ_EA);
}
DWORD owner_deny = ~owner_allow & (group_allow | other_allow);
owner_deny &= ~(STANDARD_RIGHTS_READ
| FILE_READ_ATTRIBUTES | FILE_READ_EA
| FILE_WRITE_ATTRIBUTES | FILE_WRITE_EA);
DWORD group_deny = ~group_allow & other_allow;
group_deny &= ~(STANDARD_RIGHTS_READ | FILE_READ_ATTRIBUTES | FILE_READ_EA);
/* Construct appropriate inherit attribute. */
DWORD inherit = (attribute & S_IFDIR) ? SUB_CONTAINERS_AND_OBJECTS_INHERIT
@@ -1686,18 +1696,28 @@ alloc_sd (__uid32_t uid, __gid32_t gid, int attribute,
&& !add_access_denied_ace (acl, ace_off++, owner_deny,
owner_sid, acl_len, inherit))
return NULL;
/* Set deny ACE for group here to respect the canonical order,
if this does not impact owner */
if (group_deny && !(owner_allow & group_deny))
{
if (!add_access_denied_ace (acl, ace_off++, group_deny,
group_sid, acl_len, inherit))
return NULL;
group_deny = 0;
}
/* Set allow ACE for owner. */
if (!add_access_allowed_ace (acl, ace_off++, owner_allow,
owner_sid, acl_len, inherit))
return NULL;
/* Set deny ACE for group. */
/* Set deny ACE for group, if still needed. */
if (group_deny
&& !add_access_denied_ace (acl, ace_off++, group_deny,
group_sid, acl_len, inherit))
return NULL;
/* Set allow ACE for group. */
if (!add_access_allowed_ace (acl, ace_off++, group_allow,
group_sid, acl_len, inherit))
if (group_allow
&& !add_access_allowed_ace (acl, ace_off++, group_allow,
group_sid, acl_len, inherit))
return NULL;
/* Set allow ACE for everyone. */
@@ -1710,14 +1730,6 @@ alloc_sd (__uid32_t uid, __gid32_t gid, int attribute,
well_known_null_sid, acl_len, NO_INHERITANCE))
return NULL;
/* Get owner and group from current security descriptor. */
PSID cur_owner_sid = NULL;
PSID cur_group_sid = NULL;
if (!GetSecurityDescriptorOwner (sd_ret, &cur_owner_sid, &dummy))
debug_printf ("GetSecurityDescriptorOwner %E");
if (!GetSecurityDescriptorGroup (sd_ret, &cur_group_sid, &dummy))
debug_printf ("GetSecurityDescriptorGroup %E");
/* Fill ACL with unrelated ACEs from current security descriptor. */
PACL oacl;
BOOL acl_exists;
@@ -1729,10 +1741,10 @@ alloc_sd (__uid32_t uid, __gid32_t gid, int attribute,
{
cygsid ace_sid ((PSID) &ace->SidStart);
/* Check for related ACEs. */
if ((cur_owner_sid && ace_sid == cur_owner_sid)
|| (owner_sid && ace_sid == owner_sid)
|| (cur_group_sid && ace_sid == cur_group_sid)
|| (group_sid && ace_sid == group_sid)
if ((ace_sid == cur_owner_sid)
|| (ace_sid == owner_sid)
|| (ace_sid == cur_group_sid)
|| (ace_sid == group_sid)
|| (ace_sid == well_known_world_sid)
|| (ace_sid == well_known_null_sid))
continue;