initial stretch branch release 2.4.0-6

1 files changed, 47 insertions, 131 deletions

diff --git a/src/openvpnserv/validate.c b/src/openvpnserv/validate.c
index f6a97e9..c9c3855 100644
--- a/src/openvpnserv/validate.c
+++ b/src/openvpnserv/validate.c
@@ -16,9 +16,10 @@
  *  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.,
- *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program (see the file COPYING included with this
+ *  distribution); if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
 #include "validate.h"
@@ -48,9 +49,6 @@ static const WCHAR *white_list[] =
     NULL                                /* last value */
 };
 
-static BOOL IsUserInGroup(PSID sid, const PTOKEN_GROUPS groups, const WCHAR *group_name);
-static PTOKEN_GROUPS GetTokenGroups(const HANDLE token);
-
 /*
  * Check workdir\fname is inside config_dir
  * The logic here is simple: we may reject some valid paths if ..\ is in any of the strings
@@ -149,16 +147,21 @@ GetBuiltinAdminGroupName(WCHAR *name, DWORD nlen)
 
 /*
  * Check whether user is a member of Administrators group or
- * the group specified in ovpn_admin_group
+ * the group specified in s->ovpn_admin_group
  */
 BOOL
-IsAuthorizedUser(PSID sid, const HANDLE token, const WCHAR *ovpn_admin_group)
+IsAuthorizedUser(SID *sid, settings_t *s)
 {
+    LOCALGROUP_USERS_INFO_0 *groups = NULL;
+    DWORD nread;
+    DWORD nmax;
+    WCHAR *tmp = NULL;
     const WCHAR *admin_group[2];
     WCHAR username[MAX_NAME];
     WCHAR domain[MAX_NAME];
     WCHAR sysadmin_group[MAX_NAME];
-    DWORD len = MAX_NAME;
+    DWORD err, len = MAX_NAME;
+    int i;
     BOOL ret = FALSE;
     SID_NAME_USE sid_type;
 
@@ -166,9 +169,17 @@ IsAuthorizedUser(PSID sid, const HANDLE token, const WCHAR *ovpn_admin_group)
     if (!LookupAccountSidW(NULL, sid, username, &len, domain, &len, &sid_type))
     {
         MsgToEventLog(M_SYSERR, TEXT("LookupAccountSid"));
-        /* not fatal as this is now used only for logging */
-        username[0] = '\0';
-        domain[0] = '\0';
+        goto out;
+    }
+
+    /* Get an array of groups the user is member of */
+    err = NetUserGetLocalGroups(NULL, username, 0, LG_INCLUDE_INDIRECT, (LPBYTE *) &groups,
+                                MAX_PREFERRED_LENGTH, &nread, &nmax);
+    if (err && err != ERROR_MORE_DATA)
+    {
+        SetLastError(err);
+        MsgToEventLog(M_SYSERR, TEXT("NetUserGetLocalGroups"));
+        goto out;
     }
 
     if (GetBuiltinAdminGroupName(sysadmin_group, _countof(sysadmin_group)))
@@ -181,136 +192,41 @@ IsAuthorizedUser(PSID sid, const HANDLE token, const WCHAR *ovpn_admin_group)
         /* use the default value */
         admin_group[0] = SYSTEM_ADMIN_GROUP;
     }
-    admin_group[1] = ovpn_admin_group;
-
-    PTOKEN_GROUPS token_groups = GetTokenGroups(token);
-    for (int i = 0; i < 2; ++i)
-    {
-        ret = IsUserInGroup(sid, token_groups, admin_group[i]);
-        if (ret)
-        {
-            MsgToEventLog(M_INFO, TEXT("Authorizing user '%s@%s' by virtue of membership in group '%s'"),
-                          username, domain, admin_group[i]);
-            goto out;
-        }
-    }
-
-out:
-    free(token_groups);
-    return ret;
-}
-
-/**
- * Get a list of groups in token.
- * Returns a pointer to TOKEN_GROUPS struct or NULL on error.
- * The caller should free the returned pointer.
- */
-static PTOKEN_GROUPS
-GetTokenGroups(const HANDLE token)
-{
-    PTOKEN_GROUPS groups = NULL;
-    DWORD buf_size = 0;
-
-    if (!GetTokenInformation(token, TokenGroups, groups, buf_size, &buf_size)
-        && GetLastError() == ERROR_INSUFFICIENT_BUFFER)
-    {
-        groups = malloc(buf_size);
-    }
-    if (!groups)
-    {
-        MsgToEventLog(M_SYSERR, L"GetTokenGroups");
-    }
-    else if (!GetTokenInformation(token, TokenGroups, groups, buf_size, &buf_size))
-    {
-        MsgToEventLog(M_SYSERR, L"GetTokenInformation");
-        free(groups);
-    }
-    return groups;
-}
 
-/*
- * Find SID from name
- *
- * On input sid buffer should have space for at least sid_size bytes.
- * Returns true on success, false on failure.
- * Suggest: in caller allocate sid to hold SECURITY_MAX_SID_SIZE bytes
- */
-static BOOL
-LookupSID(const WCHAR *name, PSID sid, DWORD sid_size)
-{
-    SID_NAME_USE su;
-    WCHAR domain[MAX_NAME];
-    DWORD dlen = _countof(domain);
-
-    if (!LookupAccountName(NULL, name, sid, &sid_size, domain, &dlen, &su))
-    {
-        return FALSE; /* not fatal as the group may not exist */
-    }
-    return TRUE;
-}
-
-/**
- * User is in group if the token groups contain the SID of the group
- * of if the user is a direct member of the group. The latter check
- * catches dynamic changes in group membership in the local user
- * database not reflected in the token.
- * If token_groups or sid is NULL the corresponding check is skipped.
- *
- * Using sid and list of groups in token avoids reference to domains so that
- * this could be completed without access to a Domain Controller.
- *
- * Returns true if the user is in the group, false otherwise.
- */
-static BOOL
-IsUserInGroup(PSID sid, const PTOKEN_GROUPS token_groups, const WCHAR *group_name)
-{
-    BOOL ret = FALSE;
-    DWORD_PTR resume = 0;
-    DWORD err;
-    BYTE grp_sid[SECURITY_MAX_SID_SIZE];
-    int nloop = 0; /* a counter used to not get stuck in the do .. while() */
-
-    /* first check in the token groups */
-    if (token_groups && LookupSID(group_name, (PSID) grp_sid, _countof(grp_sid)))
+#ifdef UNICODE
+    admin_group[1] = s->ovpn_admin_group;
+#else
+    tmp = NULL;
+    len = MultiByteToWideChar(CP_UTF8, 0, s->ovpn_admin_group, -1, NULL, 0);
+    if (len == 0 || (tmp = malloc(len*sizeof(WCHAR))) == NULL)
     {
-        for (DWORD i = 0; i < token_groups->GroupCount; ++i)
-        {
-            if (EqualSid((PSID) grp_sid, token_groups->Groups[i].Sid))
-            {
-                return TRUE;
-            }
-        }
+        MsgToEventLog(M_SYSERR, TEXT("Failed to convert admin group name to WideChar"));
+        goto out;
     }
+    MultiByteToWideChar(CP_UTF8, 0, s->ovpn_admin_group, -1, tmp, len);
+    admin_group[1] = tmp;
+#endif
 
-    /* check user's SID is a member of the group */
-    if (!sid)
-    {
-        return FALSE;
-    }
-    do
+    /* Check if user's groups include any of the admin groups */
+    for (i = 0; i < nread; i++)
     {
-        DWORD nread, nmax;
-        LOCALGROUP_MEMBERS_INFO_0 *members = NULL;
-        err = NetLocalGroupGetMembers(NULL, group_name, 0, (LPBYTE *) &members,
-                                      MAX_PREFERRED_LENGTH, &nread, &nmax, &resume);
-        if ((err != NERR_Success && err != ERROR_MORE_DATA))
+        if (wcscmp(groups[i].lgrui0_name, admin_group[0]) == 0
+            || wcscmp(groups[i].lgrui0_name, admin_group[1]) == 0
+            )
         {
+            MsgToEventLog(M_INFO, TEXT("Authorizing user %s by virtue of membership in group %s"),
+                          username, groups[i].lgrui0_name);
+            ret = TRUE;
             break;
         }
-        /* If a match is already found, ret == TRUE and the loop is skipped */
-        for (int i = 0; i < nread && !ret; ++i)
-        {
-            ret = EqualSid(members[i].lgrmi0_sid, sid);
-        }
-        NetApiBufferFree(members);
-    /* MSDN says the lookup should always iterate until err != ERROR_MORE_DATA */
-    } while (err == ERROR_MORE_DATA && nloop++ < 100);
+    }
 
-    if (err != NERR_Success && err != NERR_GroupNotFound)
+out:
+    if (groups)
     {
-        SetLastError(err);
-        MsgToEventLog(M_SYSERR, TEXT("In NetLocalGroupGetMembers for group '%s'"), group_name);
+        NetApiBufferFree(groups);
     }
+    free(tmp);
 
     return ret;
 }