[BusyBox] patch to login, dmesg and obscure

[Vladimir N. Oleynik]

  Erik,

>> I've discovered some bugs in the BusyBox unstable branch and since it 
>> doesn't seem to fixed in the 1.0.0-pre1 release I created a patch 
>> with my changes. Description below:

> * libbb/obscure.c:password_check()
> There was a buffer overflow bug which cased passwd command to 
> segfault when invoked by any other than the superuser.


This moment have algoritmicaly problem, not overflow:
strcat(wrapped, wrapped) - may be looped.

Hand patch:

- else if (strstr(strcat(wrapped, wrapped), newmono))
+ else {
+    safe_strncpy(wrapped + lenwrap, wrapped, lenwrap + 1);
+    if (strstr(wrapped, newmono))
+}


--w
vodz