Type Access Matrix (TAM) Xapp- -. Xapp- - , , .
:
O = [oj], 1,n;
S = [si],
1, m.
, .
R = [rg], 1, k.
, A = [aij], i = 1, m, j = 1,n+m, aij R.
aij si oj.
, T = [ tb ], b = 1,w.
=[ cz ( )], z=1,...I, . Xapp- - .
Command cz ( )
End.
, Xapp- - .
. :
(S);
(O), , (SO);
()
Q (S, O, A).
, Q Q'.
:
si rg oj .
Enter rg into aij
si rg oj.
Delete rg from aij
, Xapp--.
.
si tsx
Create subject si of type tsx
, Xapp--.
sx ox tsx T, .
si tsx
Destroy subject sx of type tsx
, Xapp--.
sx ox , .
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oj toy
Create object oy of type toy
, Xapp- -.
oy toy T, .
oy toy
Destroy object oy of type toy
, Xapp- -.
oy , .
, --, , .
, , .
.
Cz (sj: tsj, oi: toi, sx:tsx, oy: toy)
c , :
Create Subject sj of type tsj;
Create Object oi of type toi,
. . , . . , , .
:
tsj toi ;
tsx toy .
, , oi toi sj tsj oy toy sx tsx.
, . ,
Command_1 (s1: t1, s2: t1)
Create Subject s2 of type t1
End.
t1 s1 s2.
, .
, ti tj , , ti , a tj .
:
, , ;
, .
( ), : Delete, Destroy Subject, Destroy Object.
, , .
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, , --, , . , , . . , , . , . . . , , , .
, . . , .
. , .
, , , .
: -- , .
42.
:
- , .
- .
- , , . ( , , ).
- , , .
- , (, , )
- , - .
:
- ( ), , - ( 1, -7, -5, -5 -4, -6, -6, -7, -2, -2, -6, -4, -4, -5, -46, -46)
- , , () .
- , , . ( -2; , ; - -8, -10, -11; - )
| |
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43.
, " ", , , . .
, .
1. . , , . , .. . , . , . .
2. , .
2.1. .
2.2. ( 1).
1
, ( ). | |
... mov word ptr cs:m[1],1234h ... m: jmp place ... | - |
... mov word ptr cs:m[1],es mov word ptr cs:m[3],5678h ... m: call far 0000h ... | |
mov bx,1234h jmp dword ptr cs:[bx] ...; call word ptr es:[si] | , |
and byte ptr cs:m, 0EFh; ;4 ; m m: push ax; ; inc ax |
2.3. (jmp ret, ret call jmp) ( 2).
2
... jmp m ... m: | ... mov ax,offset m; push ax; . ret; ... m: |
... call subr m: ... subr: ... ret | mov ax,offset m; push ax; . jmp subr; - m:; ... subr: ... ret |
... int 13h | ... pushf; . push cs; CS. mov ax,offset m; push ax; . xor ax,ax mov es,ax jmp dword ptr es:[13h*4] m: ... |
... ret | ... ; pop bx; jmp bx; |
iret ... | mov bp,sp; jmp dword ptr [bp]; - ; . ... add sp,4; . popf |
44.
́ (. Authentication) ; . .
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. , , , , . , , . , : , (), (, -), ( ).
, , . , , , , . , Windows NT 4 NTLM (NT LAN Manager NT). Windows 2000/2003 Kerberos.
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