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Insight into the set of rights

The set of rights $ R$ can be broken into two subsets : $ R=R_C \cup
R_F$ where $ R_C$ is the set of capabilities and $ R_F$ is the set of permissions that can be given to a file, for each possible uid. Let $ U$ be the set of available uids plus a special element that will mean that the uid check is not needed. Let $ C$ be the set of capabilities seen in section [*]. Let $ A=\{r,a,t,x\}$ be the set of file accesses.

We can write $ R_C=U \times C$ and $ R_F=U \times A \times F$. Thus an insight of $ R$ could be the union of the two following tables where each row is an element of $ R$. Let's have a very reduced disk with three files : $ F=\{$/$ ,$/bin/$ ,$/bin/vi$ \}$, and $ U={-1,0,1000}$ (no uid test, id=root and first user).

-1 CAP_CHOWN
0 CAP_CHOWN
1000 CAP_CHOWN
-1 CAP_DAC_OVERRIDE
0 CAP_DAC_OVERRIDE
1000 CAP_DAC_OVERRIDE
... ...
-1 LIDS_OUTLAW
0 LIDS_OUTLAW
1000 LIDS_OUTLAW
-1 r /
0 r /
1000 r /
-1 a /
0 a /
1000 a /
-1 t /
0 t /
1000 t /
-1 x /
0 x /
1000 x /
-1 r /bin/
0 r /bin/
1000 r /bin/
... ... ...
1000 x /bin/vi


next up previous contents
Next: Enhancing rights mapping Up: Privileges and permissions Previous: Privileges   Contents
Biondi Philippe 2000-12-15