A Methodology and Toolkit for Deploying Reliable Security Policies in Critical Infrastructures

Algorithm 4

Validation of the conformity of concrete access control policies.

Inputs:specifications.mch,implementations.mch.

Outputs: HiddenUsers,  HiddenRoles,HiddenAUR, HiddenARR, HiddenAPR, HiddenACFlow,

MissedUsers,  MissedRoles,  MissedAUR,  MissedARR, MissedAPR, MissedACFlow,  RenamedUsers,

RenamedRoles, Redundancy,  DacRedundancy, conformity.

Begin

read_specifications_machines ();

read_implementations_machines ();

conformity = true;

// checking the equivalence between users

HiddenUsers  = calculate_hiddenusers (Users, Users_imp);

MissedUsers = calculate_missedusers (Users, Users_imp);

RenamedUsers = calculate_renamedusers (HiddenUsers, MissedUsers, AUR, AUR_imp, APR, APR_imp);

if (HiddenUsers  ≠  ∅ or MissedUsers  ≠  ∅ or RenamedUsers  ≠  ∅) then

conformity = false;

end if;

// checking the equivalence between roles

HiddenRoles  =  calculate_hiddenroles (Roles, Roles_imp);

MissedRoles = calculate_missedroles (Roles, Roles_imp);

RenamedRoles = calculate_renamedroles (HiddenRoles, MissedRoles, APR, APR_imp);

if (HiddenRoles  ≠  ∅ or MissedRoles  ≠  ∅ or RenamedRoles  ≠  ∅) then

conformity = false;

end if;

// checking the equivalence between users-roles assignments

HiddenAUR = calculate_hiddenAUR (AUR, AUR_imp);

MissedAUR = calculate_missedAUR (AUR, AUR_imp);

if (HiddenAUR  ≠  ∅ or MissedAUR  ≠  ∅) then

conformity = false;

end if;

// checking the equivalence between hierarchies of roles

HiddenARR = calculate_hiddenARR (ARR, ARR_imp);

MissedARR = calculate_missedARR (ARR, ARR_imp);

if (HiddenARR  ≠  ∅ or MissedARR  ≠  ∅) then

conformity = false;

end if;

// checking the equivalence between permissions-roles assignments

HiddenAPR = calculate_hiddenAPR (APR, APR_imp);

MissedAPR = calculate_missedAPR (APR, APR_imp);

if (HiddenAPR  ≠  ∅ or MissedAPR  ≠  ∅) then

conformity = false;

end if;

// checking the equivalence between access flows

HiddenACFlow = calculate_hiddenACFlow (HiddenAUR, HiddenARR, HiddenAPR);

MissedACFlow = calculate_missedACFlow (HiddenAUR, HiddenARR, HiddenAPR);

// checking redundancies

Redundancy = verifyRED();

DacRedundancy = verifyDACRED();

if (Redundancy  ≠  ∅ or DacRedundancy  ≠  ∅) then

conformity = false;

end if;

if (conformity = true) then

return (conformity);

else

save_&_return_report ();

return (non-conformity);

end if;

end.