edu.mit.csail.aeolus.api
Class AeolusTag

java.lang.Object
  edu.mit.csail.aeolus.api.AeolusTag

All Implemented Interfaces:

AeolusSafe, java.io.Serializable, java.lang.Cloneable

public final class AeolusTag
extends java.lang.Object
implements java.io.Serializable, AeolusSafe, java.lang.Cloneable

This class provides AeolusTags.

See Also:

Serialized Form

Constructor Summary

AeolusTag()
Create a new top-level tag.

AeolusTag(AeolusTag t)
Create a sub-tag of tag t.

Method Summary

AeolusTag	clone() Returns a new AeolusTag which will be equal to this.
void	delegate(PID p1, PID p2) Assuming that the current thread acts for principal p1, and p2 isn't the public pid, and p1 is a node in the delegation graph of this, the delegate method gives authority for this to grantee p2.
boolean	equals(AeolusTag t) Returns true if this is the same as tag t, otherwise false.
boolean	hasAuthority() Returns true if current thread has authority for the tag, otherwise false.
boolean	hasAuthority(PID p) Returns true if principal p has authority for the tag, otherwise false.
boolean	isSubTag(AeolusTag t) Returns true if t is a subTag of this, otherwise false.
boolean	isSuperTag(AeolusTag t) Returns true if t is a superTag of this, otherwise false.
void	revoke(PID p1, PID p2) Revokes authority for this tag from grantor principal from p1 to grantee principal to p2.
java.lang.String	toString() Returns a string representation of this.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

AeolusTag

public AeolusTag()
          throws AeolusException,
                 InfoFlowControlException,
                 AuthorityException

Create a new top-level tag. Caller principal will have authority for the new tag.

Throws:

AuthorityException - - if caller principal not authorized to create a new tag (i.e. if the caller is the public principal)

AeolusException - - if failure in communicating with the authority server or an unexpected platform failure occurred

InfoFlowControlException - - if caller's secrecy label is not null

AeolusTag

public AeolusTag(AeolusTag t)
          throws AeolusException,
                 InfoFlowControlException,
                 AuthorityException

Create a sub-tag of tag t. Tag t must be a top-level tag. Caller principal will have authority for the new sub-tag.

Throws:

AuthorityException - - if caller principal not authorized to create a new sub-tag (i.e. if the caller is the public principal or t is not a top-level tag.)

AeolusException - - if caller is inside a shared state object

InfoFlowControlException - - if caller's secrecy label is not null

Method Detail

clone

public AeolusTag clone()

Returns a new AeolusTag which will be equal to this.

Overrides:

clone in class java.lang.Object

delegate

public void delegate(PID p1,
                     PID p2)
              throws AeolusException,
                     InfoFlowControlException,
                     AeolusException

Assuming that the current thread acts for principal p1, and p2 isn't the public pid, and p1 is a node in the delegation graph of this, the delegate method gives authority for this to grantee p2. The principal p1 must have authority for the tag. The caller's secrecy label must be null.

Parameters:

p1 - principal that is authoritative for tag

p2 - principal that will be authoritative for tag

Throws:

AuthorityException - - if thread does not act for p1 or p1 does not have authority for this or p2 is the public pid

InfoFlowControlException - - if caller's secrecy label isn't null

AeolusException - if failure in communicating with the authority server or an unexpected platform failure occurred or p1 isn't a node in the delegation graph for this or adding the link would cause a cycle in the graph

equals

public boolean equals(AeolusTag t)

Returns true if this is the same as tag t, otherwise false.

Parameters:

t - - an AeolusTag

hasAuthority

public boolean hasAuthority()

Returns true if current thread has authority for the tag, otherwise false.

hasAuthority

public boolean hasAuthority(PID p)

Returns true if principal p has authority for the tag, otherwise false.

Parameters:

p - principal with respect to which authority checking is requested

isSubTag

public boolean isSubTag(AeolusTag t)

Returns true if t is a subTag of this, otherwise false.

Parameters:

t - possible child of this

isSuperTag

public boolean isSuperTag(AeolusTag t)

Returns true if t is a superTag of this, otherwise false.

Parameters:

t - possible parent of this

revoke

public void revoke(PID p1,
                   PID p2)
            throws AeolusException,
                   AuthorityException

Revokes authority for this tag from grantor principal from p1 to grantee principal to p2. Current thread must act for the grantor principal p1 and the tag t should have been previously delegated from p1 to p2. Secrecy label must be null.

Parameters:

p1 - principal that is authoritative for tag and granted authority to p2 for tag

p2 - principal to remove from being authoritative for tag

Throws:

AuthorityException - - if caller principal does not act for p1 or if p1 isn't a node in the delegation graph of this

InfoFlowControlException - - if caller's secrecy label is not null an unexpected platform failure occurred

AeolusException - - if failure in communicating with the authority server or

toString

public java.lang.String toString()

Returns a string representation of this.

Overrides:

toString in class java.lang.Object