Re: Multiple signatures

schemers@Eng
Sat, 17 Oct 1998 20:28:46 -0700 (PDT)

Morten Helles writes:
> Hi!
>
> I have a question about the purpose of multiple signed JAR-files in JDK
> 1.2: What does it mean exactly that a JAR-file is signed by two (or
> more) principals in regards to permissions (as specified in the policy
> conf. file), i.e. what permissions will granted to a multiple signed
> JAR-file? The intersection or union of code sources/signers, or what?

If you have a policy which looks like:

grant signedby "A" { permission X; };
grant signedby "B" { permission Y; };
grant signedby "A,B" { permission Z; };
grant signedby "A,C" { permission Q; };

Then you have the following:

signedBy permissions granted
A X
B Y
A and B X, Y, Z
C nothing
A and D X

You end up with the union. i.e., if something is signed by A and B,
its gets the permissions granted A, granted to B, and granted to code
signed by both A and B.

> Where can I read more about the implications of multiple signed
> JAR-files?

I think its described in the security architecture spec and the policy
file guide, both of which are included with the JDK1.2 docs.

roland