Abstract
Iroha Special Instructions processing requires to have a permissions based security model.
Whitepaper and Iroha v1 documentation were researched. The proposal is to use already existing Iroha Special Instructions + Assets mechanisms for Permissions implementation.
Introduction
https://github.com/hyperledger/iroha/blob/iroha2-dev/iroha_2_whitepaper.md#211-data-permissions require protection of data from read and write cases.
https://iroha.readthedocs.io/en/master/concepts_architecture/glossary.html#permission gives a Permission definition:
A named rule that gives the privilege to perform a command. Permission cannot be granted to an account directly, instead, account has roles, which are collections of permissions. Although, there is an exception, see Grantable Permission.
and Grant-able Permission:
Only grantable permission is given to anaccountdirectly. An account that holds grantable permission is allowed to perform some particular action on behalf of another account. For example, if accounta@domain1gives the accountb@domain2a permission that it can transfer assets — thenb@domain2can transfer assets ofa@domain1to anyone.
As you can see permissions were a first-level entities in Iroha v1 while they can be easily implemented by Iroha Special Instructions.
pub mod isi {
...
enum Instruction {
Add(...),
Register(...),
...
Check(permissions::isi::CheckInstruction),
}
}
pub mod permissions::isi {
pub struct CheckInstruction<C, O> {
condition: C,
object: O,
}
}
Signature of `Instruction::execute` method provides an ability to return error result which for `Check` variant will prevent execution of Instructions for which account has no permissions. Each OOB Instruction and Query will include `Check` instructions in it:
impl Register {
fn execute(...) -> Result<...> {
Check{|account| account.asset("role") == ADMIN }.execute(...)?;
...
}
}
In this example you can see that we do not need to add permission related attributes to the `Account` and can use assets instead.
The same can be done with custom permissions, storing them in assets components of the account.