Check if function is called from another canister

Developers
20

Ultimately I implemented it with a custom solution - i.e. I’ve got an environment modules that contains a list of canister ids and a function that checks if a caller match this list.

// env.mo
module {
    public let manager: [Text] = ["aaaaa-ziaaa-aaaai-aaafq-cai"];
}

// utils.mo
import Principal "mo:base/Principal";
import Array "mo:base/Array";

import Env "../env";

module {
    public func isManager(caller: Principal): Bool {
        hasPrivilege(caller, Env.manager);
    };

    private func hasPrivilege(caller: Principal, privileges: [Text]): Bool {
        func toPrincipal(entry: Text) : Principal {
            Principal.fromText(entry);
        };

        let principals: [Principal] = Array.map(privileges, toPrincipal);

        func filterAdmin(admin: Principal): Bool {
            admin == caller
        };

        let admin: ?Principal = Array.find(principals, filterAdmin);

        switch (admin) {
            case (null) {
                return false;
            };
            case (?admin) {
                return true;
            }
        }
    };
}

// used in one of my actor

public shared({ caller }) func doSomething(): async() {
        if (not Utils.isManager(caller)) {
            throw Error.reject("Unauthorized access. Caller is not a manager.");
        };

        ...
    };
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