Kevin Reid: link to mailing list message

Kevin Reid — Mon, 22 Nov 2010 21:44:47 GMT

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Mailing list post of this: [http://www.eros-os.org/pipermail/cap-talk/2008-May/011062.html]

<pre>
# Copyright 2008 Kevin Reid, under the terms of the MIT X license
# found at http://www.opensource.org/licenses/mit-license.html ................

pragma.syntax("0.9")

# --- Utilities ---

def makeProxy := <elib:ref.makeProxy>
def makeBrand := <elib:sealing.makeBrand>

def everything {
to contains(_) { return true }
}

# --- Signing ---

interface ::"Signed" guards SignedStamp {}

def makeSigner(label) {
def who {
to __printOn(out) {
out.print("<", label, ">")
}
}
def signer {
to __printOn(out) {
out.print("<signing as ", label, ">")
}
to who() { return who }
to run(what) {
def ::"signed" implements SignedStamp {
to _who() { return who }
to _get() { return what }
}
return ::"signed"
}
}
return signer
}

def verifyAndGet(::"signed" : ::"Signed") {
return [::"signed"._get(), ::"signed"._who()]
}

# --- Operations ---

def ::"delegate"(scap, filter, note) {
def [cert, signer, host] := scap
def newSigner := makeSigner(note)
return [signer(["delegate", cert, newSigner.who(), filter]), newSigner, host]
}

/** Turn an object whose methods take an extra argument for the delegation chain into a scap. */
def exportOD(handler) {
def rootSigner := makeSigner("export root")

def handleMessage(delegators, verb :String, args :List, cert) {
def [[=="delegate", prevCert, whoTo, filter], whoBy] := verifyAndGet(cert)
if (!filter.contains(verb)) {
throw(`$verb not permitted by $whoBy`)
}

def delegators1 := delegators.with(whoTo)
return if (whoBy != rootSigner.who()) {
handleMessage(delegators1, verb, args, prevCert)
} else {
E.call(handler, verb, [delegators1] + args)
}
}

def host(verb, args, cert) {
handleMessage([], verb, args, cert)
}

return [rootSigner(["delegate", Ref.broken("n/a"), rootSigner.who(), everything]), rootSigner, host]
}

/** Turn a scap into a normal invokable reference. */
def importOD(scap) {
def [cert, signer, host] := scap
return makeProxy(def handler {
to handleSend(verb, args) {
return host <- (verb, args, cert)
}
to handleSendOnly(verb, args) {
return host <- (verb, args, cert)
}
to handleOptSealedDispatch(_) {}
}, Ref.whenBroken(host, fn _ {Ref.optProblem(host)}), true)
}

# --- Example ---

def carol(x) {
def xr := importOD(x)
xr <- hello("world")
}

def bob(x) {
def xr := importOD(x)
when ( carol <- (::"delegate"(x, ["hello"].asSet(), "Carol")) ) -> {
xr <- goodbye()
}
}

def alice(x) {
bob <- (::"delegate"(x, ["hello", "goodbye"].asSet(), "Bob"))
}

def root := exportOD(def root0 {
to hello(chain, greeted) {
println(chain, " greeted ", greeted)
}
to goodbye(chain) {
println(chain, " said goodbye")
}
})
alice(::"delegate"(root, ["hello", "goodbye"].asSet(), "Alice"))
</pre>

Kevin Reid: fix missed "certificate" -> "scap"

Kevin Reid — Sat, 31 May 2008 21:05:20 GMT

fix missed "certificate" -> "scap"

←Older revision		Revision as of 21:05, 31 May 2008
Line 52:		Line 52:
	}		}

-	/** Turn an object whose methods take an extra argument for the delegation chain into a ~~certificate~~. */	+	/** Turn an object whose methods take an extra argument for the delegation chain into a scap. */
	def exportOD(handler) {		def exportOD(handler) {
	def rootSigner := makeSigner("export root")		def rootSigner := makeSigner("export root")

Kevin Reid: publishing offline delegation attempt #2

Kevin Reid — Fri, 30 May 2008 16:59:26 GMT

publishing offline delegation attempt #2

←Older revision		Revision as of 16:59, 30 May 2008
Line 1:		Line 1:
-	~~Mailing list post of this: [http://www.eros-os.org/pipermail/cap-talk/2008-May/011062.html]~~
-
	<pre>		<pre>
	# Copyright 2008 Kevin Reid, under the terms of the MIT X license		# Copyright 2008 Kevin Reid, under the terms of the MIT X license
Line 54:		Line 52:
	}		}

-	/** Turn an object whose methods take an extra argument for the delegation chain into a ~~scap~~. */	+	/** Turn an object whose methods take an extra argument for the delegation chain into a certificate. */
	def exportOD(handler) {		def exportOD(handler) {
	def rootSigner := makeSigner("export root")		def rootSigner := makeSigner("export root")

User:Kevin Reid/Offline delegation - Revision history

Kevin Reid: link to mailing list message

Kevin Reid: fix missed "certificate" -> "scap"

Kevin Reid: publishing offline delegation attempt #2