actions: Simplify the callback mechanism

This commit makes the callbacks for getting keys easier to understand.
Functions which need keys now take a KeyFunc callback. This callback
contains a ProtectorInfo parameter (basically a read-only version of
metadata.ProtectorData) and a boolean which indicates if the call is
being retried. The documentation is also updated to say which functions
will retry the KeyFunc.

For selecting a protector, there is now an OptionFunc callback which
takes a slice of ProtectorOptions. A ProtectorOption is a ProtectorInfo
along with additional information about a linked filesystem (if
applicable).

This commit also adds in methods for getting the protector options for a
specific filesystem or policy. It also adds a function for getting the
policy descriptor for a specific path.

Change-Id: I41e0d94ffd44e7166b0c5cf1b5d18437960bdf90

1 files changed, 5 insertions, 5 deletions

diff --git a/actions/protector_test.go b/actions/protector_test.go
index bb59dba..08d9aed 100644
--- a/actions/protector_test.go
+++ b/actions/protector_test.go
@@ -32,23 +32,23 @@ const testProtectorName2 = testProtectorName + "2"
 
 var errCallback = errors.New("bad callback")
 
-func goodCallback(data ProtectorData) (*Key, error) {
+func goodCallback(info ProtectorInfo, retry bool) (*Key, error) {
 	return NewFixedLengthKeyFromReader(bytes.NewReader(timingPassphrase), len(timingPassphrase))
 }
 
-func badCallback(data ProtectorData) (*Key, error) {
+func badCallback(info ProtectorInfo, retry bool) (*Key, error) {
 	return nil, errCallback
 }
 
 // Tests that we can create a valid protector.
-func TestNewProtector(t *testing.T) {
+func TestCreateProtector(t *testing.T) {
 	ctx, err := makeContext()
 	defer cleaupContext()
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	p, err := ctx.NewProtector(testProtectorName, goodCallback)
+	p, err := CreateProtector(ctx, testProtectorName, goodCallback)
 	if err != nil {
 		t.Error(err)
 	} else {
@@ -64,7 +64,7 @@ func TestBadCallback(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	p, err := ctx.NewProtector(testProtectorName, badCallback)
+	p, err := CreateProtector(ctx, testProtectorName, badCallback)
 	if err == nil {
 		p.Wipe()
 	}