actions: error handling and API changed

This commit changes the error handling for the actions package to use
the error handling library github.com/pkg/errors. This means replacing
"errors" with "github.com/pkg/errors", reworking some of the error
values, and wrapping some errors with additional context.

This commit also changes the Protector/Policy API, moving most of the
package functionality into Protector or Policy methods. These types are
now "locked" when they are queried from the filesystem, and Unlock()
must be used to get their corresponding keys. Note that only certain
operations will require unlocking the keys. Certain unnecessary
functions and methods are also removed.

This CL also fixes two bugs reported by Tyler Hicks in CreateConfigFile.
CPU time is used instead of wall time, and kiB is used instead of kB.

Change-Id: I88f45659e9fe4938d148843e3289e7b6d5b698d8

1 files changed, 8 insertions, 17 deletions

diff --git a/actions/protector_test.go b/actions/protector_test.go
index 08d9aed..eacba83 100644
--- a/actions/protector_test.go
+++ b/actions/protector_test.go
@@ -21,9 +21,10 @@ package actions
 
 import (
 	"bytes"
-	"errors"
 	"testing"
 
+	"github.com/pkg/errors"
+
 	. "fscrypt/crypto"
 )
 
@@ -42,31 +43,21 @@ func badCallback(info ProtectorInfo, retry bool) (*Key, error) {
 
 // Tests that we can create a valid protector.
 func TestCreateProtector(t *testing.T) {
-	ctx, err := makeContext()
-	defer cleaupContext()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	p, err := CreateProtector(ctx, testProtectorName, goodCallback)
+	p, err := CreateProtector(testContext, testProtectorName, goodCallback)
 	if err != nil {
 		t.Error(err)
 	} else {
-		p.Wipe()
+		p.Lock()
+		p.Destroy()
 	}
 }
 
 // Tests that a failure in the callback is relayed back to the caller.
 func TestBadCallback(t *testing.T) {
-	ctx, err := makeContext()
-	defer cleaupContext()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	p, err := CreateProtector(ctx, testProtectorName, badCallback)
+	p, err := CreateProtector(testContext, testProtectorName, badCallback)
 	if err == nil {
-		p.Wipe()
+		p.Lock()
+		p.Destroy()
 	}
 	if err != errCallback {
 		t.Error("callback error was not relayed back to caller")