bootenv: add scope tests

the mockPlatformhandler was copied over to the bootenv package and
all the test logic related to the new scope functionality was decoupled
from keydata_test.go.

bootenv/export_test.go

@@ -24,6 +24,7 @@ import (
 	"crypto"
 	"crypto/ecdsa"
 	"crypto/elliptic"
+	"crypto/rand"
 	"crypto/x509"
 	"errors"
 
@@ -146,3 +147,13 @@ func NewEcdsaPublicKey(rand []byte) (ecdsaPublicKey, error) {
 
 	return pk, nil
 }
+
+func NewPrimaryKey(sz1 int) (secboot.PrimaryKey, error) {
+	primaryKey := make(secboot.PrimaryKey, sz1)
+	_, err := rand.Read(primaryKey)
+	if err != nil {
+		return nil, err
+	}
+
+	return primaryKey, nil
+}