Address review feedback

builtin/logical/transit/path_keys.go

@@ -74,7 +74,6 @@ func pathPolicyRead(
 			"deletion_allowed":       p.DeletionAllowed,
 			"min_decryption_version": p.MinDecryptionVersion,
 			"latest_version":         p.LatestVersion,
-			"archive_version":        p.ArchiveVersion,
 		},
 	}
 	if p.Derived {

builtin/logical/transit/policy.go

@@ -162,12 +162,21 @@ func (p *Policy) handleArchiving(storage logical.Storage) error {
 		return err
 	}
 
-	if keysContainsMinimum {
+	if !keysContainsMinimum {
+		// Need to move keys *from* archive
+
+		for i := p.MinDecryptionVersion; i <= p.LatestVersion; i++ {
+			p.Keys[i] = archive.Keys[i]
+		}
+
+		return nil
+	}
+
 	// Need to move keys *to* archive
 
-		// We need a size that is equivalent to the latest version (number of
-		// keys) but adding one since slice numbering starts at 0 and we're
-		// indexing by key version
+	// We need a size that is equivalent to the latest version (number of keys)
+	// but adding one since slice numbering starts at 0 and we're indexing by
+	// key version
 	if len(archive.Keys) < p.LatestVersion+1 {
 		// Increase the size of the archive slice
 		newKeys := make([]KeyEntry, p.LatestVersion+1)
@@ -175,8 +184,8 @@ func (p *Policy) handleArchiving(storage logical.Storage) error {
 		archive.Keys = newKeys
 	}
 
-		// We are storing all keys in the archive, so we ensure that it is up
-		// to date up to p.LatestVersion
+	// We are storing all keys in the archive, so we ensure that it is up to
+	// date up to p.LatestVersion
 	for i := p.ArchiveVersion + 1; i <= p.LatestVersion; i++ {
 		archive.Keys[i] = p.Keys[i]
 		p.ArchiveVersion = i
@@ -193,14 +202,6 @@ func (p *Policy) handleArchiving(storage logical.Storage) error {
 		delete(p.Keys, i)
 	}
 
-	} else {
-		// Need to move keys *from* archive
-
-		for i := p.MinDecryptionVersion; i <= p.LatestVersion; i++ {
-			p.Keys[i] = archive.Keys[i]
-		}
-	}
-
 	return nil
 }
 
@@ -238,11 +239,8 @@ func (p *Policy) Serialize() ([]byte, error) {
 // mode is used with the context to derive the proper key.
 func (p *Policy) DeriveKey(context []byte, ver int) ([]byte, error) {
 	if p.Keys == nil || p.LatestVersion == 0 {
-		if p.Key == nil || len(p.Key) == 0 {
 		return nil, certutil.InternalError{Err: "unable to access the key; no key versions found"}
 	}
-		p.migrateKeyToKeysMap()
-	}
 
 	if p.LatestVersion == 0 {
 		return nil, certutil.InternalError{Err: "unable to access the key; no key versions found"}
@@ -398,7 +396,10 @@ func (p *Policy) Decrypt(context []byte, value string) (string, error) {
 
 func (p *Policy) rotate(storage logical.Storage) error {
 	if p.Keys == nil {
-		p.migrateKeyToKeysMap()
+		// This is an initial key rotation when generating a new policy. We
+		// don't need to call migrate here because if we've called getPolicy to
+		// get the policy in the first place it will have been run.
+		p.Keys = KeyEntryMap{}
 	}
 
 	// Generate a 256bit key
@@ -426,12 +427,6 @@ func (p *Policy) rotate(storage logical.Storage) error {
 }
 
 func (p *Policy) migrateKeyToKeysMap() {
-	if p.Key == nil || len(p.Key) == 0 {
-		p.Key = nil
-		p.Keys = KeyEntryMap{}
-		return
-	}
-
 	p.Keys = KeyEntryMap{
 		1: KeyEntry{
 			Key:          p.Key,

builtin/logical/transit/policy_test.go

@@ -11,6 +11,33 @@ var (
 	keysArchive = []KeyEntry{KeyEntry{}}
 )
 
+func Test_KeyUpgrade(t *testing.T) {
+	storage := &logical.InmemStorage{}
+	policy, err := generatePolicy(storage, "test", false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if policy == nil {
+		t.Fatal("nil policy")
+	}
+
+	testBytes := make([]byte, len(policy.Keys[1].Key))
+	copy(testBytes, policy.Keys[1].Key)
+
+	policy.Key = policy.Keys[1].Key
+	policy.Keys = nil
+	policy.migrateKeyToKeysMap()
+	if policy.Key != nil {
+		t.Fatal("policy.Key is not nil")
+	}
+	if len(policy.Keys) != 1 {
+		t.Fatal("policy.Keys is the wrong size")
+	}
+	if !reflect.DeepEqual(testBytes, policy.Keys[1].Key) {
+		t.Fatal("key mismatch")
+	}
+}
+
 func Test_Archiving(t *testing.T) {
 	// First, we generate a policy and rotate it a number of times. Each time
 	// we'll ensure that we have the expected number of keys in the archive and
@@ -18,9 +45,8 @@ func Test_Archiving(t *testing.T) {
 	// zero and latest, respectively
 
 	storage := &logical.InmemStorage{}
-	testName := "test"
 
-	policy, err := generatePolicy(storage, testName, false)
+	policy, err := generatePolicy(storage, "test", false)
 	if err != nil {
 		t.Fatal(err)
 	}