Allow building libfec without libavb

Add stub implementation for avb related functions to allow building
libfec without libavb support. This is useful to build the fec binary
when libavb isn't available on mac.

Test: build, unittests pass
Change-Id: I26f8de390c3c2c37bf48418fb31038ddd9863866

1 files changed, 30 insertions, 0 deletions

diff --git a/libfec/avb_utils.h b/libfec/avb_utils.h
new file mode 100644
index 00000000..78254508
--- /dev/null
+++ b/libfec/avb_utils.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <vector>
+
+struct fec_handle;
+
+// Checks if there is a valid AVB footer in the end of the image. If so, parses
+// the contents of vbmeta struct from the given AVB footer. Returns 0 on
+// success.
+int parse_vbmeta_from_footer(fec_handle *f, std::vector<uint8_t> *vbmeta);
+
+// Parses the AVB vbmeta for the information of hashtree and fec data.
+int parse_avb_image(fec_handle *f, const std::vector<uint8_t> &vbmeta);