1 files changed, 80 insertions, 0 deletions
diff --git a/lib/libavb/avb_hashtree_descriptor.h b/lib/libavb/avb_hashtree_descriptor.h
new file mode 100644
index 0000000000..3d3e647fe1
--- /dev/null
+++ b/lib/libavb/avb_hashtree_descriptor.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * SPDX-License-Identifier:	MIT
+ */
+
+#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION)
+#error "Never include this file directly, include libavb.h instead."
+#endif
+
+#ifndef AVB_HASHTREE_DESCRIPTOR_H_
+#define AVB_HASHTREE_DESCRIPTOR_H_
+
+#include "avb_descriptor.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Flags for hashtree descriptors.
+ *
+ * AVB_HASHTREE_DESCRIPTOR_FLAGS_DO_NOT_USE_AB: Do not apply the default A/B
+ *   partition logic to this partition. This is intentionally a negative boolean
+ *   because A/B should be both the default and most used in practice.
+ */
+typedef enum {
+  AVB_HASHTREE_DESCRIPTOR_FLAGS_DO_NOT_USE_AB = (1 << 0),
+} AvbHashtreeDescriptorFlags;
+
+/* A descriptor containing information about a dm-verity hashtree.
+ *
+ * Hash-trees are used to verify large partitions typically containing
+ * file systems. See
+ * https://gitlab.com/cryptsetup/cryptsetup/wikis/DMVerity for more
+ * information about dm-verity.
+ *
+ * Following this struct are |partition_name_len| bytes of the
+ * partition name (UTF-8 encoded), |salt_len| bytes of salt, and then
+ * |root_digest_len| bytes of the root digest.
+ *
+ * The |reserved| field is for future expansion and must be set to NUL
+ * bytes.
+ *
+ * Changes in v1.1:
+ *   - flags field is added which supports AVB_HASHTREE_DESCRIPTOR_FLAGS_USE_AB
+ *   - digest_len may be zero, which indicates the use of a persistent digest
+ */
+typedef struct AvbHashtreeDescriptor {
+  AvbDescriptor parent_descriptor;
+  uint32_t dm_verity_version;
+  uint64_t image_size;
+  uint64_t tree_offset;
+  uint64_t tree_size;
+  uint32_t data_block_size;
+  uint32_t hash_block_size;
+  uint32_t fec_num_roots;
+  uint64_t fec_offset;
+  uint64_t fec_size;
+  uint8_t hash_algorithm[32];
+  uint32_t partition_name_len;
+  uint32_t salt_len;
+  uint32_t root_digest_len;
+  uint32_t flags;
+  uint8_t reserved[60];
+} AVB_ATTR_PACKED AvbHashtreeDescriptor;
+
+/* Copies |src| to |dest| and validates, byte-swapping fields in the
+ * process if needed. Returns true if valid, false if invalid.
+ *
+ * Data following the struct is not validated nor copied.
+ */
+bool avb_hashtree_descriptor_validate_and_byteswap(
+    const AvbHashtreeDescriptor* src,
+    AvbHashtreeDescriptor* dest) AVB_ATTR_WARN_UNUSED_RESULT;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* AVB_HASHTREE_DESCRIPTOR_H_ */