diff --git a/fs_mgr/fs_mgr.cpp b/fs_mgr/fs_mgr.cpp index 5f15aad82..002b30239 100644 --- a/fs_mgr/fs_mgr.cpp +++ b/fs_mgr/fs_mgr.cpp @@ -2231,16 +2231,16 @@ bool fs_mgr_is_verity_enabled(const FstabEntry& entry) { return false; } -std::string fs_mgr_get_hashtree_algorithm(const android::fs_mgr::FstabEntry& entry) { +std::optional fs_mgr_get_hashtree_info(const android::fs_mgr::FstabEntry& entry) { if (!entry.fs_mgr_flags.verify && !entry.fs_mgr_flags.avb) { - return ""; + return {}; } DeviceMapper& dm = DeviceMapper::Instance(); std::string device = GetVerityDeviceName(entry); std::vector table; if (dm.GetState(device) == DmDeviceState::INVALID || !dm.GetTableInfo(device, &table)) { - return ""; + return {}; } for (const auto& target : table) { if (strcmp(target.spec.target_type, "verity") != 0) { @@ -2256,14 +2256,15 @@ std::string fs_mgr_get_hashtree_algorithm(const android::fs_mgr::FstabEntry& ent std::vector tokens = android::base::Split(target.data, " \t\r\n"); if (tokens[0] != "0" && tokens[0] != "1") { LOG(WARNING) << "Unrecognized device mapper version in " << target.data; - return ""; + return {}; } - // Hashtree algorithm is the 8th token in the output - return android::base::Trim(tokens[7]); + // Hashtree algorithm & root digest are the 8th & 9th token in the output. + return HashtreeInfo{.algorithm = android::base::Trim(tokens[7]), + .root_digest = android::base::Trim(tokens[8])}; } - return ""; + return {}; } bool fs_mgr_verity_is_check_at_most_once(const android::fs_mgr::FstabEntry& entry) { diff --git a/fs_mgr/include/fs_mgr.h b/fs_mgr/include/fs_mgr.h index 4d3ecc9dc..21c998946 100644 --- a/fs_mgr/include/fs_mgr.h +++ b/fs_mgr/include/fs_mgr.h @@ -22,6 +22,7 @@ #include #include +#include #include #include @@ -68,6 +69,13 @@ struct MountAllResult { bool userdata_mounted; }; +struct HashtreeInfo { + // The hash algorithm used to build the merkle tree. + std::string algorithm; + // The root digest of the merkle tree. + std::string root_digest; +}; + // fs_mgr_mount_all() updates fstab entries that reference device-mapper. // Returns a |MountAllResult|. The first element is one of the FS_MNG_MNTALL_* return codes // defined above, and the second element tells whether this call to fs_mgr_mount_all was responsible @@ -88,9 +96,9 @@ int fs_mgr_do_tmpfs_mount(const char *n_name); bool fs_mgr_load_verity_state(int* mode); // Returns true if verity is enabled on this particular FstabEntry. bool fs_mgr_is_verity_enabled(const android::fs_mgr::FstabEntry& entry); -// Returns the hash algorithm used to build the hashtree of this particular FstabEntry. Returns an -// empty string if the input isn't a dm-verity entry, or if there is an error. -std::string fs_mgr_get_hashtree_algorithm(const android::fs_mgr::FstabEntry& entry); +// Returns the verity hashtree information of this particular FstabEntry. Returns std::nullopt +// if the input isn't a dm-verity entry, or if there is an error. +std::optional fs_mgr_get_hashtree_info(const android::fs_mgr::FstabEntry& entry); bool fs_mgr_swapon_all(const android::fs_mgr::Fstab& fstab); bool fs_mgr_update_logical_partition(android::fs_mgr::FstabEntry* entry); diff --git a/init/builtins.cpp b/init/builtins.cpp index 7633d9c03..994eed9e0 100644 --- a/init/builtins.cpp +++ b/init/builtins.cpp @@ -894,9 +894,11 @@ static Result do_verity_update_state(const BuiltinArguments& args) { std::string partition = entry.mount_point == "/" ? "system" : Basename(entry.mount_point); SetProperty("partition." + partition + ".verified", std::to_string(mode)); - std::string hash_alg = fs_mgr_get_hashtree_algorithm(entry); - if (!hash_alg.empty()) { - SetProperty("partition." + partition + ".verified.hash_alg", hash_alg); + auto hashtree_info = fs_mgr_get_hashtree_info(entry); + if (hashtree_info) { + SetProperty("partition." + partition + ".verified.hash_alg", hashtree_info->algorithm); + SetProperty("partition." + partition + ".verified.root_digest", + hashtree_info->root_digest); } }