Merge "libfs_avb: support key rotation for standalone partitions" (33f344cb) · Commits · e / os / android_system_core

fs_mgr/fs_mgr.cpp

+2 −2

Original line number	Diff line number	Diff line
		@@ -1089,7 +1089,7 @@ int fs_mgr_mount_all(Fstab* fstab, int mount_mode) {
		// Skips mounting the device.
		continue;
		}
		} else if (!current_entry.avb_key.empty()) {
		} else if (!current_entry.avb_keys.empty()) {
		if (AvbHandle::SetUpStandaloneAvbHashtree(&current_entry) == AvbHashtreeResult::kFail) {
		LERROR << "Failed to set up AVB on standalone partition: "
		<< current_entry.mount_point << ", skipping!";
		@@ -1320,7 +1320,7 @@ static int fs_mgr_do_mount_helper(Fstab* fstab, const std::string& n_name,
		// Skips mounting the device.
		continue;
		}
		} else if (!fstab_entry.avb_key.empty()) {
		} else if (!fstab_entry.avb_keys.empty()) {
		if (AvbHandle::SetUpStandaloneAvbHashtree(&fstab_entry) == AvbHashtreeResult::kFail) {
		LERROR << "Failed to set up AVB on standalone partition: "
		<< fstab_entry.mount_point << ", skipping!";

fs_mgr/fs_mgr_fstab.cpp

+4 −3

Original line number	Diff line number	Diff line
		@@ -325,8 +325,8 @@ void ParseFsMgrFlags(const std::string& flags, FstabEntry* entry) {
		}
		} else if (StartsWith(flag, "zram_backing_dev_path=")) {
		entry->zram_backing_dev_path = arg;
		} else if (StartsWith(flag, "avb_key=")) {
		entry->avb_key = arg;
		} else if (StartsWith(flag, "avb_keys=")) {
		entry->avb_keys = arg;
		} else {
		LWARNING << "Warning: unknown flag: " << flag;
		}
		@@ -759,7 +759,8 @@ FstabEntry BuildGsiSystemFstabEntry() {
		.fs_type = "ext4",
		.flags = MS_RDONLY,
		.fs_options = "barrier=1",
		.avb_key = "/gsi.avbpubkey",
		// could add more keys separated by ':'.
		.avb_keys = "/avb/gsi.avbpubkey:",
		.logical_partition_name = "system"};
		system.fs_mgr_flags.wait = true;
		system.fs_mgr_flags.logical = true;

fs_mgr/include_fstab/fstab/fstab.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -55,7 +55,7 @@ struct FstabEntry {
		std::string zram_loopback_path;
		uint64_t zram_loopback_size = 512 * 1024 * 1024; // 512MB by default;
		std::string zram_backing_dev_path;
		std::string avb_key;
		std::string avb_keys;

		struct FsMgrFlags {
		bool wait : 1;

fs_mgr/libfs_avb/avb_util.cpp

+19 −2

Original line number	Diff line number	Diff line
		@@ -28,6 +28,7 @@
		#include "util.h"

		using android::base::Basename;
		using android::base::ReadFileToString;
		using android::base::StartsWith;
		using android::base::unique_fd;

		@@ -311,7 +312,8 @@ std::unique_ptr<AvbFooter> GetAvbFooter(int fd) {
		return footer;
		}

		bool VerifyPublicKeyBlob(const uint8_t* key, size_t length, const std::string& expected_key_blob) {
		bool ValidatePublicKeyBlob(const uint8_t* key, size_t length,
		const std::string& expected_key_blob) {
		if (expected_key_blob.empty()) { // no expectation of the key, return true.
		return true;
		}
		@@ -324,6 +326,21 @@ bool VerifyPublicKeyBlob(const uint8_t* key, size_t length, const std::string& e
		return false;
		}

		bool ValidatePublicKeyBlob(const std::string key_blob_to_validate,
		const std::vector<std::string>& allowed_key_paths) {
		std::string allowed_key_blob;
		if (key_blob_to_validate.empty()) {
		LWARNING << "Failed to validate an empty key";
		return false;
		}
		for (const auto& path : allowed_key_paths) {
		if (ReadFileToString(path, &allowed_key_blob)) {
		if (key_blob_to_validate == allowed_key_blob) return true;
		}
		}
		return false;
		}

		VBMetaVerifyResult VerifyVBMetaSignature(const VBMetaData& vbmeta,
		const std::string& expected_public_key_blob,
		std::string* out_public_key_data) {
		@@ -347,7 +364,7 @@ VBMetaVerifyResult VerifyVBMetaSignature(const VBMetaData& vbmeta,
		<< ": Error verifying vbmeta image: failed to get public key";
		return VBMetaVerifyResult::kError;
		}
		if (!VerifyPublicKeyBlob(pk_data, pk_len, expected_public_key_blob)) {
		if (!ValidatePublicKeyBlob(pk_data, pk_len, expected_public_key_blob)) {
		LERROR << vbmeta.partition() << ": Error verifying vbmeta image: public key used to"
		<< " sign data does not match key in chain descriptor";
		return VBMetaVerifyResult::kErrorVerification;

fs_mgr/libfs_avb/avb_util.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -78,7 +78,10 @@ VBMetaVerifyResult VerifyVBMetaSignature(const VBMetaData& vbmeta,
		const std::string& expected_public_key_blob,
		std::string* out_public_key_data);

		bool VerifyPublicKeyBlob(const uint8_t* key, size_t length, const std::string& expected_key_blob);
		bool ValidatePublicKeyBlob(const uint8_t* key, size_t length, const std::string& expected_key_blob);

		bool ValidatePublicKeyBlob(const std::string key_blob_to_validate,
		const std::vector<std::string>& expected_key_paths);

		// Detects if whether a partition contains a rollback image.
		bool RollbackDetected(const std::string& partition_name, uint64_t rollback_index);