From 5e6c4e9a91674826bf11cab604250b41a9326fd8 Mon Sep 17 00:00:00 2001 From: Tianjie Xu Date: Tue, 6 Aug 2019 12:32:05 -0700 Subject: Force package installation with FUSE unless the package stores on device The non-A/B package installation is subject to TOC/TOU flaw if the attacker can switch the package in the middle of installation. And the most pratical case is to store the package on an external device, e.g. a sdcard, and swap the device in the middle. To prevent that, we can adopt the same protection as used in sideloading a package with FUSE. Specifically, when we install the package with FUSE, we read the entire package to cryptographically verify its signature. The hash for each transfer block is recorded in the memory (TOC), and the subsequent reads (TOU) will be rejected upon dectecting a mismatch. This CL forces the package installation with FUSE when the package stays on a removable media. Bug: 136498130 Test: Run bin/recovery --update_package with various paths; and packages are installed from FUSE as expected Test: recovery_component_test - all passing Change-Id: Ibc9b095036a2fa624e8edf6c347ed4f12aef072f Merged-In: Ibc9b095036a2fa624e8edf6c347ed4f12aef072f --- install/include/install/install.h | 4 ++++ install/install.cpp | 47 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+) (limited to 'install') diff --git a/install/include/install/install.h b/install/include/install/install.h index 87d43ab09..bef23e9ca 100644 --- a/install/include/install/install.h +++ b/install/include/install/install.h @@ -63,3 +63,7 @@ bool ReadMetadataFromPackage(ZipArchiveHandle zip, std::map& metadata, OtaType ota_type); + +// Ensures the path to the update package is mounted. Also set the |should_use_fuse| to true if the +// package stays on a removable media. +bool SetupPackageMount(const std::string& package_path, bool* should_use_fuse); diff --git a/install/install.cpp b/install/install.cpp index 4bb0903cc..1c9bf2fd2 100644 --- a/install/install.cpp +++ b/install/install.cpp @@ -30,6 +30,7 @@ #include #include #include +#include #include #include #include @@ -641,3 +642,49 @@ bool verify_package(Package* package, RecoveryUI* ui) { } return true; } + +bool SetupPackageMount(const std::string& package_path, bool* should_use_fuse) { + CHECK(should_use_fuse != nullptr); + + if (package_path.empty()) { + return false; + } + + *should_use_fuse = true; + if (package_path[0] == '@') { + auto block_map_path = package_path.substr(1); + if (ensure_path_mounted(block_map_path) != 0) { + LOG(ERROR) << "Failed to mount " << block_map_path; + return false; + } + // uncrypt only produces block map only if the package stays on /data. + *should_use_fuse = false; + return true; + } + + // Package is not a block map file. + if (ensure_path_mounted(package_path) != 0) { + LOG(ERROR) << "Failed to mount " << package_path; + return false; + } + + // Reject the package if the input path doesn't equal the canonicalized path. + // e.g. /cache/../sdcard/update_package. + std::error_code ec; + auto canonical_path = std::filesystem::canonical(package_path, ec); + if (ec) { + LOG(ERROR) << "Failed to get canonical of " << package_path << ", " << ec.message(); + return false; + } + if (canonical_path.string() != package_path) { + LOG(ERROR) << "Installation aborts. The canonical path " << canonical_path.string() + << " doesn't equal the original path " << package_path; + return false; + } + + constexpr const char* CACHE_ROOT = "/cache"; + if (android::base::StartsWith(package_path, CACHE_ROOT)) { + *should_use_fuse = false; + } + return true; +} -- cgit v1.2.3 From daaacea96ebfc55b47f44240e2082c820c8eb234 Mon Sep 17 00:00:00 2001 From: Raman Tenneti Date: Thu, 13 Feb 2020 02:50:42 +0000 Subject: Revert "Force package installation with FUSE unless the package stores on device" This reverts commit 5e6c4e9a91674826bf11cab604250b41a9326fd8. Reason for revert: BUG: 149432069 - build failure on git_qt-qpr1-dev-plus-aosp on docs. 'otautil/roots.h' file not found is the error. Forrest run: https://android-build.googleplex.com/builds/forrest/run/L85900000460577420 Change-Id: I35119c2334895aa0ef4ed71b3ddd08f280c0c031 Merged-In: I35119c2334895aa0ef4ed71b3ddd08f280c0c031 --- install/include/install/install.h | 4 ---- install/install.cpp | 47 --------------------------------------- 2 files changed, 51 deletions(-) (limited to 'install') diff --git a/install/include/install/install.h b/install/include/install/install.h index bef23e9ca..87d43ab09 100644 --- a/install/include/install/install.h +++ b/install/include/install/install.h @@ -63,7 +63,3 @@ bool ReadMetadataFromPackage(ZipArchiveHandle zip, std::map& metadata, OtaType ota_type); - -// Ensures the path to the update package is mounted. Also set the |should_use_fuse| to true if the -// package stays on a removable media. -bool SetupPackageMount(const std::string& package_path, bool* should_use_fuse); diff --git a/install/install.cpp b/install/install.cpp index 1c9bf2fd2..4bb0903cc 100644 --- a/install/install.cpp +++ b/install/install.cpp @@ -30,7 +30,6 @@ #include #include #include -#include #include #include #include @@ -642,49 +641,3 @@ bool verify_package(Package* package, RecoveryUI* ui) { } return true; } - -bool SetupPackageMount(const std::string& package_path, bool* should_use_fuse) { - CHECK(should_use_fuse != nullptr); - - if (package_path.empty()) { - return false; - } - - *should_use_fuse = true; - if (package_path[0] == '@') { - auto block_map_path = package_path.substr(1); - if (ensure_path_mounted(block_map_path) != 0) { - LOG(ERROR) << "Failed to mount " << block_map_path; - return false; - } - // uncrypt only produces block map only if the package stays on /data. - *should_use_fuse = false; - return true; - } - - // Package is not a block map file. - if (ensure_path_mounted(package_path) != 0) { - LOG(ERROR) << "Failed to mount " << package_path; - return false; - } - - // Reject the package if the input path doesn't equal the canonicalized path. - // e.g. /cache/../sdcard/update_package. - std::error_code ec; - auto canonical_path = std::filesystem::canonical(package_path, ec); - if (ec) { - LOG(ERROR) << "Failed to get canonical of " << package_path << ", " << ec.message(); - return false; - } - if (canonical_path.string() != package_path) { - LOG(ERROR) << "Installation aborts. The canonical path " << canonical_path.string() - << " doesn't equal the original path " << package_path; - return false; - } - - constexpr const char* CACHE_ROOT = "/cache"; - if (android::base::StartsWith(package_path, CACHE_ROOT)) { - *should_use_fuse = false; - } - return true; -} -- cgit v1.2.3 From cd8faf7eeead6fd6ee5912ddd26dab5ab6c7dda7 Mon Sep 17 00:00:00 2001 From: Tianjie Xu Date: Tue, 6 Aug 2019 12:32:05 -0700 Subject: Force off-device package installation with FUSE The non-A/B package installation is subject to TOC/TOU flaw if the attacker can switch the package in the middle of installation. And the most pratical case is to store the package on an external device, e.g. a sdcard, and swap the device in the middle. To prevent that, we can adopt the same protection as used in sideloading a package with FUSE. Specifically, when we install the package with FUSE, we read the entire package to cryptographically verify its signature. The hash for each transfer block is recorded in the memory (TOC), and the subsequent reads (TOU) will be rejected upon dectecting a mismatch. This CL forces the package installation with FUSE when the package stays on a removable media. Bug: 136498130 Test: Run bin/recovery --update_package with various paths; and packages are installed from FUSE as expected Test: recovery_unit_test - no new failures Change-Id: Ia5afd19854c3737110339fd59491b96708926ae5 Merged-In: I35119c2334895aa0ef4ed71b3ddd08f280c0c031 --- install/include/install/install.h | 4 ++++ install/install.cpp | 47 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+) (limited to 'install') diff --git a/install/include/install/install.h b/install/include/install/install.h index 87d43ab09..bef23e9ca 100644 --- a/install/include/install/install.h +++ b/install/include/install/install.h @@ -63,3 +63,7 @@ bool ReadMetadataFromPackage(ZipArchiveHandle zip, std::map& metadata, OtaType ota_type); + +// Ensures the path to the update package is mounted. Also set the |should_use_fuse| to true if the +// package stays on a removable media. +bool SetupPackageMount(const std::string& package_path, bool* should_use_fuse); diff --git a/install/install.cpp b/install/install.cpp index 4bb0903cc..1c9bf2fd2 100644 --- a/install/install.cpp +++ b/install/install.cpp @@ -30,6 +30,7 @@ #include #include #include +#include #include #include #include @@ -641,3 +642,49 @@ bool verify_package(Package* package, RecoveryUI* ui) { } return true; } + +bool SetupPackageMount(const std::string& package_path, bool* should_use_fuse) { + CHECK(should_use_fuse != nullptr); + + if (package_path.empty()) { + return false; + } + + *should_use_fuse = true; + if (package_path[0] == '@') { + auto block_map_path = package_path.substr(1); + if (ensure_path_mounted(block_map_path) != 0) { + LOG(ERROR) << "Failed to mount " << block_map_path; + return false; + } + // uncrypt only produces block map only if the package stays on /data. + *should_use_fuse = false; + return true; + } + + // Package is not a block map file. + if (ensure_path_mounted(package_path) != 0) { + LOG(ERROR) << "Failed to mount " << package_path; + return false; + } + + // Reject the package if the input path doesn't equal the canonicalized path. + // e.g. /cache/../sdcard/update_package. + std::error_code ec; + auto canonical_path = std::filesystem::canonical(package_path, ec); + if (ec) { + LOG(ERROR) << "Failed to get canonical of " << package_path << ", " << ec.message(); + return false; + } + if (canonical_path.string() != package_path) { + LOG(ERROR) << "Installation aborts. The canonical path " << canonical_path.string() + << " doesn't equal the original path " << package_path; + return false; + } + + constexpr const char* CACHE_ROOT = "/cache"; + if (android::base::StartsWith(package_path, CACHE_ROOT)) { + *should_use_fuse = false; + } + return true; +} -- cgit v1.2.3