From 77df7f207dcef1f967695fca2e131097abebe28c Mon Sep 17 00:00:00 2001 From: Paul Crowley Date: Thu, 23 Jan 2020 15:29:30 -0800 Subject: [PATCH] Refactor to use EncryptionPolicy everywhere we used to use raw_ref Test: Boots, no bad log messages: Cuttlefish with v2 policies, Taimen Bug: 147733587 Change-Id: Ice4acac3236b6b7d90e60a2f57b46814aa1949f5 --- FsCrypt.cpp | 150 +++++++++++++++++++++++----------------------- KeyUtil.cpp | 100 ++++++++++--------------------- KeyUtil.h | 38 +++++++++--- MetadataCrypt.cpp | 4 +- 4 files changed, 136 insertions(+), 156 deletions(-) diff --git a/FsCrypt.cpp b/FsCrypt.cpp index 603362f..712f544 100644 --- a/FsCrypt.cpp +++ b/FsCrypt.cpp @@ -63,6 +63,7 @@ using android::base::StringPrintf; using android::fs_mgr::GetEntryForMountPoint; +using android::vold::BuildDataPath; using android::vold::kEmptyAuthentication; using android::vold::KeyBuffer; using android::vold::writeStringToFile; @@ -86,9 +87,9 @@ bool s_systemwide_keys_initialized = false; // Some users are ephemeral, don't try to wipe their keys from disk std::set s_ephemeral_users; -// Map user ids to key references -std::map s_de_key_raw_refs; -std::map s_ce_key_raw_refs; +// Map user ids to encryption policies +std::map s_de_policies; +std::map s_ce_policies; } // namespace @@ -195,23 +196,18 @@ static bool read_and_fixate_user_ce_key(userid_t user_id, } // Retrieve the options to use for encryption policies on the /data filesystem. -static void get_data_file_encryption_options(EncryptionOptions* options) { +static bool get_data_file_encryption_options(EncryptionOptions* options) { auto entry = GetEntryForMountPoint(&fstab_default, DATA_MNT_POINT); if (entry == nullptr) { - return; + LOG(ERROR) << "No mount point entry for " << DATA_MNT_POINT; + return false; } if (!ParseOptions(entry->encryption_options, options)) { LOG(ERROR) << "Unable to parse encryption options for " << DATA_MNT_POINT ": " << entry->encryption_options; - return; + return false; } -} - -// Retrieve the version to use for encryption policies on the /data filesystem. -static int get_data_file_policy_version(void) { - EncryptionOptions options; - get_data_file_encryption_options(&options); - return options.version; + return true; } // Retrieve the options to use for encryption policies on adoptable storage. @@ -220,29 +216,25 @@ static bool get_volume_file_encryption_options(EncryptionOptions* options) { android::base::GetProperty("ro.crypto.volume.contents_mode", "aes-256-xts"); auto filenames_mode = android::base::GetProperty("ro.crypto.volume.filenames_mode", "aes-256-heh"); - return ParseOptions(android::base::GetProperty("ro.crypto.volume.options", - contents_mode + ":" + filenames_mode + ":v1"), - options); -} - -// Install a key for use by encrypted files on the /data filesystem. -static bool install_data_key(const KeyBuffer& key, std::string* raw_ref) { - return android::vold::installKey(key, DATA_MNT_POINT, get_data_file_policy_version(), raw_ref); -} - -// Evict a key for use by encrypted files on the /data filesystem. -static bool evict_data_key(const std::string& raw_ref) { - return android::vold::evictKey(DATA_MNT_POINT, raw_ref, get_data_file_policy_version()); + auto options_string = android::base::GetProperty("ro.crypto.volume.options", + contents_mode + ":" + filenames_mode + ":v1"); + if (!ParseOptions(options_string, options)) { + LOG(ERROR) << "Unable to parse volume encryption options: " << options_string; + return false; + } + return true; } static bool read_and_install_user_ce_key(userid_t user_id, const android::vold::KeyAuthentication& auth) { - if (s_ce_key_raw_refs.count(user_id) != 0) return true; + if (s_ce_policies.count(user_id) != 0) return true; + EncryptionOptions options; + if (!get_data_file_encryption_options(&options)) return false; KeyBuffer ce_key; if (!read_and_fixate_user_ce_key(user_id, auth, &ce_key)) return false; - std::string ce_raw_ref; - if (!install_data_key(ce_key, &ce_raw_ref)) return false; - s_ce_key_raw_refs[user_id] = ce_raw_ref; + EncryptionPolicy ce_policy; + if (!installKey(DATA_MNT_POINT, options, ce_key, &ce_policy)) return false; + s_ce_policies[user_id] = ce_policy; LOG(DEBUG) << "Installed ce key for user " << user_id; return true; } @@ -268,6 +260,8 @@ static bool destroy_dir(const std::string& dir) { // NB this assumes that there is only one thread listening for crypt commands, because // it creates keys in a fixed location. static bool create_and_install_user_keys(userid_t user_id, bool create_ephemeral) { + EncryptionOptions options; + if (!get_data_file_encryption_options(&options)) return false; KeyBuffer de_key, ce_key; if (!android::vold::randomKey(&de_key)) return false; if (!android::vold::randomKey(&ce_key)) return false; @@ -289,24 +283,24 @@ static bool create_and_install_user_keys(userid_t user_id, bool create_ephemeral kEmptyAuthentication, de_key)) return false; } - std::string de_raw_ref; - if (!install_data_key(de_key, &de_raw_ref)) return false; - s_de_key_raw_refs[user_id] = de_raw_ref; - std::string ce_raw_ref; - if (!install_data_key(ce_key, &ce_raw_ref)) return false; - s_ce_key_raw_refs[user_id] = ce_raw_ref; + EncryptionPolicy de_policy; + if (!installKey(DATA_MNT_POINT, options, de_key, &de_policy)) return false; + s_de_policies[user_id] = de_policy; + EncryptionPolicy ce_policy; + if (!installKey(DATA_MNT_POINT, options, ce_key, &ce_policy)) return false; + s_ce_policies[user_id] = ce_policy; LOG(DEBUG) << "Created keys for user " << user_id; return true; } -static bool lookup_key_ref(const std::map& key_map, userid_t user_id, - std::string* raw_ref) { +static bool lookup_policy(const std::map& key_map, userid_t user_id, + EncryptionPolicy* policy) { auto refi = key_map.find(user_id); if (refi == key_map.end()) { LOG(DEBUG) << "Cannot find key for " << user_id; return false; } - *raw_ref = refi->second; + *policy = refi->second; return true; } @@ -318,6 +312,8 @@ static bool is_numeric(const char* name) { } static bool load_all_de_keys() { + EncryptionOptions options; + if (!get_data_file_encryption_options(&options)) return false; auto de_dir = user_key_dir + "/de"; auto dirp = std::unique_ptr(opendir(de_dir.c_str()), closedir); if (!dirp) { @@ -339,13 +335,13 @@ static bool load_all_de_keys() { continue; } userid_t user_id = std::stoi(entry->d_name); - if (s_de_key_raw_refs.count(user_id) == 0) { + if (s_de_policies.count(user_id) == 0) { auto key_path = de_dir + "/" + entry->d_name; - KeyBuffer key; - if (!android::vold::retrieveKey(key_path, kEmptyAuthentication, &key)) return false; - std::string raw_ref; - if (!install_data_key(key, &raw_ref)) return false; - s_de_key_raw_refs[user_id] = raw_ref; + KeyBuffer de_key; + if (!android::vold::retrieveKey(key_path, kEmptyAuthentication, &de_key)) return false; + EncryptionPolicy de_policy; + if (!installKey(DATA_MNT_POINT, options, de_key, &de_policy)) return false; + s_de_policies[user_id] = de_policy; LOG(DEBUG) << "Installed de key for user " << user_id; } } @@ -361,13 +357,16 @@ bool fscrypt_initialize_systemwide_keys() { LOG(INFO) << "Already initialized"; return true; } + EncryptionOptions options; + if (!get_data_file_encryption_options(&options)) return false; + + KeyBuffer device_key; + if (!android::vold::retrieveKey(true, kEmptyAuthentication, device_key_path, device_key_temp, + &device_key)) + return false; EncryptionPolicy device_policy; - get_data_file_encryption_options(&device_policy.options); - - if (!android::vold::retrieveAndInstallKey(true, kEmptyAuthentication, device_key_path, - device_key_temp, "", device_policy.options.version, - &device_policy.key_raw_ref)) + if (!android::vold::installKey(DATA_MNT_POINT, options, device_key, &device_policy)) return false; std::string options_string; @@ -375,19 +374,21 @@ bool fscrypt_initialize_systemwide_keys() { LOG(ERROR) << "Unable to serialize options"; return false; } - std::string options_filename = std::string("/data") + fscrypt_key_mode; + std::string options_filename = std::string(DATA_MNT_POINT) + fscrypt_key_mode; if (!android::vold::writeStringToFile(options_string, options_filename)) return false; - std::string ref_filename = std::string("/data") + fscrypt_key_ref; + std::string ref_filename = std::string(DATA_MNT_POINT) + fscrypt_key_ref; if (!android::vold::writeStringToFile(device_policy.key_raw_ref, ref_filename)) return false; LOG(INFO) << "Wrote system DE key reference to:" << ref_filename; KeyBuffer per_boot_key; if (!android::vold::randomKey(&per_boot_key)) return false; - std::string per_boot_raw_ref; - if (!install_data_key(per_boot_key, &per_boot_raw_ref)) return false; + EncryptionPolicy per_boot_policy; + if (!android::vold::installKey(DATA_MNT_POINT, options, per_boot_key, &per_boot_policy)) + return false; std::string per_boot_ref_filename = std::string("/data") + fscrypt_key_per_boot_ref; - if (!android::vold::writeStringToFile(per_boot_raw_ref, per_boot_ref_filename)) return false; + if (!android::vold::writeStringToFile(per_boot_policy.key_raw_ref, per_boot_ref_filename)) + return false; LOG(INFO) << "Wrote per boot key reference to:" << per_boot_ref_filename; if (!android::vold::FsyncDirectory(device_key_dir)) return false; @@ -431,7 +432,7 @@ bool fscrypt_vold_create_user_key(userid_t user_id, int serial, bool ephemeral) return true; } // FIXME test for existence of key that is not loaded yet - if (s_ce_key_raw_refs.count(user_id) != 0) { + if (s_ce_policies.count(user_id) != 0) { LOG(ERROR) << "Already exists, can't fscrypt_vold_create_user_key for " << user_id << " serial " << serial; // FIXME should we fail the command? @@ -466,13 +467,13 @@ static void drop_caches_if_needed() { static bool evict_ce_key(userid_t user_id) { bool success = true; - std::string raw_ref; + EncryptionPolicy policy; // If we haven't loaded the CE key, no need to evict it. - if (lookup_key_ref(s_ce_key_raw_refs, user_id, &raw_ref)) { - success &= evict_data_key(raw_ref); + if (lookup_policy(s_ce_policies, user_id, &policy)) { + success &= android::vold::evictKey(DATA_MNT_POINT, policy); drop_caches_if_needed(); } - s_ce_key_raw_refs.erase(user_id); + s_ce_policies.erase(user_id); return success; } @@ -482,10 +483,11 @@ bool fscrypt_destroy_user_key(userid_t user_id) { return true; } bool success = true; - std::string raw_ref; success &= evict_ce_key(user_id); - success &= lookup_key_ref(s_de_key_raw_refs, user_id, &raw_ref) && evict_data_key(raw_ref); - s_de_key_raw_refs.erase(user_id); + EncryptionPolicy de_policy; + success &= lookup_policy(s_de_policies, user_id, &de_policy) && + android::vold::evictKey(DATA_MNT_POINT, de_policy); + s_de_policies.erase(user_id); auto it = s_ephemeral_users.find(user_id); if (it != s_ephemeral_users.end()) { s_ephemeral_users.erase(it); @@ -587,11 +589,12 @@ static bool read_or_create_volkey(const std::string& misc_path, const std::strin } android::vold::KeyAuthentication auth("", secdiscardable_hash); - if (!get_volume_file_encryption_options(&policy->options)) return false; - - return android::vold::retrieveAndInstallKey(true, auth, key_path, key_path + "_tmp", - volume_uuid, policy->options.version, - &policy->key_raw_ref); + EncryptionOptions options; + if (!get_volume_file_encryption_options(&options)) return false; + KeyBuffer key; + if (!android::vold::retrieveKey(true, auth, key_path, key_path + "_tmp", &key)) return false; + if (!android::vold::installKey(BuildDataPath(volume_uuid), options, key, policy)) return false; + return true; } static bool destroy_volkey(const std::string& misc_path, const std::string& volume_uuid) { @@ -667,7 +670,7 @@ bool fscrypt_unlock_user_key(userid_t user_id, int serial, const std::string& to LOG(DEBUG) << "fscrypt_unlock_user_key " << user_id << " serial=" << serial << " token_present=" << (token_hex != "!"); if (fscrypt_is_native()) { - if (s_ce_key_raw_refs.count(user_id) != 0) { + if (s_ce_policies.count(user_id) != 0) { LOG(WARNING) << "Tried to unlock already-unlocked key for user " << user_id; return true; } @@ -757,9 +760,7 @@ bool fscrypt_prepare_user_storage(const std::string& volume_uuid, userid_t user_ if (fscrypt_is_native()) { EncryptionPolicy de_policy; if (volume_uuid.empty()) { - if (!lookup_key_ref(s_de_key_raw_refs, user_id, &de_policy.key_raw_ref)) - return false; - get_data_file_encryption_options(&de_policy.options); + if (!lookup_policy(s_de_policies, user_id, &de_policy)) return false; if (!EnsurePolicy(de_policy, system_de_path)) return false; if (!EnsurePolicy(de_policy, misc_de_path)) return false; if (!EnsurePolicy(de_policy, vendor_de_path)) return false; @@ -789,13 +790,10 @@ bool fscrypt_prepare_user_storage(const std::string& volume_uuid, userid_t user_ if (fscrypt_is_native()) { EncryptionPolicy ce_policy; if (volume_uuid.empty()) { - if (!lookup_key_ref(s_ce_key_raw_refs, user_id, &ce_policy.key_raw_ref)) - return false; - get_data_file_encryption_options(&ce_policy.options); + if (!lookup_policy(s_ce_policies, user_id, &ce_policy)) return false; if (!EnsurePolicy(ce_policy, system_ce_path)) return false; if (!EnsurePolicy(ce_policy, misc_ce_path)) return false; if (!EnsurePolicy(ce_policy, vendor_ce_path)) return false; - } else { if (!read_or_create_volkey(misc_ce_path, volume_uuid, &ce_policy)) return false; } diff --git a/KeyUtil.cpp b/KeyUtil.cpp index d2d51e1..d4a653b 100644 --- a/KeyUtil.cpp +++ b/KeyUtil.cpp @@ -161,62 +161,51 @@ static bool installKeyLegacy(const KeyBuffer& key, const std::string& raw_ref) { } // Build a struct fscrypt_key_specifier for use in the key management ioctls. -static bool buildKeySpecifier(fscrypt_key_specifier* spec, const std::string& raw_ref, - int policy_version) { - switch (policy_version) { +static bool buildKeySpecifier(fscrypt_key_specifier* spec, const EncryptionPolicy& policy) { + switch (policy.options.version) { case 1: - if (raw_ref.size() != FSCRYPT_KEY_DESCRIPTOR_SIZE) { + if (policy.key_raw_ref.size() != FSCRYPT_KEY_DESCRIPTOR_SIZE) { LOG(ERROR) << "Invalid key specifier size for v1 encryption policy: " - << raw_ref.size(); + << policy.key_raw_ref.size(); return false; } spec->type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR; - memcpy(spec->u.descriptor, raw_ref.c_str(), FSCRYPT_KEY_DESCRIPTOR_SIZE); + memcpy(spec->u.descriptor, policy.key_raw_ref.c_str(), FSCRYPT_KEY_DESCRIPTOR_SIZE); return true; case 2: - if (raw_ref.size() != FSCRYPT_KEY_IDENTIFIER_SIZE) { + if (policy.key_raw_ref.size() != FSCRYPT_KEY_IDENTIFIER_SIZE) { LOG(ERROR) << "Invalid key specifier size for v2 encryption policy: " - << raw_ref.size(); + << policy.key_raw_ref.size(); return false; } spec->type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER; - memcpy(spec->u.identifier, raw_ref.c_str(), FSCRYPT_KEY_IDENTIFIER_SIZE); + memcpy(spec->u.identifier, policy.key_raw_ref.c_str(), FSCRYPT_KEY_IDENTIFIER_SIZE); return true; default: - LOG(ERROR) << "Invalid encryption policy version: " << policy_version; + LOG(ERROR) << "Invalid encryption policy version: " << policy.options.version; return false; } } -// Install a file-based encryption key to the kernel, for use by encrypted files -// on the specified filesystem using the specified encryption policy version. -// -// For v1 policies, we use FS_IOC_ADD_ENCRYPTION_KEY if the kernel supports it. -// Otherwise we add the key to the legacy global session keyring. -// -// For v2 policies, we always use FS_IOC_ADD_ENCRYPTION_KEY; it's the only way -// the kernel supports. -// -// Returns %true on success, %false on failure. On success also sets *raw_ref -// to the raw key reference for use in the encryption policy. -bool installKey(const KeyBuffer& key, const std::string& mountpoint, int policy_version, - std::string* raw_ref) { +bool installKey(const std::string& mountpoint, const EncryptionOptions& options, + const KeyBuffer& key, EncryptionPolicy* policy) { + policy->options = options; // Put the fscrypt_add_key_arg in an automatically-zeroing buffer, since we // have to copy the raw key into it. KeyBuffer arg_buf(sizeof(struct fscrypt_add_key_arg) + key.size(), 0); struct fscrypt_add_key_arg* arg = (struct fscrypt_add_key_arg*)arg_buf.data(); // Initialize the "key specifier", which is like a name for the key. - switch (policy_version) { + switch (options.version) { case 1: // A key for a v1 policy is specified by an arbitrary 8-byte // "descriptor", which must be provided by userspace. We use the // first 8 bytes from the double SHA-512 of the key itself. - *raw_ref = generateKeyRef((const uint8_t*)key.data(), key.size()); + policy->key_raw_ref = generateKeyRef((const uint8_t*)key.data(), key.size()); if (!isFsKeyringSupported()) { - return installKeyLegacy(key, *raw_ref); + return installKeyLegacy(key, policy->key_raw_ref); } - if (!buildKeySpecifier(&arg->key_spec, *raw_ref, policy_version)) { + if (!buildKeySpecifier(&arg->key_spec, *policy)) { return false; } break; @@ -229,7 +218,7 @@ bool installKey(const KeyBuffer& key, const std::string& mountpoint, int policy_ arg->key_spec.type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER; break; default: - LOG(ERROR) << "Invalid encryption policy version: " << policy_version; + LOG(ERROR) << "Invalid encryption policy version: " << options.version; return false; } @@ -250,9 +239,10 @@ bool installKey(const KeyBuffer& key, const std::string& mountpoint, int policy_ if (arg->key_spec.type == FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER) { // Retrieve the key identifier that the kernel computed. - *raw_ref = std::string((char*)arg->key_spec.u.identifier, FSCRYPT_KEY_IDENTIFIER_SIZE); + policy->key_raw_ref = + std::string((char*)arg->key_spec.u.identifier, FSCRYPT_KEY_IDENTIFIER_SIZE); } - LOG(DEBUG) << "Installed fscrypt key with ref " << keyrefstring(*raw_ref) << " to " + LOG(DEBUG) << "Installed fscrypt key with ref " << keyrefstring(policy->key_raw_ref) << " to " << mountpoint; return true; } @@ -280,15 +270,9 @@ static bool evictKeyLegacy(const std::string& raw_ref) { return success; } -// Evict a file-based encryption key from the kernel. -// -// We use FS_IOC_REMOVE_ENCRYPTION_KEY if the kernel supports it. Otherwise we -// remove the key from the legacy global session keyring. -// -// In the latter case, the caller is responsible for dropping caches. -bool evictKey(const std::string& mountpoint, const std::string& raw_ref, int policy_version) { - if (policy_version == 1 && !isFsKeyringSupported()) { - return evictKeyLegacy(raw_ref); +bool evictKey(const std::string& mountpoint, const EncryptionPolicy& policy) { + if (policy.options.version == 1 && !isFsKeyringSupported()) { + return evictKeyLegacy(policy.key_raw_ref); } android::base::unique_fd fd(open(mountpoint.c_str(), O_RDONLY | O_DIRECTORY | O_CLOEXEC)); @@ -300,11 +284,11 @@ bool evictKey(const std::string& mountpoint, const std::string& raw_ref, int pol struct fscrypt_remove_key_arg arg; memset(&arg, 0, sizeof(arg)); - if (!buildKeySpecifier(&arg.key_spec, raw_ref, policy_version)) { + if (!buildKeySpecifier(&arg.key_spec, policy)) { return false; } - std::string ref = keyrefstring(raw_ref); + std::string ref = keyrefstring(policy.key_raw_ref); if (ioctl(fd, FS_IOC_REMOVE_ENCRYPTION_KEY, &arg) != 0) { PLOG(ERROR) << "Failed to evict fscrypt key with ref " << ref << " from " << mountpoint; @@ -322,36 +306,12 @@ bool evictKey(const std::string& mountpoint, const std::string& raw_ref, int pol return true; } -bool retrieveAndInstallKey(bool create_if_absent, const KeyAuthentication& key_authentication, - const std::string& key_path, const std::string& tmp_path, - const std::string& volume_uuid, int policy_version, - std::string* key_ref) { - KeyBuffer key; +bool retrieveKey(bool create_if_absent, const KeyAuthentication& key_authentication, + const std::string& key_path, const std::string& tmp_path, KeyBuffer* key, + bool keepOld) { if (pathExists(key_path)) { LOG(DEBUG) << "Key exists, using: " << key_path; - if (!retrieveKey(key_path, key_authentication, &key)) return false; - } else { - if (!create_if_absent) { - LOG(ERROR) << "No key found in " << key_path; - return false; - } - LOG(INFO) << "Creating new key in " << key_path; - if (!randomKey(&key)) return false; - if (!storeKeyAtomically(key_path, tmp_path, key_authentication, key)) return false; - } - - if (!installKey(key, BuildDataPath(volume_uuid), policy_version, key_ref)) { - LOG(ERROR) << "Failed to install key in " << key_path; - return false; - } - return true; -} - -bool retrieveKey(bool create_if_absent, const std::string& key_path, const std::string& tmp_path, - KeyBuffer* key, bool keepOld) { - if (pathExists(key_path)) { - LOG(DEBUG) << "Key exists, using: " << key_path; - if (!retrieveKey(key_path, kEmptyAuthentication, key, keepOld)) return false; + if (!retrieveKey(key_path, key_authentication, key, keepOld)) return false; } else { if (!create_if_absent) { LOG(ERROR) << "No key found in " << key_path; @@ -359,7 +319,7 @@ bool retrieveKey(bool create_if_absent, const std::string& key_path, const std:: } LOG(INFO) << "Creating new key in " << key_path; if (!randomKey(key)) return false; - if (!storeKeyAtomically(key_path, tmp_path, kEmptyAuthentication, *key)) return false; + if (!storeKeyAtomically(key_path, tmp_path, key_authentication, *key)) return false; } return true; } diff --git a/KeyUtil.h b/KeyUtil.h index f6799d9..be5a2ed 100644 --- a/KeyUtil.h +++ b/KeyUtil.h @@ -20,25 +20,45 @@ #include "KeyBuffer.h" #include "KeyStorage.h" +#include + #include #include namespace android { namespace vold { +using namespace android::fscrypt; + bool randomKey(KeyBuffer* key); bool isFsKeyringSupported(void); -bool installKey(const KeyBuffer& key, const std::string& mountpoint, int policy_version, - std::string* raw_ref); -bool evictKey(const std::string& mountpoint, const std::string& raw_ref, int policy_version); -bool retrieveAndInstallKey(bool create_if_absent, const KeyAuthentication& key_authentication, - const std::string& key_path, const std::string& tmp_path, - const std::string& volume_uuid, int policy_version, - std::string* key_ref); -bool retrieveKey(bool create_if_absent, const std::string& key_path, const std::string& tmp_path, - KeyBuffer* key, bool keepOld = true); +// Install a file-based encryption key to the kernel, for use by encrypted files +// on the specified filesystem using the specified encryption policy version. +// +// For v1 policies, we use FS_IOC_ADD_ENCRYPTION_KEY if the kernel supports it. +// Otherwise we add the key to the legacy global session keyring. +// +// For v2 policies, we always use FS_IOC_ADD_ENCRYPTION_KEY; it's the only way +// the kernel supports. +// +// Returns %true on success, %false on failure. On success also sets *policy +// to the EncryptionPolicy used to refer to this key. +bool installKey(const std::string& mountpoint, const EncryptionOptions& options, + const KeyBuffer& key, EncryptionPolicy* policy); + +// Evict a file-based encryption key from the kernel. +// +// We use FS_IOC_REMOVE_ENCRYPTION_KEY if the kernel supports it. Otherwise we +// remove the key from the legacy global session keyring. +// +// In the latter case, the caller is responsible for dropping caches. +bool evictKey(const std::string& mountpoint, const EncryptionPolicy& policy); + +bool retrieveKey(bool create_if_absent, const KeyAuthentication& key_authentication, + const std::string& key_path, const std::string& tmp_path, KeyBuffer* key, + bool keepOld = true); } // namespace vold } // namespace android diff --git a/MetadataCrypt.cpp b/MetadataCrypt.cpp index 3c2e0d5..c621823 100644 --- a/MetadataCrypt.cpp +++ b/MetadataCrypt.cpp @@ -135,7 +135,9 @@ static bool read_key(const FstabEntry& data_rec, bool create_if_absent, KeyBuffe unlink(newKeyPath.c_str()); } bool needs_cp = cp_needsCheckpoint(); - if (!android::vold::retrieveKey(create_if_absent, dir, temp, key, needs_cp)) return false; + if (!android::vold::retrieveKey(create_if_absent, kEmptyAuthentication, dir, temp, key, + needs_cp)) + return false; if (needs_cp && pathExists(newKeyPath)) std::thread(commit_key, dir).detach(); return true; }