Merge RP1A.191024.001
Change-Id: I83100b049d157a2ccd4158178a65ab1d3e5f0685
diff --git a/FsCrypt.cpp b/FsCrypt.cpp
index e97b540..a84b497 100644
--- a/FsCrypt.cpp
+++ b/FsCrypt.cpp
@@ -59,6 +59,7 @@
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
#include <android-base/unique_fd.h>
using android::base::StringPrintf;
@@ -74,7 +75,10 @@
struct PolicyKeyRef {
std::string contents_mode;
std::string filenames_mode;
+ int policy_version;
std::string key_raw_ref;
+
+ PolicyKeyRef() : policy_version(0) {}
};
const std::string device_key_dir = std::string() + DATA_MNT_POINT + fscrypt_unencrypted_folder;
@@ -203,6 +207,59 @@
return false;
}
+// Retrieve the options to use for encryption policies on the /data filesystem.
+static void get_data_file_encryption_options(PolicyKeyRef* key_ref) {
+ auto entry = GetEntryForMountPoint(&fstab_default, DATA_MNT_POINT);
+ if (entry == nullptr) {
+ return;
+ }
+ key_ref->contents_mode = entry->file_contents_mode;
+ key_ref->filenames_mode = entry->file_names_mode;
+ key_ref->policy_version = entry->file_policy_version;
+}
+
+// Retrieve the version to use for encryption policies on the /data filesystem.
+static int get_data_file_policy_version(void) {
+ auto entry = GetEntryForMountPoint(&fstab_default, DATA_MNT_POINT);
+ if (entry == nullptr) {
+ return 0;
+ }
+ return entry->file_policy_version;
+}
+
+// Retrieve the options to use for encryption policies on adoptable storage.
+static bool get_volume_file_encryption_options(PolicyKeyRef* key_ref) {
+ key_ref->contents_mode =
+ android::base::GetProperty("ro.crypto.volume.contents_mode", "aes-256-xts");
+ key_ref->filenames_mode =
+ android::base::GetProperty("ro.crypto.volume.filenames_mode", "aes-256-heh");
+ key_ref->policy_version = 1;
+
+ std::string raw_flags = android::base::GetProperty("ro.crypto.volume.flags", "");
+ auto flags = android::base::Split(raw_flags, "+");
+ for (const auto& flag : flags) {
+ if (flag == "v1") {
+ key_ref->policy_version = 1;
+ } else if (flag == "v2") {
+ key_ref->policy_version = 2;
+ } else {
+ LOG(ERROR) << "Unknown flag in ro.crypto.volume.flags: " << flag;
+ return false;
+ }
+ }
+ return true;
+}
+
+// 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());
+}
+
bool is_ice_supported_external(int flags) {
/*
* Logic can be changed when more card controllers start supporting ICE.
@@ -243,7 +300,7 @@
}
ce_key = std::move(ephemeral_wrapped_key);
}
- if (!android::vold::installKey(ce_key, &ce_raw_ref)) return false;
+ if (!install_data_key(ce_key, &ce_raw_ref)) return false;
s_ce_keys[user_id] = std::move(ce_key);
s_ce_key_raw_refs[user_id] = ce_raw_ref;
LOG(DEBUG) << "Installed ce key for user " << user_id;
@@ -322,8 +379,8 @@
de_key = std::move(ephemeral_wrapped_de_key);
ce_key = std::move(ephemeral_wrapped_ce_key);
}
- if (!android::vold::installKey(de_key, &de_raw_ref)) return false;
- if (!android::vold::installKey(ce_key, &ce_raw_ref)) return false;
+ if (!install_data_key(de_key, &de_raw_ref)) return false;
+ if (!install_data_key(ce_key, &ce_raw_ref)) return false;
s_ce_keys[user_id] = std::move(ce_key);
s_de_key_raw_refs[user_id] = de_raw_ref;
@@ -344,19 +401,10 @@
return true;
}
-static void get_data_file_encryption_modes(PolicyKeyRef* key_ref) {
- auto entry = GetEntryForMountPoint(&fstab_default, DATA_MNT_POINT);
- if (entry == nullptr) {
- return;
- }
- key_ref->contents_mode = entry->file_contents_mode;
- key_ref->filenames_mode = entry->file_names_mode;
-}
-
static bool ensure_policy(const PolicyKeyRef& key_ref, const std::string& path) {
return fscrypt_policy_ensure(path.c_str(), key_ref.key_raw_ref.data(),
key_ref.key_raw_ref.size(), key_ref.contents_mode.c_str(),
- key_ref.filenames_mode.c_str()) == 0;
+ key_ref.filenames_mode.c_str(), key_ref.policy_version) == 0;
}
static bool is_numeric(const char* name) {
@@ -401,7 +449,7 @@
}
key = std::move(ephemeral_wrapped_key);
}
- if (!android::vold::installKey(key, &raw_ref)) return false;
+ if (!install_data_key(key, &raw_ref)) return false;
s_de_key_raw_refs[user_id] = raw_ref;
LOG(DEBUG) << "Installed de key for user " << user_id;
}
@@ -421,17 +469,19 @@
}
PolicyKeyRef device_ref;
+ get_data_file_encryption_options(&device_ref);
wrapped_key_supported = is_wrapped_key_supported();
- if (!android::vold::retrieveAndInstallKey(true, kEmptyAuthentication,
- device_key_path, device_key_temp,
- &device_ref.key_raw_ref, wrapped_key_supported))
+ if (!android::vold::retrieveAndInstallKey(true, kEmptyAuthentication, device_key_path,
+ device_key_temp, "", device_ref.policy_version,
+ &device_ref.key_raw_ref, wrapped_key_supported))
return false;
- get_data_file_encryption_modes(&device_ref);
- std::string modestring = device_ref.contents_mode + ":" + device_ref.filenames_mode;
- std::string mode_filename = std::string("/data") + fscrypt_key_mode;
- if (!android::vold::writeStringToFile(modestring, mode_filename)) return false;
+ std::string options_string =
+ StringPrintf("%s:%s:v%d", device_ref.contents_mode.c_str(),
+ device_ref.filenames_mode.c_str(), device_ref.policy_version);
+ std::string options_filename = std::string("/data") + fscrypt_key_mode;
+ if (!android::vold::writeStringToFile(options_string, options_filename)) return false;
std::string ref_filename = std::string("/data") + fscrypt_key_ref;
if (!android::vold::writeStringToFile(device_ref.key_raw_ref, ref_filename)) return false;
@@ -440,7 +490,7 @@
KeyBuffer per_boot_key;
if (!android::vold::randomKey(&per_boot_key)) return false;
std::string per_boot_raw_ref;
- if (!android::vold::installKey(per_boot_key, &per_boot_raw_ref)) return false;
+ if (!install_data_key(per_boot_key, &per_boot_raw_ref)) 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;
LOG(INFO) << "Wrote per boot key reference to:" << per_boot_ref_filename;
@@ -499,15 +549,20 @@
}
// "Lock" all encrypted directories whose key has been removed. This is needed
-// because merely removing the keyring key doesn't affect inodes in the kernel's
-// inode cache whose per-file key was already set up. So to remove the per-file
-// keys and make the files "appear encrypted", these inodes must be evicted.
+// in the case where the keys are being put in the session keyring (rather in
+// the newer filesystem-level keyrings), because removing a key from the session
+// keyring doesn't affect inodes in the kernel's inode cache whose per-file key
+// was already set up. So to remove the per-file keys and make the files
+// "appear encrypted", these inodes must be evicted.
//
// To do this, sync() to clean all dirty inodes, then drop all reclaimable slab
// objects systemwide. This is overkill, but it's the best available method
// currently. Don't use drop_caches mode "3" because that also evicts pagecache
// for in-use files; all files relevant here are already closed and sync'ed.
-static void drop_caches() {
+static void drop_caches_if_needed() {
+ if (android::vold::isFsKeyringSupported()) {
+ return;
+ }
sync();
if (!writeStringToFile("2", "/proc/sys/vm/drop_caches")) {
PLOG(ERROR) << "Failed to drop caches during key eviction";
@@ -519,8 +574,8 @@
std::string raw_ref;
// 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 &= android::vold::evictKey(raw_ref);
- drop_caches();
+ success &= evict_data_key(raw_ref);
+ drop_caches_if_needed();
}
if(is_wrapped_key_supported()) {
@@ -551,8 +606,7 @@
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) && android::vold::evictKey(raw_ref);
+ 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);
auto it = s_ephemeral_users.find(user_id);
if (it != s_ephemeral_users.end()) {
@@ -643,9 +697,12 @@
return false;
}
android::vold::KeyAuthentication auth("", secdiscardable_hash);
+
+ if (!get_volume_file_encryption_options(key_ref)) return false;
wrapped_key_supported = is_wrapped_key_supported_external(flags);
if (!android::vold::retrieveAndInstallKey(true, auth, key_path, key_path + "_tmp",
+ volume_uuid, key_ref->policy_version,
&key_ref->key_raw_ref, wrapped_key_supported))
return false;
@@ -861,7 +918,7 @@
PolicyKeyRef de_ref;
if (volume_uuid.empty()) {
if (!lookup_key_ref(s_de_key_raw_refs, user_id, &de_ref.key_raw_ref)) return false;
- get_data_file_encryption_modes(&de_ref);
+ get_data_file_encryption_options(&de_ref);
if (!ensure_policy(de_ref, system_de_path)) return false;
if (!ensure_policy(de_ref, misc_de_path)) return false;
if (!ensure_policy(de_ref, vendor_de_path)) return false;
@@ -892,7 +949,7 @@
PolicyKeyRef ce_ref;
if (volume_uuid.empty()) {
if (!lookup_key_ref(s_ce_key_raw_refs, user_id, &ce_ref.key_raw_ref)) return false;
- get_data_file_encryption_modes(&ce_ref);
+ get_data_file_encryption_options(&ce_ref);
if (!ensure_policy(ce_ref, system_ce_path)) return false;
if (!ensure_policy(ce_ref, misc_ce_path)) return false;
if (!ensure_policy(ce_ref, vendor_ce_path)) return false;