diff --git a/FsCrypt.cpp b/FsCrypt.cpp
new file mode 100644
index 0000000..087b916
--- /dev/null
+++ b/FsCrypt.cpp
@@ -0,0 +1,839 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "FsCrypt.h"
+
+#include "KeyStorage.h"
+#include "KeyUtil.h"
+#include "Utils.h"
+#include "VoldUtil.h"
+
+#include <algorithm>
+#include <map>
+#include <set>
+#include <sstream>
+#include <string>
+#include <vector>
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <selinux/android.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <private/android_filesystem_config.h>
+
+#include "android/os/IVold.h"
+
+#include "cryptfs.h"
+
+#define EMULATED_USES_SELINUX 0
+#define MANAGE_MISC_DIRS 0
+
+#include <cutils/fs.h>
+#include <cutils/properties.h>
+
+#include <fscrypt/fscrypt.h>
+#include <keyutils.h>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+#include <android-base/stringprintf.h>
+
+using android::base::StringPrintf;
+using android::base::WriteStringToFile;
+using android::vold::kEmptyAuthentication;
+using android::vold::KeyBuffer;
+
+namespace {
+
+struct PolicyKeyRef {
+    std::string contents_mode;
+    std::string filenames_mode;
+    std::string key_raw_ref;
+};
+
+const std::string device_key_dir = std::string() + DATA_MNT_POINT + fscrypt_unencrypted_folder;
+const std::string device_key_path = device_key_dir + "/key";
+const std::string device_key_temp = device_key_dir + "/temp";
+
+const std::string user_key_dir = std::string() + DATA_MNT_POINT + "/misc/vold/user_keys";
+const std::string user_key_temp = user_key_dir + "/temp";
+const std::string prepare_subdirs_path = "/system/bin/vold_prepare_subdirs";
+
+const std::string systemwide_volume_key_dir =
+    std::string() + DATA_MNT_POINT + "/misc/vold/volume_keys";
+
+bool s_global_de_initialized = false;
+
+// Some users are ephemeral, don't try to wipe their keys from disk
+std::set<userid_t> s_ephemeral_users;
+
+// Map user ids to key references
+std::map<userid_t, std::string> s_de_key_raw_refs;
+std::map<userid_t, std::string> s_ce_key_raw_refs;
+// TODO abolish this map, per b/26948053
+std::map<userid_t, KeyBuffer> s_ce_keys;
+
+}  // namespace
+
+static bool fscrypt_is_emulated() {
+    return property_get_bool("persist.sys.emulate_fbe", false);
+}
+
+static const char* escape_empty(const std::string& value) {
+    return value.empty() ? "null" : value.c_str();
+}
+
+static std::string get_de_key_path(userid_t user_id) {
+    return StringPrintf("%s/de/%d", user_key_dir.c_str(), user_id);
+}
+
+static std::string get_ce_key_directory_path(userid_t user_id) {
+    return StringPrintf("%s/ce/%d", user_key_dir.c_str(), user_id);
+}
+
+// Returns the keys newest first
+static std::vector<std::string> get_ce_key_paths(const std::string& directory_path) {
+    auto dirp = std::unique_ptr<DIR, int (*)(DIR*)>(opendir(directory_path.c_str()), closedir);
+    if (!dirp) {
+        PLOG(ERROR) << "Unable to open ce key directory: " + directory_path;
+        return std::vector<std::string>();
+    }
+    std::vector<std::string> result;
+    for (;;) {
+        errno = 0;
+        auto const entry = readdir(dirp.get());
+        if (!entry) {
+            if (errno) {
+                PLOG(ERROR) << "Unable to read ce key directory: " + directory_path;
+                return std::vector<std::string>();
+            }
+            break;
+        }
+        if (entry->d_type != DT_DIR || entry->d_name[0] != 'c') {
+            LOG(DEBUG) << "Skipping non-key " << entry->d_name;
+            continue;
+        }
+        result.emplace_back(directory_path + "/" + entry->d_name);
+    }
+    std::sort(result.begin(), result.end());
+    std::reverse(result.begin(), result.end());
+    return result;
+}
+
+static std::string get_ce_key_current_path(const std::string& directory_path) {
+    return directory_path + "/current";
+}
+
+static bool get_ce_key_new_path(const std::string& directory_path,
+                                const std::vector<std::string>& paths, std::string* ce_key_path) {
+    if (paths.empty()) {
+        *ce_key_path = get_ce_key_current_path(directory_path);
+        return true;
+    }
+    for (unsigned int i = 0; i < UINT_MAX; i++) {
+        auto const candidate = StringPrintf("%s/cx%010u", directory_path.c_str(), i);
+        if (paths[0] < candidate) {
+            *ce_key_path = candidate;
+            return true;
+        }
+    }
+    return false;
+}
+
+// Discard all keys but the named one; rename it to canonical name.
+// No point in acting on errors in this; ignore them.
+static void fixate_user_ce_key(const std::string& directory_path, const std::string& to_fix,
+                               const std::vector<std::string>& paths) {
+    for (auto const other_path : paths) {
+        if (other_path != to_fix) {
+            android::vold::destroyKey(other_path);
+        }
+    }
+    auto const current_path = get_ce_key_current_path(directory_path);
+    if (to_fix != current_path) {
+        LOG(DEBUG) << "Renaming " << to_fix << " to " << current_path;
+        if (rename(to_fix.c_str(), current_path.c_str()) != 0) {
+            PLOG(WARNING) << "Unable to rename " << to_fix << " to " << current_path;
+        }
+    }
+}
+
+static bool read_and_fixate_user_ce_key(userid_t user_id,
+                                        const android::vold::KeyAuthentication& auth,
+                                        KeyBuffer* ce_key) {
+    auto const directory_path = get_ce_key_directory_path(user_id);
+    auto const paths = get_ce_key_paths(directory_path);
+    for (auto const ce_key_path : paths) {
+        LOG(DEBUG) << "Trying user CE key " << ce_key_path;
+        if (android::vold::retrieveKey(ce_key_path, auth, ce_key)) {
+            LOG(DEBUG) << "Successfully retrieved key";
+            fixate_user_ce_key(directory_path, ce_key_path, paths);
+            return true;
+        }
+    }
+    LOG(ERROR) << "Failed to find working ce key for user " << user_id;
+    return false;
+}
+
+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;
+    KeyBuffer ce_key;
+    if (!read_and_fixate_user_ce_key(user_id, auth, &ce_key)) return false;
+    std::string ce_raw_ref;
+    if (!android::vold::installKey(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;
+    return true;
+}
+
+static bool prepare_dir(const std::string& dir, mode_t mode, uid_t uid, gid_t gid) {
+    LOG(DEBUG) << "Preparing: " << dir;
+    if (fs_prepare_dir(dir.c_str(), mode, uid, gid) != 0) {
+        PLOG(ERROR) << "Failed to prepare " << dir;
+        return false;
+    }
+    return true;
+}
+
+static bool destroy_dir(const std::string& dir) {
+    LOG(DEBUG) << "Destroying: " << dir;
+    if (rmdir(dir.c_str()) != 0 && errno != ENOENT) {
+        PLOG(ERROR) << "Failed to destroy " << dir;
+        return false;
+    }
+    return true;
+}
+
+// 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) {
+    KeyBuffer de_key, ce_key;
+    if (!android::vold::randomKey(&de_key)) return false;
+    if (!android::vold::randomKey(&ce_key)) return false;
+    if (create_ephemeral) {
+        // If the key should be created as ephemeral, don't store it.
+        s_ephemeral_users.insert(user_id);
+    } else {
+        auto const directory_path = get_ce_key_directory_path(user_id);
+        if (!prepare_dir(directory_path, 0700, AID_ROOT, AID_ROOT)) return false;
+        auto const paths = get_ce_key_paths(directory_path);
+        std::string ce_key_path;
+        if (!get_ce_key_new_path(directory_path, paths, &ce_key_path)) return false;
+        if (!android::vold::storeKeyAtomically(ce_key_path, user_key_temp, kEmptyAuthentication,
+                                               ce_key))
+            return false;
+        fixate_user_ce_key(directory_path, ce_key_path, paths);
+        // Write DE key second; once this is written, all is good.
+        if (!android::vold::storeKeyAtomically(get_de_key_path(user_id), user_key_temp,
+                                               kEmptyAuthentication, de_key))
+            return false;
+    }
+    std::string de_raw_ref;
+    if (!android::vold::installKey(de_key, &de_raw_ref)) return false;
+    s_de_key_raw_refs[user_id] = de_raw_ref;
+    std::string ce_raw_ref;
+    if (!android::vold::installKey(ce_key, &ce_raw_ref)) return false;
+    s_ce_keys[user_id] = ce_key;
+    s_ce_key_raw_refs[user_id] = ce_raw_ref;
+    LOG(DEBUG) << "Created keys for user " << user_id;
+    return true;
+}
+
+static bool lookup_key_ref(const std::map<userid_t, std::string>& key_map, userid_t user_id,
+                           std::string* raw_ref) {
+    auto refi = key_map.find(user_id);
+    if (refi == key_map.end()) {
+        LOG(ERROR) << "Cannot find key for " << user_id;
+        return false;
+    }
+    *raw_ref = refi->second;
+    return true;
+}
+
+static void get_data_file_encryption_modes(PolicyKeyRef* key_ref) {
+    struct fstab_rec* rec = fs_mgr_get_entry_for_mount_point(fstab_default, DATA_MNT_POINT);
+    char const* contents_mode;
+    char const* filenames_mode;
+    fs_mgr_get_file_encryption_modes(rec, &contents_mode, &filenames_mode);
+    key_ref->contents_mode = contents_mode;
+    key_ref->filenames_mode = filenames_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;
+}
+
+static bool is_numeric(const char* name) {
+    for (const char* p = name; *p != '\0'; p++) {
+        if (!isdigit(*p)) return false;
+    }
+    return true;
+}
+
+static bool load_all_de_keys() {
+    auto de_dir = user_key_dir + "/de";
+    auto dirp = std::unique_ptr<DIR, int (*)(DIR*)>(opendir(de_dir.c_str()), closedir);
+    if (!dirp) {
+        PLOG(ERROR) << "Unable to read de key directory";
+        return false;
+    }
+    for (;;) {
+        errno = 0;
+        auto entry = readdir(dirp.get());
+        if (!entry) {
+            if (errno) {
+                PLOG(ERROR) << "Unable to read de key directory";
+                return false;
+            }
+            break;
+        }
+        if (entry->d_type != DT_DIR || !is_numeric(entry->d_name)) {
+            LOG(DEBUG) << "Skipping non-de-key " << entry->d_name;
+            continue;
+        }
+        userid_t user_id = std::stoi(entry->d_name);
+        if (s_de_key_raw_refs.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 (!android::vold::installKey(key, &raw_ref)) return false;
+            s_de_key_raw_refs[user_id] = raw_ref;
+            LOG(DEBUG) << "Installed de key for user " << user_id;
+        }
+    }
+    // fscrypt:TODO: go through all DE directories, ensure that all user dirs have the
+    // correct policy set on them, and that no rogue ones exist.
+    return true;
+}
+
+bool fscrypt_initialize_global_de() {
+    LOG(INFO) << "fscrypt_initialize_global_de";
+
+    if (s_global_de_initialized) {
+        LOG(INFO) << "Already initialized";
+        return true;
+    }
+
+    PolicyKeyRef device_ref;
+    if (!android::vold::retrieveAndInstallKey(true, kEmptyAuthentication, device_key_path,
+                                              device_key_temp, &device_ref.key_raw_ref))
+        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::base::WriteStringToFile(modestring, mode_filename)) {
+        PLOG(ERROR) << "Cannot save type";
+        return false;
+    }
+
+    std::string ref_filename = std::string("/data") + fscrypt_key_ref;
+    if (!android::base::WriteStringToFile(device_ref.key_raw_ref, ref_filename)) {
+        PLOG(ERROR) << "Cannot save key reference to:" << ref_filename;
+        return false;
+    }
+    LOG(INFO) << "Wrote system DE key reference to:" << ref_filename;
+
+    s_global_de_initialized = true;
+    return true;
+}
+
+bool fscrypt_init_user0() {
+    LOG(DEBUG) << "fscrypt_init_user0";
+    if (fscrypt_is_native()) {
+        if (!prepare_dir(user_key_dir, 0700, AID_ROOT, AID_ROOT)) return false;
+        if (!prepare_dir(user_key_dir + "/ce", 0700, AID_ROOT, AID_ROOT)) return false;
+        if (!prepare_dir(user_key_dir + "/de", 0700, AID_ROOT, AID_ROOT)) return false;
+        if (!android::vold::pathExists(get_de_key_path(0))) {
+            if (!create_and_install_user_keys(0, false)) return false;
+        }
+        // TODO: switch to loading only DE_0 here once framework makes
+        // explicit calls to install DE keys for secondary users
+        if (!load_all_de_keys()) return false;
+    }
+    // We can only safely prepare DE storage here, since CE keys are probably
+    // entangled with user credentials.  The framework will always prepare CE
+    // storage once CE keys are installed.
+    if (!fscrypt_prepare_user_storage("", 0, 0, android::os::IVold::STORAGE_FLAG_DE)) {
+        LOG(ERROR) << "Failed to prepare user 0 storage";
+        return false;
+    }
+
+    // If this is a non-FBE device that recently left an emulated mode,
+    // restore user data directories to known-good state.
+    if (!fscrypt_is_native() && !fscrypt_is_emulated()) {
+        fscrypt_unlock_user_key(0, 0, "!", "!");
+    }
+
+    return true;
+}
+
+bool fscrypt_vold_create_user_key(userid_t user_id, int serial, bool ephemeral) {
+    LOG(DEBUG) << "fscrypt_vold_create_user_key for " << user_id << " serial " << serial;
+    if (!fscrypt_is_native()) {
+        return true;
+    }
+    // FIXME test for existence of key that is not loaded yet
+    if (s_ce_key_raw_refs.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?
+        return true;
+    }
+    if (!create_and_install_user_keys(user_id, ephemeral)) {
+        return false;
+    }
+    return true;
+}
+
+static void drop_caches() {
+    // Clean any dirty pages (otherwise they won't be dropped).
+    sync();
+    // Drop inode and page caches.
+    if (!WriteStringToFile("3", "/proc/sys/vm/drop_caches")) {
+        PLOG(ERROR) << "Failed to drop caches during key eviction";
+    }
+}
+
+static bool evict_ce_key(userid_t user_id) {
+    s_ce_keys.erase(user_id);
+    bool success = true;
+    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();
+    }
+    s_ce_key_raw_refs.erase(user_id);
+    return success;
+}
+
+bool fscrypt_destroy_user_key(userid_t user_id) {
+    LOG(DEBUG) << "fscrypt_destroy_user_key(" << user_id << ")";
+    if (!fscrypt_is_native()) {
+        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) && android::vold::evictKey(raw_ref);
+    s_de_key_raw_refs.erase(user_id);
+    auto it = s_ephemeral_users.find(user_id);
+    if (it != s_ephemeral_users.end()) {
+        s_ephemeral_users.erase(it);
+    } else {
+        for (auto const path : get_ce_key_paths(get_ce_key_directory_path(user_id))) {
+            success &= android::vold::destroyKey(path);
+        }
+        auto de_key_path = get_de_key_path(user_id);
+        if (android::vold::pathExists(de_key_path)) {
+            success &= android::vold::destroyKey(de_key_path);
+        } else {
+            LOG(INFO) << "Not present so not erasing: " << de_key_path;
+        }
+    }
+    return success;
+}
+
+static bool emulated_lock(const std::string& path) {
+    if (chmod(path.c_str(), 0000) != 0) {
+        PLOG(ERROR) << "Failed to chmod " << path;
+        return false;
+    }
+#if EMULATED_USES_SELINUX
+    if (setfilecon(path.c_str(), "u:object_r:storage_stub_file:s0") != 0) {
+        PLOG(WARNING) << "Failed to setfilecon " << path;
+        return false;
+    }
+#endif
+    return true;
+}
+
+static bool emulated_unlock(const std::string& path, mode_t mode) {
+    if (chmod(path.c_str(), mode) != 0) {
+        PLOG(ERROR) << "Failed to chmod " << path;
+        // FIXME temporary workaround for b/26713622
+        if (fscrypt_is_emulated()) return false;
+    }
+#if EMULATED_USES_SELINUX
+    if (selinux_android_restorecon(path.c_str(), SELINUX_ANDROID_RESTORECON_FORCE) != 0) {
+        PLOG(WARNING) << "Failed to restorecon " << path;
+        // FIXME temporary workaround for b/26713622
+        if (fscrypt_is_emulated()) return false;
+    }
+#endif
+    return true;
+}
+
+static bool parse_hex(const std::string& hex, std::string* result) {
+    if (hex == "!") {
+        *result = "";
+        return true;
+    }
+    if (android::vold::HexToStr(hex, *result) != 0) {
+        LOG(ERROR) << "Invalid FBE hex string";  // Don't log the string for security reasons
+        return false;
+    }
+    return true;
+}
+
+static std::string volkey_path(const std::string& misc_path, const std::string& volume_uuid) {
+    return misc_path + "/vold/volume_keys/" + volume_uuid + "/default";
+}
+
+static std::string volume_secdiscardable_path(const std::string& volume_uuid) {
+    return systemwide_volume_key_dir + "/" + volume_uuid + "/secdiscardable";
+}
+
+static bool read_or_create_volkey(const std::string& misc_path, const std::string& volume_uuid,
+                                  PolicyKeyRef* key_ref) {
+    auto secdiscardable_path = volume_secdiscardable_path(volume_uuid);
+    std::string secdiscardable_hash;
+    if (android::vold::pathExists(secdiscardable_path)) {
+        if (!android::vold::readSecdiscardable(secdiscardable_path, &secdiscardable_hash))
+            return false;
+    } else {
+        if (fs_mkdirs(secdiscardable_path.c_str(), 0700) != 0) {
+            PLOG(ERROR) << "Creating directories for: " << secdiscardable_path;
+            return false;
+        }
+        if (!android::vold::createSecdiscardable(secdiscardable_path, &secdiscardable_hash))
+            return false;
+    }
+    auto key_path = volkey_path(misc_path, volume_uuid);
+    if (fs_mkdirs(key_path.c_str(), 0700) != 0) {
+        PLOG(ERROR) << "Creating directories for: " << key_path;
+        return false;
+    }
+    android::vold::KeyAuthentication auth("", secdiscardable_hash);
+    if (!android::vold::retrieveAndInstallKey(true, auth, key_path, key_path + "_tmp",
+                                              &key_ref->key_raw_ref))
+        return false;
+    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");
+    return true;
+}
+
+static bool destroy_volkey(const std::string& misc_path, const std::string& volume_uuid) {
+    auto path = volkey_path(misc_path, volume_uuid);
+    if (!android::vold::pathExists(path)) return true;
+    return android::vold::destroyKey(path);
+}
+
+bool fscrypt_add_user_key_auth(userid_t user_id, int serial, const std::string& token_hex,
+                               const std::string& secret_hex) {
+    LOG(DEBUG) << "fscrypt_add_user_key_auth " << user_id << " serial=" << serial
+               << " token_present=" << (token_hex != "!");
+    if (!fscrypt_is_native()) return true;
+    if (s_ephemeral_users.count(user_id) != 0) return true;
+    std::string token, secret;
+    if (!parse_hex(token_hex, &token)) return false;
+    if (!parse_hex(secret_hex, &secret)) return false;
+    auto auth =
+        secret.empty() ? kEmptyAuthentication : android::vold::KeyAuthentication(token, secret);
+    auto it = s_ce_keys.find(user_id);
+    if (it == s_ce_keys.end()) {
+        LOG(ERROR) << "Key not loaded into memory, can't change for user " << user_id;
+        return false;
+    }
+    const auto& ce_key = it->second;
+    auto const directory_path = get_ce_key_directory_path(user_id);
+    auto const paths = get_ce_key_paths(directory_path);
+    std::string ce_key_path;
+    if (!get_ce_key_new_path(directory_path, paths, &ce_key_path)) return false;
+    if (!android::vold::storeKeyAtomically(ce_key_path, user_key_temp, auth, ce_key)) return false;
+    return true;
+}
+
+bool fscrypt_fixate_newest_user_key_auth(userid_t user_id) {
+    LOG(DEBUG) << "fscrypt_fixate_newest_user_key_auth " << user_id;
+    if (!fscrypt_is_native()) return true;
+    if (s_ephemeral_users.count(user_id) != 0) return true;
+    auto const directory_path = get_ce_key_directory_path(user_id);
+    auto const paths = get_ce_key_paths(directory_path);
+    if (paths.empty()) {
+        LOG(ERROR) << "No ce keys present, cannot fixate for user " << user_id;
+        return false;
+    }
+    fixate_user_ce_key(directory_path, paths[0], paths);
+    return true;
+}
+
+// TODO: rename to 'install' for consistency, and take flags to know which keys to install
+bool fscrypt_unlock_user_key(userid_t user_id, int serial, const std::string& token_hex,
+                             const std::string& secret_hex) {
+    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) {
+            LOG(WARNING) << "Tried to unlock already-unlocked key for user " << user_id;
+            return true;
+        }
+        std::string token, secret;
+        if (!parse_hex(token_hex, &token)) return false;
+        if (!parse_hex(secret_hex, &secret)) return false;
+        android::vold::KeyAuthentication auth(token, secret);
+        if (!read_and_install_user_ce_key(user_id, auth)) {
+            LOG(ERROR) << "Couldn't read key for " << user_id;
+            return false;
+        }
+    } else {
+        // When in emulation mode, we just use chmod. However, we also
+        // unlock directories when not in emulation mode, to bring devices
+        // back into a known-good state.
+        if (!emulated_unlock(android::vold::BuildDataSystemCePath(user_id), 0771) ||
+            !emulated_unlock(android::vold::BuildDataMiscCePath(user_id), 01771) ||
+            !emulated_unlock(android::vold::BuildDataMediaCePath("", user_id), 0770) ||
+            !emulated_unlock(android::vold::BuildDataUserCePath("", user_id), 0771)) {
+            LOG(ERROR) << "Failed to unlock user " << user_id;
+            return false;
+        }
+    }
+    return true;
+}
+
+// TODO: rename to 'evict' for consistency
+bool fscrypt_lock_user_key(userid_t user_id) {
+    LOG(DEBUG) << "fscrypt_lock_user_key " << user_id;
+    if (fscrypt_is_native()) {
+        return evict_ce_key(user_id);
+    } else if (fscrypt_is_emulated()) {
+        // When in emulation mode, we just use chmod
+        if (!emulated_lock(android::vold::BuildDataSystemCePath(user_id)) ||
+            !emulated_lock(android::vold::BuildDataMiscCePath(user_id)) ||
+            !emulated_lock(android::vold::BuildDataMediaCePath("", user_id)) ||
+            !emulated_lock(android::vold::BuildDataUserCePath("", user_id))) {
+            LOG(ERROR) << "Failed to lock user " << user_id;
+            return false;
+        }
+    }
+
+    return true;
+}
+
+static bool prepare_subdirs(const std::string& action, const std::string& volume_uuid,
+                            userid_t user_id, int flags) {
+    if (0 != android::vold::ForkExecvp(
+                 std::vector<std::string>{prepare_subdirs_path, action, volume_uuid,
+                                          std::to_string(user_id), std::to_string(flags)})) {
+        LOG(ERROR) << "vold_prepare_subdirs failed";
+        return false;
+    }
+    return true;
+}
+
+bool fscrypt_prepare_user_storage(const std::string& volume_uuid, userid_t user_id, int serial,
+                                  int flags) {
+    LOG(DEBUG) << "fscrypt_prepare_user_storage for volume " << escape_empty(volume_uuid)
+               << ", user " << user_id << ", serial " << serial << ", flags " << flags;
+
+    if (flags & android::os::IVold::STORAGE_FLAG_DE) {
+        // DE_sys key
+        auto system_legacy_path = android::vold::BuildDataSystemLegacyPath(user_id);
+        auto misc_legacy_path = android::vold::BuildDataMiscLegacyPath(user_id);
+        auto profiles_de_path = android::vold::BuildDataProfilesDePath(user_id);
+
+        // DE_n key
+        auto system_de_path = android::vold::BuildDataSystemDePath(user_id);
+        auto misc_de_path = android::vold::BuildDataMiscDePath(user_id);
+        auto vendor_de_path = android::vold::BuildDataVendorDePath(user_id);
+        auto user_de_path = android::vold::BuildDataUserDePath(volume_uuid, user_id);
+
+        if (volume_uuid.empty()) {
+            if (!prepare_dir(system_legacy_path, 0700, AID_SYSTEM, AID_SYSTEM)) return false;
+#if MANAGE_MISC_DIRS
+            if (!prepare_dir(misc_legacy_path, 0750, multiuser_get_uid(user_id, AID_SYSTEM),
+                             multiuser_get_uid(user_id, AID_EVERYBODY)))
+                return false;
+#endif
+            if (!prepare_dir(profiles_de_path, 0771, AID_SYSTEM, AID_SYSTEM)) return false;
+
+            if (!prepare_dir(system_de_path, 0770, AID_SYSTEM, AID_SYSTEM)) return false;
+            if (!prepare_dir(misc_de_path, 01771, AID_SYSTEM, AID_MISC)) return false;
+            if (!prepare_dir(vendor_de_path, 0771, AID_ROOT, AID_ROOT)) return false;
+        }
+        if (!prepare_dir(user_de_path, 0771, AID_SYSTEM, AID_SYSTEM)) return false;
+
+        if (fscrypt_is_native()) {
+            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);
+                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;
+            } else {
+                if (!read_or_create_volkey(misc_de_path, volume_uuid, &de_ref)) return false;
+            }
+            if (!ensure_policy(de_ref, user_de_path)) return false;
+        }
+    }
+
+    if (flags & android::os::IVold::STORAGE_FLAG_CE) {
+        // CE_n key
+        auto system_ce_path = android::vold::BuildDataSystemCePath(user_id);
+        auto misc_ce_path = android::vold::BuildDataMiscCePath(user_id);
+        auto vendor_ce_path = android::vold::BuildDataVendorCePath(user_id);
+        auto media_ce_path = android::vold::BuildDataMediaCePath(volume_uuid, user_id);
+        auto user_ce_path = android::vold::BuildDataUserCePath(volume_uuid, user_id);
+
+        if (volume_uuid.empty()) {
+            if (!prepare_dir(system_ce_path, 0770, AID_SYSTEM, AID_SYSTEM)) return false;
+            if (!prepare_dir(misc_ce_path, 01771, AID_SYSTEM, AID_MISC)) return false;
+            if (!prepare_dir(vendor_ce_path, 0771, AID_ROOT, AID_ROOT)) return false;
+        }
+        if (!prepare_dir(media_ce_path, 0770, AID_MEDIA_RW, AID_MEDIA_RW)) return false;
+        if (!prepare_dir(user_ce_path, 0771, AID_SYSTEM, AID_SYSTEM)) return false;
+
+        if (fscrypt_is_native()) {
+            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);
+                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;
+
+            } else {
+                if (!read_or_create_volkey(misc_ce_path, volume_uuid, &ce_ref)) return false;
+            }
+            if (!ensure_policy(ce_ref, media_ce_path)) return false;
+            if (!ensure_policy(ce_ref, user_ce_path)) return false;
+        }
+
+        if (volume_uuid.empty()) {
+            // Now that credentials have been installed, we can run restorecon
+            // over these paths
+            // NOTE: these paths need to be kept in sync with libselinux
+            android::vold::RestoreconRecursive(system_ce_path);
+            android::vold::RestoreconRecursive(misc_ce_path);
+        }
+    }
+    if (!prepare_subdirs("prepare", volume_uuid, user_id, flags)) return false;
+
+    return true;
+}
+
+bool fscrypt_destroy_user_storage(const std::string& volume_uuid, userid_t user_id, int flags) {
+    LOG(DEBUG) << "fscrypt_destroy_user_storage for volume " << escape_empty(volume_uuid)
+               << ", user " << user_id << ", flags " << flags;
+    bool res = true;
+
+    res &= prepare_subdirs("destroy", volume_uuid, user_id, flags);
+
+    if (flags & android::os::IVold::STORAGE_FLAG_CE) {
+        // CE_n key
+        auto system_ce_path = android::vold::BuildDataSystemCePath(user_id);
+        auto misc_ce_path = android::vold::BuildDataMiscCePath(user_id);
+        auto vendor_ce_path = android::vold::BuildDataVendorCePath(user_id);
+        auto media_ce_path = android::vold::BuildDataMediaCePath(volume_uuid, user_id);
+        auto user_ce_path = android::vold::BuildDataUserCePath(volume_uuid, user_id);
+
+        res &= destroy_dir(media_ce_path);
+        res &= destroy_dir(user_ce_path);
+        if (volume_uuid.empty()) {
+            res &= destroy_dir(system_ce_path);
+            res &= destroy_dir(misc_ce_path);
+            res &= destroy_dir(vendor_ce_path);
+        } else {
+            if (fscrypt_is_native()) {
+                res &= destroy_volkey(misc_ce_path, volume_uuid);
+            }
+        }
+    }
+
+    if (flags & android::os::IVold::STORAGE_FLAG_DE) {
+        // DE_sys key
+        auto system_legacy_path = android::vold::BuildDataSystemLegacyPath(user_id);
+        auto misc_legacy_path = android::vold::BuildDataMiscLegacyPath(user_id);
+        auto profiles_de_path = android::vold::BuildDataProfilesDePath(user_id);
+
+        // DE_n key
+        auto system_de_path = android::vold::BuildDataSystemDePath(user_id);
+        auto misc_de_path = android::vold::BuildDataMiscDePath(user_id);
+        auto vendor_de_path = android::vold::BuildDataVendorDePath(user_id);
+        auto user_de_path = android::vold::BuildDataUserDePath(volume_uuid, user_id);
+
+        res &= destroy_dir(user_de_path);
+        if (volume_uuid.empty()) {
+            res &= destroy_dir(system_legacy_path);
+#if MANAGE_MISC_DIRS
+            res &= destroy_dir(misc_legacy_path);
+#endif
+            res &= destroy_dir(profiles_de_path);
+            res &= destroy_dir(system_de_path);
+            res &= destroy_dir(misc_de_path);
+            res &= destroy_dir(vendor_de_path);
+        } else {
+            if (fscrypt_is_native()) {
+                res &= destroy_volkey(misc_de_path, volume_uuid);
+            }
+        }
+    }
+
+    return res;
+}
+
+static bool destroy_volume_keys(const std::string& directory_path, const std::string& volume_uuid) {
+    auto dirp = std::unique_ptr<DIR, int (*)(DIR*)>(opendir(directory_path.c_str()), closedir);
+    if (!dirp) {
+        PLOG(ERROR) << "Unable to open directory: " + directory_path;
+        return false;
+    }
+    bool res = true;
+    for (;;) {
+        errno = 0;
+        auto const entry = readdir(dirp.get());
+        if (!entry) {
+            if (errno) {
+                PLOG(ERROR) << "Unable to read directory: " + directory_path;
+                return false;
+            }
+            break;
+        }
+        if (entry->d_type != DT_DIR || entry->d_name[0] == '.') {
+            LOG(DEBUG) << "Skipping non-user " << entry->d_name;
+            continue;
+        }
+        res &= destroy_volkey(directory_path + "/" + entry->d_name, volume_uuid);
+    }
+    return res;
+}
+
+bool fscrypt_destroy_volume_keys(const std::string& volume_uuid) {
+    bool res = true;
+    LOG(DEBUG) << "fscrypt_destroy_volume_keys for volume " << escape_empty(volume_uuid);
+    auto secdiscardable_path = volume_secdiscardable_path(volume_uuid);
+    res &= android::vold::runSecdiscardSingle(secdiscardable_path);
+    res &= destroy_volume_keys("/data/misc_ce", volume_uuid);
+    res &= destroy_volume_keys("/data/misc_de", volume_uuid);
+    return res;
+}