Revert "Add support for multi-user decryption"

This reverts commit 0b25b1d79b79bc4d45dfff2aaf575e10bd24ef2d.

Reason for revert: Changes need to be made to libtwrpfscrypt to include this patchset. Will cherry-pick this patch later and make necessary modifications.

Change-Id: I7601d7b820129709b05d9b4368573b6f1048de02
diff --git a/crypto/ext4crypt/Decrypt.cpp b/crypto/ext4crypt/Decrypt.cpp
index fe27017..dcd390f 100755
--- a/crypto/ext4crypt/Decrypt.cpp
+++ b/crypto/ext4crypt/Decrypt.cpp
@@ -549,16 +549,13 @@
 	std::string disk_decryption_secret_key = "";
 
 	std::string keystore_alias_subid;
-	// Can be stored in user 0, so check for both.
-	if (!Find_Keystore_Alias_SubID_And_Prep_Files(user_id, keystore_alias_subid, handle_str) &&
-		!Find_Keystore_Alias_SubID_And_Prep_Files(0, keystore_alias_subid, handle_str)) 
-	{
-    	printf("failed to scan keystore alias subid and prep keystore files\n");
-    	return disk_decryption_secret_key;
-  	}
+	if (!Find_Keystore_Alias_SubID_And_Prep_Files(user_id, keystore_alias_subid, handle_str)) {
+		printf("failed to scan keystore alias subid and prep keystore files\n");
+		return disk_decryption_secret_key;
+	}
 
 	// First get the keystore service
-	sp<IBinder> binder = getKeystoreBinderRetry();
+    sp<IBinder> binder = getKeystoreBinderRetry();
 #ifdef USE_KEYSTORAGE_4
 	sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder);
 #else
@@ -1168,15 +1165,15 @@
 		printf("e4crypt_unlock_user_key returned fail\n");
 		return Free_Return(retval, weaver_key, &pwd);
 	}
-/*#ifdef USE_KEYSTORAGE_4
+#ifdef USE_KEYSTORAGE_4
 	if (!e4crypt_prepare_user_storage("", user_id, 0, flags)) {
 #else
 	if (!e4crypt_prepare_user_storage(nullptr, user_id, 0, flags)) {
 #endif
 		printf("failed to e4crypt_prepare_user_storage\n");
 		return Free_Return(retval, weaver_key, &pwd);
-	}*/
-	printf("User %i Decrypted Successfully!\n", user_id);
+	}
+	printf("Decrypted Successfully!\n");
 	retval = true;
 	return Free_Return(retval, weaver_key, &pwd);
 }
@@ -1258,15 +1255,15 @@
 			printf("e4crypt_unlock_user_key returned fail\n");
 			return false;
 		}
-/*#ifdef USE_KEYSTORAGE_4
+#ifdef USE_KEYSTORAGE_4
 		if (!e4crypt_prepare_user_storage("", user_id, 0, flags)) {
 #else
 		if (!e4crypt_prepare_user_storage(nullptr, user_id, 0, flags)) {
 #endif
 			printf("failed to e4crypt_prepare_user_storage\n");
 			return false;
-		}*/
-		printf("User %i Decrypted Successfully!\n", user_id);
+		}
+		printf("Decrypted Successfully!\n");
 		return true;
 	}
 	if (stat("/data/system_de/0/spblob", &st) == 0) {
@@ -1346,14 +1343,14 @@
 		printf("e4crypt_unlock_user_key returned fail\n");
 		return false;
 	}
-/*#ifdef USE_KEYSTORAGE_4
+#ifdef USE_KEYSTORAGE_4
 		if (!e4crypt_prepare_user_storage("", user_id, 0, flags)) {
 #else
 		if (!e4crypt_prepare_user_storage(nullptr, user_id, 0, flags)) {
 #endif
 		printf("failed to e4crypt_prepare_user_storage\n");
 		return false;
-	}*/
-	printf("User %i Decrypted Successfully!\n", user_id);
+	}
+	printf("Decrypted Successfully!\n");
 	return true;
 }
diff --git a/crypto/ext4crypt/Ext4Crypt.cpp b/crypto/ext4crypt/Ext4Crypt.cpp
index 9360b1a..c9e71fd 100644
--- a/crypto/ext4crypt/Ext4Crypt.cpp
+++ b/crypto/ext4crypt/Ext4Crypt.cpp
@@ -63,7 +63,6 @@
 #define MANAGE_MISC_DIRS 0
 
 #include <cutils/fs.h>
-#include <cutils/properties.h>
 
 #include <android-base/file.h>
 //#include <android-base/logging.h>
@@ -317,6 +316,16 @@
     return true;
 }
 
+static bool ensure_policy(const std::string& raw_ref __unused, const std::string& path) {
+    return true;
+    // ensure policy will set a policy if one is not set on an empty folder - we don't want to do this in recovery
+    /*if (e4crypt_policy_ensure(path.c_str(), raw_ref.data(), raw_ref.size()) != 0) {
+        LOG(ERROR) << "Failed to set policy on: " << path << "\n";
+        return false;
+    }
+    return true;*/
+}
+
 static bool is_numeric(const char* name) {
     for (const char* p = name; *p != '\0'; p++) {
         if (!isdigit(*p)) return false;
@@ -354,9 +363,6 @@
             if (!install_key(key, &raw_ref)) return false;
             s_de_key_raw_refs[user_id] = raw_ref;
             LOG(DEBUG) << "Installed de key for user " << user_id;
-
-            std::string user_prop = "twrp.user." + std::to_string(user_id) + ".decrypt";
-            property_set(user_prop.c_str(), "0");
         }
     }
     // ext4enc:TODO: go through all DE directories, ensure that all user dirs have the
@@ -405,6 +411,13 @@
         // 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 (!e4crypt_prepare_user_storage(nullptr, 0, 0, FLAG_STORAGE_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.
@@ -445,6 +458,79 @@
         }
     } else {
 		printf("Emulation mode not supported in TWRP\n");
+        // 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(nullptr, user_id), 0770) ||
+            !emulated_unlock(android::vold::BuildDataUserCePath(nullptr, user_id), 0771)) {
+            LOG(ERROR) << "Failed to unlock user " << user_id;
+            return false;
+        }*/
     }
     return true;
 }
+
+bool e4crypt_prepare_user_storage(const char* volume_uuid, userid_t user_id, int serial __unused,
+        int flags) {
+
+    if (flags & FLAG_STORAGE_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);
+        auto foreign_de_path = android::vold::BuildDataProfilesForeignDexDePath(user_id);
+
+        // DE_n key
+        auto system_de_path = android::vold::BuildDataSystemDePath(user_id);
+        auto misc_de_path = android::vold::BuildDataMiscDePath(user_id);
+        auto user_de_path = android::vold::BuildDataUserDePath(volume_uuid, user_id);
+
+        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(foreign_de_path, 0773, 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(user_de_path, 0771, AID_SYSTEM, AID_SYSTEM)) return false;
+
+        // For now, FBE is only supported on internal storage
+        if (e4crypt_is_native() && volume_uuid == nullptr) {
+            std::string de_raw_ref;
+            if (!lookup_key_ref(s_de_key_raw_refs, user_id, &de_raw_ref)) return false;
+            if (!ensure_policy(de_raw_ref, system_de_path)) return false;
+            if (!ensure_policy(de_raw_ref, misc_de_path)) return false;
+            if (!ensure_policy(de_raw_ref, user_de_path)) return false;
+        }
+    }
+
+    if (flags & FLAG_STORAGE_CE) {
+        // CE_n key
+        auto system_ce_path = android::vold::BuildDataSystemCePath(user_id);
+        auto misc_ce_path = android::vold::BuildDataMiscCePath(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 (!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(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;
+
+        // For now, FBE is only supported on internal storage
+        if (e4crypt_is_native() && volume_uuid == nullptr) {
+            std::string ce_raw_ref;
+            if (!lookup_key_ref(s_ce_key_raw_refs, user_id, &ce_raw_ref)) return false;
+            if (!ensure_policy(ce_raw_ref, system_ce_path)) return false;
+            if (!ensure_policy(ce_raw_ref, misc_ce_path)) return false;
+            if (!ensure_policy(ce_raw_ref, media_ce_path)) return false;
+            if (!ensure_policy(ce_raw_ref, user_ce_path)) return false;
+        }
+    }
+
+    return true;
+}
diff --git a/crypto/ext4crypt/Ext4Crypt.h b/crypto/ext4crypt/Ext4Crypt.h
index beb5d8f..57623e3 100644
--- a/crypto/ext4crypt/Ext4Crypt.h
+++ b/crypto/ext4crypt/Ext4Crypt.h
@@ -38,7 +38,7 @@
 bool e4crypt_unlock_user_key(userid_t user_id, int serial, const char* token, const char* secret);
 //bool e4crypt_lock_user_key(userid_t user_id);
 
-//bool e4crypt_prepare_user_storage(const char* volume_uuid, userid_t user_id, int serial, int flags);
+bool e4crypt_prepare_user_storage(const char* volume_uuid, userid_t user_id, int serial, int flags);
 //bool e4crypt_destroy_user_storage(const char* volume_uuid, userid_t user_id, int flags);
 
 bool lookup_key_ref(const std::map<userid_t, std::string>& key_map, userid_t user_id,
diff --git a/crypto/ext4crypt/Ext4CryptPie.cpp b/crypto/ext4crypt/Ext4CryptPie.cpp
index 48b4ec9..548e4e4 100644
--- a/crypto/ext4crypt/Ext4CryptPie.cpp
+++ b/crypto/ext4crypt/Ext4CryptPie.cpp
@@ -110,9 +110,9 @@
     return property_get_bool("persist.sys.emulate_fbe", false);
 }
 
-/*static const char* escape_empty(const std::string& value) {
+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);
@@ -155,6 +155,23 @@
     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,
@@ -242,6 +259,15 @@
     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) {
@@ -301,6 +327,13 @@
         android::base::GetProperty("fbe.filenames", "aes-256-heh");
 }
 
+static bool ensure_policy(const PolicyKeyRef& key_ref, const std::string& path) {
+    return true;
+    /*return e4crypt_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;
@@ -346,9 +379,6 @@
             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 << std::endl;
-
-            std::string user_prop = "twrp.user." + std::to_string(user_id) + ".decrypt";
-            property_set(user_prop.c_str(), "0");
         }
     }
     // ext4enc:TODO: go through all DE directories, ensure that all user dirs have the
@@ -405,6 +435,13 @@
         // 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 (!e4crypt_prepare_user_storage("", 0, 0, /*android::os::IVold::*/STORAGE_FLAG_DE)) {
+        LOG(ERROR) << "Failed to prepare user 0 storage" << std::endl;
+        return false;
+    }
 
     // If this is a non-FBE device that recently left an emulated mode,
     // restore user data directories to known-good state.
@@ -415,6 +452,92 @@
     return true;
 }
 
+/*bool e4crypt_vold_create_user_key(userid_t user_id, int serial, bool ephemeral) {
+    LOG(DEBUG) << "TWRP NOT e4crypt_vold_create_user_key for " << user_id << " serial " << serial;
+    return true;
+    if (!e4crypt_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 e4crypt_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) {
+	LOG(ERROR) << "TWRP NOT evict_ce_key\n";
+	return true;
+    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 e4crypt_destroy_user_key(userid_t user_id) {
+    LOG(DEBUG) << "NOT e4crypt_destroy_user_key(" << user_id << ")";
+    return true;
+    if (!e4crypt_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 << std::endl;
@@ -443,6 +566,92 @@
     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;
+    bool wrapped_key_supported = false;
+    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 << std::endl;
+            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 << std::endl;
+        return false;
+    }
+    android::vold::KeyAuthentication auth("", secdiscardable_hash);
+    wrapped_key_supported = is_wrapped_key_supported_external();
+    if (!android::vold::retrieveAndInstallKey(true, auth, key_path, key_path + "_tmp",
+                                              &key_ref->key_raw_ref, wrapped_key_supported))
+        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 e4crypt_add_user_key_auth(userid_t user_id, int serial, const std::string& token_hex,
+                               const std::string& secret_hex) {
+    LOG(DEBUG) << "e4crypt_add_user_key_auth " << user_id << " serial=" << serial
+               << " token_present=" << (token_hex != "!");
+    if (!e4crypt_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 e4crypt_fixate_newest_user_key_auth(userid_t user_id) {
+    LOG(DEBUG) << "e4crypt_fixate_newest_user_key_auth " << user_id;
+    if (!e4crypt_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 e4crypt_unlock_user_key(userid_t user_id, int serial, const std::string& token_hex,
                              const std::string& secret_hex) {
@@ -475,3 +684,224 @@
     }
     return true;
 }
+
+// TODO: rename to 'evict' for consistency
+/*bool e4crypt_lock_user_key(userid_t user_id) {
+    LOG(DEBUG) << "TWRP NOTe4crypt_lock_user_key " << user_id;
+    return true;
+    if (e4crypt_is_native()) {
+        return evict_ce_key(user_id);
+    } else if (e4crypt_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) {
+    LOG(ERROR) << "not actually forking for vold_prepare_subdirs\n";
+    return true;
+    /*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 e4crypt_prepare_user_storage(const std::string& volume_uuid, userid_t user_id, int serial,
+                                  int flags) {
+    LOG(DEBUG) << "e4crypt_prepare_user_storage for volume " << escape_empty(volume_uuid)
+               << ", user " << user_id << ", serial " << serial << ", flags " << flags << std::endl;
+
+    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(nullptr, 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 (e4crypt_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, nullptr, &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(nullptr, user_id);
+        auto user_ce_path = android::vold::BuildDataUserCePath(nullptr, 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 (e4crypt_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, nullptr, &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 e4crypt_destroy_user_storage(const std::string& volume_uuid, userid_t user_id, int flags) {
+    LOG(DEBUG) << "TWRP NOT e4crypt_destroy_user_storage for volume " << escape_empty(volume_uuid)
+               << ", user " << user_id << ", flags " << flags;
+    bool res = true;
+    return res;
+
+    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(nullptr, user_id);
+        auto user_ce_path = android::vold::BuildDataUserCePath(nullptr, 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 (e4crypt_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(nullptr, 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 (e4crypt_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) {
+	LOG(ERROR) << "TWRP NOT destroy_volume_keys\n";
+	return true;
+    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 e4crypt_destroy_volume_keys(const std::string& volume_uuid) {
+    bool res = true;
+    LOG(DEBUG) << "TWRP NOT e4crypt_destroy_volume_keys for volume " << escape_empty(volume_uuid);
+    /*return res;
+    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;
+}*/
diff --git a/crypto/ext4crypt/Ext4CryptPie.h b/crypto/ext4crypt/Ext4CryptPie.h
index 7236bc0..d6d6ecf 100644
--- a/crypto/ext4crypt/Ext4CryptPie.h
+++ b/crypto/ext4crypt/Ext4CryptPie.h
@@ -32,8 +32,8 @@
                              const std::string& secret);
 //bool e4crypt_lock_user_key(userid_t user_id);
 
-/*bool e4crypt_prepare_user_storage(const std::string& volume_uuid, userid_t user_id, int serial,
-                                  int flags);*/
+bool e4crypt_prepare_user_storage(const std::string& volume_uuid, userid_t user_id, int serial,
+                                  int flags);
 /*bool e4crypt_destroy_user_storage(const std::string& volume_uuid, userid_t user_id, int flags);
 
 bool e4crypt_destroy_volume_keys(const std::string& volume_uuid);*/