Merge "Support emulator's virtio-blk based SD card" into nyc-dev
diff --git a/Ext4Crypt.cpp b/Ext4Crypt.cpp
index fdc0197..3a31861 100644
--- a/Ext4Crypt.cpp
+++ b/Ext4Crypt.cpp
@@ -22,25 +22,25 @@
 #include <iomanip>
 #include <map>
 #include <set>
-#include <string>
 #include <sstream>
+#include <string>
 
-#include <stdio.h>
-#include <errno.h>
-#include <dirent.h>
-#include <sys/mount.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
 #include <cutils/properties.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
 #include <openssl/sha.h>
 #include <selinux/android.h>
+#include <stdio.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 
 #include <private/android_filesystem_config.h>
 
-#include "key_control.h"
 #include "cryptfs.h"
 #include "ext4_crypt.h"
+#include "key_control.h"
 
 #define EMULATED_USES_SELINUX 0
 
@@ -58,38 +58,38 @@
 static constexpr int FLAG_STORAGE_CE = 1 << 1;
 
 namespace {
-    const std::string device_key_dir = std::string() + DATA_MNT_POINT + "/unencrypted";
-    const std::string device_key_path = device_key_dir + "/key";
-    const std::string device_key_temp = device_key_dir + "/temp";
+const std::string device_key_dir = std::string() + DATA_MNT_POINT + "/unencrypted";
+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 user_key_dir = std::string() + DATA_MNT_POINT + "/misc/vold/user_keys";
+const std::string user_key_temp = user_key_dir + "/temp";
 
-    bool s_global_de_initialized = false;
+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;
+// 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. Keys should not be long-lived in user memory, only kernel memory.
-    // See b/26948053
-    std::map<userid_t, std::string> s_ce_keys;
+// 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. Keys should not be long-lived in user memory, only kernel memory.
+// See b/26948053
+std::map<userid_t, std::string> s_ce_keys;
 
-    // ext4enc:TODO get this const from somewhere good
-    const int EXT4_KEY_DESCRIPTOR_SIZE = 8;
+// ext4enc:TODO get this const from somewhere good
+const int EXT4_KEY_DESCRIPTOR_SIZE = 8;
 
-    // ext4enc:TODO Include structure from somewhere sensible
-    // MUST be in sync with ext4_crypto.c in kernel
-    constexpr int EXT4_ENCRYPTION_MODE_AES_256_XTS = 1;
-    constexpr int EXT4_AES_256_XTS_KEY_SIZE = 64;
-    constexpr int EXT4_MAX_KEY_SIZE = 64;
-    struct ext4_encryption_key {
-        uint32_t mode;
-        char raw[EXT4_MAX_KEY_SIZE];
-        uint32_t size;
-    };
+// ext4enc:TODO Include structure from somewhere sensible
+// MUST be in sync with ext4_crypto.c in kernel
+constexpr int EXT4_ENCRYPTION_MODE_AES_256_XTS = 1;
+constexpr int EXT4_AES_256_XTS_KEY_SIZE = 64;
+constexpr int EXT4_MAX_KEY_SIZE = 64;
+struct ext4_encryption_key {
+    uint32_t mode;
+    char raw[EXT4_MAX_KEY_SIZE];
+    uint32_t size;
+};
 }
 
 // TODO replace with proper function to test for file encryption
@@ -108,8 +108,7 @@
 }
 
 // Get raw keyref - used to make keyname and to pass to ioctl
-static std::string generate_key_ref(const char* key, int length)
-{
+static std::string generate_key_ref(const char* key, int length) {
     SHA512_CTX c;
 
     SHA512_Init(&c);
@@ -122,58 +121,60 @@
     unsigned char key_ref2[SHA512_DIGEST_LENGTH];
     SHA512_Final(key_ref2, &c);
 
+    static_assert(EXT4_KEY_DESCRIPTOR_SIZE <= SHA512_DIGEST_LENGTH,
+                  "Hash too short for descriptor");
     return std::string((char*)key_ref2, EXT4_KEY_DESCRIPTOR_SIZE);
 }
 
-static bool fill_key(const std::string& key, ext4_encryption_key& ext4_key)
-{
+static bool fill_key(const std::string& key, ext4_encryption_key* ext4_key) {
     if (key.size() != EXT4_AES_256_XTS_KEY_SIZE) {
         LOG(ERROR) << "Wrong size key " << key.size();
         return false;
     }
-    static_assert(EXT4_AES_256_XTS_KEY_SIZE <= sizeof(ext4_key.raw),
-                  "Key too long!");
-    ext4_key.mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
-    ext4_key.size = key.size();
-    memset(ext4_key.raw, 0, sizeof(ext4_key.raw));
-    memcpy(ext4_key.raw, key.data(), key.size());
+    static_assert(EXT4_AES_256_XTS_KEY_SIZE <= sizeof(ext4_key->raw), "Key too long!");
+    ext4_key->mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
+    ext4_key->size = key.size();
+    memset(ext4_key->raw, 0, sizeof(ext4_key->raw));
+    memcpy(ext4_key->raw, key.data(), key.size());
     return true;
 }
 
-static std::string keyname(const std::string &raw_ref)
-{
+static std::string keyname(const std::string& raw_ref) {
     std::ostringstream o;
     o << "ext4:";
-    for (auto i = raw_ref.begin(); i != raw_ref.end(); ++i) {
-        o << std::hex << std::setw(2) << std::setfill('0') << (int)*i;
+    for (auto i : raw_ref) {
+        o << std::hex << std::setw(2) << std::setfill('0') << (int)i;
     }
     return o.str();
 }
 
 // Get the keyring we store all keys in
-static key_serial_t e4crypt_keyring()
-{
-    return keyctl_search(KEY_SPEC_SESSION_KEYRING, "keyring", "e4crypt", 0);
+static bool e4crypt_keyring(key_serial_t* device_keyring) {
+    *device_keyring = keyctl_search(KEY_SPEC_SESSION_KEYRING, "keyring", "e4crypt", 0);
+    if (*device_keyring == -1) {
+        PLOG(ERROR) << "Unable to find device keyring";
+        return false;
+    }
+    return true;
 }
 
 // Install password into global keyring
 // Return raw key reference for use in policy
-static bool install_key(const std::string &key, std::string &raw_ref)
-{
+static bool install_key(const std::string& key, std::string* raw_ref) {
     ext4_encryption_key ext4_key;
-    if (!fill_key(key, ext4_key)) return false;
-    raw_ref = generate_key_ref(ext4_key.raw, ext4_key.size);
-    auto ref = keyname(raw_ref);
-    key_serial_t device_keyring = e4crypt_keyring();
-    key_serial_t key_id = add_key("logon", ref.c_str(),
-                                  (void*)&ext4_key, sizeof(ext4_key),
-                                  device_keyring);
+    if (!fill_key(key, &ext4_key)) return false;
+    *raw_ref = generate_key_ref(ext4_key.raw, ext4_key.size);
+    auto ref = keyname(*raw_ref);
+    key_serial_t device_keyring;
+    if (!e4crypt_keyring(&device_keyring)) return false;
+    key_serial_t key_id =
+        add_key("logon", ref.c_str(), (void*)&ext4_key, sizeof(ext4_key), device_keyring);
     if (key_id == -1) {
         PLOG(ERROR) << "Failed to insert key into keyring " << device_keyring;
         return false;
     }
-    LOG(INFO) << "Added key " << key_id << " (" << ref << ") to keyring "
-        << device_keyring << " in process " << getpid();
+    LOG(DEBUG) << "Added key " << key_id << " (" << ref << ") to keyring " << device_keyring
+               << " in process " << getpid();
     return true;
 }
 
@@ -185,21 +186,21 @@
     return StringPrintf("%s/ce/%d/current", user_key_dir.c_str(), user_id);
 }
 
-static bool read_and_install_user_ce_key(
-        userid_t user_id, const android::vold::KeyAuthentication &auth) {
+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;
     const auto ce_key_path = get_ce_key_path(user_id);
     std::string ce_key;
-    if (!android::vold::retrieveKey(ce_key_path, auth, ce_key)) return false;
+    if (!android::vold::retrieveKey(ce_key_path, auth, &ce_key)) return false;
     std::string ce_raw_ref;
-    if (!install_key(ce_key, ce_raw_ref)) return false;
+    if (!install_key(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) << "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) {
+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;
@@ -208,8 +209,8 @@
     return true;
 }
 
-static bool random_key(std::string &key) {
-    if (android::vold::ReadRandomBytes(EXT4_AES_256_XTS_KEY_SIZE, key) != 0) {
+static bool random_key(std::string* key) {
+    if (android::vold::ReadRandomBytes(EXT4_AES_256_XTS_KEY_SIZE, *key) != 0) {
         // TODO status_t plays badly with PLOG, fix it.
         LOG(ERROR) << "Random read failed";
         return false;
@@ -217,20 +218,20 @@
     return true;
 }
 
-static bool path_exists(const std::string &path) {
+static bool path_exists(const std::string& path) {
     return access(path.c_str(), F_OK) == 0;
 }
 
 // NB this assumes that there is only one thread listening for crypt commands, because
 // it creates keys in a fixed location.
-static bool store_key(const std::string &key_path, const std::string &tmp_path,
-        const android::vold::KeyAuthentication &auth, const std::string &key) {
+static bool store_key(const std::string& key_path, const std::string& tmp_path,
+                      const android::vold::KeyAuthentication& auth, const std::string& key) {
     if (path_exists(key_path)) {
         LOG(ERROR) << "Already exists, cannot create key at: " << key_path;
         return false;
     }
     if (path_exists(tmp_path)) {
-        android::vold::destroyKey(tmp_path);
+        android::vold::destroyKey(tmp_path);  // May be partially created so ignore errors
     }
     if (!android::vold::storeKey(tmp_path, auth, key)) return false;
     if (rename(tmp_path.c_str(), key_path.c_str()) != 0) {
@@ -243,8 +244,8 @@
 
 static bool create_and_install_user_keys(userid_t user_id, bool create_ephemeral) {
     std::string de_key, ce_key;
-    if (!random_key(de_key)) return false;
-    if (!random_key(ce_key)) return false;
+    if (!random_key(&de_key)) return false;
+    if (!random_key(&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);
@@ -257,28 +258,28 @@
                 kEmptyAuthentication, ce_key)) return false;
     }
     std::string de_raw_ref;
-    if (!install_key(de_key, de_raw_ref)) return false;
+    if (!install_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_key(ce_key, ce_raw_ref)) return false;
+    if (!install_key(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) {
+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;
+    *raw_ref = refi->second;
     return true;
 }
 
-static bool ensure_policy(const std::string &raw_ref, const std::string& path) {
+static bool ensure_policy(const std::string& raw_ref, const std::string& path) {
     if (e4crypt_policy_ensure(path.c_str(), raw_ref.data(), raw_ref.size()) != 0) {
         LOG(ERROR) << "Failed to set policy on: " << path;
         return false;
@@ -286,17 +287,16 @@
     return true;
 }
 
-static bool is_numeric(const char *name) {
-    for (const char *p = name; *p != '\0'; p++) {
-        if (!isdigit(*p))
-            return false;
+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);
+    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;
@@ -319,9 +319,9 @@
         if (s_de_key_raw_refs.count(user_id) == 0) {
             auto key_path = de_dir + "/" + entry->d_name;
             std::string key;
-            if (!android::vold::retrieveKey(key_path, kEmptyAuthentication, key)) return false;
+            if (!android::vold::retrieveKey(key_path, kEmptyAuthentication, &key)) return false;
             std::string raw_ref;
-            if (!install_key(key, raw_ref)) return false;
+            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;
         }
@@ -331,8 +331,7 @@
     return true;
 }
 
-bool e4crypt_initialize_global_de()
-{
+bool e4crypt_initialize_global_de() {
     LOG(INFO) << "e4crypt_initialize_global_de";
 
     if (s_global_de_initialized) {
@@ -343,16 +342,16 @@
     std::string device_key;
     if (path_exists(device_key_path)) {
         if (!android::vold::retrieveKey(device_key_path,
-                kEmptyAuthentication, device_key)) return false;
+                kEmptyAuthentication, &device_key)) return false;
     } else {
         LOG(INFO) << "Creating new key";
-        if (!random_key(device_key)) return false;
+        if (!random_key(&device_key)) return false;
         if (!store_key(device_key_path, device_key_temp,
                 kEmptyAuthentication, device_key)) return false;
     }
 
     std::string device_key_ref;
-    if (!install_key(device_key, device_key_ref)) {
+    if (!install_key(device_key, &device_key_ref)) {
         LOG(ERROR) << "Failed to install device key";
         return false;
     }
@@ -377,10 +376,10 @@
         auto ce_path = get_ce_key_path(0);
         if (!path_exists(de_path) || !path_exists(ce_path)) {
             if (path_exists(de_path)) {
-                android::vold::destroyKey(de_path); // Ignore failure
+                android::vold::destroyKey(de_path);  // May be partially created so ignore errors
             }
             if (path_exists(ce_path)) {
-                android::vold::destroyKey(ce_path); // Ignore failure
+                android::vold::destroyKey(ce_path);  // May be partially created so ignore errors
             }
             if (!create_and_install_user_keys(0, false)) return false;
         }
@@ -412,21 +411,22 @@
     }
     // 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;
+        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;
     }
-    // TODO: create second key for user_de data
     return true;
 }
 
-static bool evict_key(const std::string &raw_ref) {
+static bool evict_key(const std::string& raw_ref) {
     auto ref = keyname(raw_ref);
-    auto key_serial = keyctl_search(e4crypt_keyring(), "logon", ref.c_str(), 0);
+    key_serial_t device_keyring;
+    if (!e4crypt_keyring(&device_keyring)) return false;
+    auto key_serial = keyctl_search(device_keyring, "logon", ref.c_str(), 0);
     if (keyctl_revoke(key_serial) != 0) {
         PLOG(ERROR) << "Failed to revoke key with serial " << key_serial << " ref " << ref;
         return false;
@@ -443,9 +443,9 @@
     bool success = true;
     s_ce_keys.erase(user_id);
     std::string raw_ref;
-    success &= lookup_key_ref(s_ce_key_raw_refs, user_id, raw_ref) && evict_key(raw_ref);
+    success &= lookup_key_ref(s_ce_key_raw_refs, user_id, &raw_ref) && evict_key(raw_ref);
     s_ce_key_raw_refs.erase(user_id);
-    success &= lookup_key_ref(s_de_key_raw_refs, user_id, raw_ref) && evict_key(raw_ref);
+    success &= lookup_key_ref(s_de_key_raw_refs, user_id, &raw_ref) && evict_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()) {
@@ -487,34 +487,32 @@
     return true;
 }
 
-static bool parse_hex(const char *hex, std::string &result) {
+static bool parse_hex(const char* hex, std::string* result) {
     if (strcmp("!", hex) == 0) {
-        result = "";
+        *result = "";
         return true;
     }
-    if (android::vold::HexToStr(hex, result) != 0) {
-        LOG(ERROR) << "Invalid FBE hex string"; // Don't log the string for security reasons
+    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;
 }
 
-bool e4crypt_change_user_key(userid_t user_id, int serial,
-        const char* token_hex, const char* old_secret_hex, const char* new_secret_hex) {
-    LOG(DEBUG) << "e4crypt_change_user_key " << user_id << " serial=" << serial <<
-        " token_present=" << (strcmp(token_hex, "!") != 0);
+bool e4crypt_change_user_key(userid_t user_id, int serial, const char* token_hex,
+                             const char* old_secret_hex, const char* new_secret_hex) {
+    LOG(DEBUG) << "e4crypt_change_user_key " << user_id << " serial=" << serial
+               << " token_present=" << (strcmp(token_hex, "!") != 0);
     if (!e4crypt_is_native()) return true;
     if (s_ephemeral_users.count(user_id) != 0) return true;
     std::string token, old_secret, new_secret;
-    if (!parse_hex(token_hex, token)) return false;
-    if (!parse_hex(old_secret_hex, old_secret)) return false;
-    if (!parse_hex(new_secret_hex, new_secret)) return false;
-    auto old_auth = old_secret.empty()
-        ? kEmptyAuthentication
-        : android::vold::KeyAuthentication(token, old_secret);
-    auto new_auth = new_secret.empty()
-        ? kEmptyAuthentication
-        : android::vold::KeyAuthentication(token, new_secret);
+    if (!parse_hex(token_hex, &token)) return false;
+    if (!parse_hex(old_secret_hex, &old_secret)) return false;
+    if (!parse_hex(new_secret_hex, &new_secret)) return false;
+    auto old_auth = old_secret.empty() ? kEmptyAuthentication
+                                       : android::vold::KeyAuthentication(token, old_secret);
+    auto new_auth = new_secret.empty() ? kEmptyAuthentication
+                                       : android::vold::KeyAuthentication(token, new_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;
@@ -523,7 +521,7 @@
     auto ce_key = it->second;
     auto ce_key_path = get_ce_key_path(user_id);
     std::string trial_key;
-    if (!android::vold::retrieveKey(ce_key_path, old_auth, trial_key)) {
+    if (!android::vold::retrieveKey(ce_key_path, old_auth, &trial_key)) {
         LOG(WARNING) << "change_user_key wasn't given enough info to reconstruct the key";
     } else if (ce_key != trial_key) {
         LOG(WARNING) << "Reconstructed key != stored key";
@@ -534,18 +532,18 @@
 }
 
 // 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 char* token_hex, const char* secret_hex) {
-    LOG(DEBUG) << "e4crypt_unlock_user_key " << user_id << " serial=" << serial <<
-        " token_present=" << (strcmp(token_hex, "!") != 0);
+bool e4crypt_unlock_user_key(userid_t user_id, int serial, const char* token_hex,
+                             const char* secret_hex) {
+    LOG(DEBUG) << "e4crypt_unlock_user_key " << user_id << " serial=" << serial
+               << " token_present=" << (strcmp(token_hex, "!") != 0);
     if (e4crypt_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;
+        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;
@@ -556,9 +554,9 @@
         // 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::BuildDataMediaPath(nullptr, user_id), 0770) ||
-                !emulated_unlock(android::vold::BuildDataUserPath(nullptr, user_id), 0771)) {
+            !emulated_unlock(android::vold::BuildDataMiscCePath(user_id), 01771) ||
+            !emulated_unlock(android::vold::BuildDataMediaPath(nullptr, user_id), 0770) ||
+            !emulated_unlock(android::vold::BuildDataUserPath(nullptr, user_id), 0771)) {
             LOG(ERROR) << "Failed to unlock user " << user_id;
             return false;
         }
@@ -573,9 +571,9 @@
     } 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::BuildDataMediaPath(nullptr, user_id)) ||
-                !emulated_lock(android::vold::BuildDataUserPath(nullptr, user_id))) {
+            !emulated_lock(android::vold::BuildDataMiscCePath(user_id)) ||
+            !emulated_lock(android::vold::BuildDataMediaPath(nullptr, user_id)) ||
+            !emulated_lock(android::vold::BuildDataUserPath(nullptr, user_id))) {
             LOG(ERROR) << "Failed to lock user " << user_id;
             return false;
         }
@@ -584,10 +582,10 @@
     return true;
 }
 
-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) {
     LOG(DEBUG) << "e4crypt_prepare_user_storage for volume " << escape_null(volume_uuid)
-            << ", user " << user_id << ", serial " << serial << ", flags " << flags;
+               << ", user " << user_id << ", serial " << serial << ", flags " << flags;
 
     if (flags & FLAG_STORAGE_DE) {
         auto system_de_path = android::vold::BuildDataSystemDePath(user_id);
@@ -603,7 +601,7 @@
             // For now, we do not store profiles on the adopted storage.
             auto profiles_de_path = android::vold::BuildDataProfilesDePath(user_id);
             auto foreign_dex_profiles_de_path =
-                    android::vold::BuildDataProfilesForeignDexDePath(user_id);
+                android::vold::BuildDataProfilesForeignDexDePath(user_id);
             if (!prepare_dir(profiles_de_path, 0771, AID_SYSTEM, AID_SYSTEM)) return false;
             if (!prepare_dir(foreign_dex_profiles_de_path, 0773, AID_SYSTEM, AID_SYSTEM)) {
                 return false;
@@ -612,7 +610,7 @@
 
         if (e4crypt_is_native()) {
             std::string de_raw_ref;
-            if (!lookup_key_ref(s_de_key_raw_refs, user_id, de_raw_ref)) return false;
+            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;
@@ -634,7 +632,7 @@
 
         if (e4crypt_is_native()) {
             std::string ce_raw_ref;
-            if (!lookup_key_ref(s_ce_key_raw_refs, user_id, ce_raw_ref)) return false;
+            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;
diff --git a/Ext4Crypt.h b/Ext4Crypt.h
index f183c58..dff2953 100644
--- a/Ext4Crypt.h
+++ b/Ext4Crypt.h
@@ -28,14 +28,12 @@
 bool e4crypt_init_user0();
 bool e4crypt_vold_create_user_key(userid_t user_id, int serial, bool ephemeral);
 bool e4crypt_destroy_user_key(userid_t user_id);
-bool e4crypt_change_user_key(userid_t user_id, int serial,
-    const char* token, const char* old_secret, const char* new_secret);
+bool e4crypt_change_user_key(userid_t user_id, int serial, const char* token,
+                             const char* old_secret, const char* new_secret);
 
-bool e4crypt_unlock_user_key(userid_t user_id, int serial,
-    const char* token, const char* secret);
+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);
 
 __END_DECLS
diff --git a/KeyStorage.cpp b/KeyStorage.cpp
index 2338f23..f2b16e3 100644
--- a/KeyStorage.cpp
+++ b/KeyStorage.cpp
@@ -35,25 +35,26 @@
 
 #include <cutils/properties.h>
 
+#include <hardware/hw_auth_token.h>
+
 #include <keymaster/authorization_set.h>
 
 extern "C" {
 
 #include "crypto_scrypt.h"
-
 }
 
 namespace android {
 namespace vold {
 
-const KeyAuthentication kEmptyAuthentication { "", "" };
+const KeyAuthentication kEmptyAuthentication{"", ""};
 
 static constexpr size_t AES_KEY_BYTES = 32;
 static constexpr size_t GCM_NONCE_BYTES = 12;
 static constexpr size_t GCM_MAC_BYTES = 16;
-static constexpr size_t SALT_BYTES = 1<<4;
-static constexpr size_t SECDISCARDABLE_BYTES = 1<<14;
-static constexpr size_t STRETCHED_BYTES = 1<<6;
+static constexpr size_t SALT_BYTES = 1 << 4;
+static constexpr size_t SECDISCARDABLE_BYTES = 1 << 14;
+static constexpr size_t STRETCHED_BYTES = 1 << 6;
 
 static const char* kCurrentVersion = "1";
 static const char* kRmPath = "/system/bin/rm";
@@ -70,14 +71,14 @@
 
 static bool checkSize(const std::string& kind, size_t actual, size_t expected) {
     if (actual != expected) {
-        LOG(ERROR) << "Wrong number of bytes in " << kind << ", expected " << expected
-            << " got " << actual;
+        LOG(ERROR) << "Wrong number of bytes in " << kind << ", expected " << expected << " got "
+                   << actual;
         return false;
     }
     return true;
 }
 
-static std::string hashSecdiscardable(const std::string &secdiscardable) {
+static std::string hashSecdiscardable(const std::string& secdiscardable) {
     SHA512_CTX c;
 
     SHA512_Init(&c);
@@ -89,39 +90,56 @@
     SHA512_Update(&c, secdiscardableHashingPrefix.data(), secdiscardableHashingPrefix.size());
     SHA512_Update(&c, secdiscardable.data(), secdiscardable.size());
     std::string res(SHA512_DIGEST_LENGTH, '\0');
-    SHA512_Final(reinterpret_cast<uint8_t *>(&res[0]), &c);
+    SHA512_Final(reinterpret_cast<uint8_t*>(&res[0]), &c);
     return res;
 }
 
-static bool generateKeymasterKey(Keymaster &keymaster,
-        const keymaster::AuthorizationSet &extraParams,
-        std::string &key) {
-    auto params = keymaster::AuthorizationSetBuilder()
-        .AesEncryptionKey(AES_KEY_BYTES * 8)
-        .Authorization(keymaster::TAG_BLOCK_MODE, KM_MODE_GCM)
-        .Authorization(keymaster::TAG_MIN_MAC_LENGTH, GCM_MAC_BYTES * 8)
-        .Authorization(keymaster::TAG_PADDING, KM_PAD_NONE)
-        .Authorization(keymaster::TAG_NO_AUTH_REQUIRED) // FIXME integrate with gatekeeper
-        .build();
-    params.push_back(extraParams);
-    return keymaster.generateKey(params, key);
+static bool generateKeymasterKey(Keymaster& keymaster, const KeyAuthentication& auth,
+                                 const std::string& appId, std::string* key) {
+    auto paramBuilder = keymaster::AuthorizationSetBuilder()
+                            .AesEncryptionKey(AES_KEY_BYTES * 8)
+                            .Authorization(keymaster::TAG_BLOCK_MODE, KM_MODE_GCM)
+                            .Authorization(keymaster::TAG_MIN_MAC_LENGTH, GCM_MAC_BYTES * 8)
+                            .Authorization(keymaster::TAG_PADDING, KM_PAD_NONE);
+    addStringParam(&paramBuilder, keymaster::TAG_APPLICATION_ID, appId);
+    if (auth.token.empty()) {
+        LOG(DEBUG) << "Creating key that doesn't need auth token";
+        paramBuilder.Authorization(keymaster::TAG_NO_AUTH_REQUIRED);
+    } else {
+        LOG(DEBUG) << "Auth token required for key";
+        if (auth.token.size() != sizeof(hw_auth_token_t)) {
+            LOG(ERROR) << "Auth token should be " << sizeof(hw_auth_token_t) << " bytes, was "
+                       << auth.token.size() << " bytes";
+            return false;
+        }
+        const hw_auth_token_t* at = reinterpret_cast<const hw_auth_token_t*>(auth.token.data());
+        paramBuilder.Authorization(keymaster::TAG_USER_SECURE_ID, at->user_id);
+        paramBuilder.Authorization(keymaster::TAG_USER_AUTH_TYPE, HW_AUTH_PASSWORD);
+        paramBuilder.Authorization(keymaster::TAG_AUTH_TIMEOUT, 5);
+    }
+    return keymaster.generateKey(paramBuilder.build(), key);
 }
 
-static bool encryptWithKeymasterKey(
-        Keymaster &keymaster,
-        const std::string &key,
-        const keymaster::AuthorizationSet &extraParams,
-        const std::string &message,
-        std::string &ciphertext) {
-    // FIXME fix repetition
-    auto params = keymaster::AuthorizationSetBuilder()
-        .Authorization(keymaster::TAG_BLOCK_MODE, KM_MODE_GCM)
-        .Authorization(keymaster::TAG_MAC_LENGTH, GCM_MAC_BYTES * 8)
-        .Authorization(keymaster::TAG_PADDING, KM_PAD_NONE)
-        .build();
-    params.push_back(extraParams);
+static keymaster::AuthorizationSetBuilder beginParams(const KeyAuthentication& auth,
+                                                      const std::string& appId) {
+    auto paramBuilder = keymaster::AuthorizationSetBuilder()
+                            .Authorization(keymaster::TAG_BLOCK_MODE, KM_MODE_GCM)
+                            .Authorization(keymaster::TAG_MAC_LENGTH, GCM_MAC_BYTES * 8)
+                            .Authorization(keymaster::TAG_PADDING, KM_PAD_NONE);
+    addStringParam(&paramBuilder, keymaster::TAG_APPLICATION_ID, appId);
+    if (!auth.token.empty()) {
+        LOG(DEBUG) << "Supplying auth token to Keymaster";
+        addStringParam(&paramBuilder, keymaster::TAG_AUTH_TOKEN, auth.token);
+    }
+    return paramBuilder;
+}
+
+static bool encryptWithKeymasterKey(Keymaster& keymaster, const std::string& key,
+                                    const KeyAuthentication& auth, const std::string& appId,
+                                    const std::string& message, std::string* ciphertext) {
+    auto params = beginParams(auth, appId).build();
     keymaster::AuthorizationSet outParams;
-    auto opHandle = keymaster.begin(KM_PURPOSE_ENCRYPT, key, params, outParams);
+    auto opHandle = keymaster.begin(KM_PURPOSE_ENCRYPT, key, params, &outParams);
     if (!opHandle) return false;
     keymaster_blob_t nonceBlob;
     if (!outParams.GetTagValue(keymaster::TAG_NONCE, &nonceBlob)) {
@@ -129,33 +147,24 @@
         return false;
     }
     // nonceBlob here is just a pointer into existing data, must not be freed
-    std::string nonce(reinterpret_cast<const char *>(nonceBlob.data), nonceBlob.data_length);
+    std::string nonce(reinterpret_cast<const char*>(nonceBlob.data), nonceBlob.data_length);
     if (!checkSize("nonce", nonce.size(), GCM_NONCE_BYTES)) return false;
     std::string body;
-    if (!opHandle.updateCompletely(message, body)) return false;
+    if (!opHandle.updateCompletely(message, &body)) return false;
 
     std::string mac;
-    if (!opHandle.finishWithOutput(mac)) return false;
+    if (!opHandle.finishWithOutput(&mac)) return false;
     if (!checkSize("mac", mac.size(), GCM_MAC_BYTES)) return false;
-    ciphertext = nonce + body + mac;
+    *ciphertext = nonce + body + mac;
     return true;
 }
 
-static bool decryptWithKeymasterKey(
-        Keymaster &keymaster, const std::string &key,
-        const keymaster::AuthorizationSet &extraParams,
-        const std::string &ciphertext,
-        std::string &message) {
+static bool decryptWithKeymasterKey(Keymaster& keymaster, const std::string& key,
+                                    const KeyAuthentication& auth, const std::string& appId,
+                                    const std::string& ciphertext, std::string* message) {
     auto nonce = ciphertext.substr(0, GCM_NONCE_BYTES);
     auto bodyAndMac = ciphertext.substr(GCM_NONCE_BYTES);
-    // FIXME fix repetition
-    auto params = addStringParam(keymaster::AuthorizationSetBuilder(), keymaster::TAG_NONCE, nonce)
-        .Authorization(keymaster::TAG_BLOCK_MODE, KM_MODE_GCM)
-        .Authorization(keymaster::TAG_MAC_LENGTH, GCM_MAC_BYTES * 8)
-        .Authorization(keymaster::TAG_PADDING, KM_PAD_NONE)
-        .build();
-    params.push_back(extraParams);
-
+    auto params = addStringParam(beginParams(auth, appId), keymaster::TAG_NONCE, nonce).build();
     auto opHandle = keymaster.begin(KM_PURPOSE_DECRYPT, key, params);
     if (!opHandle) return false;
     if (!opHandle.updateCompletely(bodyAndMac, message)) return false;
@@ -163,18 +172,18 @@
     return true;
 }
 
-static bool readFileToString(const std::string &filename, std::string &result) {
-    if (!android::base::ReadFileToString(filename, &result)) {
-         PLOG(ERROR) << "Failed to read from " << filename;
-         return false;
+static bool readFileToString(const std::string& filename, std::string* result) {
+    if (!android::base::ReadFileToString(filename, result)) {
+        PLOG(ERROR) << "Failed to read from " << filename;
+        return false;
     }
     return true;
 }
 
-static bool writeStringToFile(const std::string &payload, const std::string &filename) {
+static bool writeStringToFile(const std::string& payload, const std::string& filename) {
     if (!android::base::WriteStringToFile(payload, filename)) {
-         PLOG(ERROR) << "Failed to write to " << filename;
-         return false;
+        PLOG(ERROR) << "Failed to write to " << filename;
+        return false;
     }
     return true;
 }
@@ -186,34 +195,33 @@
     return std::string() + kStretchPrefix_scrypt + paramstr;
 }
 
-static bool stretchingNeedsSalt(const std::string &stretching) {
+static bool stretchingNeedsSalt(const std::string& stretching) {
     return stretching != kStretch_nopassword && stretching != kStretch_none;
 }
 
-static bool stretchSecret(const std::string &stretching, const std::string &secret,
-        const std::string &salt, std::string &stretched) {
+static bool stretchSecret(const std::string& stretching, const std::string& secret,
+                          const std::string& salt, std::string* stretched) {
     if (stretching == kStretch_nopassword) {
         if (!secret.empty()) {
-            LOG(ERROR) << "Password present but stretching is nopasswd";
+            LOG(WARNING) << "Password present but stretching is nopassword";
             // Continue anyway
         }
-        stretched.clear();
+        stretched->clear();
     } else if (stretching == kStretch_none) {
-        stretched = secret;
-    } else if (std::equal(kStretchPrefix_scrypt.begin(),
-            kStretchPrefix_scrypt.end(), stretching.begin())) {
+        *stretched = secret;
+    } else if (std::equal(kStretchPrefix_scrypt.begin(), kStretchPrefix_scrypt.end(),
+                          stretching.begin())) {
         int Nf, rf, pf;
-        if (!parse_scrypt_parameters(
-                stretching.substr(kStretchPrefix_scrypt.size()).c_str(), &Nf, &rf, &pf)) {
+        if (!parse_scrypt_parameters(stretching.substr(kStretchPrefix_scrypt.size()).c_str(), &Nf,
+                                     &rf, &pf)) {
             LOG(ERROR) << "Unable to parse scrypt params in stretching: " << stretching;
             return false;
         }
-        stretched.assign(STRETCHED_BYTES, '\0');
-        if (crypto_scrypt(
-                reinterpret_cast<const uint8_t *>(secret.data()), secret.size(),
-                reinterpret_cast<const uint8_t *>(salt.data()), salt.size(),
-                1 << Nf, 1 << rf, 1 << pf,
-                reinterpret_cast<uint8_t *>(&stretched[0]), stretched.size()) != 0) {
+        stretched->assign(STRETCHED_BYTES, '\0');
+        if (crypto_scrypt(reinterpret_cast<const uint8_t*>(secret.data()), secret.size(),
+                          reinterpret_cast<const uint8_t*>(salt.data()), salt.size(),
+                          1 << Nf, 1 << rf, 1 << pf,
+                          reinterpret_cast<uint8_t*>(&(*stretched)[0]), stretched->size()) != 0) {
             LOG(ERROR) << "scrypt failed with params: " << stretching;
             return false;
         }
@@ -224,27 +232,21 @@
     return true;
 }
 
-static bool buildParams(const KeyAuthentication &auth, const std::string &stretching,
-        const std::string &salt, const std::string &secdiscardable,
-        keymaster::AuthorizationSet &result) {
+static bool generateAppId(const KeyAuthentication& auth, const std::string& stretching,
+                          const std::string& salt, const std::string& secdiscardable,
+                          std::string* appId) {
     std::string stretched;
-    if (!stretchSecret(stretching, auth.secret, salt, stretched)) return false;
-    auto appId = hashSecdiscardable(secdiscardable) + stretched;
-    keymaster::AuthorizationSetBuilder paramBuilder;
-    addStringParam(paramBuilder, keymaster::TAG_APPLICATION_ID, appId);
-    if (!auth.token.empty()) {
-        addStringParam(paramBuilder, keymaster::TAG_AUTH_TOKEN, auth.token);
-    }
-    result = paramBuilder.build();
+    if (!stretchSecret(stretching, auth.secret, salt, &stretched)) return false;
+    *appId = hashSecdiscardable(secdiscardable) + stretched;
     return true;
 }
 
-bool storeKey(const std::string &dir, const KeyAuthentication &auth, const std::string &key) {
+bool storeKey(const std::string& dir, const KeyAuthentication& auth, const std::string& key) {
     if (TEMP_FAILURE_RETRY(mkdir(dir.c_str(), 0700)) == -1) {
         PLOG(ERROR) << "key mkdir " << dir;
         return false;
     }
-    if (!writeStringToFile(kCurrentVersion, dir + "/" +  kFn_version)) return false;
+    if (!writeStringToFile(kCurrentVersion, dir + "/" + kFn_version)) return false;
     std::string secdiscardable;
     if (ReadRandomBytes(SECDISCARDABLE_BYTES, secdiscardable) != OK) {
         // TODO status_t plays badly with PLOG, fix it.
@@ -253,82 +255,81 @@
     }
     if (!writeStringToFile(secdiscardable, dir + "/" + kFn_secdiscardable)) return false;
     std::string stretching = auth.secret.empty() ? kStretch_nopassword : getStretching();
-    if (!writeStringToFile(stretching, dir + "/" +  kFn_stretching)) return false;
+    if (!writeStringToFile(stretching, dir + "/" + kFn_stretching)) return false;
     std::string salt;
     if (stretchingNeedsSalt(stretching)) {
         if (ReadRandomBytes(SALT_BYTES, salt) != OK) {
             LOG(ERROR) << "Random read failed";
             return false;
         }
-        if (!writeStringToFile(salt, dir + "/" +  kFn_salt)) return false;
+        if (!writeStringToFile(salt, dir + "/" + kFn_salt)) return false;
     }
-    keymaster::AuthorizationSet extraParams;
-    if (!buildParams(auth, stretching, salt, secdiscardable, extraParams)) return false;
+    std::string appId;
+    if (!generateAppId(auth, stretching, salt, secdiscardable, &appId)) return false;
     Keymaster keymaster;
     if (!keymaster) return false;
     std::string kmKey;
-    if (!generateKeymasterKey(keymaster, extraParams, kmKey)) return false;
-    std::string encryptedKey;
-    if (!encryptWithKeymasterKey(keymaster, kmKey, extraParams, key, encryptedKey)) return false;
+    if (!generateKeymasterKey(keymaster, auth, appId, &kmKey)) return false;
     if (!writeStringToFile(kmKey, dir + "/" + kFn_keymaster_key_blob)) return false;
+    std::string encryptedKey;
+    if (!encryptWithKeymasterKey(keymaster, kmKey, auth, appId, key, &encryptedKey)) return false;
     if (!writeStringToFile(encryptedKey, dir + "/" + kFn_encrypted_key)) return false;
     return true;
 }
 
-bool retrieveKey(const std::string &dir, const KeyAuthentication &auth, std::string &key) {
+bool retrieveKey(const std::string& dir, const KeyAuthentication& auth, std::string* key) {
     std::string version;
-    if (!readFileToString(dir + "/" + kFn_version, version)) return false;
+    if (!readFileToString(dir + "/" + kFn_version, &version)) return false;
     if (version != kCurrentVersion) {
         LOG(ERROR) << "Version mismatch, expected " << kCurrentVersion << " got " << version;
         return false;
     }
     std::string secdiscardable;
-    if (!readFileToString(dir + "/" + kFn_secdiscardable, secdiscardable)) return false;
+    if (!readFileToString(dir + "/" + kFn_secdiscardable, &secdiscardable)) return false;
     std::string stretching;
-    if (!readFileToString(dir + "/" + kFn_stretching, stretching)) return false;
+    if (!readFileToString(dir + "/" + kFn_stretching, &stretching)) return false;
     std::string salt;
     if (stretchingNeedsSalt(stretching)) {
-        if (!readFileToString(dir + "/" +  kFn_salt, salt)) return false;
+        if (!readFileToString(dir + "/" + kFn_salt, &salt)) return false;
     }
-    keymaster::AuthorizationSet extraParams;
-    if (!buildParams(auth, stretching, salt, secdiscardable, extraParams)) return false;
+    std::string appId;
+    if (!generateAppId(auth, stretching, salt, secdiscardable, &appId)) return false;
     std::string kmKey;
-    if (!readFileToString(dir + "/" + kFn_keymaster_key_blob, kmKey)) return false;
+    if (!readFileToString(dir + "/" + kFn_keymaster_key_blob, &kmKey)) return false;
     std::string encryptedMessage;
-    if (!readFileToString(dir + "/" + kFn_encrypted_key, encryptedMessage)) return false;
+    if (!readFileToString(dir + "/" + kFn_encrypted_key, &encryptedMessage)) return false;
     Keymaster keymaster;
     if (!keymaster) return false;
-    return decryptWithKeymasterKey(keymaster, kmKey, extraParams, encryptedMessage, key);
+    return decryptWithKeymasterKey(keymaster, kmKey, auth, appId, encryptedMessage, key);
 }
 
-static bool deleteKey(const std::string &dir) {
+static bool deleteKey(const std::string& dir) {
     std::string kmKey;
-    if (!readFileToString(dir + "/" + kFn_keymaster_key_blob, kmKey)) return false;
+    if (!readFileToString(dir + "/" + kFn_keymaster_key_blob, &kmKey)) return false;
     Keymaster keymaster;
     if (!keymaster) return false;
     if (!keymaster.deleteKey(kmKey)) return false;
     return true;
 }
 
-static bool secdiscardSecdiscardable(const std::string &dir) {
-    if (ForkExecvp(std::vector<std::string> {
-            kSecdiscardPath, "--", dir + "/" + kFn_secdiscardable}) != 0) {
+static bool secdiscardSecdiscardable(const std::string& dir) {
+    if (ForkExecvp(
+            std::vector<std::string>{kSecdiscardPath, "--", dir + "/" + kFn_secdiscardable}) != 0) {
         LOG(ERROR) << "secdiscard failed";
         return false;
     }
     return true;
 }
 
-static bool recursiveDeleteKey(const std::string &dir) {
-    if (ForkExecvp(std::vector<std::string> {
-            kRmPath, "-rf", dir}) != 0) {
+static bool recursiveDeleteKey(const std::string& dir) {
+    if (ForkExecvp(std::vector<std::string>{kRmPath, "-rf", dir}) != 0) {
         LOG(ERROR) << "recursive delete failed";
         return false;
     }
     return true;
 }
 
-bool destroyKey(const std::string &dir) {
+bool destroyKey(const std::string& dir) {
     bool success = true;
     // Try each thing, even if previous things failed.
     success &= deleteKey(dir);
diff --git a/KeyStorage.h b/KeyStorage.h
index 54c3b2c..10ed789 100644
--- a/KeyStorage.h
+++ b/KeyStorage.h
@@ -27,8 +27,8 @@
 // If "secret" is nonempty, it is appended to the application-specific
 // binary needed to unlock.
 class KeyAuthentication {
-public:
-    KeyAuthentication(std::string t, std::string s): token {t}, secret {s} {};
+  public:
+    KeyAuthentication(std::string t, std::string s) : token{t}, secret{s} {};
     const std::string token;
     const std::string secret;
 };
@@ -39,13 +39,13 @@
 // in such a way that it can only be retrieved via Keymaster and
 // can be securely deleted.
 // It's safe to move/rename the directory after creation.
-bool storeKey(const std::string &dir, const KeyAuthentication &auth, const std::string &key);
+bool storeKey(const std::string& dir, const KeyAuthentication& auth, const std::string& key);
 
 // Retrieve the key from the named directory.
-bool retrieveKey(const std::string &dir, const KeyAuthentication &auth, std::string &key);
+bool retrieveKey(const std::string& dir, const KeyAuthentication& auth, std::string* key);
 
 // Securely destroy the key stored in the named directory and delete the directory.
-bool destroyKey(const std::string &dir);
+bool destroyKey(const std::string& dir);
 
 }  // namespace vold
 }  // namespace android
diff --git a/Keymaster.cpp b/Keymaster.cpp
index 0fde8fa..222b930 100644
--- a/Keymaster.cpp
+++ b/Keymaster.cpp
@@ -21,25 +21,23 @@
 namespace android {
 namespace vold {
 
-bool KeymasterOperation::updateCompletely(
-        const std::string &input,
-        std::string &output) {
-    output.clear();
+bool KeymasterOperation::updateCompletely(const std::string& input, std::string* output) {
+    output->clear();
     auto it = input.begin();
     while (it != input.end()) {
         size_t toRead = static_cast<size_t>(input.end() - it);
-        keymaster_blob_t inputBlob {reinterpret_cast<const uint8_t *>(&*it),  toRead};
+        keymaster_blob_t inputBlob{reinterpret_cast<const uint8_t*>(&*it), toRead};
         keymaster_blob_t outputBlob;
         size_t inputConsumed;
-        auto error = mDevice->update(mDevice, mOpHandle,
-            nullptr, &inputBlob, &inputConsumed, nullptr, &outputBlob);
+        auto error = mDevice->update(mDevice, mOpHandle, nullptr, &inputBlob, &inputConsumed,
+                                     nullptr, &outputBlob);
         if (error != KM_ERROR_OK) {
             LOG(ERROR) << "update failed, code " << error;
             mDevice = nullptr;
             return false;
         }
-        output.append(reinterpret_cast<const char *>(outputBlob.data), outputBlob.data_length);
-        free(const_cast<uint8_t *>(outputBlob.data));
+        output->append(reinterpret_cast<const char*>(outputBlob.data), outputBlob.data_length);
+        free(const_cast<uint8_t*>(outputBlob.data));
         if (inputConsumed > toRead) {
             LOG(ERROR) << "update reported too much input consumed";
             mDevice = nullptr;
@@ -51,8 +49,7 @@
 }
 
 bool KeymasterOperation::finish() {
-    auto error = mDevice->finish(mDevice, mOpHandle,
-        nullptr, nullptr, nullptr, nullptr);
+    auto error = mDevice->finish(mDevice, mOpHandle, nullptr, nullptr, nullptr, nullptr);
     mDevice = nullptr;
     if (error != KM_ERROR_OK) {
         LOG(ERROR) << "finish failed, code " << error;
@@ -61,23 +58,22 @@
     return true;
 }
 
-bool KeymasterOperation::finishWithOutput(std::string &output) {
+bool KeymasterOperation::finishWithOutput(std::string* output) {
     keymaster_blob_t outputBlob;
-    auto error = mDevice->finish(mDevice, mOpHandle,
-        nullptr, nullptr, nullptr, &outputBlob);
+    auto error = mDevice->finish(mDevice, mOpHandle, nullptr, nullptr, nullptr, &outputBlob);
     mDevice = nullptr;
     if (error != KM_ERROR_OK) {
         LOG(ERROR) << "finish failed, code " << error;
         return false;
     }
-    output.assign(reinterpret_cast<const char *>(outputBlob.data), outputBlob.data_length);
-    free(const_cast<uint8_t *>(outputBlob.data));
+    output->assign(reinterpret_cast<const char*>(outputBlob.data), outputBlob.data_length);
+    free(const_cast<uint8_t*>(outputBlob.data));
     return true;
 }
 
 Keymaster::Keymaster() {
     mDevice = nullptr;
-    const hw_module_t *module;
+    const hw_module_t* module;
     int ret = hw_get_module_by_class(KEYSTORE_HARDWARE_MODULE_ID, NULL, &module);
     if (ret != 0) {
         LOG(ERROR) << "hw_get_module_by_class returned " << ret;
@@ -96,22 +92,21 @@
     }
 }
 
-bool Keymaster::generateKey(
-        const keymaster::AuthorizationSet &inParams,
-        std::string &key) {
+bool Keymaster::generateKey(const keymaster::AuthorizationSet& inParams, std::string* key) {
     keymaster_key_blob_t keyBlob;
     auto error = mDevice->generate_key(mDevice, &inParams, &keyBlob, nullptr);
     if (error != KM_ERROR_OK) {
         LOG(ERROR) << "generate_key failed, code " << error;
         return false;
     }
-    key.assign(reinterpret_cast<const char *>(keyBlob.key_material), keyBlob.key_material_size);
+    key->assign(reinterpret_cast<const char*>(keyBlob.key_material), keyBlob.key_material_size);
+    free(const_cast<uint8_t*>(keyBlob.key_material));
     return true;
 }
 
-bool Keymaster::deleteKey(const std::string &key) {
+bool Keymaster::deleteKey(const std::string& key) {
     if (mDevice->delete_key == nullptr) return true;
-    keymaster_key_blob_t keyBlob { reinterpret_cast<const uint8_t *>(key.data()), key.size() };
+    keymaster_key_blob_t keyBlob{reinterpret_cast<const uint8_t*>(key.data()), key.size()};
     auto error = mDevice->delete_key(mDevice, &keyBlob);
     if (error != KM_ERROR_OK) {
         LOG(ERROR) << "delete_key failed, code " << error;
@@ -120,34 +115,28 @@
     return true;
 }
 
-KeymasterOperation Keymaster::begin(
-        keymaster_purpose_t purpose,
-        const std::string &key,
-        const keymaster::AuthorizationSet &inParams,
-        keymaster::AuthorizationSet &outParams) {
-    keymaster_key_blob_t keyBlob { reinterpret_cast<const uint8_t *>(key.data()), key.size() };
+KeymasterOperation Keymaster::begin(keymaster_purpose_t purpose, const std::string& key,
+                                    const keymaster::AuthorizationSet& inParams,
+                                    keymaster::AuthorizationSet* outParams) {
+    keymaster_key_blob_t keyBlob{reinterpret_cast<const uint8_t*>(key.data()), key.size()};
     keymaster_operation_handle_t mOpHandle;
     keymaster_key_param_set_t outParams_set;
-    auto error = mDevice->begin(mDevice, purpose,
-        &keyBlob, &inParams, &outParams_set, &mOpHandle);
+    auto error = mDevice->begin(mDevice, purpose, &keyBlob, &inParams, &outParams_set, &mOpHandle);
     if (error != KM_ERROR_OK) {
         LOG(ERROR) << "begin failed, code " << error;
         return KeymasterOperation(nullptr, mOpHandle);
     }
-    outParams.Clear();
-    outParams.push_back(outParams_set);
+    outParams->Clear();
+    outParams->push_back(outParams_set);
     keymaster_free_param_set(&outParams_set);
     return KeymasterOperation(mDevice, mOpHandle);
 }
 
-KeymasterOperation Keymaster::begin(
-        keymaster_purpose_t purpose,
-        const std::string &key,
-        const keymaster::AuthorizationSet &inParams) {
-    keymaster_key_blob_t keyBlob { reinterpret_cast<const uint8_t *>(key.data()), key.size() };
+KeymasterOperation Keymaster::begin(keymaster_purpose_t purpose, const std::string& key,
+                                    const keymaster::AuthorizationSet& inParams) {
+    keymaster_key_blob_t keyBlob{reinterpret_cast<const uint8_t*>(key.data()), key.size()};
     keymaster_operation_handle_t mOpHandle;
-    auto error = mDevice->begin(mDevice, purpose,
-        &keyBlob, &inParams, nullptr, &mOpHandle);
+    auto error = mDevice->begin(mDevice, purpose, &keyBlob, &inParams, nullptr, &mOpHandle);
     if (error != KM_ERROR_OK) {
         LOG(ERROR) << "begin failed, code " << error;
         return KeymasterOperation(nullptr, mOpHandle);
diff --git a/Keymaster.h b/Keymaster.h
index a4deddf..cf692f3 100644
--- a/Keymaster.h
+++ b/Keymaster.h
@@ -38,28 +38,31 @@
 // in the destructor if it is unfinished. Methods log failures
 // to LOG(ERROR).
 class KeymasterOperation {
-public:
-    ~KeymasterOperation() { if (mDevice) mDevice->abort(mDevice, mOpHandle); }
+  public:
+    ~KeymasterOperation() {
+        if (mDevice) mDevice->abort(mDevice, mOpHandle);
+    }
     // Is this instance valid? This is false if creation fails, and becomes
     // false on finish or if an update fails.
-    explicit operator bool() {return mDevice != nullptr;}
+    explicit operator bool() { return mDevice != nullptr; }
     // Call "update" repeatedly until all of the input is consumed, and
     // concatenate the output. Return true on success.
-    bool updateCompletely(const std::string &input, std::string &output);
+    bool updateCompletely(const std::string& input, std::string* output);
     // Finish; pass nullptr for the "output" param.
     bool finish();
     // Finish and write the output to this string.
-    bool finishWithOutput(std::string &output);
+    bool finishWithOutput(std::string* output);
     // Move constructor
     KeymasterOperation(KeymasterOperation&& rhs) {
         mOpHandle = rhs.mOpHandle;
         mDevice = rhs.mDevice;
         rhs.mDevice = nullptr;
     }
-private:
-    KeymasterOperation(keymaster1_device_t *d, keymaster_operation_handle_t h):
-        mDevice {d}, mOpHandle {h} {}
-    keymaster1_device_t *mDevice;
+
+  private:
+    KeymasterOperation(keymaster1_device_t* d, keymaster_operation_handle_t h)
+        : mDevice{d}, mOpHandle{h} {}
+    keymaster1_device_t* mDevice;
     keymaster_operation_handle_t mOpHandle;
     DISALLOW_COPY_AND_ASSIGN(KeymasterOperation);
     friend class Keymaster;
@@ -68,41 +71,40 @@
 // Wrapper for a keymaster1_device_t representing an open connection
 // to the keymaster, which is closed in the destructor.
 class Keymaster {
-public:
+  public:
     Keymaster();
-    ~Keymaster() { if (mDevice) keymaster1_close(mDevice); }
+    ~Keymaster() {
+        if (mDevice) keymaster1_close(mDevice);
+    }
     // false if we failed to open the keymaster device.
-    explicit operator bool() {return mDevice != nullptr;}
+    explicit operator bool() { return mDevice != nullptr; }
     // Generate a key in the keymaster from the given params.
-    bool generateKey(const AuthorizationSet &inParams, std::string &key);
+    bool generateKey(const AuthorizationSet& inParams, std::string* key);
     // If the keymaster supports it, permanently delete a key.
-    bool deleteKey(const std::string &key);
+    bool deleteKey(const std::string& key);
     // Begin a new cryptographic operation, collecting output parameters.
-    KeymasterOperation begin(
-            keymaster_purpose_t purpose,
-            const std::string &key,
-            const AuthorizationSet &inParams,
-            AuthorizationSet &outParams);
+    KeymasterOperation begin(keymaster_purpose_t purpose, const std::string& key,
+                             const AuthorizationSet& inParams, AuthorizationSet* outParams);
     // Begin a new cryptographic operation; don't collect output parameters.
-    KeymasterOperation begin(
-            keymaster_purpose_t purpose,
-            const std::string &key,
-            const AuthorizationSet &inParams);
-private:
-    keymaster1_device_t *mDevice;
+    KeymasterOperation begin(keymaster_purpose_t purpose, const std::string& key,
+                             const AuthorizationSet& inParams);
+
+  private:
+    keymaster1_device_t* mDevice;
     DISALLOW_COPY_AND_ASSIGN(Keymaster);
 };
 
 template <keymaster_tag_t Tag>
-inline AuthorizationSetBuilder& addStringParam(AuthorizationSetBuilder &&params,
-        TypedTag<KM_BYTES, Tag> tag, const std::string& val) {
+inline AuthorizationSetBuilder& addStringParam(AuthorizationSetBuilder&& params,
+                                               TypedTag<KM_BYTES, Tag> tag,
+                                               const std::string& val) {
     return params.Authorization(tag, val.data(), val.size());
 }
 
 template <keymaster_tag_t Tag>
-inline void addStringParam(AuthorizationSetBuilder &params,
-        TypedTag<KM_BYTES, Tag> tag, const std::string& val) {
-    params.Authorization(tag, val.data(), val.size());
+inline void addStringParam(AuthorizationSetBuilder* params, TypedTag<KM_BYTES, Tag> tag,
+                           const std::string& val) {
+    params->Authorization(tag, val.data(), val.size());
 }
 
 }  // namespace vold
diff --git a/cryptfs.c b/cryptfs.c
index b99dd56..fcc9724 100644
--- a/cryptfs.c
+++ b/cryptfs.c
@@ -1154,6 +1154,7 @@
   struct dm_ioctl *io;
   unsigned int minor;
   int fd=0;
+  int err;
   int retval = -1;
   int version[3];
   char *extra_params;
@@ -1167,8 +1168,9 @@
   io = (struct dm_ioctl *) buffer;
 
   ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
-  if (ioctl(fd, DM_DEV_CREATE, io)) {
-    SLOGE("Cannot create dm-crypt device\n");
+  err = ioctl(fd, DM_DEV_CREATE, io);
+  if (err) {
+    SLOGE("Cannot create dm-crypt device %s: %s\n", name, strerror(errno));
     goto errout;
   }