am 4351c9a0: Merge "Don\'t use TEMP_FAILURE_RETRY on close in vold." into mnc-dev

* commit '4351c9a08be1d95607e2e5d431692198d60b7d94':
  Don't use TEMP_FAILURE_RETRY on close in vold.
diff --git a/Android.mk b/Android.mk
index e1b58ec..2435cf0 100644
--- a/Android.mk
+++ b/Android.mk
@@ -13,6 +13,7 @@
 	Devmapper.cpp \
 	ResponseCode.cpp \
 	CheckBattery.cpp \
+	Ext4Crypt.cpp \
 	VoldUtil.c \
 	fstrim.c \
 	cryptfs.c \
@@ -49,7 +50,7 @@
 	libutils \
 	libhardware \
 	libsoftkeymaster \
-	libbase \
+	libbase
 
 common_static_libraries := \
 	libfs_mgr \
@@ -104,7 +105,7 @@
 
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
 LOCAL_CLANG := true
-LOCAL_SRC_FILES:= vdc.c
+LOCAL_SRC_FILES:= vdc.cpp
 LOCAL_MODULE:= vdc
 LOCAL_SHARED_LIBRARIES := libcutils
 LOCAL_CFLAGS := $(vold_cflags)
diff --git a/CommandListener.cpp b/CommandListener.cpp
index 0133e17..9eb9bab 100644
--- a/CommandListener.cpp
+++ b/CommandListener.cpp
@@ -44,6 +44,7 @@
 #include "Process.h"
 #include "Loop.h"
 #include "Devmapper.h"
+#include "Ext4Crypt.h"
 #include "cryptfs.h"
 #include "fstrim.h"
 #include "MoveTask.h"
@@ -650,6 +651,14 @@
                 Process::killProcessesWithOpenFiles(DATA_MNT_POINT, SIGKILL);
             }
         }
+    } else if (!strcmp(argv[1], "enablefilecrypto")) {
+        const char* syntax = "Usage: cryptfs enablefilecrypto";
+        if (argc != 2) {
+            cli->sendMsg(ResponseCode::CommandSyntaxError, syntax, false);
+            return 0;
+        }
+        dumpArgs(argc, argv, -1);
+        rc = cryptfs_enable_file();
     } else if (!strcmp(argv[1], "changepw")) {
         const char* syntax = "Usage: cryptfs changepw "
                              "default|password|pin|pattern [newpasswd]";
@@ -756,6 +765,25 @@
         dumpArgs(argc, argv, -1);
         cryptfs_clear_password();
         rc = 0;
+    } else if (!strcmp(argv[1], "setusercryptopolicies")) {
+        if (argc != 3) {
+            cli->sendMsg(ResponseCode::CommandSyntaxError,
+                "Usage: cryptfs setusercryptopolicies <path>", false);
+            return 0;
+        }
+        SLOGD("cryptfs setusercryptopolicies");
+        dumpArgs(argc, argv, -1);
+        rc = e4crypt_set_user_crypto_policies(argv[2]);
+    } else if (!strcmp(argv[1], "createnewuserdir")) {
+        if (argc != 4) {
+            cli->sendMsg(ResponseCode::CommandSyntaxError,
+                "Usage: cryptfs createnewuserdir <userHandle> <path>", false);
+            return 0;
+        }
+        // ext4enc:TODO: send a CommandSyntaxError if argv[2] not an integer
+        SLOGD("cryptfs createnewuserdir");
+        dumpArgs(argc, argv, -1);
+        rc = e4crypt_create_new_user_dir(argv[2], argv[3]);
     } else {
         dumpArgs(argc, argv, -1);
         cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown cryptfs cmd", false);
diff --git a/Ext4Crypt.cpp b/Ext4Crypt.cpp
new file mode 100644
index 0000000..7470ff9
--- /dev/null
+++ b/Ext4Crypt.cpp
@@ -0,0 +1,614 @@
+#include "Ext4Crypt.h"
+
+#include <iomanip>
+#include <map>
+#include <fstream>
+#include <string>
+#include <sstream>
+
+#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 <openssl/sha.h>
+
+#include "unencrypted_properties.h"
+#include "key_control.h"
+#include "cryptfs.h"
+#include "ext4_crypt_init_extensions.h"
+
+#define LOG_TAG "Ext4Crypt"
+#include "cutils/log.h"
+#include <cutils/klog.h>
+#include <base/file.h>
+#include <base/stringprintf.h>
+
+namespace {
+    // Key length in bits
+    const int key_length = 128;
+    static_assert(key_length % 8 == 0,
+                  "Key length must be multiple of 8 bits");
+
+    // How long do we store passwords for?
+    const int password_max_age_seconds = 60;
+
+    // How is device encrypted
+    struct keys {
+        std::string master_key;
+        std::string password;
+        time_t expiry_time;
+    };
+    std::map<std::string, keys> s_key_store;
+
+    // ext4enc:TODO get these consts from somewhere good
+    const int SHA512_LENGTH = 64;
+    const int EXT4_KEY_DESCRIPTOR_SIZE = 8;
+
+    // ext4enc:TODO Include structure from somewhere sensible
+    // MUST be in sync with ext4_crypto.c in kernel
+    const int EXT4_MAX_KEY_SIZE = 64;
+    const int EXT4_ENCRYPTION_MODE_AES_256_XTS = 1;
+    struct ext4_encryption_key {
+        uint32_t mode;
+        char raw[EXT4_MAX_KEY_SIZE];
+        uint32_t size;
+    };
+
+    namespace tag {
+        const char* magic = "magic";
+        const char* major_version = "major_version";
+        const char* minor_version = "minor_version";
+        const char* flags = "flags";
+        const char* crypt_type = "crypt_type";
+        const char* failed_decrypt_count = "failed_decrypt_count";
+        const char* crypto_type_name = "crypto_type_name";
+        const char* master_key = "master_key";
+        const char* salt = "salt";
+        const char* kdf_type = "kdf_type";
+        const char* N_factor = "N_factor";
+        const char* r_factor = "r_factor";
+        const char* p_factor = "p_factor";
+        const char* keymaster_blob = "keymaster_blob";
+        const char* scrypted_intermediate_key = "scrypted_intermediate_key";
+    }
+}
+
+static std::string e4crypt_install_key(const std::string &key);
+
+static int put_crypt_ftr_and_key(const crypt_mnt_ftr& crypt_ftr,
+                                 UnencryptedProperties& props)
+{
+    SLOGI("Putting crypt footer");
+
+    bool success = props.Set<int>(tag::magic, crypt_ftr.magic)
+      && props.Set<int>(tag::major_version, crypt_ftr.major_version)
+      && props.Set<int>(tag::minor_version, crypt_ftr.minor_version)
+      && props.Set<int>(tag::flags, crypt_ftr.flags)
+      && props.Set<int>(tag::crypt_type, crypt_ftr.crypt_type)
+      && props.Set<int>(tag::failed_decrypt_count,
+                        crypt_ftr.failed_decrypt_count)
+      && props.Set<std::string>(tag::crypto_type_name,
+                                std::string(reinterpret_cast<const char*>(crypt_ftr.crypto_type_name)))
+      && props.Set<std::string>(tag::master_key,
+                                std::string((const char*) crypt_ftr.master_key,
+                                            crypt_ftr.keysize))
+      && props.Set<std::string>(tag::salt,
+                                std::string((const char*) crypt_ftr.salt,
+                                            SALT_LEN))
+      && props.Set<int>(tag::kdf_type, crypt_ftr.kdf_type)
+      && props.Set<int>(tag::N_factor, crypt_ftr.N_factor)
+      && props.Set<int>(tag::r_factor, crypt_ftr.r_factor)
+      && props.Set<int>(tag::p_factor, crypt_ftr.p_factor)
+      && props.Set<std::string>(tag::keymaster_blob,
+                                std::string((const char*) crypt_ftr.keymaster_blob,
+                                            crypt_ftr.keymaster_blob_size))
+      && props.Set<std::string>(tag::scrypted_intermediate_key,
+                                std::string((const char*) crypt_ftr.scrypted_intermediate_key,
+                                            SCRYPT_LEN));
+    return success ? 0 : -1;
+}
+
+static int get_crypt_ftr_and_key(crypt_mnt_ftr& crypt_ftr,
+                                 const UnencryptedProperties& props)
+{
+    memset(&crypt_ftr, 0, sizeof(crypt_ftr));
+    crypt_ftr.magic = props.Get<int>(tag::magic);
+    crypt_ftr.major_version = props.Get<int>(tag::major_version);
+    crypt_ftr.minor_version = props.Get<int>(tag::minor_version);
+    crypt_ftr.ftr_size = sizeof(crypt_ftr);
+    crypt_ftr.flags = props.Get<int>(tag::flags);
+    crypt_ftr.crypt_type = props.Get<int>(tag::crypt_type);
+    crypt_ftr.failed_decrypt_count = props.Get<int>(tag::failed_decrypt_count);
+    std::string crypto_type_name = props.Get<std::string>(tag::crypto_type_name);
+    strlcpy(reinterpret_cast<char*>(crypt_ftr.crypto_type_name),
+            crypto_type_name.c_str(),
+            sizeof(crypt_ftr.crypto_type_name));
+    std::string master_key = props.Get<std::string>(tag::master_key);
+    crypt_ftr.keysize = master_key.size();
+    if (crypt_ftr.keysize > sizeof(crypt_ftr.master_key)) {
+        SLOGE("Master key size too long");
+        return -1;
+    }
+    memcpy(crypt_ftr.master_key, &master_key[0], crypt_ftr.keysize);
+    std::string salt = props.Get<std::string>(tag::salt);
+    if (salt.size() != SALT_LEN) {
+        SLOGE("Salt wrong length");
+        return -1;
+    }
+    memcpy(crypt_ftr.salt, &salt[0], SALT_LEN);
+    crypt_ftr.kdf_type = props.Get<int>(tag::kdf_type);
+    crypt_ftr.N_factor = props.Get<int>(tag::N_factor);
+    crypt_ftr.r_factor = props.Get<int>(tag::r_factor);
+    crypt_ftr.p_factor = props.Get<int>(tag::p_factor);
+    std::string keymaster_blob = props.Get<std::string>(tag::keymaster_blob);
+    crypt_ftr.keymaster_blob_size = keymaster_blob.size();
+    if (crypt_ftr.keymaster_blob_size > sizeof(crypt_ftr.keymaster_blob)) {
+        SLOGE("Keymaster blob too long");
+        return -1;
+    }
+    memcpy(crypt_ftr.keymaster_blob, &keymaster_blob[0],
+           crypt_ftr.keymaster_blob_size);
+    std::string scrypted_intermediate_key = props.Get<std::string>(tag::scrypted_intermediate_key);
+    if (scrypted_intermediate_key.size() != SCRYPT_LEN) {
+        SLOGE("scrypted intermediate key wrong length");
+        return -1;
+    }
+    memcpy(crypt_ftr.scrypted_intermediate_key, &scrypted_intermediate_key[0],
+           SCRYPT_LEN);
+
+    return 0;
+}
+
+static UnencryptedProperties GetProps(const char* path)
+{
+    return UnencryptedProperties(path);
+}
+
+static UnencryptedProperties GetAltProps(const char* path)
+{
+    return UnencryptedProperties((std::string() + path + "/tmp_mnt").c_str());
+}
+
+static UnencryptedProperties GetPropsOrAltProps(const char* path)
+{
+    UnencryptedProperties props = GetProps(path);
+    if (props.OK()) {
+        return props;
+    }
+    return GetAltProps(path);
+}
+
+int e4crypt_enable(const char* path)
+{
+    // Already enabled?
+    if (s_key_store.find(path) != s_key_store.end()) {
+        return 0;
+    }
+
+    // Not an encryptable device?
+    UnencryptedProperties key_props = GetProps(path).GetChild(properties::key);
+    if (!key_props.OK()) {
+        return 0;
+    }
+
+    if (key_props.Get<std::string>(tag::master_key).empty()) {
+        crypt_mnt_ftr ftr;
+        if (cryptfs_create_default_ftr(&ftr, key_length)) {
+            SLOGE("Failed to create crypto footer");
+            return -1;
+        }
+
+        // Scrub fields not used by ext4enc
+        ftr.persist_data_offset[0] = 0;
+        ftr.persist_data_offset[1] = 0;
+        ftr.persist_data_size = 0;
+
+        if (put_crypt_ftr_and_key(ftr, key_props)) {
+            SLOGE("Failed to write crypto footer");
+            return -1;
+        }
+
+        crypt_mnt_ftr ftr2;
+        if (get_crypt_ftr_and_key(ftr2, key_props)) {
+            SLOGE("Failed to read crypto footer back");
+            return -1;
+        }
+
+        if (memcmp(&ftr, &ftr2, sizeof(ftr)) != 0) {
+            SLOGE("Crypto footer not correctly written");
+            return -1;
+        }
+    }
+
+    if (!UnencryptedProperties(path).Remove(properties::ref)) {
+        SLOGE("Failed to remove key ref");
+        return -1;
+    }
+
+    return e4crypt_check_passwd(path, "");
+}
+
+int e4crypt_change_password(const char* path, int crypt_type,
+                            const char* password)
+{
+    SLOGI("e4crypt_change_password");
+    auto key_props = GetProps(path).GetChild(properties::key);
+
+    crypt_mnt_ftr ftr;
+    if (get_crypt_ftr_and_key(ftr, key_props)) {
+        SLOGE("Failed to read crypto footer back");
+        return -1;
+    }
+
+    auto mki = s_key_store.find(path);
+    if (mki == s_key_store.end()) {
+        SLOGE("No stored master key - can't change password");
+        return -1;
+    }
+
+    const unsigned char* master_key_bytes
+        = reinterpret_cast<const unsigned char*>(&mki->second.master_key[0]);
+
+    if (cryptfs_set_password(&ftr, password, master_key_bytes)) {
+        SLOGE("Failed to set password");
+        return -1;
+    }
+
+    ftr.crypt_type = crypt_type;
+
+    if (put_crypt_ftr_and_key(ftr, key_props)) {
+        SLOGE("Failed to write crypto footer");
+        return -1;
+    }
+
+    if (!UnencryptedProperties(path).Set(properties::is_default,
+                            crypt_type == CRYPT_TYPE_DEFAULT)) {
+        SLOGE("Failed to update default flag");
+        return -1;
+    }
+
+    return 0;
+}
+
+int e4crypt_crypto_complete(const char* path)
+{
+    SLOGI("ext4 crypto complete called on %s", path);
+    auto key_props = GetPropsOrAltProps(path).GetChild(properties::key);
+    if (key_props.Get<std::string>(tag::master_key).empty()) {
+        SLOGI("No master key, so not ext4enc");
+        return -1;
+    }
+
+    return 0;
+}
+
+static std::string generate_key_ref(const char* key, int length)
+{
+    SHA512_CTX c;
+
+    SHA512_Init(&c);
+    SHA512_Update(&c, key, length);
+    unsigned char key_ref1[SHA512_LENGTH];
+    SHA512_Final(key_ref1, &c);
+
+    SHA512_Init(&c);
+    SHA512_Update(&c, key_ref1, SHA512_LENGTH);
+    unsigned char key_ref2[SHA512_LENGTH];
+    SHA512_Final(key_ref2, &c);
+
+    return std::string((char*)key_ref2, EXT4_KEY_DESCRIPTOR_SIZE);
+}
+
+int e4crypt_check_passwd(const char* path, const char* password)
+{
+    SLOGI("e4crypt_check_password");
+    auto props = GetPropsOrAltProps(path);
+    auto key_props = props.GetChild(properties::key);
+
+    crypt_mnt_ftr ftr;
+    if (get_crypt_ftr_and_key(ftr, key_props)) {
+        SLOGE("Failed to read crypto footer back");
+        return -1;
+    }
+
+    unsigned char master_key_bytes[key_length / 8];
+    if (cryptfs_get_master_key (&ftr, password, master_key_bytes)){
+        SLOGI("Incorrect password");
+        ftr.failed_decrypt_count++;
+        if (put_crypt_ftr_and_key(ftr, key_props)) {
+            SLOGW("Failed to update failed_decrypt_count");
+        }
+        return ftr.failed_decrypt_count;
+    }
+
+    if (ftr.failed_decrypt_count) {
+        ftr.failed_decrypt_count = 0;
+        if (put_crypt_ftr_and_key(ftr, key_props)) {
+            SLOGW("Failed to reset failed_decrypt_count");
+        }
+    }
+    std::string master_key(reinterpret_cast<char*>(master_key_bytes),
+                           sizeof(master_key_bytes));
+
+    struct timespec now;
+    clock_gettime(CLOCK_BOOTTIME, &now);
+    s_key_store[path] = keys{master_key, password,
+                             now.tv_sec + password_max_age_seconds};
+    auto raw_ref = e4crypt_install_key(master_key);
+    if (raw_ref.empty()) {
+        return -1;
+    }
+
+    // Save reference to key so we can set policy later
+    if (!props.Set(properties::ref, raw_ref)) {
+        SLOGE("Cannot save key reference");
+        return -1;
+    }
+
+    return 0;
+}
+
+// Install password into global keyring
+// Return raw key reference for use in policy
+static std::string e4crypt_install_key(const std::string &key)
+{
+    // ext4enc:TODO Currently raw key is required to be of length
+    // sizeof(ext4_key.raw) == EXT4_MAX_KEY_SIZE, so zero pad to
+    // this length. Change when kernel bug is fixed.
+    ext4_encryption_key ext4_key = {EXT4_ENCRYPTION_MODE_AES_256_XTS,
+                                    {0},
+                                    sizeof(ext4_key.raw)};
+    memset(ext4_key.raw, 0, sizeof(ext4_key.raw));
+    static_assert(key_length / 8 <= sizeof(ext4_key.raw),
+                  "Key too long!");
+    memcpy(ext4_key.raw, &key[0], key.size());
+
+    // Get raw keyref - used to make keyname and to pass to ioctl
+    auto raw_ref = generate_key_ref(ext4_key.raw, ext4_key.size);
+
+    // Generate keyname
+    std::ostringstream o;
+    for (auto i = raw_ref.begin(); i != raw_ref.end(); ++i) {
+        o << std::hex << std::setw(2) << std::setfill('0') << (int)*i;
+    }
+    auto ref = std::string("ext4:") + o.str();
+
+    // Find existing keyring
+    key_serial_t device_keyring = keyctl_search(KEY_SPEC_SESSION_KEYRING,
+                                                "keyring", "e4crypt", 0);
+
+    SLOGI("Found device_keyring - id is %d", device_keyring);
+
+    // Add key ...
+    key_serial_t key_id = add_key("logon", ref.c_str(),
+                                  (void*)&ext4_key, sizeof(ext4_key),
+                                  device_keyring);
+
+    if (key_id == -1) {
+        SLOGE("Failed to insert key into keyring with error %s",
+              strerror(errno));
+        return "";
+    }
+
+    SLOGI("Added key %d (%s) to keyring %d in process %d",
+          key_id, ref.c_str(), device_keyring, getpid());
+
+    return raw_ref;
+}
+
+int e4crypt_restart(const char* path)
+{
+    SLOGI("e4crypt_restart");
+
+    int rc = 0;
+
+    SLOGI("ext4 restart called on %s", path);
+    property_set("vold.decrypt", "trigger_reset_main");
+    SLOGI("Just asked init to shut down class main");
+    sleep(2);
+
+    std::string tmp_path = std::string() + path + "/tmp_mnt";
+
+    rc = wait_and_unmount(tmp_path.c_str(), true);
+    if (rc) {
+        SLOGE("umount %s failed with rc %d, msg %s",
+              tmp_path.c_str(), rc, strerror(errno));
+        return rc;
+    }
+
+    rc = wait_and_unmount(path, true);
+    if (rc) {
+        SLOGE("umount %s failed with rc %d, msg %s",
+              path, rc, strerror(errno));
+        return rc;
+    }
+
+    return 0;
+}
+
+int e4crypt_get_password_type(const char* path)
+{
+    SLOGI("e4crypt_get_password_type");
+    return GetPropsOrAltProps(path).GetChild(properties::key)
+      .Get<int>(tag::crypt_type, CRYPT_TYPE_DEFAULT);
+}
+
+const char* e4crypt_get_password(const char* path)
+{
+    SLOGI("e4crypt_get_password");
+
+    auto i = s_key_store.find(path);
+    if (i == s_key_store.end()) {
+        return 0;
+    }
+
+    struct timespec now;
+    clock_gettime(CLOCK_BOOTTIME, &now);
+    if (i->second.expiry_time < now.tv_sec) {
+        e4crypt_clear_password(path);
+        return 0;
+    }
+
+    return i->second.password.c_str();
+}
+
+void e4crypt_clear_password(const char* path)
+{
+    SLOGI("e4crypt_clear_password");
+
+    auto i = s_key_store.find(path);
+    if (i == s_key_store.end()) {
+        return;
+    }
+
+    memset(&i->second.password[0], 0, i->second.password.size());
+    i->second.password = std::string();
+}
+
+int e4crypt_get_field(const char* path, const char* fieldname,
+                      char* value, size_t len)
+{
+    auto v = GetPropsOrAltProps(path).GetChild(properties::props)
+      .Get<std::string>(fieldname);
+
+    if (v == "") {
+        return CRYPTO_GETFIELD_ERROR_NO_FIELD;
+    }
+
+    if (v.length() >= len) {
+        return CRYPTO_GETFIELD_ERROR_BUF_TOO_SMALL;
+    }
+
+    strlcpy(value, v.c_str(), len);
+    return 0;
+}
+
+int e4crypt_set_field(const char* path, const char* fieldname,
+                      const char* value)
+{
+    return GetPropsOrAltProps(path).GetChild(properties::props)
+        .Set(fieldname, std::string(value)) ? 0 : -1;
+}
+
+// ext4enc:TODO this can't be the only place keys are read from /dev/urandom
+// we should unite those places.
+static std::string e4crypt_get_user_key(
+    const char *mount_path,
+    const char *user_handle,
+    bool create_if_absent)
+{
+    // ext4enc:TODO get the path properly
+    auto key_dir = android::base::StringPrintf("%s/misc/vold/user_keys",
+        mount_path);
+    if (mkdir(key_dir.c_str(), 0700) < 0 && errno != EEXIST) {
+        SLOGE("Unable to create %s (%s)", key_dir.c_str(), strerror(errno));
+        return "";
+    }
+    auto key_path = key_dir + "/" + user_handle;
+    std::string content;
+    if (android::base::ReadFileToString(key_path, &content)) {
+        if (content.size() != key_length/8) {
+            SLOGE("Wrong size key %zu in  %s", content.size(), key_path.c_str());
+            return "";
+        }
+        return content;
+    }
+    if (!create_if_absent) {
+        SLOGE("No key found in %s", key_path.c_str());
+        return "";
+    }
+    std::ifstream urandom("/dev/urandom");
+    if (!urandom) {
+        SLOGE("Unable to open /dev/urandom (%s)", strerror(errno));
+        return "";
+    }
+    char key_bytes[key_length / 8];
+    errno = 0;
+    urandom.read(key_bytes, sizeof(key_bytes));
+    if (!urandom) {
+        SLOGE("Unable to read key from /dev/urandom (%s)", strerror(errno));
+        return "";
+    }
+    std::string user_key(key_bytes, sizeof(key_bytes));
+    if (!android::base::WriteStringToFile(user_key, key_path)) {
+        SLOGE("Unable to write key to %s (%s)",
+                key_path.c_str(), strerror(errno));
+        return "";
+    }
+    return user_key;
+}
+
+static int e4crypt_set_user_policy(const char *mount_path, const char *user_handle,
+                            const char *path, bool create_if_absent)
+{
+    SLOGD("e4crypt_set_user_policy for %s", user_handle);
+    auto user_key = e4crypt_get_user_key(mount_path, user_handle,
+        create_if_absent);
+    if (user_key.empty()) {
+        return -1;
+    }
+    auto raw_ref = e4crypt_install_key(user_key);
+    if (raw_ref.empty()) {
+        return -1;
+    }
+    return do_policy_set(path, raw_ref.c_str(), raw_ref.size());
+}
+
+int e4crypt_create_new_user_dir(const char *user_handle, const char *path) {
+    SLOGD("e4crypt_create_new_user_dir(\"%s\", \"%s\")", user_handle, path);
+    if (mkdir(path, S_IRWXU | S_IRWXG | S_IXOTH) < 0) {
+        return -1;
+    }
+    if (chmod(path, S_IRWXU | S_IRWXG | S_IXOTH) < 0) {
+        return -1;
+    }
+    if (e4crypt_crypto_complete(DATA_MNT_POINT) == 0) {
+        // ext4enc:TODO handle errors from this.
+        e4crypt_set_user_policy(DATA_MNT_POINT, user_handle, path, true);
+    }
+    return 0;
+}
+
+static bool is_numeric(const char *name) {
+    for (const char *p = name; *p != '\0'; p++) {
+        if (!isdigit(*p))
+            return false;
+    }
+    return true;
+}
+
+int e4crypt_set_user_crypto_policies(const char *dir)
+{
+    if (e4crypt_crypto_complete(DATA_MNT_POINT) != 0) {
+        return 0;
+    }
+    SLOGD("e4crypt_set_user_crypto_policies");
+    std::unique_ptr<DIR, int(*)(DIR*)> dirp(opendir(dir), closedir);
+    if (!dirp) {
+        SLOGE("Unable to read directory %s, error %s\n",
+            dir, strerror(errno));
+        return -1;
+    }
+    for (;;) {
+        struct dirent *result = readdir(dirp.get());
+        if (!result) {
+            // ext4enc:TODO check errno
+            break;
+        }
+        if (result->d_type != DT_DIR || !is_numeric(result->d_name)) {
+            continue; // skips user 0, which is a symlink
+        }
+        auto user_dir = std::string() + dir + "/" + result->d_name;
+        // ext4enc:TODO don't hardcode /data
+        if (e4crypt_set_user_policy("/data", result->d_name,
+                user_dir.c_str(), false)) {
+            // ext4enc:TODO If this function fails, stop the boot: we must
+            // deliver on promised encryption.
+            SLOGE("Unable to set policy on %s\n", user_dir.c_str());
+        }
+    }
+    return 0;
+}
diff --git a/Ext4Crypt.h b/Ext4Crypt.h
new file mode 100644
index 0000000..c502b62
--- /dev/null
+++ b/Ext4Crypt.h
@@ -0,0 +1,24 @@
+#include <stddef.h>
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+// General functions
+int e4crypt_enable(const char* path);
+int e4crypt_main(int argc, char* argv[]);
+int e4crypt_change_password(const char* path, int crypt_type,
+                            const char* password);
+int e4crypt_crypto_complete(const char* path);
+int e4crypt_check_passwd(const char* path, const char* password);
+int e4crypt_get_password_type(const char* path);
+const char* e4crypt_get_password(const char* path);
+void e4crypt_clear_password(const char* path);
+int e4crypt_restart(const char* path);
+int e4crypt_get_field(const char* path, const char* fieldname,
+                      char* value, size_t len);
+int e4crypt_set_field(const char* path, const char* fieldname,
+                      const char* value);
+int e4crypt_set_user_crypto_policies(const char *path);
+int e4crypt_create_new_user_dir(const char *user_handle, const char *path);
+
+__END_DECLS
diff --git a/cryptfs.c b/cryptfs.c
index f6bad74..154feee 100644
--- a/cryptfs.c
+++ b/cryptfs.c
@@ -53,7 +53,8 @@
 #include "VolumeManager.h"
 #include "VoldUtil.h"
 #include "crypto_scrypt.h"
-#include "ext4_crypt.h"
+#include "Ext4Crypt.h"
+#include "ext4_crypt_init_extensions.h"
 #include "ext4_utils.h"
 #include "f2fs_sparseblock.h"
 #include "CheckBattery.h"
@@ -1292,7 +1293,7 @@
 
     /* Encrypt the master key */
     if (! EVP_EncryptUpdate(&e_ctx, encrypted_master_key, &encrypted_len,
-                              decrypted_master_key, KEY_LEN_BYTES)) {
+                            decrypted_master_key, KEY_LEN_BYTES)) {
         SLOGE("EVP_EncryptUpdate failed\n");
         return -1;
     }
@@ -1327,7 +1328,7 @@
     return 0;
 }
 
-static int decrypt_master_key_aux(char *passwd, unsigned char *salt,
+static int decrypt_master_key_aux(const char *passwd, unsigned char *salt,
                                   unsigned char *encrypted_master_key,
                                   unsigned char *decrypted_master_key,
                                   kdf_func kdf, void *kdf_params,
@@ -1390,7 +1391,7 @@
     }
 }
 
-static int decrypt_master_key(char *passwd, unsigned char *decrypted_master_key,
+static int decrypt_master_key(const char *passwd, unsigned char *decrypted_master_key,
                               struct crypt_mnt_ftr *crypt_ftr,
                               unsigned char** intermediate_key,
                               size_t* intermediate_key_size)
@@ -1425,7 +1426,7 @@
     return encrypt_master_key(passwd, salt, key_buf, master_key, crypt_ftr);
 }
 
-static int wait_and_unmount(char *mountpoint, bool kill)
+int wait_and_unmount(const char *mountpoint, bool kill)
 {
     int i, err, rc;
 #define WAIT_UNMOUNT_COUNT 20
@@ -3490,6 +3491,10 @@
 /* Return the value of the specified field. */
 int cryptfs_getfield(const char *fieldname, char *value, int len)
 {
+    if (e4crypt_crypto_complete(DATA_MNT_POINT) == 0) {
+        return e4crypt_get_field(DATA_MNT_POINT, fieldname, value, len);
+    }
+
     char temp_value[PROPERTY_VALUE_MAX];
     /* CRYPTO_GETFIELD_OK is success,
      * CRYPTO_GETFIELD_ERROR_NO_FIELD is value not set,
@@ -3551,6 +3556,10 @@
 /* Set the value of the specified field. */
 int cryptfs_setfield(const char *fieldname, const char *value)
 {
+    if (e4crypt_crypto_complete(DATA_MNT_POINT) == 0) {
+        return e4crypt_set_field(DATA_MNT_POINT, fieldname, value);
+    }
+
     char encrypted_state[PROPERTY_VALUE_MAX];
     /* 0 is success, negative values are error */
     int rc = CRYPTO_SETFIELD_ERROR_OTHER;
@@ -3709,6 +3718,10 @@
 
 void cryptfs_clear_password()
 {
+    if (e4crypt_crypto_complete(DATA_MNT_POINT) == 0) {
+        e4crypt_clear_password(DATA_MNT_POINT);
+    }
+
     if (password) {
         size_t len = strlen(password);
         memset(password, 0, len);
@@ -3717,3 +3730,69 @@
         password_expiry_time = 0;
     }
 }
+
+int cryptfs_enable_file()
+{
+    return e4crypt_enable(DATA_MNT_POINT);
+}
+
+int cryptfs_create_default_ftr(struct crypt_mnt_ftr* crypt_ftr, __attribute__((unused))int key_length)
+{
+    if (cryptfs_init_crypt_mnt_ftr(crypt_ftr)) {
+        SLOGE("Failed to initialize crypt_ftr");
+        return -1;
+    }
+
+    if (create_encrypted_random_key(DEFAULT_PASSWORD, crypt_ftr->master_key,
+                                    crypt_ftr->salt, crypt_ftr)) {
+        SLOGE("Cannot create encrypted master key\n");
+        return -1;
+    }
+
+    //crypt_ftr->keysize = key_length / 8;
+    return 0;
+}
+
+int cryptfs_get_master_key(struct crypt_mnt_ftr* ftr, const char* password,
+                           unsigned char* master_key)
+{
+    int rc;
+
+    unsigned char* intermediate_key = 0;
+    size_t intermediate_key_size = 0;
+
+    if (password == 0 || *password == 0) {
+        password = DEFAULT_PASSWORD;
+    }
+
+    rc = decrypt_master_key(password, master_key, ftr, &intermediate_key,
+                            &intermediate_key_size);
+
+    int N = 1 << ftr->N_factor;
+    int r = 1 << ftr->r_factor;
+    int p = 1 << ftr->p_factor;
+
+    unsigned char scrypted_intermediate_key[sizeof(ftr->scrypted_intermediate_key)];
+
+    rc = crypto_scrypt(intermediate_key, intermediate_key_size,
+                       ftr->salt, sizeof(ftr->salt), N, r, p,
+                       scrypted_intermediate_key,
+                       sizeof(scrypted_intermediate_key));
+
+    free(intermediate_key);
+
+    if (rc) {
+        SLOGE("Can't calculate intermediate key");
+        return rc;
+    }
+
+    return memcmp(scrypted_intermediate_key, ftr->scrypted_intermediate_key,
+                  intermediate_key_size);
+}
+
+int cryptfs_set_password(struct crypt_mnt_ftr* ftr, const char* password,
+                         const unsigned char* master_key)
+{
+    return encrypt_master_key(password, ftr->salt, master_key, ftr->master_key,
+                              ftr);
+}
diff --git a/cryptfs.h b/cryptfs.h
index 6984944..94684e2 100644
--- a/cryptfs.h
+++ b/cryptfs.h
@@ -26,6 +26,7 @@
  * partition.
  */
 
+#include <stdbool.h>
 #include <cutils/properties.h>
 
 /* The current cryptfs version */
@@ -208,6 +209,8 @@
 extern "C" {
 #endif
 
+  int wait_and_unmount(const char *mountpoint, bool kill);
+
   typedef int (*kdf_func)(const char *passwd, const unsigned char *salt,
                           unsigned char *ikey, void *params);
 
@@ -221,12 +224,20 @@
   int cryptfs_setup_ext_volume(const char* label, const char* real_blkdev,
           const unsigned char* key, int keysize, char* out_crypto_blkdev);
   int cryptfs_revert_ext_volume(const char* label);
+  int cryptfs_enable_file();
   int cryptfs_getfield(const char *fieldname, char *value, int len);
   int cryptfs_setfield(const char *fieldname, const char *value);
   int cryptfs_mount_default_encrypted(void);
   int cryptfs_get_password_type(void);
   const char* cryptfs_get_password(void);
   void cryptfs_clear_password(void);
+
+  // Functions for file encryption to use to inherit our encryption logic
+  int cryptfs_create_default_ftr(struct crypt_mnt_ftr* ftr, int key_length);
+  int cryptfs_get_master_key(struct crypt_mnt_ftr* ftr, const char* password,
+                             unsigned char* master_key);
+  int cryptfs_set_password(struct crypt_mnt_ftr* ftr, const char* password,
+                           const unsigned char* master_key);
 #ifdef __cplusplus
 }
 #endif
diff --git a/vdc.c b/vdc.cpp
similarity index 98%
rename from vdc.c
rename to vdc.cpp
index 6927e92..3e80940 100644
--- a/vdc.c
+++ b/vdc.cpp
@@ -100,7 +100,7 @@
 }
 
 static int do_monitor(int sock, int stop_after_cmd) {
-    char *buffer = malloc(4096);
+    char *buffer = (char *) malloc(4096);
 
     if (!stop_after_cmd)
         printf("[Connected to Vold]\n");