am b7f0702e: (-s ours) DO NOT MERGE Use default key permissions for ext4enc
* commit 'b7f0702ea6cc32c58540d596016c2dabd8ba3541':
DO NOT MERGE Use default key permissions for ext4enc
DO NOT MERGE Simplify password checking logic
diff --git a/Android.mk b/Android.mk
index a1d5aa0..2435cf0 100644
--- a/Android.mk
+++ b/Android.mk
@@ -50,7 +50,7 @@
libutils \
libhardware \
libsoftkeymaster \
- libbase \
+ libbase
common_static_libraries := \
libfs_mgr \
@@ -105,7 +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 267b482..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"
@@ -764,6 +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
index 9c79098..7470ff9 100644
--- a/Ext4Crypt.cpp
+++ b/Ext4Crypt.cpp
@@ -7,17 +7,24 @@
#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
@@ -25,10 +32,14 @@
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;
@@ -65,6 +76,8 @@
}
}
+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)
{
@@ -105,6 +118,7 @@
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);
@@ -187,6 +201,11 @@
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;
@@ -200,8 +219,7 @@
if (memcmp(&ftr, &ftr2, sizeof(ftr)) != 0) {
SLOGE("Crypto footer not correctly written");
- // ex4enc:TODO why is this failing?
- //return -1;
+ return -1;
}
}
@@ -231,10 +249,10 @@
return -1;
}
- const unsigned char* master_key
+ const unsigned char* master_key_bytes
= reinterpret_cast<const unsigned char*>(&mki->second.master_key[0]);
- if (cryptfs_set_password(&ftr, password, master_key)) {
+ if (cryptfs_set_password(&ftr, password, master_key_bytes)) {
SLOGE("Failed to set password");
return -1;
}
@@ -296,8 +314,8 @@
return -1;
}
- unsigned char master_key[key_length / 8];
- if (cryptfs_get_master_key (&ftr, password, master_key)){
+ 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)) {
@@ -312,12 +330,31 @@
SLOGW("Failed to reset failed_decrypt_count");
}
}
+ std::string master_key(reinterpret_cast<char*>(master_key_bytes),
+ sizeof(master_key_bytes));
- s_key_store[path] = keys{std::string(reinterpret_cast<char*>(master_key),
- sizeof(master_key)),
- password};
+ 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;
+ }
- // Install password into global keyring
+ // 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.
@@ -327,7 +364,7 @@
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, master_key, key_length / 8);
+ 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);
@@ -353,19 +390,13 @@
if (key_id == -1) {
SLOGE("Failed to insert key into keyring with error %s",
strerror(errno));
- return -1;
+ return "";
}
SLOGI("Added key %d (%s) to keyring %d in process %d",
key_id, ref.c_str(), device_keyring, getpid());
- // 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;
+ return raw_ref;
}
int e4crypt_restart(const char* path)
@@ -381,16 +412,14 @@
std::string tmp_path = std::string() + path + "/tmp_mnt";
- // ext4enc:TODO add retry logic
- rc = umount(tmp_path.c_str());
+ 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;
}
- // ext4enc:TODO add retry logic
- rc = umount(path);
+ rc = wait_and_unmount(path, true);
if (rc) {
SLOGE("umount %s failed with rc %d, msg %s",
path, rc, strerror(errno));
@@ -400,19 +429,6 @@
return 0;
}
-const char* e4crypt_get_password(const char* path)
-{
- SLOGI("e4crypt_get_password");
-
- // ext4enc:TODO scrub password after timeout
- auto i = s_key_store.find(path);
- if (i == s_key_store.end()) {
- return 0;
- } else {
- return i->second.password.c_str();
- }
-}
-
int e4crypt_get_password_type(const char* path)
{
SLOGI("e4crypt_get_password_type");
@@ -420,6 +436,38 @@
.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)
{
@@ -444,3 +492,123 @@
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
index 68e0fb2..c502b62 100644
--- a/Ext4Crypt.h
+++ b/Ext4Crypt.h
@@ -12,10 +12,13 @@
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 47b19a6..154feee 100644
--- a/cryptfs.c
+++ b/cryptfs.c
@@ -1426,7 +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
@@ -3718,6 +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);
diff --git a/cryptfs.h b/cryptfs.h
index fa3d351..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);
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");