return 0;
}
+// Get raw keyref - used to make keyname and to pass to ioctl
static std::string generate_key_ref(const char* key, int length)
{
SHA512_CTX c;
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)
+static ext4_encryption_key fill_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
static_assert(key_length / 8 <= sizeof(ext4_key.raw),
"Key too long!");
memcpy(ext4_key.raw, &key[0], key.size());
+ return ext4_key;
+}
- // 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
+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;
}
- auto ref = std::string("ext4:") + o.str();
+ return o.str();
+}
- // Find existing keyring
- key_serial_t device_keyring = keyctl_search(KEY_SPEC_SESSION_KEYRING,
- "keyring", "e4crypt", 0);
+// 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 int e4crypt_install_key(const ext4_encryption_key &ext4_key, const std::string &ref)
+{
+ key_serial_t device_keyring = e4crypt_keyring();
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 "";
+ return -1;
}
-
SLOGI("Added key %d (%s) to keyring %d in process %d",
key_id, ref.c_str(), device_keyring, getpid());
+ 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)
+{
+ auto ext4_key = fill_key(key);
+ auto raw_ref = generate_key_ref(ext4_key.raw, ext4_key.size);
+ auto ref = keyname(raw_ref);
+ if (e4crypt_install_key(ext4_key, ref) == -1) {
+ return "";
+ }
return raw_ref;
}
// 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,
+static std::string e4crypt_get_key(
+ const std::string &key_path,
bool create_if_absent)
{
- auto key_path = get_key_path(mount_path, user_handle);
std::string content;
if (android::base::ReadFileToString(key_path, &content)) {
if (content.size() != key_length/8) {
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)) {
+ std::string key(key_bytes, sizeof(key_bytes));
+ if (!android::base::WriteStringToFile(key, key_path)) {
SLOGE("Unable to write key to %s (%s)",
key_path.c_str(), strerror(errno));
return "";
}
- return user_key;
+ return 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,
+ auto user_key = e4crypt_get_key(
+ get_key_path(mount_path, user_handle),
create_if_absent);
if (user_key.empty()) {
return -1;
int e4crypt_delete_user_key(const char *user_handle) {
SLOGD("e4crypt_delete_user_key(\"%s\")", user_handle);
auto key_path = get_key_path(DATA_MNT_POINT, user_handle);
- // ext4enc:TODO evict the key from the keyring.
+ auto key = e4crypt_get_key(key_path, false);
+ auto ext4_key = fill_key(key);
+ auto ref = keyname(generate_key_ref(ext4_key.raw, ext4_key.size));
+ auto key_serial = keyctl_search(e4crypt_keyring(), "logon", ref.c_str(), 0);
+ if (keyctl_revoke(key_serial) == 0) {
+ SLOGD("Revoked key with serial %ld ref %s\n", key_serial, ref.c_str());
+ } else {
+ SLOGE("Failed to revoke key with serial %ld ref %s: %s\n",
+ key_serial, ref.c_str(), strerror(errno));
+ }
int pid = fork();
if (pid < 0) {
SLOGE("Unable to fork: %s", strerror(errno));