#include <android-base/logging.h>
#include <android-base/stringprintf.h>
-// TODO - remove when switch to using keymaster keys for device data
-static int e4crypt_check_passwd(const char* path, const char* password);
-
using android::base::StringPrintf;
static bool e4crypt_is_native() {
// 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;
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 bool install_key(const std::string &key, std::string &raw_ref);
-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);
}
-int e4crypt_enable(const char* path)
-{
- // Already enabled?
- if (s_enabled) {
- 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_crypto_complete(const char* path)
{
SLOGI("ext4 crypto complete called on %s", path);
- auto key_props = GetProps(path).GetChild(properties::key);
- if (key_props.Get<std::string>(tag::master_key).empty()) {
- SLOGI("No master key, so not ext4enc");
+ if (GetProps(path).Get<std::string>(properties::ref).empty()) {
+ SLOGI("No key reference, so not ext4enc");
return -1;
}
return std::string((char*)key_ref2, EXT4_KEY_DESCRIPTOR_SIZE);
}
-static int e4crypt_check_passwd(const char* path, const char* password)
-{
- SLOGI("e4crypt_check_password");
- auto props = GetProps(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));
-
- std::string raw_ref;
- if (!install_key(master_key, raw_ref)) {
- return -1;
- }
- SLOGD("Installed master key");
-
- // Save reference to key so we can set policy later
- if (!props.Set(properties::ref, raw_ref)) {
- SLOGE("Cannot save key reference");
- return -1;
- }
-
- s_enabled = true;
- return 0;
-}
-
static ext4_encryption_key fill_key(const std::string &key)
{
// ext4enc:TODO Currently raw key is required to be of length
return true;
}
+int e4crypt_enable(const char* path)
+{
+ LOG(INFO) << "e4crypt_enable";
+
+ if (s_enabled) {
+ LOG(INFO) << "Already enabled";
+ return 0;
+ }
+
+ std::string device_key;
+ std::string device_key_path = std::string(path) + "/unencrypted/device_key";
+ if (!android::vold::retrieveKey(device_key_path, device_key)) {
+ LOG(INFO) << "Creating new key";
+ if (!random_key(device_key)) {
+ return -1;
+ }
+
+ if (!android::vold::storeKey(device_key_path, device_key)) {
+ return -1;
+ }
+ }
+
+ std::string device_key_ref;
+ if (!install_key(device_key, device_key_ref)) {
+ LOG(ERROR) << "Failed to install device key";
+ return -1;
+ }
+
+ UnencryptedProperties props(path);
+ if (!props.Remove(properties::ref)) {
+ SLOGE("Failed to remove key ref");
+ return -1;
+ }
+
+ if (!props.Set(properties::ref, device_key_ref)) {
+ SLOGE("Cannot save key reference");
+ return -1;
+ }
+
+ s_enabled = true;
+ return 0;
+}
+
int e4crypt_init_user0() {
LOG(DEBUG) << "e4crypt_init_user0";
if (e4crypt_is_native()) {
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