2916 lines
97 KiB
C++
2916 lines
97 KiB
C++
/*
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* Copyright (C) 2010 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/* TO DO:
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* 1. Perhaps keep several copies of the encrypted key, in case something
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* goes horribly wrong?
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*
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*/
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#define LOG_TAG "Cryptfs"
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#include "cryptfs.h"
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#include "Checkpoint.h"
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#include "EncryptInplace.h"
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#include "FsCrypt.h"
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#include "Keymaster.h"
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#include "Process.h"
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#include "ScryptParameters.h"
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#include "Utils.h"
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#include "VoldUtil.h"
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#include "VolumeManager.h"
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#include <android-base/parseint.h>
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#include <android-base/properties.h>
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#include <android-base/stringprintf.h>
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#include <bootloader_message/bootloader_message.h>
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#include <cutils/android_reboot.h>
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#include <cutils/properties.h>
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#include <ext4_utils/ext4_utils.h>
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#include <f2fs_sparseblock.h>
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#include <fs_mgr.h>
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#include <fscrypt/fscrypt.h>
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#include <hardware_legacy/power.h>
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#include <log/log.h>
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#include <logwrap/logwrap.h>
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#include <openssl/evp.h>
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#include <openssl/sha.h>
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#include <selinux/selinux.h>
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#include <ctype.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <inttypes.h>
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#include <libgen.h>
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#include <linux/dm-ioctl.h>
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#include <linux/kdev_t.h>
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#include <math.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/ioctl.h>
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#include <sys/mount.h>
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#include <sys/param.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <time.h>
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#include <unistd.h>
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extern "C" {
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#include <crypto_scrypt.h>
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}
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using android::base::ParseUint;
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using android::base::StringPrintf;
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using android::fs_mgr::GetEntryForMountPoint;
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using namespace std::chrono_literals;
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#define UNUSED __attribute__((unused))
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#define DM_CRYPT_BUF_SIZE 4096
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#define HASH_COUNT 2000
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constexpr size_t INTERMEDIATE_KEY_LEN_BYTES = 16;
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constexpr size_t INTERMEDIATE_IV_LEN_BYTES = 16;
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constexpr size_t INTERMEDIATE_BUF_SIZE = (INTERMEDIATE_KEY_LEN_BYTES + INTERMEDIATE_IV_LEN_BYTES);
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// SCRYPT_LEN is used by struct crypt_mnt_ftr for its intermediate key.
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static_assert(INTERMEDIATE_BUF_SIZE == SCRYPT_LEN, "Mismatch of intermediate key sizes");
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#define KEY_IN_FOOTER "footer"
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#define DEFAULT_PASSWORD "default_password"
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#define CRYPTO_BLOCK_DEVICE "userdata"
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#define BREADCRUMB_FILE "/data/misc/vold/convert_fde"
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#define EXT4_FS 1
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#define F2FS_FS 2
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#define TABLE_LOAD_RETRIES 10
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#define RSA_KEY_SIZE 2048
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#define RSA_KEY_SIZE_BYTES (RSA_KEY_SIZE / 8)
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#define RSA_EXPONENT 0x10001
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#define KEYMASTER_CRYPTFS_RATE_LIMIT 1 // Maximum one try per second
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#define RETRY_MOUNT_ATTEMPTS 10
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#define RETRY_MOUNT_DELAY_SECONDS 1
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#define CREATE_CRYPTO_BLK_DEV_FLAGS_ALLOW_ENCRYPT_OVERRIDE (1)
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static int put_crypt_ftr_and_key(struct crypt_mnt_ftr* crypt_ftr);
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static unsigned char saved_master_key[MAX_KEY_LEN];
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static char* saved_mount_point;
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static int master_key_saved = 0;
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static struct crypt_persist_data* persist_data = NULL;
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/* Should we use keymaster? */
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static int keymaster_check_compatibility() {
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return keymaster_compatibility_cryptfs_scrypt();
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}
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/* Create a new keymaster key and store it in this footer */
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static int keymaster_create_key(struct crypt_mnt_ftr* ftr) {
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if (ftr->keymaster_blob_size) {
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SLOGI("Already have key");
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return 0;
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}
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int rc = keymaster_create_key_for_cryptfs_scrypt(
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RSA_KEY_SIZE, RSA_EXPONENT, KEYMASTER_CRYPTFS_RATE_LIMIT, ftr->keymaster_blob,
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KEYMASTER_BLOB_SIZE, &ftr->keymaster_blob_size);
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if (rc) {
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if (ftr->keymaster_blob_size > KEYMASTER_BLOB_SIZE) {
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SLOGE("Keymaster key blob too large");
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ftr->keymaster_blob_size = 0;
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}
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SLOGE("Failed to generate keypair");
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return -1;
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}
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return 0;
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}
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/* This signs the given object using the keymaster key. */
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static int keymaster_sign_object(struct crypt_mnt_ftr* ftr, const unsigned char* object,
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const size_t object_size, unsigned char** signature,
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size_t* signature_size) {
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unsigned char to_sign[RSA_KEY_SIZE_BYTES];
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size_t to_sign_size = sizeof(to_sign);
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memset(to_sign, 0, RSA_KEY_SIZE_BYTES);
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// To sign a message with RSA, the message must satisfy two
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// constraints:
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//
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// 1. The message, when interpreted as a big-endian numeric value, must
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// be strictly less than the public modulus of the RSA key. Note
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// that because the most significant bit of the public modulus is
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// guaranteed to be 1 (else it's an (n-1)-bit key, not an n-bit
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// key), an n-bit message with most significant bit 0 always
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// satisfies this requirement.
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//
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// 2. The message must have the same length in bits as the public
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// modulus of the RSA key. This requirement isn't mathematically
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// necessary, but is necessary to ensure consistency in
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// implementations.
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switch (ftr->kdf_type) {
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case KDF_SCRYPT_KEYMASTER:
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// This ensures the most significant byte of the signed message
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// is zero. We could have zero-padded to the left instead, but
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// this approach is slightly more robust against changes in
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// object size. However, it's still broken (but not unusably
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// so) because we really should be using a proper deterministic
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// RSA padding function, such as PKCS1.
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memcpy(to_sign + 1, object, std::min((size_t)RSA_KEY_SIZE_BYTES - 1, object_size));
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SLOGI("Signing safely-padded object");
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break;
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default:
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SLOGE("Unknown KDF type %d", ftr->kdf_type);
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return -1;
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}
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for (;;) {
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auto result = keymaster_sign_object_for_cryptfs_scrypt(
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ftr->keymaster_blob, ftr->keymaster_blob_size, KEYMASTER_CRYPTFS_RATE_LIMIT, to_sign,
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to_sign_size, signature, signature_size);
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switch (result) {
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case KeymasterSignResult::ok:
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return 0;
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case KeymasterSignResult::upgrade:
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break;
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default:
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return -1;
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}
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SLOGD("Upgrading key");
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if (keymaster_upgrade_key_for_cryptfs_scrypt(
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RSA_KEY_SIZE, RSA_EXPONENT, KEYMASTER_CRYPTFS_RATE_LIMIT, ftr->keymaster_blob,
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ftr->keymaster_blob_size, ftr->keymaster_blob, KEYMASTER_BLOB_SIZE,
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&ftr->keymaster_blob_size) != 0) {
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SLOGE("Failed to upgrade key");
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return -1;
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}
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if (put_crypt_ftr_and_key(ftr) != 0) {
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SLOGE("Failed to write upgraded key to disk");
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}
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SLOGD("Key upgraded successfully");
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}
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}
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/* Store password when userdata is successfully decrypted and mounted.
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* Cleared by cryptfs_clear_password
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*
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* To avoid a double prompt at boot, we need to store the CryptKeeper
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* password and pass it to KeyGuard, which uses it to unlock KeyStore.
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* Since the entire framework is torn down and rebuilt after encryption,
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* we have to use a daemon or similar to store the password. Since vold
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* is secured against IPC except from system processes, it seems a reasonable
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* place to store this.
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*
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* password should be cleared once it has been used.
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*
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* password is aged out after password_max_age_seconds seconds.
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*/
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static char* password = 0;
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static int password_expiry_time = 0;
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static const int password_max_age_seconds = 60;
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enum class RebootType { reboot, recovery, shutdown };
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static void cryptfs_reboot(RebootType rt) {
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switch (rt) {
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case RebootType::reboot:
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property_set(ANDROID_RB_PROPERTY, "reboot");
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break;
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case RebootType::recovery:
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property_set(ANDROID_RB_PROPERTY, "reboot,recovery");
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break;
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case RebootType::shutdown:
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property_set(ANDROID_RB_PROPERTY, "shutdown");
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break;
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}
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sleep(20);
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/* Shouldn't get here, reboot should happen before sleep times out */
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return;
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}
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static void ioctl_init(struct dm_ioctl* io, size_t dataSize, const char* name, unsigned flags) {
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memset(io, 0, dataSize);
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io->data_size = dataSize;
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io->data_start = sizeof(struct dm_ioctl);
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io->version[0] = 4;
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io->version[1] = 0;
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io->version[2] = 0;
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io->flags = flags;
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if (name) {
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strlcpy(io->name, name, sizeof(io->name));
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}
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}
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namespace {
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struct CryptoType;
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// Use to get the CryptoType in use on this device.
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const CryptoType& get_crypto_type();
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struct CryptoType {
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// We should only be constructing CryptoTypes as part of
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// supported_crypto_types[]. We do it via this pseudo-builder pattern,
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// which isn't pure or fully protected as a concession to being able to
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// do it all at compile time. Add new CryptoTypes in
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// supported_crypto_types[] below.
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constexpr CryptoType() : CryptoType(nullptr, nullptr, 0xFFFFFFFF) {}
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constexpr CryptoType set_keysize(uint32_t size) const {
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return CryptoType(this->property_name, this->crypto_name, size);
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}
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constexpr CryptoType set_property_name(const char* property) const {
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return CryptoType(property, this->crypto_name, this->keysize);
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}
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constexpr CryptoType set_crypto_name(const char* crypto) const {
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return CryptoType(this->property_name, crypto, this->keysize);
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}
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constexpr const char* get_property_name() const { return property_name; }
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constexpr const char* get_crypto_name() const { return crypto_name; }
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constexpr uint32_t get_keysize() const { return keysize; }
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private:
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const char* property_name;
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const char* crypto_name;
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uint32_t keysize;
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constexpr CryptoType(const char* property, const char* crypto, uint32_t ksize)
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: property_name(property), crypto_name(crypto), keysize(ksize) {}
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friend const CryptoType& get_crypto_type();
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static const CryptoType& get_device_crypto_algorithm();
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};
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// We only want to parse this read-only property once. But we need to wait
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// until the system is initialized before we can read it. So we use a static
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// scoped within this function to get it only once.
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const CryptoType& get_crypto_type() {
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static CryptoType crypto_type = CryptoType::get_device_crypto_algorithm();
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return crypto_type;
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}
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constexpr CryptoType default_crypto_type = CryptoType()
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.set_property_name("AES-128-CBC")
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.set_crypto_name("aes-cbc-essiv:sha256")
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.set_keysize(16);
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constexpr CryptoType supported_crypto_types[] = {
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default_crypto_type,
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CryptoType()
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.set_property_name("adiantum")
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.set_crypto_name("xchacha12,aes-adiantum-plain64")
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.set_keysize(32),
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// Add new CryptoTypes here. Order is not important.
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};
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// ---------- START COMPILE-TIME SANITY CHECK BLOCK -------------------------
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// We confirm all supported_crypto_types have a small enough keysize and
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// had both set_property_name() and set_crypto_name() called.
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template <typename T, size_t N>
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constexpr size_t array_length(T (&)[N]) {
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return N;
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}
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constexpr bool indexOutOfBoundsForCryptoTypes(size_t index) {
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return (index >= array_length(supported_crypto_types));
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}
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constexpr bool isValidCryptoType(const CryptoType& crypto_type) {
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return ((crypto_type.get_property_name() != nullptr) &&
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(crypto_type.get_crypto_name() != nullptr) &&
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(crypto_type.get_keysize() <= MAX_KEY_LEN));
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}
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// Note in C++11 that constexpr functions can only have a single line.
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// So our code is a bit convoluted (using recursion instead of a loop),
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// but it's asserting at compile time that all of our key lengths are valid.
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constexpr bool validateSupportedCryptoTypes(size_t index) {
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return indexOutOfBoundsForCryptoTypes(index) ||
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(isValidCryptoType(supported_crypto_types[index]) &&
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validateSupportedCryptoTypes(index + 1));
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}
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static_assert(validateSupportedCryptoTypes(0),
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"We have a CryptoType with keysize > MAX_KEY_LEN or which was "
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"incompletely constructed.");
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// ---------- END COMPILE-TIME SANITY CHECK BLOCK -------------------------
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// Don't call this directly, use get_crypto_type(), which caches this result.
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const CryptoType& CryptoType::get_device_crypto_algorithm() {
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constexpr char CRYPT_ALGO_PROP[] = "ro.crypto.fde_algorithm";
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char paramstr[PROPERTY_VALUE_MAX];
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property_get(CRYPT_ALGO_PROP, paramstr, default_crypto_type.get_property_name());
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for (auto const& ctype : supported_crypto_types) {
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if (strcmp(paramstr, ctype.get_property_name()) == 0) {
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return ctype;
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}
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}
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ALOGE("Invalid name (%s) for %s. Defaulting to %s\n", paramstr, CRYPT_ALGO_PROP,
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default_crypto_type.get_property_name());
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return default_crypto_type;
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}
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} // namespace
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/**
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* Gets the default device scrypt parameters for key derivation time tuning.
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* The parameters should lead to about one second derivation time for the
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* given device.
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*/
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static void get_device_scrypt_params(struct crypt_mnt_ftr* ftr) {
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char paramstr[PROPERTY_VALUE_MAX];
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int Nf, rf, pf;
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property_get(SCRYPT_PROP, paramstr, SCRYPT_DEFAULTS);
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if (!parse_scrypt_parameters(paramstr, &Nf, &rf, &pf)) {
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SLOGW("bad scrypt parameters '%s' should be like '12:8:1'; using defaults", paramstr);
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parse_scrypt_parameters(SCRYPT_DEFAULTS, &Nf, &rf, &pf);
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}
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ftr->N_factor = Nf;
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ftr->r_factor = rf;
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ftr->p_factor = pf;
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}
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uint32_t cryptfs_get_keysize() {
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return get_crypto_type().get_keysize();
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}
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const char* cryptfs_get_crypto_name() {
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return get_crypto_type().get_crypto_name();
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}
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static uint64_t get_fs_size(const char* dev) {
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int fd, block_size;
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struct ext4_super_block sb;
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uint64_t len;
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if ((fd = open(dev, O_RDONLY | O_CLOEXEC)) < 0) {
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SLOGE("Cannot open device to get filesystem size ");
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return 0;
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}
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if (lseek64(fd, 1024, SEEK_SET) < 0) {
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SLOGE("Cannot seek to superblock");
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return 0;
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}
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if (read(fd, &sb, sizeof(sb)) != sizeof(sb)) {
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SLOGE("Cannot read superblock");
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return 0;
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}
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close(fd);
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if (le32_to_cpu(sb.s_magic) != EXT4_SUPER_MAGIC) {
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SLOGE("Not a valid ext4 superblock");
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return 0;
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}
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block_size = 1024 << sb.s_log_block_size;
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/* compute length in bytes */
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len = (((uint64_t)sb.s_blocks_count_hi << 32) + sb.s_blocks_count_lo) * block_size;
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/* return length in sectors */
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return len / 512;
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}
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static void get_crypt_info(std::string* key_loc, std::string* real_blk_device) {
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for (const auto& entry : fstab_default) {
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if (!entry.fs_mgr_flags.vold_managed &&
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(entry.fs_mgr_flags.crypt || entry.fs_mgr_flags.force_crypt ||
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entry.fs_mgr_flags.force_fde_or_fbe || entry.fs_mgr_flags.file_encryption)) {
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if (key_loc != nullptr) {
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*key_loc = entry.key_loc;
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}
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if (real_blk_device != nullptr) {
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*real_blk_device = entry.blk_device;
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}
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return;
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}
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}
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}
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static int get_crypt_ftr_info(char** metadata_fname, off64_t* off) {
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static int cached_data = 0;
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static uint64_t cached_off = 0;
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static char cached_metadata_fname[PROPERTY_VALUE_MAX] = "";
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char key_loc[PROPERTY_VALUE_MAX];
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char real_blkdev[PROPERTY_VALUE_MAX];
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int rc = -1;
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if (!cached_data) {
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std::string key_loc;
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std::string real_blkdev;
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get_crypt_info(&key_loc, &real_blkdev);
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if (key_loc == KEY_IN_FOOTER) {
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if (android::vold::GetBlockDevSize(real_blkdev, &cached_off) == android::OK) {
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/* If it's an encrypted Android partition, the last 16 Kbytes contain the
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* encryption info footer and key, and plenty of bytes to spare for future
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* growth.
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*/
|
|
strlcpy(cached_metadata_fname, real_blkdev.c_str(), sizeof(cached_metadata_fname));
|
|
cached_off -= CRYPT_FOOTER_OFFSET;
|
|
cached_data = 1;
|
|
} else {
|
|
SLOGE("Cannot get size of block device %s\n", real_blkdev.c_str());
|
|
}
|
|
} else {
|
|
strlcpy(cached_metadata_fname, key_loc.c_str(), sizeof(cached_metadata_fname));
|
|
cached_off = 0;
|
|
cached_data = 1;
|
|
}
|
|
}
|
|
|
|
if (cached_data) {
|
|
if (metadata_fname) {
|
|
*metadata_fname = cached_metadata_fname;
|
|
}
|
|
if (off) {
|
|
*off = cached_off;
|
|
}
|
|
rc = 0;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/* Set sha256 checksum in structure */
|
|
static void set_ftr_sha(struct crypt_mnt_ftr* crypt_ftr) {
|
|
SHA256_CTX c;
|
|
SHA256_Init(&c);
|
|
memset(crypt_ftr->sha256, 0, sizeof(crypt_ftr->sha256));
|
|
SHA256_Update(&c, crypt_ftr, sizeof(*crypt_ftr));
|
|
SHA256_Final(crypt_ftr->sha256, &c);
|
|
}
|
|
|
|
/* key or salt can be NULL, in which case just skip writing that value. Useful to
|
|
* update the failed mount count but not change the key.
|
|
*/
|
|
static int put_crypt_ftr_and_key(struct crypt_mnt_ftr* crypt_ftr) {
|
|
int fd;
|
|
unsigned int cnt;
|
|
/* starting_off is set to the SEEK_SET offset
|
|
* where the crypto structure starts
|
|
*/
|
|
off64_t starting_off;
|
|
int rc = -1;
|
|
char* fname = NULL;
|
|
struct stat statbuf;
|
|
|
|
set_ftr_sha(crypt_ftr);
|
|
|
|
if (get_crypt_ftr_info(&fname, &starting_off)) {
|
|
SLOGE("Unable to get crypt_ftr_info\n");
|
|
return -1;
|
|
}
|
|
if (fname[0] != '/') {
|
|
SLOGE("Unexpected value for crypto key location\n");
|
|
return -1;
|
|
}
|
|
if ((fd = open(fname, O_RDWR | O_CREAT | O_CLOEXEC, 0600)) < 0) {
|
|
SLOGE("Cannot open footer file %s for put\n", fname);
|
|
return -1;
|
|
}
|
|
|
|
/* Seek to the start of the crypt footer */
|
|
if (lseek64(fd, starting_off, SEEK_SET) == -1) {
|
|
SLOGE("Cannot seek to real block device footer\n");
|
|
goto errout;
|
|
}
|
|
|
|
if ((cnt = write(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) {
|
|
SLOGE("Cannot write real block device footer\n");
|
|
goto errout;
|
|
}
|
|
|
|
fstat(fd, &statbuf);
|
|
/* If the keys are kept on a raw block device, do not try to truncate it. */
|
|
if (S_ISREG(statbuf.st_mode)) {
|
|
if (ftruncate(fd, 0x4000)) {
|
|
SLOGE("Cannot set footer file size\n");
|
|
goto errout;
|
|
}
|
|
}
|
|
|
|
/* Success! */
|
|
rc = 0;
|
|
|
|
errout:
|
|
close(fd);
|
|
return rc;
|
|
}
|
|
|
|
static bool check_ftr_sha(const struct crypt_mnt_ftr* crypt_ftr) {
|
|
struct crypt_mnt_ftr copy;
|
|
memcpy(©, crypt_ftr, sizeof(copy));
|
|
set_ftr_sha(©);
|
|
return memcmp(copy.sha256, crypt_ftr->sha256, sizeof(copy.sha256)) == 0;
|
|
}
|
|
|
|
static inline int unix_read(int fd, void* buff, int len) {
|
|
return TEMP_FAILURE_RETRY(read(fd, buff, len));
|
|
}
|
|
|
|
static inline int unix_write(int fd, const void* buff, int len) {
|
|
return TEMP_FAILURE_RETRY(write(fd, buff, len));
|
|
}
|
|
|
|
static void init_empty_persist_data(struct crypt_persist_data* pdata, int len) {
|
|
memset(pdata, 0, len);
|
|
pdata->persist_magic = PERSIST_DATA_MAGIC;
|
|
pdata->persist_valid_entries = 0;
|
|
}
|
|
|
|
/* A routine to update the passed in crypt_ftr to the lastest version.
|
|
* fd is open read/write on the device that holds the crypto footer and persistent
|
|
* data, crypt_ftr is a pointer to the struct to be updated, and offset is the
|
|
* absolute offset to the start of the crypt_mnt_ftr on the passed in fd.
|
|
*/
|
|
static void upgrade_crypt_ftr(int fd, struct crypt_mnt_ftr* crypt_ftr, off64_t offset) {
|
|
int orig_major = crypt_ftr->major_version;
|
|
int orig_minor = crypt_ftr->minor_version;
|
|
|
|
if ((crypt_ftr->major_version == 1) && (crypt_ftr->minor_version == 0)) {
|
|
struct crypt_persist_data* pdata;
|
|
off64_t pdata_offset = offset + CRYPT_FOOTER_TO_PERSIST_OFFSET;
|
|
|
|
SLOGW("upgrading crypto footer to 1.1");
|
|
|
|
pdata = (crypt_persist_data*)malloc(CRYPT_PERSIST_DATA_SIZE);
|
|
if (pdata == NULL) {
|
|
SLOGE("Cannot allocate persisent data\n");
|
|
return;
|
|
}
|
|
memset(pdata, 0, CRYPT_PERSIST_DATA_SIZE);
|
|
|
|
/* Need to initialize the persistent data area */
|
|
if (lseek64(fd, pdata_offset, SEEK_SET) == -1) {
|
|
SLOGE("Cannot seek to persisent data offset\n");
|
|
free(pdata);
|
|
return;
|
|
}
|
|
/* Write all zeros to the first copy, making it invalid */
|
|
unix_write(fd, pdata, CRYPT_PERSIST_DATA_SIZE);
|
|
|
|
/* Write a valid but empty structure to the second copy */
|
|
init_empty_persist_data(pdata, CRYPT_PERSIST_DATA_SIZE);
|
|
unix_write(fd, pdata, CRYPT_PERSIST_DATA_SIZE);
|
|
|
|
/* Update the footer */
|
|
crypt_ftr->persist_data_size = CRYPT_PERSIST_DATA_SIZE;
|
|
crypt_ftr->persist_data_offset[0] = pdata_offset;
|
|
crypt_ftr->persist_data_offset[1] = pdata_offset + CRYPT_PERSIST_DATA_SIZE;
|
|
crypt_ftr->minor_version = 1;
|
|
free(pdata);
|
|
}
|
|
|
|
if ((crypt_ftr->major_version == 1) && (crypt_ftr->minor_version == 1)) {
|
|
SLOGW("upgrading crypto footer to 1.2");
|
|
/* But keep the old kdf_type.
|
|
* It will get updated later to KDF_SCRYPT after the password has been verified.
|
|
*/
|
|
crypt_ftr->kdf_type = KDF_PBKDF2;
|
|
get_device_scrypt_params(crypt_ftr);
|
|
crypt_ftr->minor_version = 2;
|
|
}
|
|
|
|
if ((crypt_ftr->major_version == 1) && (crypt_ftr->minor_version == 2)) {
|
|
SLOGW("upgrading crypto footer to 1.3");
|
|
crypt_ftr->crypt_type = CRYPT_TYPE_PASSWORD;
|
|
crypt_ftr->minor_version = 3;
|
|
}
|
|
|
|
if ((orig_major != crypt_ftr->major_version) || (orig_minor != crypt_ftr->minor_version)) {
|
|
if (lseek64(fd, offset, SEEK_SET) == -1) {
|
|
SLOGE("Cannot seek to crypt footer\n");
|
|
return;
|
|
}
|
|
unix_write(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr));
|
|
}
|
|
}
|
|
|
|
static int get_crypt_ftr_and_key(struct crypt_mnt_ftr* crypt_ftr) {
|
|
int fd;
|
|
unsigned int cnt;
|
|
off64_t starting_off;
|
|
int rc = -1;
|
|
char* fname = NULL;
|
|
struct stat statbuf;
|
|
|
|
if (get_crypt_ftr_info(&fname, &starting_off)) {
|
|
SLOGE("Unable to get crypt_ftr_info\n");
|
|
return -1;
|
|
}
|
|
if (fname[0] != '/') {
|
|
SLOGE("Unexpected value for crypto key location\n");
|
|
return -1;
|
|
}
|
|
if ((fd = open(fname, O_RDWR | O_CLOEXEC)) < 0) {
|
|
SLOGE("Cannot open footer file %s for get\n", fname);
|
|
return -1;
|
|
}
|
|
|
|
/* Make sure it's 16 Kbytes in length */
|
|
fstat(fd, &statbuf);
|
|
if (S_ISREG(statbuf.st_mode) && (statbuf.st_size != 0x4000)) {
|
|
SLOGE("footer file %s is not the expected size!\n", fname);
|
|
goto errout;
|
|
}
|
|
|
|
/* Seek to the start of the crypt footer */
|
|
if (lseek64(fd, starting_off, SEEK_SET) == -1) {
|
|
SLOGE("Cannot seek to real block device footer\n");
|
|
goto errout;
|
|
}
|
|
|
|
if ((cnt = read(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) {
|
|
SLOGE("Cannot read real block device footer\n");
|
|
goto errout;
|
|
}
|
|
|
|
if (crypt_ftr->magic != CRYPT_MNT_MAGIC) {
|
|
SLOGE("Bad magic for real block device %s\n", fname);
|
|
goto errout;
|
|
}
|
|
|
|
if (crypt_ftr->major_version != CURRENT_MAJOR_VERSION) {
|
|
SLOGE("Cannot understand major version %d real block device footer; expected %d\n",
|
|
crypt_ftr->major_version, CURRENT_MAJOR_VERSION);
|
|
goto errout;
|
|
}
|
|
|
|
// We risk buffer overflows with oversized keys, so we just reject them.
|
|
// 0-sized keys are problematic (essentially by-passing encryption), and
|
|
// AES-CBC key wrapping only works for multiples of 16 bytes.
|
|
if ((crypt_ftr->keysize == 0) || ((crypt_ftr->keysize % 16) != 0) ||
|
|
(crypt_ftr->keysize > MAX_KEY_LEN)) {
|
|
SLOGE(
|
|
"Invalid keysize (%u) for block device %s; Must be non-zero, "
|
|
"divisible by 16, and <= %d\n",
|
|
crypt_ftr->keysize, fname, MAX_KEY_LEN);
|
|
goto errout;
|
|
}
|
|
|
|
if (crypt_ftr->minor_version > CURRENT_MINOR_VERSION) {
|
|
SLOGW("Warning: crypto footer minor version %d, expected <= %d, continuing...\n",
|
|
crypt_ftr->minor_version, CURRENT_MINOR_VERSION);
|
|
}
|
|
|
|
/* If this is a verion 1.0 crypt_ftr, make it a 1.1 crypt footer, and update the
|
|
* copy on disk before returning.
|
|
*/
|
|
if (crypt_ftr->minor_version < CURRENT_MINOR_VERSION) {
|
|
upgrade_crypt_ftr(fd, crypt_ftr, starting_off);
|
|
}
|
|
|
|
/* Success! */
|
|
rc = 0;
|
|
|
|
errout:
|
|
close(fd);
|
|
return rc;
|
|
}
|
|
|
|
static int validate_persistent_data_storage(struct crypt_mnt_ftr* crypt_ftr) {
|
|
if (crypt_ftr->persist_data_offset[0] + crypt_ftr->persist_data_size >
|
|
crypt_ftr->persist_data_offset[1]) {
|
|
SLOGE("Crypt_ftr persist data regions overlap");
|
|
return -1;
|
|
}
|
|
|
|
if (crypt_ftr->persist_data_offset[0] >= crypt_ftr->persist_data_offset[1]) {
|
|
SLOGE("Crypt_ftr persist data region 0 starts after region 1");
|
|
return -1;
|
|
}
|
|
|
|
if (((crypt_ftr->persist_data_offset[1] + crypt_ftr->persist_data_size) -
|
|
(crypt_ftr->persist_data_offset[0] - CRYPT_FOOTER_TO_PERSIST_OFFSET)) >
|
|
CRYPT_FOOTER_OFFSET) {
|
|
SLOGE("Persistent data extends past crypto footer");
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int load_persistent_data(void) {
|
|
struct crypt_mnt_ftr crypt_ftr;
|
|
struct crypt_persist_data* pdata = NULL;
|
|
char encrypted_state[PROPERTY_VALUE_MAX];
|
|
char* fname;
|
|
int found = 0;
|
|
int fd;
|
|
int ret;
|
|
int i;
|
|
|
|
if (persist_data) {
|
|
/* Nothing to do, we've already loaded or initialized it */
|
|
return 0;
|
|
}
|
|
|
|
/* If not encrypted, just allocate an empty table and initialize it */
|
|
property_get("ro.crypto.state", encrypted_state, "");
|
|
if (strcmp(encrypted_state, "encrypted")) {
|
|
pdata = (crypt_persist_data*)malloc(CRYPT_PERSIST_DATA_SIZE);
|
|
if (pdata) {
|
|
init_empty_persist_data(pdata, CRYPT_PERSIST_DATA_SIZE);
|
|
persist_data = pdata;
|
|
return 0;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
if (get_crypt_ftr_and_key(&crypt_ftr)) {
|
|
return -1;
|
|
}
|
|
|
|
if ((crypt_ftr.major_version < 1) ||
|
|
(crypt_ftr.major_version == 1 && crypt_ftr.minor_version < 1)) {
|
|
SLOGE("Crypt_ftr version doesn't support persistent data");
|
|
return -1;
|
|
}
|
|
|
|
if (get_crypt_ftr_info(&fname, NULL)) {
|
|
return -1;
|
|
}
|
|
|
|
ret = validate_persistent_data_storage(&crypt_ftr);
|
|
if (ret) {
|
|
return -1;
|
|
}
|
|
|
|
fd = open(fname, O_RDONLY | O_CLOEXEC);
|
|
if (fd < 0) {
|
|
SLOGE("Cannot open %s metadata file", fname);
|
|
return -1;
|
|
}
|
|
|
|
pdata = (crypt_persist_data*)malloc(crypt_ftr.persist_data_size);
|
|
if (pdata == NULL) {
|
|
SLOGE("Cannot allocate memory for persistent data");
|
|
goto err;
|
|
}
|
|
|
|
for (i = 0; i < 2; i++) {
|
|
if (lseek64(fd, crypt_ftr.persist_data_offset[i], SEEK_SET) < 0) {
|
|
SLOGE("Cannot seek to read persistent data on %s", fname);
|
|
goto err2;
|
|
}
|
|
if (unix_read(fd, pdata, crypt_ftr.persist_data_size) < 0) {
|
|
SLOGE("Error reading persistent data on iteration %d", i);
|
|
goto err2;
|
|
}
|
|
if (pdata->persist_magic == PERSIST_DATA_MAGIC) {
|
|
found = 1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!found) {
|
|
SLOGI("Could not find valid persistent data, creating");
|
|
init_empty_persist_data(pdata, crypt_ftr.persist_data_size);
|
|
}
|
|
|
|
/* Success */
|
|
persist_data = pdata;
|
|
close(fd);
|
|
return 0;
|
|
|
|
err2:
|
|
free(pdata);
|
|
|
|
err:
|
|
close(fd);
|
|
return -1;
|
|
}
|
|
|
|
static int save_persistent_data(void) {
|
|
struct crypt_mnt_ftr crypt_ftr;
|
|
struct crypt_persist_data* pdata;
|
|
char* fname;
|
|
off64_t write_offset;
|
|
off64_t erase_offset;
|
|
int fd;
|
|
int ret;
|
|
|
|
if (persist_data == NULL) {
|
|
SLOGE("No persistent data to save");
|
|
return -1;
|
|
}
|
|
|
|
if (get_crypt_ftr_and_key(&crypt_ftr)) {
|
|
return -1;
|
|
}
|
|
|
|
if ((crypt_ftr.major_version < 1) ||
|
|
(crypt_ftr.major_version == 1 && crypt_ftr.minor_version < 1)) {
|
|
SLOGE("Crypt_ftr version doesn't support persistent data");
|
|
return -1;
|
|
}
|
|
|
|
ret = validate_persistent_data_storage(&crypt_ftr);
|
|
if (ret) {
|
|
return -1;
|
|
}
|
|
|
|
if (get_crypt_ftr_info(&fname, NULL)) {
|
|
return -1;
|
|
}
|
|
|
|
fd = open(fname, O_RDWR | O_CLOEXEC);
|
|
if (fd < 0) {
|
|
SLOGE("Cannot open %s metadata file", fname);
|
|
return -1;
|
|
}
|
|
|
|
pdata = (crypt_persist_data*)malloc(crypt_ftr.persist_data_size);
|
|
if (pdata == NULL) {
|
|
SLOGE("Cannot allocate persistant data");
|
|
goto err;
|
|
}
|
|
|
|
if (lseek64(fd, crypt_ftr.persist_data_offset[0], SEEK_SET) < 0) {
|
|
SLOGE("Cannot seek to read persistent data on %s", fname);
|
|
goto err2;
|
|
}
|
|
|
|
if (unix_read(fd, pdata, crypt_ftr.persist_data_size) < 0) {
|
|
SLOGE("Error reading persistent data before save");
|
|
goto err2;
|
|
}
|
|
|
|
if (pdata->persist_magic == PERSIST_DATA_MAGIC) {
|
|
/* The first copy is the curent valid copy, so write to
|
|
* the second copy and erase this one */
|
|
write_offset = crypt_ftr.persist_data_offset[1];
|
|
erase_offset = crypt_ftr.persist_data_offset[0];
|
|
} else {
|
|
/* The second copy must be the valid copy, so write to
|
|
* the first copy, and erase the second */
|
|
write_offset = crypt_ftr.persist_data_offset[0];
|
|
erase_offset = crypt_ftr.persist_data_offset[1];
|
|
}
|
|
|
|
/* Write the new copy first, if successful, then erase the old copy */
|
|
if (lseek64(fd, write_offset, SEEK_SET) < 0) {
|
|
SLOGE("Cannot seek to write persistent data");
|
|
goto err2;
|
|
}
|
|
if (unix_write(fd, persist_data, crypt_ftr.persist_data_size) ==
|
|
(int)crypt_ftr.persist_data_size) {
|
|
if (lseek64(fd, erase_offset, SEEK_SET) < 0) {
|
|
SLOGE("Cannot seek to erase previous persistent data");
|
|
goto err2;
|
|
}
|
|
fsync(fd);
|
|
memset(pdata, 0, crypt_ftr.persist_data_size);
|
|
if (unix_write(fd, pdata, crypt_ftr.persist_data_size) != (int)crypt_ftr.persist_data_size) {
|
|
SLOGE("Cannot write to erase previous persistent data");
|
|
goto err2;
|
|
}
|
|
fsync(fd);
|
|
} else {
|
|
SLOGE("Cannot write to save persistent data");
|
|
goto err2;
|
|
}
|
|
|
|
/* Success */
|
|
free(pdata);
|
|
close(fd);
|
|
return 0;
|
|
|
|
err2:
|
|
free(pdata);
|
|
err:
|
|
close(fd);
|
|
return -1;
|
|
}
|
|
|
|
/* Convert a binary key of specified length into an ascii hex string equivalent,
|
|
* without the leading 0x and with null termination
|
|
*/
|
|
static void convert_key_to_hex_ascii(const unsigned char* master_key, unsigned int keysize,
|
|
char* master_key_ascii) {
|
|
unsigned int i, a;
|
|
unsigned char nibble;
|
|
|
|
for (i = 0, a = 0; i < keysize; i++, a += 2) {
|
|
/* For each byte, write out two ascii hex digits */
|
|
nibble = (master_key[i] >> 4) & 0xf;
|
|
master_key_ascii[a] = nibble + (nibble > 9 ? 0x37 : 0x30);
|
|
|
|
nibble = master_key[i] & 0xf;
|
|
master_key_ascii[a + 1] = nibble + (nibble > 9 ? 0x37 : 0x30);
|
|
}
|
|
|
|
/* Add the null termination */
|
|
master_key_ascii[a] = '\0';
|
|
}
|
|
|
|
static int load_crypto_mapping_table(struct crypt_mnt_ftr* crypt_ftr,
|
|
const unsigned char* master_key, const char* real_blk_name,
|
|
const char* name, int fd, const char* extra_params) {
|
|
alignas(struct dm_ioctl) char buffer[DM_CRYPT_BUF_SIZE];
|
|
struct dm_ioctl* io;
|
|
struct dm_target_spec* tgt;
|
|
char* crypt_params;
|
|
// We need two ASCII characters to represent each byte, and need space for
|
|
// the '\0' terminator.
|
|
char master_key_ascii[MAX_KEY_LEN * 2 + 1];
|
|
size_t buff_offset;
|
|
int i;
|
|
|
|
io = (struct dm_ioctl*)buffer;
|
|
|
|
/* Load the mapping table for this device */
|
|
tgt = (struct dm_target_spec*)&buffer[sizeof(struct dm_ioctl)];
|
|
|
|
ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
|
|
io->target_count = 1;
|
|
tgt->status = 0;
|
|
tgt->sector_start = 0;
|
|
tgt->length = crypt_ftr->fs_size;
|
|
strlcpy(tgt->target_type, "crypt", DM_MAX_TYPE_NAME);
|
|
|
|
crypt_params = buffer + sizeof(struct dm_ioctl) + sizeof(struct dm_target_spec);
|
|
convert_key_to_hex_ascii(master_key, crypt_ftr->keysize, master_key_ascii);
|
|
|
|
buff_offset = crypt_params - buffer;
|
|
SLOGI(
|
|
"Creating crypto dev \"%s\"; cipher=%s, keysize=%u, real_dev=%s, len=%llu, params=\"%s\"\n",
|
|
name, crypt_ftr->crypto_type_name, crypt_ftr->keysize, real_blk_name, tgt->length * 512,
|
|
extra_params);
|
|
snprintf(crypt_params, sizeof(buffer) - buff_offset, "%s %s 0 %s 0 %s",
|
|
crypt_ftr->crypto_type_name, master_key_ascii, real_blk_name, extra_params);
|
|
crypt_params += strlen(crypt_params) + 1;
|
|
crypt_params =
|
|
(char*)(((unsigned long)crypt_params + 7) & ~8); /* Align to an 8 byte boundary */
|
|
tgt->next = crypt_params - buffer;
|
|
|
|
for (i = 0; i < TABLE_LOAD_RETRIES; i++) {
|
|
if (!ioctl(fd, DM_TABLE_LOAD, io)) {
|
|
break;
|
|
}
|
|
usleep(500000);
|
|
}
|
|
|
|
if (i == TABLE_LOAD_RETRIES) {
|
|
/* We failed to load the table, return an error */
|
|
return -1;
|
|
} else {
|
|
return i + 1;
|
|
}
|
|
}
|
|
|
|
static int get_dm_crypt_version(int fd, const char* name, int* version) {
|
|
char buffer[DM_CRYPT_BUF_SIZE];
|
|
struct dm_ioctl* io;
|
|
struct dm_target_versions* v;
|
|
|
|
io = (struct dm_ioctl*)buffer;
|
|
|
|
ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
|
|
|
|
if (ioctl(fd, DM_LIST_VERSIONS, io)) {
|
|
return -1;
|
|
}
|
|
|
|
/* Iterate over the returned versions, looking for name of "crypt".
|
|
* When found, get and return the version.
|
|
*/
|
|
v = (struct dm_target_versions*)&buffer[sizeof(struct dm_ioctl)];
|
|
while (v->next) {
|
|
if (!strcmp(v->name, "crypt")) {
|
|
/* We found the crypt driver, return the version, and get out */
|
|
version[0] = v->version[0];
|
|
version[1] = v->version[1];
|
|
version[2] = v->version[2];
|
|
return 0;
|
|
}
|
|
v = (struct dm_target_versions*)(((char*)v) + v->next);
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
static std::string extra_params_as_string(const std::vector<std::string>& extra_params_vec) {
|
|
if (extra_params_vec.empty()) return "";
|
|
std::string extra_params = std::to_string(extra_params_vec.size());
|
|
for (const auto& p : extra_params_vec) {
|
|
extra_params.append(" ");
|
|
extra_params.append(p);
|
|
}
|
|
return extra_params;
|
|
}
|
|
|
|
/*
|
|
* If the ro.crypto.fde_sector_size system property is set, append the
|
|
* parameters to make dm-crypt use the specified crypto sector size and round
|
|
* the crypto device size down to a crypto sector boundary.
|
|
*/
|
|
static int add_sector_size_param(std::vector<std::string>* extra_params_vec,
|
|
struct crypt_mnt_ftr* ftr) {
|
|
constexpr char DM_CRYPT_SECTOR_SIZE[] = "ro.crypto.fde_sector_size";
|
|
char value[PROPERTY_VALUE_MAX];
|
|
|
|
if (property_get(DM_CRYPT_SECTOR_SIZE, value, "") > 0) {
|
|
unsigned int sector_size;
|
|
|
|
if (!ParseUint(value, §or_size) || sector_size < 512 || sector_size > 4096 ||
|
|
(sector_size & (sector_size - 1)) != 0) {
|
|
SLOGE("Invalid value for %s: %s. Must be >= 512, <= 4096, and a power of 2\n",
|
|
DM_CRYPT_SECTOR_SIZE, value);
|
|
return -1;
|
|
}
|
|
|
|
std::string param = StringPrintf("sector_size:%u", sector_size);
|
|
extra_params_vec->push_back(std::move(param));
|
|
|
|
// With this option, IVs will match the sector numbering, instead
|
|
// of being hard-coded to being based on 512-byte sectors.
|
|
extra_params_vec->emplace_back("iv_large_sectors");
|
|
|
|
// Round the crypto device size down to a crypto sector boundary.
|
|
ftr->fs_size &= ~((sector_size / 512) - 1);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int create_crypto_blk_dev(struct crypt_mnt_ftr* crypt_ftr, const unsigned char* master_key,
|
|
const char* real_blk_name, char* crypto_blk_name, const char* name,
|
|
uint32_t flags) {
|
|
char buffer[DM_CRYPT_BUF_SIZE];
|
|
struct dm_ioctl* io;
|
|
unsigned int minor;
|
|
int fd = 0;
|
|
int err;
|
|
int retval = -1;
|
|
int version[3];
|
|
int load_count;
|
|
std::vector<std::string> extra_params_vec;
|
|
|
|
if ((fd = open("/dev/device-mapper", O_RDWR | O_CLOEXEC)) < 0) {
|
|
SLOGE("Cannot open device-mapper\n");
|
|
goto errout;
|
|
}
|
|
|
|
io = (struct dm_ioctl*)buffer;
|
|
|
|
ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
|
|
err = ioctl(fd, DM_DEV_CREATE, io);
|
|
if (err) {
|
|
SLOGE("Cannot create dm-crypt device %s: %s\n", name, strerror(errno));
|
|
goto errout;
|
|
}
|
|
|
|
/* Get the device status, in particular, the name of it's device file */
|
|
ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
|
|
if (ioctl(fd, DM_DEV_STATUS, io)) {
|
|
SLOGE("Cannot retrieve dm-crypt device status\n");
|
|
goto errout;
|
|
}
|
|
minor = (io->dev & 0xff) | ((io->dev >> 12) & 0xfff00);
|
|
snprintf(crypto_blk_name, MAXPATHLEN, "/dev/block/dm-%u", minor);
|
|
|
|
if (!get_dm_crypt_version(fd, name, version)) {
|
|
/* Support for allow_discards was added in version 1.11.0 */
|
|
if ((version[0] >= 2) || ((version[0] == 1) && (version[1] >= 11))) {
|
|
extra_params_vec.emplace_back("allow_discards");
|
|
}
|
|
}
|
|
if (flags & CREATE_CRYPTO_BLK_DEV_FLAGS_ALLOW_ENCRYPT_OVERRIDE) {
|
|
extra_params_vec.emplace_back("allow_encrypt_override");
|
|
}
|
|
if (add_sector_size_param(&extra_params_vec, crypt_ftr)) {
|
|
SLOGE("Error processing dm-crypt sector size param\n");
|
|
goto errout;
|
|
}
|
|
load_count = load_crypto_mapping_table(crypt_ftr, master_key, real_blk_name, name, fd,
|
|
extra_params_as_string(extra_params_vec).c_str());
|
|
if (load_count < 0) {
|
|
SLOGE("Cannot load dm-crypt mapping table.\n");
|
|
goto errout;
|
|
} else if (load_count > 1) {
|
|
SLOGI("Took %d tries to load dmcrypt table.\n", load_count);
|
|
}
|
|
|
|
/* Resume this device to activate it */
|
|
ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
|
|
|
|
if (ioctl(fd, DM_DEV_SUSPEND, io)) {
|
|
SLOGE("Cannot resume the dm-crypt device\n");
|
|
goto errout;
|
|
}
|
|
|
|
/* Ensure the dm device has been created before returning. */
|
|
if (android::vold::WaitForFile(crypto_blk_name, 1s) < 0) {
|
|
// WaitForFile generates a suitable log message
|
|
goto errout;
|
|
}
|
|
|
|
/* We made it here with no errors. Woot! */
|
|
retval = 0;
|
|
|
|
errout:
|
|
close(fd); /* If fd is <0 from a failed open call, it's safe to just ignore the close error */
|
|
|
|
return retval;
|
|
}
|
|
|
|
static int delete_crypto_blk_dev(const char* name) {
|
|
int fd;
|
|
char buffer[DM_CRYPT_BUF_SIZE];
|
|
struct dm_ioctl* io;
|
|
int retval = -1;
|
|
int err;
|
|
|
|
if ((fd = open("/dev/device-mapper", O_RDWR | O_CLOEXEC)) < 0) {
|
|
SLOGE("Cannot open device-mapper\n");
|
|
goto errout;
|
|
}
|
|
|
|
io = (struct dm_ioctl*)buffer;
|
|
|
|
ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
|
|
err = ioctl(fd, DM_DEV_REMOVE, io);
|
|
if (err) {
|
|
SLOGE("Cannot remove dm-crypt device %s: %s\n", name, strerror(errno));
|
|
goto errout;
|
|
}
|
|
|
|
/* We made it here with no errors. Woot! */
|
|
retval = 0;
|
|
|
|
errout:
|
|
close(fd); /* If fd is <0 from a failed open call, it's safe to just ignore the close error */
|
|
|
|
return retval;
|
|
}
|
|
|
|
static int pbkdf2(const char* passwd, const unsigned char* salt, unsigned char* ikey,
|
|
void* params UNUSED) {
|
|
SLOGI("Using pbkdf2 for cryptfs KDF");
|
|
|
|
/* Turn the password into a key and IV that can decrypt the master key */
|
|
return PKCS5_PBKDF2_HMAC_SHA1(passwd, strlen(passwd), salt, SALT_LEN, HASH_COUNT,
|
|
INTERMEDIATE_BUF_SIZE, ikey) != 1;
|
|
}
|
|
|
|
static int scrypt(const char* passwd, const unsigned char* salt, unsigned char* ikey, void* params) {
|
|
SLOGI("Using scrypt for cryptfs KDF");
|
|
|
|
struct crypt_mnt_ftr* ftr = (struct crypt_mnt_ftr*)params;
|
|
|
|
int N = 1 << ftr->N_factor;
|
|
int r = 1 << ftr->r_factor;
|
|
int p = 1 << ftr->p_factor;
|
|
|
|
/* Turn the password into a key and IV that can decrypt the master key */
|
|
crypto_scrypt((const uint8_t*)passwd, strlen(passwd), salt, SALT_LEN, N, r, p, ikey,
|
|
INTERMEDIATE_BUF_SIZE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int scrypt_keymaster(const char* passwd, const unsigned char* salt, unsigned char* ikey,
|
|
void* params) {
|
|
SLOGI("Using scrypt with keymaster for cryptfs KDF");
|
|
|
|
int rc;
|
|
size_t signature_size;
|
|
unsigned char* signature;
|
|
struct crypt_mnt_ftr* ftr = (struct crypt_mnt_ftr*)params;
|
|
|
|
int N = 1 << ftr->N_factor;
|
|
int r = 1 << ftr->r_factor;
|
|
int p = 1 << ftr->p_factor;
|
|
|
|
rc = crypto_scrypt((const uint8_t*)passwd, strlen(passwd), salt, SALT_LEN, N, r, p, ikey,
|
|
INTERMEDIATE_BUF_SIZE);
|
|
|
|
if (rc) {
|
|
SLOGE("scrypt failed");
|
|
return -1;
|
|
}
|
|
|
|
if (keymaster_sign_object(ftr, ikey, INTERMEDIATE_BUF_SIZE, &signature, &signature_size)) {
|
|
SLOGE("Signing failed");
|
|
return -1;
|
|
}
|
|
|
|
rc = crypto_scrypt(signature, signature_size, salt, SALT_LEN, N, r, p, ikey,
|
|
INTERMEDIATE_BUF_SIZE);
|
|
free(signature);
|
|
|
|
if (rc) {
|
|
SLOGE("scrypt failed");
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int encrypt_master_key(const char* passwd, const unsigned char* salt,
|
|
const unsigned char* decrypted_master_key,
|
|
unsigned char* encrypted_master_key, struct crypt_mnt_ftr* crypt_ftr) {
|
|
unsigned char ikey[INTERMEDIATE_BUF_SIZE] = {0};
|
|
EVP_CIPHER_CTX e_ctx;
|
|
int encrypted_len, final_len;
|
|
int rc = 0;
|
|
|
|
/* Turn the password into an intermediate key and IV that can decrypt the master key */
|
|
get_device_scrypt_params(crypt_ftr);
|
|
|
|
switch (crypt_ftr->kdf_type) {
|
|
case KDF_SCRYPT_KEYMASTER:
|
|
if (keymaster_create_key(crypt_ftr)) {
|
|
SLOGE("keymaster_create_key failed");
|
|
return -1;
|
|
}
|
|
|
|
if (scrypt_keymaster(passwd, salt, ikey, crypt_ftr)) {
|
|
SLOGE("scrypt failed");
|
|
return -1;
|
|
}
|
|
break;
|
|
|
|
case KDF_SCRYPT:
|
|
if (scrypt(passwd, salt, ikey, crypt_ftr)) {
|
|
SLOGE("scrypt failed");
|
|
return -1;
|
|
}
|
|
break;
|
|
|
|
default:
|
|
SLOGE("Invalid kdf_type");
|
|
return -1;
|
|
}
|
|
|
|
/* Initialize the decryption engine */
|
|
EVP_CIPHER_CTX_init(&e_ctx);
|
|
if (!EVP_EncryptInit_ex(&e_ctx, EVP_aes_128_cbc(), NULL, ikey,
|
|
ikey + INTERMEDIATE_KEY_LEN_BYTES)) {
|
|
SLOGE("EVP_EncryptInit failed\n");
|
|
return -1;
|
|
}
|
|
EVP_CIPHER_CTX_set_padding(&e_ctx, 0); /* Turn off padding as our data is block aligned */
|
|
|
|
/* Encrypt the master key */
|
|
if (!EVP_EncryptUpdate(&e_ctx, encrypted_master_key, &encrypted_len, decrypted_master_key,
|
|
crypt_ftr->keysize)) {
|
|
SLOGE("EVP_EncryptUpdate failed\n");
|
|
return -1;
|
|
}
|
|
if (!EVP_EncryptFinal_ex(&e_ctx, encrypted_master_key + encrypted_len, &final_len)) {
|
|
SLOGE("EVP_EncryptFinal failed\n");
|
|
return -1;
|
|
}
|
|
|
|
if (encrypted_len + final_len != static_cast<int>(crypt_ftr->keysize)) {
|
|
SLOGE("EVP_Encryption length check failed with %d, %d bytes\n", encrypted_len, final_len);
|
|
return -1;
|
|
}
|
|
|
|
/* Store the scrypt of the intermediate key, so we can validate if it's a
|
|
password error or mount error when things go wrong.
|
|
Note there's no need to check for errors, since if this is incorrect, we
|
|
simply won't wipe userdata, which is the correct default behavior
|
|
*/
|
|
int N = 1 << crypt_ftr->N_factor;
|
|
int r = 1 << crypt_ftr->r_factor;
|
|
int p = 1 << crypt_ftr->p_factor;
|
|
|
|
rc = crypto_scrypt(ikey, INTERMEDIATE_KEY_LEN_BYTES, crypt_ftr->salt, sizeof(crypt_ftr->salt),
|
|
N, r, p, crypt_ftr->scrypted_intermediate_key,
|
|
sizeof(crypt_ftr->scrypted_intermediate_key));
|
|
|
|
if (rc) {
|
|
SLOGE("encrypt_master_key: crypto_scrypt failed");
|
|
}
|
|
|
|
EVP_CIPHER_CTX_cleanup(&e_ctx);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int decrypt_master_key_aux(const char* passwd, unsigned char* salt,
|
|
const unsigned char* encrypted_master_key, size_t keysize,
|
|
unsigned char* decrypted_master_key, kdf_func kdf,
|
|
void* kdf_params, unsigned char** intermediate_key,
|
|
size_t* intermediate_key_size) {
|
|
unsigned char ikey[INTERMEDIATE_BUF_SIZE] = {0};
|
|
EVP_CIPHER_CTX d_ctx;
|
|
int decrypted_len, final_len;
|
|
|
|
/* Turn the password into an intermediate key and IV that can decrypt the
|
|
master key */
|
|
if (kdf(passwd, salt, ikey, kdf_params)) {
|
|
SLOGE("kdf failed");
|
|
return -1;
|
|
}
|
|
|
|
/* Initialize the decryption engine */
|
|
EVP_CIPHER_CTX_init(&d_ctx);
|
|
if (!EVP_DecryptInit_ex(&d_ctx, EVP_aes_128_cbc(), NULL, ikey,
|
|
ikey + INTERMEDIATE_KEY_LEN_BYTES)) {
|
|
return -1;
|
|
}
|
|
EVP_CIPHER_CTX_set_padding(&d_ctx, 0); /* Turn off padding as our data is block aligned */
|
|
/* Decrypt the master key */
|
|
if (!EVP_DecryptUpdate(&d_ctx, decrypted_master_key, &decrypted_len, encrypted_master_key,
|
|
keysize)) {
|
|
return -1;
|
|
}
|
|
if (!EVP_DecryptFinal_ex(&d_ctx, decrypted_master_key + decrypted_len, &final_len)) {
|
|
return -1;
|
|
}
|
|
|
|
if (decrypted_len + final_len != static_cast<int>(keysize)) {
|
|
return -1;
|
|
}
|
|
|
|
/* Copy intermediate key if needed by params */
|
|
if (intermediate_key && intermediate_key_size) {
|
|
*intermediate_key = (unsigned char*)malloc(INTERMEDIATE_KEY_LEN_BYTES);
|
|
if (*intermediate_key) {
|
|
memcpy(*intermediate_key, ikey, INTERMEDIATE_KEY_LEN_BYTES);
|
|
*intermediate_key_size = INTERMEDIATE_KEY_LEN_BYTES;
|
|
}
|
|
}
|
|
|
|
EVP_CIPHER_CTX_cleanup(&d_ctx);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void get_kdf_func(struct crypt_mnt_ftr* ftr, kdf_func* kdf, void** kdf_params) {
|
|
if (ftr->kdf_type == KDF_SCRYPT_KEYMASTER) {
|
|
*kdf = scrypt_keymaster;
|
|
*kdf_params = ftr;
|
|
} else if (ftr->kdf_type == KDF_SCRYPT) {
|
|
*kdf = scrypt;
|
|
*kdf_params = ftr;
|
|
} else {
|
|
*kdf = pbkdf2;
|
|
*kdf_params = NULL;
|
|
}
|
|
}
|
|
|
|
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) {
|
|
kdf_func kdf;
|
|
void* kdf_params;
|
|
int ret;
|
|
|
|
get_kdf_func(crypt_ftr, &kdf, &kdf_params);
|
|
ret = decrypt_master_key_aux(passwd, crypt_ftr->salt, crypt_ftr->master_key, crypt_ftr->keysize,
|
|
decrypted_master_key, kdf, kdf_params, intermediate_key,
|
|
intermediate_key_size);
|
|
if (ret != 0) {
|
|
SLOGW("failure decrypting master key");
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int create_encrypted_random_key(const char* passwd, unsigned char* master_key,
|
|
unsigned char* salt, struct crypt_mnt_ftr* crypt_ftr) {
|
|
unsigned char key_buf[MAX_KEY_LEN];
|
|
|
|
/* Get some random bits for a key and salt */
|
|
if (android::vold::ReadRandomBytes(sizeof(key_buf), reinterpret_cast<char*>(key_buf)) != 0) {
|
|
return -1;
|
|
}
|
|
if (android::vold::ReadRandomBytes(SALT_LEN, reinterpret_cast<char*>(salt)) != 0) {
|
|
return -1;
|
|
}
|
|
|
|
/* Now encrypt it with the password */
|
|
return encrypt_master_key(passwd, salt, key_buf, master_key, crypt_ftr);
|
|
}
|
|
|
|
int wait_and_unmount(const char* mountpoint, bool kill) {
|
|
int i, err, rc;
|
|
#define WAIT_UNMOUNT_COUNT 20
|
|
|
|
/* Now umount the tmpfs filesystem */
|
|
for (i = 0; i < WAIT_UNMOUNT_COUNT; i++) {
|
|
if (umount(mountpoint) == 0) {
|
|
break;
|
|
}
|
|
|
|
if (errno == EINVAL) {
|
|
/* EINVAL is returned if the directory is not a mountpoint,
|
|
* i.e. there is no filesystem mounted there. So just get out.
|
|
*/
|
|
break;
|
|
}
|
|
|
|
err = errno;
|
|
|
|
/* If allowed, be increasingly aggressive before the last two retries */
|
|
if (kill) {
|
|
if (i == (WAIT_UNMOUNT_COUNT - 3)) {
|
|
SLOGW("sending SIGHUP to processes with open files\n");
|
|
android::vold::KillProcessesWithOpenFiles(mountpoint, SIGTERM);
|
|
} else if (i == (WAIT_UNMOUNT_COUNT - 2)) {
|
|
SLOGW("sending SIGKILL to processes with open files\n");
|
|
android::vold::KillProcessesWithOpenFiles(mountpoint, SIGKILL);
|
|
}
|
|
}
|
|
|
|
sleep(1);
|
|
}
|
|
|
|
if (i < WAIT_UNMOUNT_COUNT) {
|
|
SLOGD("unmounting %s succeeded\n", mountpoint);
|
|
rc = 0;
|
|
} else {
|
|
android::vold::KillProcessesWithOpenFiles(mountpoint, 0);
|
|
SLOGE("unmounting %s failed: %s\n", mountpoint, strerror(err));
|
|
rc = -1;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
static void prep_data_fs(void) {
|
|
// NOTE: post_fs_data results in init calling back around to vold, so all
|
|
// callers to this method must be async
|
|
|
|
/* Do the prep of the /data filesystem */
|
|
property_set("vold.post_fs_data_done", "0");
|
|
property_set("vold.decrypt", "trigger_post_fs_data");
|
|
SLOGD("Just triggered post_fs_data");
|
|
|
|
/* Wait a max of 50 seconds, hopefully it takes much less */
|
|
while (!android::base::WaitForProperty("vold.post_fs_data_done", "1", std::chrono::seconds(15))) {
|
|
/* We timed out to prep /data in time. Continue wait. */
|
|
SLOGE("waited 15s for vold.post_fs_data_done, still waiting...");
|
|
}
|
|
SLOGD("post_fs_data done");
|
|
}
|
|
|
|
static void cryptfs_set_corrupt() {
|
|
// Mark the footer as bad
|
|
struct crypt_mnt_ftr crypt_ftr;
|
|
if (get_crypt_ftr_and_key(&crypt_ftr)) {
|
|
SLOGE("Failed to get crypto footer - panic");
|
|
return;
|
|
}
|
|
|
|
crypt_ftr.flags |= CRYPT_DATA_CORRUPT;
|
|
if (put_crypt_ftr_and_key(&crypt_ftr)) {
|
|
SLOGE("Failed to set crypto footer - panic");
|
|
return;
|
|
}
|
|
}
|
|
|
|
static void cryptfs_trigger_restart_min_framework() {
|
|
if (fs_mgr_do_tmpfs_mount(DATA_MNT_POINT)) {
|
|
SLOGE("Failed to mount tmpfs on data - panic");
|
|
return;
|
|
}
|
|
|
|
if (property_set("vold.decrypt", "trigger_post_fs_data")) {
|
|
SLOGE("Failed to trigger post fs data - panic");
|
|
return;
|
|
}
|
|
|
|
if (property_set("vold.decrypt", "trigger_restart_min_framework")) {
|
|
SLOGE("Failed to trigger restart min framework - panic");
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* returns < 0 on failure */
|
|
static int cryptfs_restart_internal(int restart_main) {
|
|
char crypto_blkdev[MAXPATHLEN];
|
|
int rc = -1;
|
|
static int restart_successful = 0;
|
|
|
|
/* Validate that it's OK to call this routine */
|
|
if (!master_key_saved) {
|
|
SLOGE("Encrypted filesystem not validated, aborting");
|
|
return -1;
|
|
}
|
|
|
|
if (restart_successful) {
|
|
SLOGE("System already restarted with encrypted disk, aborting");
|
|
return -1;
|
|
}
|
|
|
|
if (restart_main) {
|
|
/* Here is where we shut down the framework. The init scripts
|
|
* start all services in one of three classes: core, main or late_start.
|
|
* On boot, we start core and main. Now, we stop main, but not core,
|
|
* as core includes vold and a few other really important things that
|
|
* we need to keep running. Once main has stopped, we should be able
|
|
* to umount the tmpfs /data, then mount the encrypted /data.
|
|
* We then restart the class main, and also the class late_start.
|
|
* At the moment, I've only put a few things in late_start that I know
|
|
* are not needed to bring up the framework, and that also cause problems
|
|
* with unmounting the tmpfs /data, but I hope to add add more services
|
|
* to the late_start class as we optimize this to decrease the delay
|
|
* till the user is asked for the password to the filesystem.
|
|
*/
|
|
|
|
/* The init files are setup to stop the class main when vold.decrypt is
|
|
* set to trigger_reset_main.
|
|
*/
|
|
property_set("vold.decrypt", "trigger_reset_main");
|
|
SLOGD("Just asked init to shut down class main\n");
|
|
|
|
/* Ugh, shutting down the framework is not synchronous, so until it
|
|
* can be fixed, this horrible hack will wait a moment for it all to
|
|
* shut down before proceeding. Without it, some devices cannot
|
|
* restart the graphics services.
|
|
*/
|
|
sleep(2);
|
|
}
|
|
|
|
/* Now that the framework is shutdown, we should be able to umount()
|
|
* the tmpfs filesystem, and mount the real one.
|
|
*/
|
|
|
|
property_get("ro.crypto.fs_crypto_blkdev", crypto_blkdev, "");
|
|
if (strlen(crypto_blkdev) == 0) {
|
|
SLOGE("fs_crypto_blkdev not set\n");
|
|
return -1;
|
|
}
|
|
|
|
if (!(rc = wait_and_unmount(DATA_MNT_POINT, true))) {
|
|
/* If ro.crypto.readonly is set to 1, mount the decrypted
|
|
* filesystem readonly. This is used when /data is mounted by
|
|
* recovery mode.
|
|
*/
|
|
char ro_prop[PROPERTY_VALUE_MAX];
|
|
property_get("ro.crypto.readonly", ro_prop, "");
|
|
if (strlen(ro_prop) > 0 && std::stoi(ro_prop)) {
|
|
auto entry = GetEntryForMountPoint(&fstab_default, DATA_MNT_POINT);
|
|
if (entry != nullptr) {
|
|
entry->flags |= MS_RDONLY;
|
|
}
|
|
}
|
|
|
|
/* If that succeeded, then mount the decrypted filesystem */
|
|
int retries = RETRY_MOUNT_ATTEMPTS;
|
|
int mount_rc;
|
|
|
|
/*
|
|
* fs_mgr_do_mount runs fsck. Use setexeccon to run trusted
|
|
* partitions in the fsck domain.
|
|
*/
|
|
if (setexeccon(android::vold::sFsckContext)) {
|
|
SLOGE("Failed to setexeccon");
|
|
return -1;
|
|
}
|
|
bool needs_cp = android::vold::cp_needsCheckpoint();
|
|
while ((mount_rc = fs_mgr_do_mount(&fstab_default, DATA_MNT_POINT, crypto_blkdev, 0,
|
|
needs_cp)) != 0) {
|
|
if (mount_rc == FS_MGR_DOMNT_BUSY) {
|
|
/* TODO: invoke something similar to
|
|
Process::killProcessWithOpenFiles(DATA_MNT_POINT,
|
|
retries > RETRY_MOUNT_ATTEMPT/2 ? 1 : 2 ) */
|
|
SLOGI("Failed to mount %s because it is busy - waiting", crypto_blkdev);
|
|
if (--retries) {
|
|
sleep(RETRY_MOUNT_DELAY_SECONDS);
|
|
} else {
|
|
/* Let's hope that a reboot clears away whatever is keeping
|
|
the mount busy */
|
|
cryptfs_reboot(RebootType::reboot);
|
|
}
|
|
} else {
|
|
SLOGE("Failed to mount decrypted data");
|
|
cryptfs_set_corrupt();
|
|
cryptfs_trigger_restart_min_framework();
|
|
SLOGI("Started framework to offer wipe");
|
|
if (setexeccon(NULL)) {
|
|
SLOGE("Failed to setexeccon");
|
|
}
|
|
return -1;
|
|
}
|
|
}
|
|
if (setexeccon(NULL)) {
|
|
SLOGE("Failed to setexeccon");
|
|
return -1;
|
|
}
|
|
|
|
/* Create necessary paths on /data */
|
|
prep_data_fs();
|
|
property_set("vold.decrypt", "trigger_load_persist_props");
|
|
|
|
/* startup service classes main and late_start */
|
|
property_set("vold.decrypt", "trigger_restart_framework");
|
|
SLOGD("Just triggered restart_framework\n");
|
|
|
|
/* Give it a few moments to get started */
|
|
sleep(1);
|
|
}
|
|
|
|
if (rc == 0) {
|
|
restart_successful = 1;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
int cryptfs_restart(void) {
|
|
SLOGI("cryptfs_restart");
|
|
if (fscrypt_is_native()) {
|
|
SLOGE("cryptfs_restart not valid for file encryption:");
|
|
return -1;
|
|
}
|
|
|
|
/* Call internal implementation forcing a restart of main service group */
|
|
return cryptfs_restart_internal(1);
|
|
}
|
|
|
|
static int do_crypto_complete(const char* mount_point) {
|
|
struct crypt_mnt_ftr crypt_ftr;
|
|
char encrypted_state[PROPERTY_VALUE_MAX];
|
|
|
|
property_get("ro.crypto.state", encrypted_state, "");
|
|
if (strcmp(encrypted_state, "encrypted")) {
|
|
SLOGE("not running with encryption, aborting");
|
|
return CRYPTO_COMPLETE_NOT_ENCRYPTED;
|
|
}
|
|
|
|
// crypto_complete is full disk encrypted status
|
|
if (fscrypt_is_native()) {
|
|
return CRYPTO_COMPLETE_NOT_ENCRYPTED;
|
|
}
|
|
|
|
if (get_crypt_ftr_and_key(&crypt_ftr)) {
|
|
std::string key_loc;
|
|
get_crypt_info(&key_loc, nullptr);
|
|
|
|
/*
|
|
* Only report this error if key_loc is a file and it exists.
|
|
* If the device was never encrypted, and /data is not mountable for
|
|
* some reason, returning 1 should prevent the UI from presenting the
|
|
* a "enter password" screen, or worse, a "press button to wipe the
|
|
* device" screen.
|
|
*/
|
|
if (!key_loc.empty() && key_loc[0] == '/' && (access("key_loc", F_OK) == -1)) {
|
|
SLOGE("master key file does not exist, aborting");
|
|
return CRYPTO_COMPLETE_NOT_ENCRYPTED;
|
|
} else {
|
|
SLOGE("Error getting crypt footer and key\n");
|
|
return CRYPTO_COMPLETE_BAD_METADATA;
|
|
}
|
|
}
|
|
|
|
// Test for possible error flags
|
|
if (crypt_ftr.flags & CRYPT_ENCRYPTION_IN_PROGRESS) {
|
|
SLOGE("Encryption process is partway completed\n");
|
|
return CRYPTO_COMPLETE_PARTIAL;
|
|
}
|
|
|
|
if (crypt_ftr.flags & CRYPT_INCONSISTENT_STATE) {
|
|
SLOGE("Encryption process was interrupted but cannot continue\n");
|
|
return CRYPTO_COMPLETE_INCONSISTENT;
|
|
}
|
|
|
|
if (crypt_ftr.flags & CRYPT_DATA_CORRUPT) {
|
|
SLOGE("Encryption is successful but data is corrupt\n");
|
|
return CRYPTO_COMPLETE_CORRUPT;
|
|
}
|
|
|
|
/* We passed the test! We shall diminish, and return to the west */
|
|
return CRYPTO_COMPLETE_ENCRYPTED;
|
|
}
|
|
|
|
static int test_mount_encrypted_fs(struct crypt_mnt_ftr* crypt_ftr, const char* passwd,
|
|
const char* mount_point, const char* label) {
|
|
unsigned char decrypted_master_key[MAX_KEY_LEN];
|
|
char crypto_blkdev[MAXPATHLEN];
|
|
std::string real_blkdev;
|
|
char tmp_mount_point[64];
|
|
unsigned int orig_failed_decrypt_count;
|
|
int rc;
|
|
int use_keymaster = 0;
|
|
int upgrade = 0;
|
|
unsigned char* intermediate_key = 0;
|
|
size_t intermediate_key_size = 0;
|
|
int N = 1 << crypt_ftr->N_factor;
|
|
int r = 1 << crypt_ftr->r_factor;
|
|
int p = 1 << crypt_ftr->p_factor;
|
|
|
|
SLOGD("crypt_ftr->fs_size = %lld\n", crypt_ftr->fs_size);
|
|
orig_failed_decrypt_count = crypt_ftr->failed_decrypt_count;
|
|
|
|
if (!(crypt_ftr->flags & CRYPT_MNT_KEY_UNENCRYPTED)) {
|
|
if (decrypt_master_key(passwd, decrypted_master_key, crypt_ftr, &intermediate_key,
|
|
&intermediate_key_size)) {
|
|
SLOGE("Failed to decrypt master key\n");
|
|
rc = -1;
|
|
goto errout;
|
|
}
|
|
}
|
|
|
|
get_crypt_info(nullptr, &real_blkdev);
|
|
|
|
// Create crypto block device - all (non fatal) code paths
|
|
// need it
|
|
if (create_crypto_blk_dev(crypt_ftr, decrypted_master_key, real_blkdev.c_str(), crypto_blkdev,
|
|
label, 0)) {
|
|
SLOGE("Error creating decrypted block device\n");
|
|
rc = -1;
|
|
goto errout;
|
|
}
|
|
|
|
/* Work out if the problem is the password or the data */
|
|
unsigned char scrypted_intermediate_key[sizeof(crypt_ftr->scrypted_intermediate_key)];
|
|
|
|
rc = crypto_scrypt(intermediate_key, intermediate_key_size, crypt_ftr->salt,
|
|
sizeof(crypt_ftr->salt), N, r, p, scrypted_intermediate_key,
|
|
sizeof(scrypted_intermediate_key));
|
|
|
|
// Does the key match the crypto footer?
|
|
if (rc == 0 && memcmp(scrypted_intermediate_key, crypt_ftr->scrypted_intermediate_key,
|
|
sizeof(scrypted_intermediate_key)) == 0) {
|
|
SLOGI("Password matches");
|
|
rc = 0;
|
|
} else {
|
|
/* Try mounting the file system anyway, just in case the problem's with
|
|
* the footer, not the key. */
|
|
snprintf(tmp_mount_point, sizeof(tmp_mount_point), "%s/tmp_mnt", mount_point);
|
|
mkdir(tmp_mount_point, 0755);
|
|
if (fs_mgr_do_mount(&fstab_default, DATA_MNT_POINT, crypto_blkdev, tmp_mount_point)) {
|
|
SLOGE("Error temp mounting decrypted block device\n");
|
|
delete_crypto_blk_dev(label);
|
|
|
|
rc = ++crypt_ftr->failed_decrypt_count;
|
|
put_crypt_ftr_and_key(crypt_ftr);
|
|
} else {
|
|
/* Success! */
|
|
SLOGI("Password did not match but decrypted drive mounted - continue");
|
|
umount(tmp_mount_point);
|
|
rc = 0;
|
|
}
|
|
}
|
|
|
|
if (rc == 0) {
|
|
crypt_ftr->failed_decrypt_count = 0;
|
|
if (orig_failed_decrypt_count != 0) {
|
|
put_crypt_ftr_and_key(crypt_ftr);
|
|
}
|
|
|
|
/* Save the name of the crypto block device
|
|
* so we can mount it when restarting the framework. */
|
|
property_set("ro.crypto.fs_crypto_blkdev", crypto_blkdev);
|
|
|
|
/* Also save a the master key so we can reencrypted the key
|
|
* the key when we want to change the password on it. */
|
|
memcpy(saved_master_key, decrypted_master_key, crypt_ftr->keysize);
|
|
saved_mount_point = strdup(mount_point);
|
|
master_key_saved = 1;
|
|
SLOGD("%s(): Master key saved\n", __FUNCTION__);
|
|
rc = 0;
|
|
|
|
// Upgrade if we're not using the latest KDF.
|
|
use_keymaster = keymaster_check_compatibility();
|
|
if (crypt_ftr->kdf_type == KDF_SCRYPT_KEYMASTER) {
|
|
// Don't allow downgrade
|
|
} else if (use_keymaster == 1 && crypt_ftr->kdf_type != KDF_SCRYPT_KEYMASTER) {
|
|
crypt_ftr->kdf_type = KDF_SCRYPT_KEYMASTER;
|
|
upgrade = 1;
|
|
} else if (use_keymaster == 0 && crypt_ftr->kdf_type != KDF_SCRYPT) {
|
|
crypt_ftr->kdf_type = KDF_SCRYPT;
|
|
upgrade = 1;
|
|
}
|
|
|
|
if (upgrade) {
|
|
rc = encrypt_master_key(passwd, crypt_ftr->salt, saved_master_key,
|
|
crypt_ftr->master_key, crypt_ftr);
|
|
if (!rc) {
|
|
rc = put_crypt_ftr_and_key(crypt_ftr);
|
|
}
|
|
SLOGD("Key Derivation Function upgrade: rc=%d\n", rc);
|
|
|
|
// Do not fail even if upgrade failed - machine is bootable
|
|
// Note that if this code is ever hit, there is a *serious* problem
|
|
// since KDFs should never fail. You *must* fix the kdf before
|
|
// proceeding!
|
|
if (rc) {
|
|
SLOGW(
|
|
"Upgrade failed with error %d,"
|
|
" but continuing with previous state",
|
|
rc);
|
|
rc = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
errout:
|
|
if (intermediate_key) {
|
|
memset(intermediate_key, 0, intermediate_key_size);
|
|
free(intermediate_key);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Called by vold when it's asked to mount an encrypted external
|
|
* storage volume. The incoming partition has no crypto header/footer,
|
|
* as any metadata is been stored in a separate, small partition. We
|
|
* assume it must be using our same crypt type and keysize.
|
|
*
|
|
* out_crypto_blkdev must be MAXPATHLEN.
|
|
*/
|
|
int cryptfs_setup_ext_volume(const char* label, const char* real_blkdev, const unsigned char* key,
|
|
char* out_crypto_blkdev) {
|
|
uint64_t nr_sec = 0;
|
|
if (android::vold::GetBlockDev512Sectors(real_blkdev, &nr_sec) != android::OK) {
|
|
SLOGE("Failed to get size of %s: %s", real_blkdev, strerror(errno));
|
|
return -1;
|
|
}
|
|
|
|
struct crypt_mnt_ftr ext_crypt_ftr;
|
|
memset(&ext_crypt_ftr, 0, sizeof(ext_crypt_ftr));
|
|
ext_crypt_ftr.fs_size = nr_sec;
|
|
ext_crypt_ftr.keysize = cryptfs_get_keysize();
|
|
strlcpy((char*)ext_crypt_ftr.crypto_type_name, cryptfs_get_crypto_name(),
|
|
MAX_CRYPTO_TYPE_NAME_LEN);
|
|
uint32_t flags = 0;
|
|
if (fscrypt_is_native() &&
|
|
android::base::GetBoolProperty("ro.crypto.allow_encrypt_override", false))
|
|
flags |= CREATE_CRYPTO_BLK_DEV_FLAGS_ALLOW_ENCRYPT_OVERRIDE;
|
|
|
|
return create_crypto_blk_dev(&ext_crypt_ftr, key, real_blkdev, out_crypto_blkdev, label, flags);
|
|
}
|
|
|
|
/*
|
|
* Called by vold when it's asked to unmount an encrypted external
|
|
* storage volume.
|
|
*/
|
|
int cryptfs_revert_ext_volume(const char* label) {
|
|
return delete_crypto_blk_dev((char*)label);
|
|
}
|
|
|
|
int cryptfs_crypto_complete(void) {
|
|
return do_crypto_complete("/data");
|
|
}
|
|
|
|
int check_unmounted_and_get_ftr(struct crypt_mnt_ftr* crypt_ftr) {
|
|
char encrypted_state[PROPERTY_VALUE_MAX];
|
|
property_get("ro.crypto.state", encrypted_state, "");
|
|
if (master_key_saved || strcmp(encrypted_state, "encrypted")) {
|
|
SLOGE(
|
|
"encrypted fs already validated or not running with encryption,"
|
|
" aborting");
|
|
return -1;
|
|
}
|
|
|
|
if (get_crypt_ftr_and_key(crypt_ftr)) {
|
|
SLOGE("Error getting crypt footer and key");
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int cryptfs_check_passwd(const char* passwd) {
|
|
SLOGI("cryptfs_check_passwd");
|
|
if (fscrypt_is_native()) {
|
|
SLOGE("cryptfs_check_passwd not valid for file encryption");
|
|
return -1;
|
|
}
|
|
|
|
struct crypt_mnt_ftr crypt_ftr;
|
|
int rc;
|
|
|
|
rc = check_unmounted_and_get_ftr(&crypt_ftr);
|
|
if (rc) {
|
|
SLOGE("Could not get footer");
|
|
return rc;
|
|
}
|
|
|
|
rc = test_mount_encrypted_fs(&crypt_ftr, passwd, DATA_MNT_POINT, CRYPTO_BLOCK_DEVICE);
|
|
if (rc) {
|
|
SLOGE("Password did not match");
|
|
return rc;
|
|
}
|
|
|
|
if (crypt_ftr.flags & CRYPT_FORCE_COMPLETE) {
|
|
// Here we have a default actual password but a real password
|
|
// we must test against the scrypted value
|
|
// First, we must delete the crypto block device that
|
|
// test_mount_encrypted_fs leaves behind as a side effect
|
|
delete_crypto_blk_dev(CRYPTO_BLOCK_DEVICE);
|
|
rc = test_mount_encrypted_fs(&crypt_ftr, DEFAULT_PASSWORD, DATA_MNT_POINT,
|
|
CRYPTO_BLOCK_DEVICE);
|
|
if (rc) {
|
|
SLOGE("Default password did not match on reboot encryption");
|
|
return rc;
|
|
}
|
|
|
|
crypt_ftr.flags &= ~CRYPT_FORCE_COMPLETE;
|
|
put_crypt_ftr_and_key(&crypt_ftr);
|
|
rc = cryptfs_changepw(crypt_ftr.crypt_type, passwd);
|
|
if (rc) {
|
|
SLOGE("Could not change password on reboot encryption");
|
|
return rc;
|
|
}
|
|
}
|
|
|
|
if (crypt_ftr.crypt_type != CRYPT_TYPE_DEFAULT) {
|
|
cryptfs_clear_password();
|
|
password = strdup(passwd);
|
|
struct timespec now;
|
|
clock_gettime(CLOCK_BOOTTIME, &now);
|
|
password_expiry_time = now.tv_sec + password_max_age_seconds;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
int cryptfs_verify_passwd(const char* passwd) {
|
|
struct crypt_mnt_ftr crypt_ftr;
|
|
unsigned char decrypted_master_key[MAX_KEY_LEN];
|
|
char encrypted_state[PROPERTY_VALUE_MAX];
|
|
int rc;
|
|
|
|
property_get("ro.crypto.state", encrypted_state, "");
|
|
if (strcmp(encrypted_state, "encrypted")) {
|
|
SLOGE("device not encrypted, aborting");
|
|
return -2;
|
|
}
|
|
|
|
if (!master_key_saved) {
|
|
SLOGE("encrypted fs not yet mounted, aborting");
|
|
return -1;
|
|
}
|
|
|
|
if (!saved_mount_point) {
|
|
SLOGE("encrypted fs failed to save mount point, aborting");
|
|
return -1;
|
|
}
|
|
|
|
if (get_crypt_ftr_and_key(&crypt_ftr)) {
|
|
SLOGE("Error getting crypt footer and key\n");
|
|
return -1;
|
|
}
|
|
|
|
if (crypt_ftr.flags & CRYPT_MNT_KEY_UNENCRYPTED) {
|
|
/* If the device has no password, then just say the password is valid */
|
|
rc = 0;
|
|
} else {
|
|
decrypt_master_key(passwd, decrypted_master_key, &crypt_ftr, 0, 0);
|
|
if (!memcmp(decrypted_master_key, saved_master_key, crypt_ftr.keysize)) {
|
|
/* They match, the password is correct */
|
|
rc = 0;
|
|
} else {
|
|
/* If incorrect, sleep for a bit to prevent dictionary attacks */
|
|
sleep(1);
|
|
rc = 1;
|
|
}
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/* Initialize a crypt_mnt_ftr structure. The keysize is
|
|
* defaulted to cryptfs_get_keysize() bytes, and the filesystem size to 0.
|
|
* Presumably, at a minimum, the caller will update the
|
|
* filesystem size and crypto_type_name after calling this function.
|
|
*/
|
|
static int cryptfs_init_crypt_mnt_ftr(struct crypt_mnt_ftr* ftr) {
|
|
off64_t off;
|
|
|
|
memset(ftr, 0, sizeof(struct crypt_mnt_ftr));
|
|
ftr->magic = CRYPT_MNT_MAGIC;
|
|
ftr->major_version = CURRENT_MAJOR_VERSION;
|
|
ftr->minor_version = CURRENT_MINOR_VERSION;
|
|
ftr->ftr_size = sizeof(struct crypt_mnt_ftr);
|
|
ftr->keysize = cryptfs_get_keysize();
|
|
|
|
switch (keymaster_check_compatibility()) {
|
|
case 1:
|
|
ftr->kdf_type = KDF_SCRYPT_KEYMASTER;
|
|
break;
|
|
|
|
case 0:
|
|
ftr->kdf_type = KDF_SCRYPT;
|
|
break;
|
|
|
|
default:
|
|
SLOGE("keymaster_check_compatibility failed");
|
|
return -1;
|
|
}
|
|
|
|
get_device_scrypt_params(ftr);
|
|
|
|
ftr->persist_data_size = CRYPT_PERSIST_DATA_SIZE;
|
|
if (get_crypt_ftr_info(NULL, &off) == 0) {
|
|
ftr->persist_data_offset[0] = off + CRYPT_FOOTER_TO_PERSIST_OFFSET;
|
|
ftr->persist_data_offset[1] = off + CRYPT_FOOTER_TO_PERSIST_OFFSET + ftr->persist_data_size;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define FRAMEWORK_BOOT_WAIT 60
|
|
|
|
static int cryptfs_SHA256_fileblock(const char* filename, __le8* buf) {
|
|
int fd = open(filename, O_RDONLY | O_CLOEXEC);
|
|
if (fd == -1) {
|
|
SLOGE("Error opening file %s", filename);
|
|
return -1;
|
|
}
|
|
|
|
char block[CRYPT_INPLACE_BUFSIZE];
|
|
memset(block, 0, sizeof(block));
|
|
if (unix_read(fd, block, sizeof(block)) < 0) {
|
|
SLOGE("Error reading file %s", filename);
|
|
close(fd);
|
|
return -1;
|
|
}
|
|
|
|
close(fd);
|
|
|
|
SHA256_CTX c;
|
|
SHA256_Init(&c);
|
|
SHA256_Update(&c, block, sizeof(block));
|
|
SHA256_Final(buf, &c);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int cryptfs_enable_all_volumes(struct crypt_mnt_ftr* crypt_ftr, char* crypto_blkdev,
|
|
char* real_blkdev, int previously_encrypted_upto) {
|
|
off64_t cur_encryption_done = 0, tot_encryption_size = 0;
|
|
int rc = -1;
|
|
|
|
/* The size of the userdata partition, and add in the vold volumes below */
|
|
tot_encryption_size = crypt_ftr->fs_size;
|
|
|
|
rc = cryptfs_enable_inplace(crypto_blkdev, real_blkdev, crypt_ftr->fs_size, &cur_encryption_done,
|
|
tot_encryption_size, previously_encrypted_upto, true);
|
|
|
|
if (rc == ENABLE_INPLACE_ERR_DEV) {
|
|
/* Hack for b/17898962 */
|
|
SLOGE("cryptfs_enable: crypto block dev failure. Must reboot...\n");
|
|
cryptfs_reboot(RebootType::reboot);
|
|
}
|
|
|
|
if (!rc) {
|
|
crypt_ftr->encrypted_upto = cur_encryption_done;
|
|
}
|
|
|
|
if (!rc && crypt_ftr->encrypted_upto == crypt_ftr->fs_size) {
|
|
/* The inplace routine never actually sets the progress to 100% due
|
|
* to the round down nature of integer division, so set it here */
|
|
property_set("vold.encrypt_progress", "100");
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int vold_unmountAll(void) {
|
|
VolumeManager* vm = VolumeManager::Instance();
|
|
return vm->unmountAll();
|
|
}
|
|
|
|
int cryptfs_enable_internal(int crypt_type, const char* passwd, int no_ui) {
|
|
char crypto_blkdev[MAXPATHLEN];
|
|
std::string real_blkdev;
|
|
unsigned char decrypted_master_key[MAX_KEY_LEN];
|
|
int rc = -1, i;
|
|
struct crypt_mnt_ftr crypt_ftr;
|
|
struct crypt_persist_data* pdata;
|
|
char encrypted_state[PROPERTY_VALUE_MAX];
|
|
char lockid[32] = {0};
|
|
std::string key_loc;
|
|
int num_vols;
|
|
off64_t previously_encrypted_upto = 0;
|
|
bool rebootEncryption = false;
|
|
bool onlyCreateHeader = false;
|
|
|
|
if (get_crypt_ftr_and_key(&crypt_ftr) == 0) {
|
|
if (crypt_ftr.flags & CRYPT_ENCRYPTION_IN_PROGRESS) {
|
|
/* An encryption was underway and was interrupted */
|
|
previously_encrypted_upto = crypt_ftr.encrypted_upto;
|
|
crypt_ftr.encrypted_upto = 0;
|
|
crypt_ftr.flags &= ~CRYPT_ENCRYPTION_IN_PROGRESS;
|
|
|
|
/* At this point, we are in an inconsistent state. Until we successfully
|
|
complete encryption, a reboot will leave us broken. So mark the
|
|
encryption failed in case that happens.
|
|
On successfully completing encryption, remove this flag */
|
|
crypt_ftr.flags |= CRYPT_INCONSISTENT_STATE;
|
|
|
|
put_crypt_ftr_and_key(&crypt_ftr);
|
|
} else if (crypt_ftr.flags & CRYPT_FORCE_ENCRYPTION) {
|
|
if (!check_ftr_sha(&crypt_ftr)) {
|
|
memset(&crypt_ftr, 0, sizeof(crypt_ftr));
|
|
put_crypt_ftr_and_key(&crypt_ftr);
|
|
goto error_unencrypted;
|
|
}
|
|
|
|
/* Doing a reboot-encryption*/
|
|
crypt_ftr.flags &= ~CRYPT_FORCE_ENCRYPTION;
|
|
crypt_ftr.flags |= CRYPT_FORCE_COMPLETE;
|
|
rebootEncryption = true;
|
|
}
|
|
} else {
|
|
// We don't want to accidentally reference invalid data.
|
|
memset(&crypt_ftr, 0, sizeof(crypt_ftr));
|
|
}
|
|
|
|
property_get("ro.crypto.state", encrypted_state, "");
|
|
if (!strcmp(encrypted_state, "encrypted") && !previously_encrypted_upto) {
|
|
SLOGE("Device is already running encrypted, aborting");
|
|
goto error_unencrypted;
|
|
}
|
|
|
|
get_crypt_info(&key_loc, &real_blkdev);
|
|
|
|
/* Get the size of the real block device */
|
|
uint64_t nr_sec;
|
|
if (android::vold::GetBlockDev512Sectors(real_blkdev, &nr_sec) != android::OK) {
|
|
SLOGE("Cannot get size of block device %s\n", real_blkdev.c_str());
|
|
goto error_unencrypted;
|
|
}
|
|
|
|
/* If doing inplace encryption, make sure the orig fs doesn't include the crypto footer */
|
|
if (key_loc == KEY_IN_FOOTER) {
|
|
uint64_t fs_size_sec, max_fs_size_sec;
|
|
fs_size_sec = get_fs_size(real_blkdev.c_str());
|
|
if (fs_size_sec == 0) fs_size_sec = get_f2fs_filesystem_size_sec(real_blkdev.data());
|
|
|
|
max_fs_size_sec = nr_sec - (CRYPT_FOOTER_OFFSET / CRYPT_SECTOR_SIZE);
|
|
|
|
if (fs_size_sec > max_fs_size_sec) {
|
|
SLOGE("Orig filesystem overlaps crypto footer region. Cannot encrypt in place.");
|
|
goto error_unencrypted;
|
|
}
|
|
}
|
|
|
|
/* Get a wakelock as this may take a while, and we don't want the
|
|
* device to sleep on us. We'll grab a partial wakelock, and if the UI
|
|
* wants to keep the screen on, it can grab a full wakelock.
|
|
*/
|
|
snprintf(lockid, sizeof(lockid), "enablecrypto%d", (int)getpid());
|
|
acquire_wake_lock(PARTIAL_WAKE_LOCK, lockid);
|
|
|
|
/* The init files are setup to stop the class main and late start when
|
|
* vold sets trigger_shutdown_framework.
|
|
*/
|
|
property_set("vold.decrypt", "trigger_shutdown_framework");
|
|
SLOGD("Just asked init to shut down class main\n");
|
|
|
|
/* Ask vold to unmount all devices that it manages */
|
|
if (vold_unmountAll()) {
|
|
SLOGE("Failed to unmount all vold managed devices");
|
|
}
|
|
|
|
/* no_ui means we are being called from init, not settings.
|
|
Now we always reboot from settings, so !no_ui means reboot
|
|
*/
|
|
if (!no_ui) {
|
|
/* Try fallback, which is to reboot and try there */
|
|
onlyCreateHeader = true;
|
|
FILE* breadcrumb = fopen(BREADCRUMB_FILE, "we");
|
|
if (breadcrumb == 0) {
|
|
SLOGE("Failed to create breadcrumb file");
|
|
goto error_shutting_down;
|
|
}
|
|
fclose(breadcrumb);
|
|
}
|
|
|
|
/* Do extra work for a better UX when doing the long inplace encryption */
|
|
if (!onlyCreateHeader) {
|
|
/* Now that /data is unmounted, we need to mount a tmpfs
|
|
* /data, set a property saying we're doing inplace encryption,
|
|
* and restart the framework.
|
|
*/
|
|
if (fs_mgr_do_tmpfs_mount(DATA_MNT_POINT)) {
|
|
goto error_shutting_down;
|
|
}
|
|
/* Tells the framework that inplace encryption is starting */
|
|
property_set("vold.encrypt_progress", "0");
|
|
|
|
/* restart the framework. */
|
|
/* Create necessary paths on /data */
|
|
prep_data_fs();
|
|
|
|
/* Ugh, shutting down the framework is not synchronous, so until it
|
|
* can be fixed, this horrible hack will wait a moment for it all to
|
|
* shut down before proceeding. Without it, some devices cannot
|
|
* restart the graphics services.
|
|
*/
|
|
sleep(2);
|
|
}
|
|
|
|
/* Start the actual work of making an encrypted filesystem */
|
|
/* Initialize a crypt_mnt_ftr for the partition */
|
|
if (previously_encrypted_upto == 0 && !rebootEncryption) {
|
|
if (cryptfs_init_crypt_mnt_ftr(&crypt_ftr)) {
|
|
goto error_shutting_down;
|
|
}
|
|
|
|
if (key_loc == KEY_IN_FOOTER) {
|
|
crypt_ftr.fs_size = nr_sec - (CRYPT_FOOTER_OFFSET / CRYPT_SECTOR_SIZE);
|
|
} else {
|
|
crypt_ftr.fs_size = nr_sec;
|
|
}
|
|
/* At this point, we are in an inconsistent state. Until we successfully
|
|
complete encryption, a reboot will leave us broken. So mark the
|
|
encryption failed in case that happens.
|
|
On successfully completing encryption, remove this flag */
|
|
if (onlyCreateHeader) {
|
|
crypt_ftr.flags |= CRYPT_FORCE_ENCRYPTION;
|
|
} else {
|
|
crypt_ftr.flags |= CRYPT_INCONSISTENT_STATE;
|
|
}
|
|
crypt_ftr.crypt_type = crypt_type;
|
|
strlcpy((char*)crypt_ftr.crypto_type_name, cryptfs_get_crypto_name(),
|
|
MAX_CRYPTO_TYPE_NAME_LEN);
|
|
|
|
/* Make an encrypted master key */
|
|
if (create_encrypted_random_key(onlyCreateHeader ? DEFAULT_PASSWORD : passwd,
|
|
crypt_ftr.master_key, crypt_ftr.salt, &crypt_ftr)) {
|
|
SLOGE("Cannot create encrypted master key\n");
|
|
goto error_shutting_down;
|
|
}
|
|
|
|
/* Replace scrypted intermediate key if we are preparing for a reboot */
|
|
if (onlyCreateHeader) {
|
|
unsigned char fake_master_key[MAX_KEY_LEN];
|
|
unsigned char encrypted_fake_master_key[MAX_KEY_LEN];
|
|
memset(fake_master_key, 0, sizeof(fake_master_key));
|
|
encrypt_master_key(passwd, crypt_ftr.salt, fake_master_key, encrypted_fake_master_key,
|
|
&crypt_ftr);
|
|
}
|
|
|
|
/* Write the key to the end of the partition */
|
|
put_crypt_ftr_and_key(&crypt_ftr);
|
|
|
|
/* If any persistent data has been remembered, save it.
|
|
* If none, create a valid empty table and save that.
|
|
*/
|
|
if (!persist_data) {
|
|
pdata = (crypt_persist_data*)malloc(CRYPT_PERSIST_DATA_SIZE);
|
|
if (pdata) {
|
|
init_empty_persist_data(pdata, CRYPT_PERSIST_DATA_SIZE);
|
|
persist_data = pdata;
|
|
}
|
|
}
|
|
if (persist_data) {
|
|
save_persistent_data();
|
|
}
|
|
}
|
|
|
|
if (onlyCreateHeader) {
|
|
sleep(2);
|
|
cryptfs_reboot(RebootType::reboot);
|
|
}
|
|
|
|
if (!no_ui || rebootEncryption) {
|
|
/* startup service classes main and late_start */
|
|
property_set("vold.decrypt", "trigger_restart_min_framework");
|
|
SLOGD("Just triggered restart_min_framework\n");
|
|
|
|
/* OK, the framework is restarted and will soon be showing a
|
|
* progress bar. Time to setup an encrypted mapping, and
|
|
* either write a new filesystem, or encrypt in place updating
|
|
* the progress bar as we work.
|
|
*/
|
|
}
|
|
|
|
decrypt_master_key(passwd, decrypted_master_key, &crypt_ftr, 0, 0);
|
|
create_crypto_blk_dev(&crypt_ftr, decrypted_master_key, real_blkdev.c_str(), crypto_blkdev,
|
|
CRYPTO_BLOCK_DEVICE, 0);
|
|
|
|
/* If we are continuing, check checksums match */
|
|
rc = 0;
|
|
if (previously_encrypted_upto) {
|
|
__le8 hash_first_block[SHA256_DIGEST_LENGTH];
|
|
rc = cryptfs_SHA256_fileblock(crypto_blkdev, hash_first_block);
|
|
|
|
if (!rc &&
|
|
memcmp(hash_first_block, crypt_ftr.hash_first_block, sizeof(hash_first_block)) != 0) {
|
|
SLOGE("Checksums do not match - trigger wipe");
|
|
rc = -1;
|
|
}
|
|
}
|
|
|
|
if (!rc) {
|
|
rc = cryptfs_enable_all_volumes(&crypt_ftr, crypto_blkdev, real_blkdev.data(),
|
|
previously_encrypted_upto);
|
|
}
|
|
|
|
/* Calculate checksum if we are not finished */
|
|
if (!rc && crypt_ftr.encrypted_upto != crypt_ftr.fs_size) {
|
|
rc = cryptfs_SHA256_fileblock(crypto_blkdev, crypt_ftr.hash_first_block);
|
|
if (rc) {
|
|
SLOGE("Error calculating checksum for continuing encryption");
|
|
rc = -1;
|
|
}
|
|
}
|
|
|
|
/* Undo the dm-crypt mapping whether we succeed or not */
|
|
delete_crypto_blk_dev(CRYPTO_BLOCK_DEVICE);
|
|
|
|
if (!rc) {
|
|
/* Success */
|
|
crypt_ftr.flags &= ~CRYPT_INCONSISTENT_STATE;
|
|
|
|
if (crypt_ftr.encrypted_upto != crypt_ftr.fs_size) {
|
|
SLOGD("Encrypted up to sector %lld - will continue after reboot",
|
|
crypt_ftr.encrypted_upto);
|
|
crypt_ftr.flags |= CRYPT_ENCRYPTION_IN_PROGRESS;
|
|
}
|
|
|
|
put_crypt_ftr_and_key(&crypt_ftr);
|
|
|
|
if (crypt_ftr.encrypted_upto == crypt_ftr.fs_size) {
|
|
char value[PROPERTY_VALUE_MAX];
|
|
property_get("ro.crypto.state", value, "");
|
|
if (!strcmp(value, "")) {
|
|
/* default encryption - continue first boot sequence */
|
|
property_set("ro.crypto.state", "encrypted");
|
|
property_set("ro.crypto.type", "block");
|
|
release_wake_lock(lockid);
|
|
if (rebootEncryption && crypt_ftr.crypt_type != CRYPT_TYPE_DEFAULT) {
|
|
// Bring up cryptkeeper that will check the password and set it
|
|
property_set("vold.decrypt", "trigger_shutdown_framework");
|
|
sleep(2);
|
|
property_set("vold.encrypt_progress", "");
|
|
cryptfs_trigger_restart_min_framework();
|
|
} else {
|
|
cryptfs_check_passwd(DEFAULT_PASSWORD);
|
|
cryptfs_restart_internal(1);
|
|
}
|
|
return 0;
|
|
} else {
|
|
sleep(2); /* Give the UI a chance to show 100% progress */
|
|
cryptfs_reboot(RebootType::reboot);
|
|
}
|
|
} else {
|
|
sleep(2); /* Partially encrypted, ensure writes flushed to ssd */
|
|
cryptfs_reboot(RebootType::shutdown);
|
|
}
|
|
} else {
|
|
char value[PROPERTY_VALUE_MAX];
|
|
|
|
property_get("ro.vold.wipe_on_crypt_fail", value, "0");
|
|
if (!strcmp(value, "1")) {
|
|
/* wipe data if encryption failed */
|
|
SLOGE("encryption failed - rebooting into recovery to wipe data\n");
|
|
std::string err;
|
|
const std::vector<std::string> options = {
|
|
"--wipe_data\n--reason=cryptfs_enable_internal\n"};
|
|
if (!write_bootloader_message(options, &err)) {
|
|
SLOGE("could not write bootloader message: %s", err.c_str());
|
|
}
|
|
cryptfs_reboot(RebootType::recovery);
|
|
} else {
|
|
/* set property to trigger dialog */
|
|
property_set("vold.encrypt_progress", "error_partially_encrypted");
|
|
release_wake_lock(lockid);
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/* hrm, the encrypt step claims success, but the reboot failed.
|
|
* This should not happen.
|
|
* Set the property and return. Hope the framework can deal with it.
|
|
*/
|
|
property_set("vold.encrypt_progress", "error_reboot_failed");
|
|
release_wake_lock(lockid);
|
|
return rc;
|
|
|
|
error_unencrypted:
|
|
property_set("vold.encrypt_progress", "error_not_encrypted");
|
|
if (lockid[0]) {
|
|
release_wake_lock(lockid);
|
|
}
|
|
return -1;
|
|
|
|
error_shutting_down:
|
|
/* we failed, and have not encrypted anthing, so the users's data is still intact,
|
|
* but the framework is stopped and not restarted to show the error, so it's up to
|
|
* vold to restart the system.
|
|
*/
|
|
SLOGE(
|
|
"Error enabling encryption after framework is shutdown, no data changed, restarting "
|
|
"system");
|
|
cryptfs_reboot(RebootType::reboot);
|
|
|
|
/* shouldn't get here */
|
|
property_set("vold.encrypt_progress", "error_shutting_down");
|
|
if (lockid[0]) {
|
|
release_wake_lock(lockid);
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
int cryptfs_enable(int type, const char* passwd, int no_ui) {
|
|
return cryptfs_enable_internal(type, passwd, no_ui);
|
|
}
|
|
|
|
int cryptfs_enable_default(int no_ui) {
|
|
return cryptfs_enable_internal(CRYPT_TYPE_DEFAULT, DEFAULT_PASSWORD, no_ui);
|
|
}
|
|
|
|
int cryptfs_changepw(int crypt_type, const char* newpw) {
|
|
if (fscrypt_is_native()) {
|
|
SLOGE("cryptfs_changepw not valid for file encryption");
|
|
return -1;
|
|
}
|
|
|
|
struct crypt_mnt_ftr crypt_ftr;
|
|
int rc;
|
|
|
|
/* This is only allowed after we've successfully decrypted the master key */
|
|
if (!master_key_saved) {
|
|
SLOGE("Key not saved, aborting");
|
|
return -1;
|
|
}
|
|
|
|
if (crypt_type < 0 || crypt_type > CRYPT_TYPE_MAX_TYPE) {
|
|
SLOGE("Invalid crypt_type %d", crypt_type);
|
|
return -1;
|
|
}
|
|
|
|
/* get key */
|
|
if (get_crypt_ftr_and_key(&crypt_ftr)) {
|
|
SLOGE("Error getting crypt footer and key");
|
|
return -1;
|
|
}
|
|
|
|
crypt_ftr.crypt_type = crypt_type;
|
|
|
|
rc = encrypt_master_key(crypt_type == CRYPT_TYPE_DEFAULT ? DEFAULT_PASSWORD : newpw,
|
|
crypt_ftr.salt, saved_master_key, crypt_ftr.master_key, &crypt_ftr);
|
|
if (rc) {
|
|
SLOGE("Encrypt master key failed: %d", rc);
|
|
return -1;
|
|
}
|
|
/* save the key */
|
|
put_crypt_ftr_and_key(&crypt_ftr);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned int persist_get_max_entries(int encrypted) {
|
|
struct crypt_mnt_ftr crypt_ftr;
|
|
unsigned int dsize;
|
|
|
|
/* If encrypted, use the values from the crypt_ftr, otherwise
|
|
* use the values for the current spec.
|
|
*/
|
|
if (encrypted) {
|
|
if (get_crypt_ftr_and_key(&crypt_ftr)) {
|
|
/* Something is wrong, assume no space for entries */
|
|
return 0;
|
|
}
|
|
dsize = crypt_ftr.persist_data_size;
|
|
} else {
|
|
dsize = CRYPT_PERSIST_DATA_SIZE;
|
|
}
|
|
|
|
if (dsize > sizeof(struct crypt_persist_data)) {
|
|
return (dsize - sizeof(struct crypt_persist_data)) / sizeof(struct crypt_persist_entry);
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
static int persist_get_key(const char* fieldname, char* value) {
|
|
unsigned int i;
|
|
|
|
if (persist_data == NULL) {
|
|
return -1;
|
|
}
|
|
for (i = 0; i < persist_data->persist_valid_entries; i++) {
|
|
if (!strncmp(persist_data->persist_entry[i].key, fieldname, PROPERTY_KEY_MAX)) {
|
|
/* We found it! */
|
|
strlcpy(value, persist_data->persist_entry[i].val, PROPERTY_VALUE_MAX);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
static int persist_set_key(const char* fieldname, const char* value, int encrypted) {
|
|
unsigned int i;
|
|
unsigned int num;
|
|
unsigned int max_persistent_entries;
|
|
|
|
if (persist_data == NULL) {
|
|
return -1;
|
|
}
|
|
|
|
max_persistent_entries = persist_get_max_entries(encrypted);
|
|
|
|
num = persist_data->persist_valid_entries;
|
|
|
|
for (i = 0; i < num; i++) {
|
|
if (!strncmp(persist_data->persist_entry[i].key, fieldname, PROPERTY_KEY_MAX)) {
|
|
/* We found an existing entry, update it! */
|
|
memset(persist_data->persist_entry[i].val, 0, PROPERTY_VALUE_MAX);
|
|
strlcpy(persist_data->persist_entry[i].val, value, PROPERTY_VALUE_MAX);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* We didn't find it, add it to the end, if there is room */
|
|
if (persist_data->persist_valid_entries < max_persistent_entries) {
|
|
memset(&persist_data->persist_entry[num], 0, sizeof(struct crypt_persist_entry));
|
|
strlcpy(persist_data->persist_entry[num].key, fieldname, PROPERTY_KEY_MAX);
|
|
strlcpy(persist_data->persist_entry[num].val, value, PROPERTY_VALUE_MAX);
|
|
persist_data->persist_valid_entries++;
|
|
return 0;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* Test if key is part of the multi-entry (field, index) sequence. Return non-zero if key is in the
|
|
* sequence and its index is greater than or equal to index. Return 0 otherwise.
|
|
*/
|
|
int match_multi_entry(const char* key, const char* field, unsigned index) {
|
|
std::string key_ = key;
|
|
std::string field_ = field;
|
|
|
|
std::string parsed_field;
|
|
unsigned parsed_index;
|
|
|
|
std::string::size_type split = key_.find_last_of('_');
|
|
if (split == std::string::npos) {
|
|
parsed_field = key_;
|
|
parsed_index = 0;
|
|
} else {
|
|
parsed_field = key_.substr(0, split);
|
|
parsed_index = std::stoi(key_.substr(split + 1));
|
|
}
|
|
|
|
return parsed_field == field_ && parsed_index >= index;
|
|
}
|
|
|
|
/*
|
|
* Delete entry/entries from persist_data. If the entries are part of a multi-segment field, all
|
|
* remaining entries starting from index will be deleted.
|
|
* returns PERSIST_DEL_KEY_OK if deletion succeeds,
|
|
* PERSIST_DEL_KEY_ERROR_NO_FIELD if the field does not exist,
|
|
* and PERSIST_DEL_KEY_ERROR_OTHER if error occurs.
|
|
*
|
|
*/
|
|
static int persist_del_keys(const char* fieldname, unsigned index) {
|
|
unsigned int i;
|
|
unsigned int j;
|
|
unsigned int num;
|
|
|
|
if (persist_data == NULL) {
|
|
return PERSIST_DEL_KEY_ERROR_OTHER;
|
|
}
|
|
|
|
num = persist_data->persist_valid_entries;
|
|
|
|
j = 0; // points to the end of non-deleted entries.
|
|
// Filter out to-be-deleted entries in place.
|
|
for (i = 0; i < num; i++) {
|
|
if (!match_multi_entry(persist_data->persist_entry[i].key, fieldname, index)) {
|
|
persist_data->persist_entry[j] = persist_data->persist_entry[i];
|
|
j++;
|
|
}
|
|
}
|
|
|
|
if (j < num) {
|
|
persist_data->persist_valid_entries = j;
|
|
// Zeroise the remaining entries
|
|
memset(&persist_data->persist_entry[j], 0, (num - j) * sizeof(struct crypt_persist_entry));
|
|
return PERSIST_DEL_KEY_OK;
|
|
} else {
|
|
// Did not find an entry matching the given fieldname
|
|
return PERSIST_DEL_KEY_ERROR_NO_FIELD;
|
|
}
|
|
}
|
|
|
|
static int persist_count_keys(const char* fieldname) {
|
|
unsigned int i;
|
|
unsigned int count;
|
|
|
|
if (persist_data == NULL) {
|
|
return -1;
|
|
}
|
|
|
|
count = 0;
|
|
for (i = 0; i < persist_data->persist_valid_entries; i++) {
|
|
if (match_multi_entry(persist_data->persist_entry[i].key, fieldname, 0)) {
|
|
count++;
|
|
}
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
/* Return the value of the specified field. */
|
|
int cryptfs_getfield(const char* fieldname, char* value, int len) {
|
|
if (fscrypt_is_native()) {
|
|
SLOGE("Cannot get field when file encrypted");
|
|
return -1;
|
|
}
|
|
|
|
char temp_value[PROPERTY_VALUE_MAX];
|
|
/* CRYPTO_GETFIELD_OK is success,
|
|
* CRYPTO_GETFIELD_ERROR_NO_FIELD is value not set,
|
|
* CRYPTO_GETFIELD_ERROR_BUF_TOO_SMALL is buffer (as given by len) too small,
|
|
* CRYPTO_GETFIELD_ERROR_OTHER is any other error
|
|
*/
|
|
int rc = CRYPTO_GETFIELD_ERROR_OTHER;
|
|
int i;
|
|
char temp_field[PROPERTY_KEY_MAX];
|
|
|
|
if (persist_data == NULL) {
|
|
load_persistent_data();
|
|
if (persist_data == NULL) {
|
|
SLOGE("Getfield error, cannot load persistent data");
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
// Read value from persistent entries. If the original value is split into multiple entries,
|
|
// stitch them back together.
|
|
if (!persist_get_key(fieldname, temp_value)) {
|
|
// We found it, copy it to the caller's buffer and keep going until all entries are read.
|
|
if (strlcpy(value, temp_value, len) >= (unsigned)len) {
|
|
// value too small
|
|
rc = CRYPTO_GETFIELD_ERROR_BUF_TOO_SMALL;
|
|
goto out;
|
|
}
|
|
rc = CRYPTO_GETFIELD_OK;
|
|
|
|
for (i = 1; /* break explicitly */; i++) {
|
|
if (snprintf(temp_field, sizeof(temp_field), "%s_%d", fieldname, i) >=
|
|
(int)sizeof(temp_field)) {
|
|
// If the fieldname is very long, we stop as soon as it begins to overflow the
|
|
// maximum field length. At this point we have in fact fully read out the original
|
|
// value because cryptfs_setfield would not allow fields with longer names to be
|
|
// written in the first place.
|
|
break;
|
|
}
|
|
if (!persist_get_key(temp_field, temp_value)) {
|
|
if (strlcat(value, temp_value, len) >= (unsigned)len) {
|
|
// value too small.
|
|
rc = CRYPTO_GETFIELD_ERROR_BUF_TOO_SMALL;
|
|
goto out;
|
|
}
|
|
} else {
|
|
// Exhaust all entries.
|
|
break;
|
|
}
|
|
}
|
|
} else {
|
|
/* Sadness, it's not there. Return the error */
|
|
rc = CRYPTO_GETFIELD_ERROR_NO_FIELD;
|
|
}
|
|
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
/* Set the value of the specified field. */
|
|
int cryptfs_setfield(const char* fieldname, const char* value) {
|
|
if (fscrypt_is_native()) {
|
|
SLOGE("Cannot set field when file encrypted");
|
|
return -1;
|
|
}
|
|
|
|
char encrypted_state[PROPERTY_VALUE_MAX];
|
|
/* 0 is success, negative values are error */
|
|
int rc = CRYPTO_SETFIELD_ERROR_OTHER;
|
|
int encrypted = 0;
|
|
unsigned int field_id;
|
|
char temp_field[PROPERTY_KEY_MAX];
|
|
unsigned int num_entries;
|
|
unsigned int max_keylen;
|
|
|
|
if (persist_data == NULL) {
|
|
load_persistent_data();
|
|
if (persist_data == NULL) {
|
|
SLOGE("Setfield error, cannot load persistent data");
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
property_get("ro.crypto.state", encrypted_state, "");
|
|
if (!strcmp(encrypted_state, "encrypted")) {
|
|
encrypted = 1;
|
|
}
|
|
|
|
// Compute the number of entries required to store value, each entry can store up to
|
|
// (PROPERTY_VALUE_MAX - 1) chars
|
|
if (strlen(value) == 0) {
|
|
// Empty value also needs one entry to store.
|
|
num_entries = 1;
|
|
} else {
|
|
num_entries = (strlen(value) + (PROPERTY_VALUE_MAX - 1) - 1) / (PROPERTY_VALUE_MAX - 1);
|
|
}
|
|
|
|
max_keylen = strlen(fieldname);
|
|
if (num_entries > 1) {
|
|
// Need an extra "_%d" suffix.
|
|
max_keylen += 1 + log10(num_entries);
|
|
}
|
|
if (max_keylen > PROPERTY_KEY_MAX - 1) {
|
|
rc = CRYPTO_SETFIELD_ERROR_FIELD_TOO_LONG;
|
|
goto out;
|
|
}
|
|
|
|
// Make sure we have enough space to write the new value
|
|
if (persist_data->persist_valid_entries + num_entries - persist_count_keys(fieldname) >
|
|
persist_get_max_entries(encrypted)) {
|
|
rc = CRYPTO_SETFIELD_ERROR_VALUE_TOO_LONG;
|
|
goto out;
|
|
}
|
|
|
|
// Now that we know persist_data has enough space for value, let's delete the old field first
|
|
// to make up space.
|
|
persist_del_keys(fieldname, 0);
|
|
|
|
if (persist_set_key(fieldname, value, encrypted)) {
|
|
// fail to set key, should not happen as we have already checked the available space
|
|
SLOGE("persist_set_key() error during setfield()");
|
|
goto out;
|
|
}
|
|
|
|
for (field_id = 1; field_id < num_entries; field_id++) {
|
|
snprintf(temp_field, sizeof(temp_field), "%s_%u", fieldname, field_id);
|
|
|
|
if (persist_set_key(temp_field, value + field_id * (PROPERTY_VALUE_MAX - 1), encrypted)) {
|
|
// fail to set key, should not happen as we have already checked the available space.
|
|
SLOGE("persist_set_key() error during setfield()");
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/* If we are running encrypted, save the persistent data now */
|
|
if (encrypted) {
|
|
if (save_persistent_data()) {
|
|
SLOGE("Setfield error, cannot save persistent data");
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
rc = CRYPTO_SETFIELD_OK;
|
|
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
/* Checks userdata. Attempt to mount the volume if default-
|
|
* encrypted.
|
|
* On success trigger next init phase and return 0.
|
|
* Currently do not handle failure - see TODO below.
|
|
*/
|
|
int cryptfs_mount_default_encrypted(void) {
|
|
int crypt_type = cryptfs_get_password_type();
|
|
if (crypt_type < 0 || crypt_type > CRYPT_TYPE_MAX_TYPE) {
|
|
SLOGE("Bad crypt type - error");
|
|
} else if (crypt_type != CRYPT_TYPE_DEFAULT) {
|
|
SLOGD(
|
|
"Password is not default - "
|
|
"starting min framework to prompt");
|
|
property_set("vold.decrypt", "trigger_restart_min_framework");
|
|
return 0;
|
|
} else if (cryptfs_check_passwd(DEFAULT_PASSWORD) == 0) {
|
|
SLOGD("Password is default - restarting filesystem");
|
|
cryptfs_restart_internal(0);
|
|
return 0;
|
|
} else {
|
|
SLOGE("Encrypted, default crypt type but can't decrypt");
|
|
}
|
|
|
|
/** Corrupt. Allow us to boot into framework, which will detect bad
|
|
crypto when it calls do_crypto_complete, then do a factory reset
|
|
*/
|
|
property_set("vold.decrypt", "trigger_restart_min_framework");
|
|
return 0;
|
|
}
|
|
|
|
/* Returns type of the password, default, pattern, pin or password.
|
|
*/
|
|
int cryptfs_get_password_type(void) {
|
|
if (fscrypt_is_native()) {
|
|
SLOGE("cryptfs_get_password_type not valid for file encryption");
|
|
return -1;
|
|
}
|
|
|
|
struct crypt_mnt_ftr crypt_ftr;
|
|
|
|
if (get_crypt_ftr_and_key(&crypt_ftr)) {
|
|
SLOGE("Error getting crypt footer and key\n");
|
|
return -1;
|
|
}
|
|
|
|
if (crypt_ftr.flags & CRYPT_INCONSISTENT_STATE) {
|
|
return -1;
|
|
}
|
|
|
|
return crypt_ftr.crypt_type;
|
|
}
|
|
|
|
const char* cryptfs_get_password() {
|
|
if (fscrypt_is_native()) {
|
|
SLOGE("cryptfs_get_password not valid for file encryption");
|
|
return 0;
|
|
}
|
|
|
|
struct timespec now;
|
|
clock_gettime(CLOCK_BOOTTIME, &now);
|
|
if (now.tv_sec < password_expiry_time) {
|
|
return password;
|
|
} else {
|
|
cryptfs_clear_password();
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
void cryptfs_clear_password() {
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if (password) {
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size_t len = strlen(password);
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memset(password, 0, len);
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free(password);
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password = 0;
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password_expiry_time = 0;
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}
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}
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int cryptfs_isConvertibleToFBE() {
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auto entry = GetEntryForMountPoint(&fstab_default, DATA_MNT_POINT);
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return entry && entry->fs_mgr_flags.force_fde_or_fbe;
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}
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