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2949 lines
99 KiB
2949 lines
99 KiB
/* |
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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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|
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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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|
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#include "cryptfs.h" |
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|
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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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|
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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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|
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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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using android::vold::write_file_bootprof; |
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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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write_file_bootprof("vold:keymaster_create_key:START"); |
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if (ftr->keymaster_blob_size) { |
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SLOGI("Already have key"); |
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write_file_bootprof("vold:keymaster_create_key:END"); |
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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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write_file_bootprof("vold:keymaster_create_key:END"); |
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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/* return length in sectors */ |
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return len / 512; |
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} |
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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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|
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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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|
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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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*/ |
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strlcpy(cached_metadata_fname, real_blkdev.c_str(), sizeof(cached_metadata_fname)); |
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cached_off -= CRYPT_FOOTER_OFFSET; |
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cached_data = 1; |
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} else { |
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SLOGE("Cannot get size of block device %s\n", real_blkdev.c_str()); |
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} |
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} else { |
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strlcpy(cached_metadata_fname, key_loc.c_str(), sizeof(cached_metadata_fname)); |
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cached_off = 0; |
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cached_data = 1; |
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} |
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} |
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|
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if (cached_data) { |
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if (metadata_fname) { |
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*metadata_fname = cached_metadata_fname; |
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} |
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if (off) { |
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*off = cached_off; |
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} |
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rc = 0; |
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} |
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|
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return rc; |
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} |
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|
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/* Set sha256 checksum in structure */ |
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static void set_ftr_sha(struct crypt_mnt_ftr* crypt_ftr) { |
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SHA256_CTX c; |
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SHA256_Init(&c); |
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memset(crypt_ftr->sha256, 0, sizeof(crypt_ftr->sha256)); |
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SHA256_Update(&c, crypt_ftr, sizeof(*crypt_ftr)); |
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SHA256_Final(crypt_ftr->sha256, &c); |
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} |
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|
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/* key or salt can be NULL, in which case just skip writing that value. Useful to |
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* update the failed mount count but not change the key. |
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*/ |
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static int put_crypt_ftr_and_key(struct crypt_mnt_ftr* crypt_ftr) { |
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int fd; |
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unsigned int cnt; |
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/* starting_off is set to the SEEK_SET offset |
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* where the crypto structure starts |
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*/ |
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off64_t starting_off; |
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int rc = -1; |
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char* fname = NULL; |
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struct stat statbuf; |
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|
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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; |
|
|
|
write_file_bootprof("vold:scrypt_keymaster:START"); |
|
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; |
|
} |
|
write_file_bootprof("vold:scrypt_keymaster:END"); |
|
|
|
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; |
|
write_file_bootprof("vold:encrypt_master_key:START"); |
|
|
|
/* 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); |
|
|
|
write_file_bootprof("vold:encrypt_master_key:END"); |
|
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; |
|
|
|
write_file_bootprof("vold:decrypt_master_key:START"); |
|
/* 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); |
|
write_file_bootprof("vold:decrypt_master_key:END"); |
|
|
|
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; |
|
} |
|
write_file_bootprof("vold:cryptfs_restart_internal:START"); |
|
|
|
if (restart_main) { |
|
/* Here is where we shut down the framework. The init scripts |
|
* start all services in one of these classes: core, early_hal, hal, |
|
* main and late_start. To get to the minimal UI for PIN entry, we |
|
* need to start core, early_hal, hal and main. When we want to |
|
* shutdown the framework again, we need to stop most of the services in |
|
* these classes, but only those services that were started after |
|
* /data was mounted. This excludes critical services like vold and |
|
* ueventd, which need to keep running. We could possible stop |
|
* even fewer services, but because we want services to pick up APEX |
|
* libraries from the real /data, restarting is better, as it makes |
|
* these devices consistent with FBE devices and lets them use the |
|
* most recent code. |
|
* |
|
* Once these services have stopped, we should be able |
|
* to umount the tmpfs /data, then mount the encrypted /data. |
|
* We then restart the class core, hal, 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 right set of services when |
|
* vold.decrypt is set to trigger_shutdown_framework. |
|
*/ |
|
property_set("vold.decrypt", "trigger_shutdown_framework"); |
|
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; |
|
} |
|
|
|
write_file_bootprof("vold:cryptfs_restart_internal:END"); |
|
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; |
|
|
|
write_file_bootprof("vold:cryptfs_enable_inplace:START"); |
|
rc = cryptfs_enable_inplace(crypto_blkdev, real_blkdev, crypt_ftr->fs_size, &cur_encryption_done, |
|
tot_encryption_size, previously_encrypted_upto, true); |
|
write_file_bootprof("vold:cryptfs_enable_inplace:END"); |
|
|
|
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) { |
|
int ret = 0; |
|
write_file_bootprof("vold:cryptfs_enable_internal:START"); |
|
ret = cryptfs_enable_internal(type, passwd, no_ui); |
|
write_file_bootprof(StringPrintf("vold:cryptfs_enable_internal:END, ret=%d", ret).c_str()); |
|
return ret; |
|
} |
|
|
|
int cryptfs_enable_default(int no_ui) { |
|
int ret = 0; |
|
write_file_bootprof("vold:cryptfs_enable_internal:START"); |
|
ret = cryptfs_enable_internal(CRYPT_TYPE_DEFAULT, DEFAULT_PASSWORD, no_ui); |
|
write_file_bootprof(StringPrintf("vold:cryptfs_enable_internal:END, ret=%d", ret).c_str()); |
|
return ret; |
|
} |
|
|
|
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() { |
|
if (password) { |
|
size_t len = strlen(password); |
|
memset(password, 0, len); |
|
free(password); |
|
password = 0; |
|
password_expiry_time = 0; |
|
} |
|
} |
|
|
|
int cryptfs_isConvertibleToFBE() { |
|
auto entry = GetEntryForMountPoint(&fstab_default, DATA_MNT_POINT); |
|
return entry && entry->fs_mgr_flags.force_fde_or_fbe; |
|
}
|
|
|