FsCrypt update: support fscrypt policies v1 and v2
This patchset introduces support decryption for Android 11.
In this update we deprecate ext4crypt. To specify the
policy version to use, use TW_USE_FSCRYPT_POLICY := 1 or
TW_USE_FSCRYPT_POLICY := 2. By default policy version will
be set to 2 if this variable is omitted.
Change-Id: I62a29c1bef36c259ec4b11259f71be613d20a112
diff --git a/crypto/fscrypt/cryptfs.cpp b/crypto/fscrypt/cryptfs.cpp
new file mode 100644
index 0000000..b58c343
--- /dev/null
+++ b/crypto/fscrypt/cryptfs.cpp
@@ -0,0 +1,2902 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "Cryptfs"
+
+#include "cryptfs.h"
+
+#include "Checkpoint.h"
+#include "CryptoType.h"
+#include "EncryptInplace.h"
+#include "FsCrypt.h"
+#include "Keymaster.h"
+#include "Process.h"
+#include "ScryptParameters.h"
+#include "Utils.h"
+#include "VoldUtil.h"
+#include "VolumeManager.h"
+
+#include <android-base/parseint.h>
+#include <android-base/properties.h>
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
+#include <bootloader_message/bootloader_message.h>
+#include <cutils/android_reboot.h>
+#include <cutils/properties.h>
+#include <ext4_utils/ext4_utils.h>
+#include <f2fs_sparseblock.h>
+#include <fs_mgr.h>
+#include <fscrypt/fscrypt.h>
+#include <libdm/dm.h>
+#include <log/log.h>
+#include <logwrap/logwrap.h>
+#include <openssl/evp.h>
+#include <openssl/sha.h>
+#include <selinux/selinux.h>
+// #include <wakelock/wakelock.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <libgen.h>
+#include <linux/kdev_t.h>
+#include <math.h>
+#include <mntent.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <chrono>
+#include <thread>
+
+extern "C" {
+#include <crypto_scrypt.h>
+}
+
+using android::base::ParseUint;
+using android::base::StringPrintf;
+using android::fs_mgr::GetEntryForMountPoint;
+using ::CryptoType;
+using ::KeyBuffer;
+using ::KeyGeneration;
+using namespace android::dm;
+using namespace std::chrono_literals;
+
+/* The current cryptfs version */
+#define CURRENT_MAJOR_VERSION 1
+#define CURRENT_MINOR_VERSION 3
+
+#define CRYPT_FOOTER_TO_PERSIST_OFFSET 0x1000
+#define CRYPT_PERSIST_DATA_SIZE 0x1000
+
+#define MAX_CRYPTO_TYPE_NAME_LEN 64
+
+#define MAX_KEY_LEN 48
+#define SALT_LEN 16
+#define SCRYPT_LEN 32
+
+/* definitions of flags in the structure below */
+#define CRYPT_MNT_KEY_UNENCRYPTED 0x1 /* The key for the partition is not encrypted. */
+#define CRYPT_ENCRYPTION_IN_PROGRESS \
+ 0x2 /* Encryption partially completed, \
+ encrypted_upto valid*/
+#define CRYPT_INCONSISTENT_STATE \
+ 0x4 /* Set when starting encryption, clear when \
+ exit cleanly, either through success or \
+ correctly marked partial encryption */
+#define CRYPT_DATA_CORRUPT \
+ 0x8 /* Set when encryption is fine, but the \
+ underlying volume is corrupt */
+#define CRYPT_FORCE_ENCRYPTION \
+ 0x10 /* Set when it is time to encrypt this \
+ volume on boot. Everything in this \
+ structure is set up correctly as \
+ though device is encrypted except \
+ that the master key is encrypted with the \
+ default password. */
+#define CRYPT_FORCE_COMPLETE \
+ 0x20 /* Set when the above encryption cycle is \
+ complete. On next cryptkeeper entry, match \
+ the password. If it matches fix the master \
+ key and remove this flag. */
+
+/* Allowed values for type in the structure below */
+#define CRYPT_TYPE_PASSWORD \
+ 0 /* master_key is encrypted with a password \
+ * Must be zero to be compatible with pre-L \
+ * devices where type is always password.*/
+#define CRYPT_TYPE_DEFAULT \
+ 1 /* master_key is encrypted with default \
+ * password */
+#define CRYPT_TYPE_PATTERN 2 /* master_key is encrypted with a pattern */
+#define CRYPT_TYPE_PIN 3 /* master_key is encrypted with a pin */
+#define CRYPT_TYPE_MAX_TYPE 3 /* type cannot be larger than this value */
+
+#define CRYPT_MNT_MAGIC 0xD0B5B1C4
+#define PERSIST_DATA_MAGIC 0xE950CD44
+
+/* Key Derivation Function algorithms */
+#define KDF_PBKDF2 1
+#define KDF_SCRYPT 2
+/* Algorithms 3 & 4 deprecated before shipping outside of google, so removed */
+#define KDF_SCRYPT_KEYMASTER 5
+
+/* Maximum allowed keymaster blob size. */
+#define KEYMASTER_BLOB_SIZE 2048
+
+/* __le32 and __le16 defined in system/extras/ext4_utils/ext4_utils.h */
+#define __le8 unsigned char
+
+#if !defined(SHA256_DIGEST_LENGTH)
+#define SHA256_DIGEST_LENGTH 32
+#endif
+
+/* This structure starts 16,384 bytes before the end of a hardware
+ * partition that is encrypted, or in a separate partition. It's location
+ * is specified by a property set in init.<device>.rc.
+ * The structure allocates 48 bytes for a key, but the real key size is
+ * specified in the struct. Currently, the code is hardcoded to use 128
+ * bit keys.
+ * The fields after salt are only valid in rev 1.1 and later stuctures.
+ * Obviously, the filesystem does not include the last 16 kbytes
+ * of the partition if the crypt_mnt_ftr lives at the end of the
+ * partition.
+ */
+
+struct crypt_mnt_ftr {
+ __le32 magic; /* See above */
+ __le16 major_version;
+ __le16 minor_version;
+ __le32 ftr_size; /* in bytes, not including key following */
+ __le32 flags; /* See above */
+ __le32 keysize; /* in bytes */
+ __le32 crypt_type; /* how master_key is encrypted. Must be a
+ * CRYPT_TYPE_XXX value */
+ __le64 fs_size; /* Size of the encrypted fs, in 512 byte sectors */
+ __le32 failed_decrypt_count; /* count of # of failed attempts to decrypt and
+ mount, set to 0 on successful mount */
+ unsigned char crypto_type_name[MAX_CRYPTO_TYPE_NAME_LEN]; /* The type of encryption
+ needed to decrypt this
+ partition, null terminated */
+ __le32 spare2; /* ignored */
+ unsigned char master_key[MAX_KEY_LEN]; /* The encrypted key for decrypting the filesystem */
+ unsigned char salt[SALT_LEN]; /* The salt used for this encryption */
+ __le64 persist_data_offset[2]; /* Absolute offset to both copies of crypt_persist_data
+ * on device with that info, either the footer of the
+ * real_blkdevice or the metadata partition. */
+
+ __le32 persist_data_size; /* The number of bytes allocated to each copy of the
+ * persistent data table*/
+
+ __le8 kdf_type; /* The key derivation function used. */
+
+ /* scrypt parameters. See www.tarsnap.com/scrypt/scrypt.pdf */
+ __le8 N_factor; /* (1 << N) */
+ __le8 r_factor; /* (1 << r) */
+ __le8 p_factor; /* (1 << p) */
+ __le64 encrypted_upto; /* If we are in state CRYPT_ENCRYPTION_IN_PROGRESS and
+ we have to stop (e.g. power low) this is the last
+ encrypted 512 byte sector.*/
+ __le8 hash_first_block[SHA256_DIGEST_LENGTH]; /* When CRYPT_ENCRYPTION_IN_PROGRESS
+ set, hash of first block, used
+ to validate before continuing*/
+
+ /* key_master key, used to sign the derived key which is then used to generate
+ * the intermediate key
+ * This key should be used for no other purposes! We use this key to sign unpadded
+ * data, which is acceptable but only if the key is not reused elsewhere. */
+ __le8 keymaster_blob[KEYMASTER_BLOB_SIZE];
+ __le32 keymaster_blob_size;
+
+ /* Store scrypt of salted intermediate key. When decryption fails, we can
+ check if this matches, and if it does, we know that the problem is with the
+ drive, and there is no point in asking the user for more passwords.
+
+ Note that if any part of this structure is corrupt, this will not match and
+ we will continue to believe the user entered the wrong password. In that
+ case the only solution is for the user to enter a password enough times to
+ force a wipe.
+
+ Note also that there is no need to worry about migration. If this data is
+ wrong, we simply won't recognise a right password, and will continue to
+ prompt. On the first password change, this value will be populated and
+ then we will be OK.
+ */
+ unsigned char scrypted_intermediate_key[SCRYPT_LEN];
+
+ /* sha of this structure with this element set to zero
+ Used when encrypting on reboot to validate structure before doing something
+ fatal
+ */
+ unsigned char sha256[SHA256_DIGEST_LENGTH];
+};
+
+/* Persistant data that should be available before decryption.
+ * Things like airplane mode, locale and timezone are kept
+ * here and can be retrieved by the CryptKeeper UI to properly
+ * configure the phone before asking for the password
+ * This is only valid if the major and minor version above
+ * is set to 1.1 or higher.
+ *
+ * This is a 4K structure. There are 2 copies, and the code alternates
+ * writing one and then clearing the previous one. The reading
+ * code reads the first valid copy it finds, based on the magic number.
+ * The absolute offset to the first of the two copies is kept in rev 1.1
+ * and higher crypt_mnt_ftr structures.
+ */
+struct crypt_persist_entry {
+ char key[PROPERTY_KEY_MAX];
+ char val[PROPERTY_VALUE_MAX];
+};
+
+/* Should be exactly 4K in size */
+struct crypt_persist_data {
+ __le32 persist_magic;
+ __le32 persist_valid_entries;
+ __le32 persist_spare[30];
+ struct crypt_persist_entry persist_entry[0];
+};
+
+static int wait_and_unmount(const char* mountpoint, bool kill);
+
+typedef int (*kdf_func)(const char* passwd, const unsigned char* salt, unsigned char* ikey,
+ void* params);
+
+#define UNUSED __attribute__((unused))
+
+#define HASH_COUNT 2000
+
+constexpr size_t INTERMEDIATE_KEY_LEN_BYTES = 16;
+constexpr size_t INTERMEDIATE_IV_LEN_BYTES = 16;
+constexpr size_t INTERMEDIATE_BUF_SIZE = (INTERMEDIATE_KEY_LEN_BYTES + INTERMEDIATE_IV_LEN_BYTES);
+
+// SCRYPT_LEN is used by struct crypt_mnt_ftr for its intermediate key.
+static_assert(INTERMEDIATE_BUF_SIZE == SCRYPT_LEN, "Mismatch of intermediate key sizes");
+
+#define KEY_IN_FOOTER "footer"
+
+#define DEFAULT_PASSWORD "default_password"
+
+#define CRYPTO_BLOCK_DEVICE "userdata"
+
+#define BREADCRUMB_FILE "/data/misc/vold/convert_fde"
+
+#define EXT4_FS 1
+#define F2FS_FS 2
+
+#define TABLE_LOAD_RETRIES 10
+
+#define RSA_KEY_SIZE 2048
+#define RSA_KEY_SIZE_BYTES (RSA_KEY_SIZE / 8)
+#define RSA_EXPONENT 0x10001
+#define KEYMASTER_CRYPTFS_RATE_LIMIT 1 // Maximum one try per second
+
+#define RETRY_MOUNT_ATTEMPTS 10
+#define RETRY_MOUNT_DELAY_SECONDS 1
+
+#define CREATE_CRYPTO_BLK_DEV_FLAGS_ALLOW_ENCRYPT_OVERRIDE (1)
+
+static int put_crypt_ftr_and_key(struct crypt_mnt_ftr* crypt_ftr);
+
+static unsigned char saved_master_key[MAX_KEY_LEN];
+static char* saved_mount_point;
+static int master_key_saved = 0;
+static struct crypt_persist_data* persist_data = NULL;
+
+constexpr CryptoType aes_128_cbc = CryptoType()
+ .set_config_name("AES-128-CBC")
+ .set_kernel_name("aes-cbc-essiv:sha256")
+ .set_keysize(16);
+
+constexpr CryptoType supported_crypto_types[] = {aes_128_cbc, ::adiantum};
+
+static_assert(validateSupportedCryptoTypes(MAX_KEY_LEN, supported_crypto_types,
+ array_length(supported_crypto_types)),
+ "We have a CryptoType with keysize > MAX_KEY_LEN or which was "
+ "incompletely constructed.");
+
+static const CryptoType& get_crypto_type() {
+ // We only want to parse this read-only property once. But we need to wait
+ // until the system is initialized before we can read it. So we use a static
+ // scoped within this function to get it only once.
+ static CryptoType crypto_type =
+ lookup_crypto_algorithm(supported_crypto_types, array_length(supported_crypto_types),
+ aes_128_cbc, "ro.crypto.fde_algorithm");
+ return crypto_type;
+}
+
+const KeyGeneration cryptfs_get_keygen() {
+ return KeyGeneration{get_crypto_type().get_keysize(), true, false};
+}
+
+/* Should we use keymaster? */
+static int keymaster_check_compatibility() {
+ return keymaster_compatibility_cryptfs_scrypt();
+}
+
+/* Create a new keymaster key and store it in this footer */
+static int keymaster_create_key(struct crypt_mnt_ftr* ftr) {
+ if (ftr->keymaster_blob_size) {
+ SLOGI("Already have key");
+ return 0;
+ }
+
+ int rc = keymaster_create_key_for_cryptfs_scrypt(
+ RSA_KEY_SIZE, RSA_EXPONENT, KEYMASTER_CRYPTFS_RATE_LIMIT, ftr->keymaster_blob,
+ KEYMASTER_BLOB_SIZE, &ftr->keymaster_blob_size);
+ if (rc) {
+ if (ftr->keymaster_blob_size > KEYMASTER_BLOB_SIZE) {
+ SLOGE("Keymaster key blob too large");
+ ftr->keymaster_blob_size = 0;
+ }
+ SLOGE("Failed to generate keypair");
+ return -1;
+ }
+ return 0;
+}
+
+/* This signs the given object using the keymaster key. */
+static int keymaster_sign_object(struct crypt_mnt_ftr* ftr, const unsigned char* object,
+ const size_t object_size, unsigned char** signature,
+ size_t* signature_size) {
+ unsigned char to_sign[RSA_KEY_SIZE_BYTES];
+ size_t to_sign_size = sizeof(to_sign);
+ memset(to_sign, 0, RSA_KEY_SIZE_BYTES);
+
+ // To sign a message with RSA, the message must satisfy two
+ // constraints:
+ //
+ // 1. The message, when interpreted as a big-endian numeric value, must
+ // be strictly less than the public modulus of the RSA key. Note
+ // that because the most significant bit of the public modulus is
+ // guaranteed to be 1 (else it's an (n-1)-bit key, not an n-bit
+ // key), an n-bit message with most significant bit 0 always
+ // satisfies this requirement.
+ //
+ // 2. The message must have the same length in bits as the public
+ // modulus of the RSA key. This requirement isn't mathematically
+ // necessary, but is necessary to ensure consistency in
+ // implementations.
+ switch (ftr->kdf_type) {
+ case KDF_SCRYPT_KEYMASTER:
+ // This ensures the most significant byte of the signed message
+ // is zero. We could have zero-padded to the left instead, but
+ // this approach is slightly more robust against changes in
+ // object size. However, it's still broken (but not unusably
+ // so) because we really should be using a proper deterministic
+ // RSA padding function, such as PKCS1.
+ memcpy(to_sign + 1, object, std::min((size_t)RSA_KEY_SIZE_BYTES - 1, object_size));
+ SLOGI("Signing safely-padded object");
+ break;
+ default:
+ SLOGE("Unknown KDF type %d", ftr->kdf_type);
+ return -1;
+ }
+ for (;;) {
+ auto result = keymaster_sign_object_for_cryptfs_scrypt(
+ ftr->keymaster_blob, ftr->keymaster_blob_size, KEYMASTER_CRYPTFS_RATE_LIMIT, to_sign,
+ to_sign_size, signature, signature_size);
+ switch (result) {
+ case KeymasterSignResult::ok:
+ return 0;
+ case KeymasterSignResult::upgrade:
+ break;
+ default:
+ return -1;
+ }
+ SLOGD("Upgrading key");
+ if (keymaster_upgrade_key_for_cryptfs_scrypt(
+ RSA_KEY_SIZE, RSA_EXPONENT, KEYMASTER_CRYPTFS_RATE_LIMIT, ftr->keymaster_blob,
+ ftr->keymaster_blob_size, ftr->keymaster_blob, KEYMASTER_BLOB_SIZE,
+ &ftr->keymaster_blob_size) != 0) {
+ SLOGE("Failed to upgrade key");
+ return -1;
+ }
+ if (put_crypt_ftr_and_key(ftr) != 0) {
+ SLOGE("Failed to write upgraded key to disk");
+ }
+ SLOGD("Key upgraded successfully");
+ }
+}
+
+/* Store password when userdata is successfully decrypted and mounted.
+ * Cleared by cryptfs_clear_password
+ *
+ * To avoid a double prompt at boot, we need to store the CryptKeeper
+ * password and pass it to KeyGuard, which uses it to unlock KeyStore.
+ * Since the entire framework is torn down and rebuilt after encryption,
+ * we have to use a daemon or similar to store the password. Since vold
+ * is secured against IPC except from system processes, it seems a reasonable
+ * place to store this.
+ *
+ * password should be cleared once it has been used.
+ *
+ * password is aged out after password_max_age_seconds seconds.
+ */
+static char* password = 0;
+static int password_expiry_time = 0;
+static const int password_max_age_seconds = 60;
+
+enum class RebootType { reboot, recovery, shutdown };
+static void cryptfs_reboot(RebootType rt) {
+ switch (rt) {
+ case RebootType::reboot:
+ property_set(ANDROID_RB_PROPERTY, "reboot");
+ break;
+
+ case RebootType::recovery:
+ property_set(ANDROID_RB_PROPERTY, "reboot,recovery");
+ break;
+
+ case RebootType::shutdown:
+ property_set(ANDROID_RB_PROPERTY, "shutdown");
+ break;
+ }
+
+ sleep(20);
+
+ /* Shouldn't get here, reboot should happen before sleep times out */
+ return;
+}
+
+/**
+ * Gets the default device scrypt parameters for key derivation time tuning.
+ * The parameters should lead to about one second derivation time for the
+ * given device.
+ */
+static void get_device_scrypt_params(struct crypt_mnt_ftr* ftr) {
+ char paramstr[PROPERTY_VALUE_MAX];
+ int Nf, rf, pf;
+
+ property_get(SCRYPT_PROP, paramstr, SCRYPT_DEFAULTS);
+ if (!parse_scrypt_parameters(paramstr, &Nf, &rf, &pf)) {
+ SLOGW("bad scrypt parameters '%s' should be like '12:8:1'; using defaults", paramstr);
+ parse_scrypt_parameters(SCRYPT_DEFAULTS, &Nf, &rf, &pf);
+ }
+ ftr->N_factor = Nf;
+ ftr->r_factor = rf;
+ ftr->p_factor = pf;
+}
+
+static uint64_t get_fs_size(const char* dev) {
+ int fd, block_size;
+ struct ext4_super_block sb;
+ uint64_t len;
+
+ if ((fd = open(dev, O_RDONLY | O_CLOEXEC)) < 0) {
+ SLOGE("Cannot open device to get filesystem size ");
+ return 0;
+ }
+
+ if (lseek64(fd, 1024, SEEK_SET) < 0) {
+ SLOGE("Cannot seek to superblock");
+ return 0;
+ }
+
+ if (read(fd, &sb, sizeof(sb)) != sizeof(sb)) {
+ SLOGE("Cannot read superblock");
+ return 0;
+ }
+
+ close(fd);
+
+ if (le32_to_cpu(sb.s_magic) != EXT4_SUPER_MAGIC) {
+ SLOGE("Not a valid ext4 superblock");
+ return 0;
+ }
+ block_size = 1024 << sb.s_log_block_size;
+ /* compute length in bytes */
+ len = (((uint64_t)sb.s_blocks_count_hi << 32) + sb.s_blocks_count_lo) * block_size;
+
+ /* return length in sectors */
+ return len / 512;
+}
+
+static void get_crypt_info(std::string* key_loc, std::string* real_blk_device) {
+ for (const auto& entry : fstab_default) {
+ if (!entry.fs_mgr_flags.vold_managed &&
+ (entry.fs_mgr_flags.crypt || entry.fs_mgr_flags.force_crypt ||
+ entry.fs_mgr_flags.force_fde_or_fbe || entry.fs_mgr_flags.file_encryption)) {
+ if (key_loc != nullptr) {
+ *key_loc = entry.key_loc;
+ }
+ if (real_blk_device != nullptr) {
+ *real_blk_device = entry.blk_device;
+ }
+ return;
+ }
+ }
+}
+
+static int get_crypt_ftr_info(char** metadata_fname, off64_t* off) {
+ static int cached_data = 0;
+ static uint64_t cached_off = 0;
+ static char cached_metadata_fname[PROPERTY_VALUE_MAX] = "";
+ char key_loc[PROPERTY_VALUE_MAX];
+ char real_blkdev[PROPERTY_VALUE_MAX];
+ int rc = -1;
+
+ if (!cached_data) {
+ std::string key_loc;
+ std::string real_blkdev;
+ get_crypt_info(&key_loc, &real_blkdev);
+
+ if (key_loc == KEY_IN_FOOTER) {
+ if (::GetBlockDevSize(real_blkdev, &cached_off) == android::OK) {
+ /* If it's an encrypted Android partition, the last 16 Kbytes contain the
+ * encryption info footer and key, and plenty of bytes to spare for future
+ * growth.
+ */
+ strlcpy(cached_metadata_fname, real_blkdev.c_str(), sizeof(cached_metadata_fname));
+ cached_off -= CRYPT_FOOTER_OFFSET;
+ cached_data = 1;
+ } else {
+ SLOGE("Cannot get size of block device %s\n", real_blkdev.c_str());
+ }
+ } else {
+ strlcpy(cached_metadata_fname, key_loc.c_str(), sizeof(cached_metadata_fname));
+ cached_off = 0;
+ cached_data = 1;
+ }
+ }
+
+ if (cached_data) {
+ if (metadata_fname) {
+ *metadata_fname = cached_metadata_fname;
+ }
+ if (off) {
+ *off = cached_off;
+ }
+ rc = 0;
+ }
+
+ return rc;
+}
+
+/* Set sha256 checksum in structure */
+static void set_ftr_sha(struct crypt_mnt_ftr* crypt_ftr) {
+ SHA256_CTX c;
+ SHA256_Init(&c);
+ memset(crypt_ftr->sha256, 0, sizeof(crypt_ftr->sha256));
+ SHA256_Update(&c, crypt_ftr, sizeof(*crypt_ftr));
+ SHA256_Final(crypt_ftr->sha256, &c);
+}
+
+/* key or salt can be NULL, in which case just skip writing that value. Useful to
+ * update the failed mount count but not change the key.
+ */
+static int put_crypt_ftr_and_key(struct crypt_mnt_ftr* crypt_ftr) {
+ int fd;
+ unsigned int cnt;
+ /* starting_off is set to the SEEK_SET offset
+ * where the crypto structure starts
+ */
+ off64_t starting_off;
+ int rc = -1;
+ char* fname = NULL;
+ struct stat statbuf;
+
+ set_ftr_sha(crypt_ftr);
+
+ if (get_crypt_ftr_info(&fname, &starting_off)) {
+ SLOGE("Unable to get crypt_ftr_info\n");
+ return -1;
+ }
+ if (fname[0] != '/') {
+ SLOGE("put_crypt_ftr_and_key::Unexpected value for crypto key location: %s\n", fname);
+ 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("get_crypt_ftr_and_key::Unexpected value for crypto key location: %s\n", fname);
+ 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';
+}
+
+/*
+ * 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(DmTargetCrypt* target, 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;
+ }
+
+ target->SetSectorSize(sector_size);
+
+ // With this option, IVs will match the sector numbering, instead
+ // of being hard-coded to being based on 512-byte sectors.
+ target->SetIvLargeSectors();
+
+ // 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, std::string* crypto_blk_name,
+ const char* name, uint32_t flags) {
+ auto& dm = DeviceMapper::Instance();
+ ALOGE("create_crypto_blk_dev\n");
+
+ // 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];
+ convert_key_to_hex_ascii(master_key, crypt_ftr->keysize, master_key_ascii);
+
+ auto target = std::make_unique<DmTargetCrypt>(0, crypt_ftr->fs_size,
+ (const char*)crypt_ftr->crypto_type_name,
+ master_key_ascii, 0, real_blk_name, 0);
+ target->AllowDiscards();
+
+ if (flags & CREATE_CRYPTO_BLK_DEV_FLAGS_ALLOW_ENCRYPT_OVERRIDE) {
+ target->AllowEncryptOverride();
+ }
+ if (add_sector_size_param(target.get(), crypt_ftr)) {
+ SLOGE("Error processing dm-crypt sector size param\n");
+ return -1;
+ }
+
+ DmTable table;
+ table.AddTarget(std::move(target));
+
+ int load_count = 1;
+ while (load_count < TABLE_LOAD_RETRIES) {
+ if (dm.CreateDevice(name, table)) {
+ break;
+ }
+ load_count++;
+ }
+
+ if (load_count >= TABLE_LOAD_RETRIES) {
+ SLOGE("Cannot load dm-crypt mapping table.\n");
+ return -1;
+ }
+ if (load_count > 1) {
+ SLOGI("Took %d tries to load dmcrypt table.\n", load_count);
+ }
+
+ // ALOGE("GetDmDevicePathByName::%s::%s\n", name, crypto_blk_name->c_str());
+ if (!dm.GetDmDevicePathByName(name, crypto_blk_name)) {
+ SLOGE("Cannot determine dm-crypt path for %s.\n", name);
+ return -1;
+ }
+
+ /* Ensure the dm device has been created before returning. */
+ if (::WaitForFile(crypto_blk_name->c_str(), 1s) < 0) {
+ // WaitForFile generates a suitable log message
+ return -1;
+ }
+ return 0;
+}
+
+static int delete_crypto_blk_dev(const std::string& name) {
+ bool ret;
+ auto& dm = DeviceMapper::Instance();
+ // TODO(b/149396179) there appears to be a race somewhere in the system where trying
+ // to delete the device fails with EBUSY; for now, work around this by retrying.
+ int tries = 5;
+ while (tries-- > 0) {
+ ret = dm.DeleteDevice(name);
+ if (ret || errno != EBUSY) {
+ break;
+ }
+ SLOGW("DM_DEV Cannot remove dm-crypt device %s: %s, retrying...\n", name.c_str(),
+ strerror(errno));
+ std::this_thread::sleep_for(std::chrono::milliseconds(100));
+ }
+ if (!ret) {
+ SLOGE("DM_DEV Cannot remove dm-crypt device %s: %s\n", name.c_str(), strerror(errno));
+ return -1;
+ }
+ return 0;
+}
+
+static int pbkdf2(const char* passwd, const unsigned char* salt, unsigned char* ikey,
+ void* params UNUSED) {
+ SLOGI("Using pbkdf2 for cryptfs KDF");
+
+ /* Turn the password into a key and IV that can decrypt the master key */
+ return PKCS5_PBKDF2_HMAC_SHA1(passwd, strlen(passwd), salt, SALT_LEN, HASH_COUNT,
+ INTERMEDIATE_BUF_SIZE, ikey) != 1;
+}
+
+static int scrypt(const char* passwd, const unsigned char* salt, unsigned char* ikey, void* params) {
+ SLOGI("Using scrypt for cryptfs KDF");
+
+ struct crypt_mnt_ftr* ftr = (struct crypt_mnt_ftr*)params;
+
+ int N = 1 << ftr->N_factor;
+ int r = 1 << ftr->r_factor;
+ int p = 1 << ftr->p_factor;
+
+ /* Turn the password into a key and IV that can decrypt the master key */
+ crypto_scrypt((const uint8_t*)passwd, strlen(passwd), salt, SALT_LEN, N, r, p, ikey,
+ INTERMEDIATE_BUF_SIZE);
+
+ return 0;
+}
+
+static int scrypt_keymaster(const char* passwd, const unsigned char* salt, unsigned char* ikey,
+ void* params) {
+ SLOGI("Using scrypt with keymaster for cryptfs KDF");
+
+ int rc;
+ size_t signature_size;
+ unsigned char* signature;
+ struct crypt_mnt_ftr* ftr = (struct crypt_mnt_ftr*)params;
+
+ int N = 1 << ftr->N_factor;
+ int r = 1 << ftr->r_factor;
+ int p = 1 << ftr->p_factor;
+
+ rc = crypto_scrypt((const uint8_t*)passwd, strlen(passwd), salt, SALT_LEN, N, r, p, ikey,
+ INTERMEDIATE_BUF_SIZE);
+
+ if (rc) {
+ SLOGE("scrypt failed");
+ return -1;
+ }
+
+ if (keymaster_sign_object(ftr, ikey, INTERMEDIATE_BUF_SIZE, &signature, &signature_size)) {
+ SLOGE("Signing failed");
+ return -1;
+ }
+
+ rc = crypto_scrypt(signature, signature_size, salt, SALT_LEN, N, r, p, ikey,
+ INTERMEDIATE_BUF_SIZE);
+ free(signature);
+
+ if (rc) {
+ SLOGE("scrypt failed");
+ return -1;
+ }
+
+ return 0;
+}
+
+static int encrypt_master_key(const char* passwd, const unsigned char* salt,
+ const unsigned char* decrypted_master_key,
+ unsigned char* encrypted_master_key, struct crypt_mnt_ftr* crypt_ftr) {
+ unsigned char ikey[INTERMEDIATE_BUF_SIZE] = {0};
+ EVP_CIPHER_CTX e_ctx;
+ int encrypted_len, final_len;
+ int rc = 0;
+
+ /* Turn the password into an intermediate key and IV that can decrypt the master key */
+ get_device_scrypt_params(crypt_ftr);
+
+ switch (crypt_ftr->kdf_type) {
+ case KDF_SCRYPT_KEYMASTER:
+ if (keymaster_create_key(crypt_ftr)) {
+ SLOGE("keymaster_create_key failed");
+ return -1;
+ }
+
+ if (scrypt_keymaster(passwd, salt, ikey, crypt_ftr)) {
+ SLOGE("scrypt failed");
+ return -1;
+ }
+ break;
+
+ case KDF_SCRYPT:
+ if (scrypt(passwd, salt, ikey, crypt_ftr)) {
+ SLOGE("scrypt failed");
+ return -1;
+ }
+ break;
+
+ default:
+ SLOGE("Invalid kdf_type");
+ return -1;
+ }
+
+ /* Initialize the decryption engine */
+ EVP_CIPHER_CTX_init(&e_ctx);
+ if (!EVP_EncryptInit_ex(&e_ctx, EVP_aes_128_cbc(), NULL, ikey,
+ ikey + INTERMEDIATE_KEY_LEN_BYTES)) {
+ SLOGE("EVP_EncryptInit failed\n");
+ return -1;
+ }
+ EVP_CIPHER_CTX_set_padding(&e_ctx, 0); /* Turn off padding as our data is block aligned */
+
+ /* Encrypt the master key */
+ if (!EVP_EncryptUpdate(&e_ctx, encrypted_master_key, &encrypted_len, decrypted_master_key,
+ crypt_ftr->keysize)) {
+ SLOGE("EVP_EncryptUpdate failed\n");
+ return -1;
+ }
+ if (!EVP_EncryptFinal_ex(&e_ctx, encrypted_master_key + encrypted_len, &final_len)) {
+ SLOGE("EVP_EncryptFinal failed\n");
+ return -1;
+ }
+
+ if (encrypted_len + final_len != static_cast<int>(crypt_ftr->keysize)) {
+ SLOGE("EVP_Encryption length check failed with %d, %d bytes\n", encrypted_len, final_len);
+ return -1;
+ }
+
+ /* Store the scrypt of the intermediate key, so we can validate if it's a
+ password error or mount error when things go wrong.
+ Note there's no need to check for errors, since if this is incorrect, we
+ simply won't wipe userdata, which is the correct default behavior
+ */
+ int N = 1 << crypt_ftr->N_factor;
+ int r = 1 << crypt_ftr->r_factor;
+ int p = 1 << crypt_ftr->p_factor;
+
+ rc = crypto_scrypt(ikey, INTERMEDIATE_KEY_LEN_BYTES, crypt_ftr->salt, sizeof(crypt_ftr->salt),
+ N, r, p, crypt_ftr->scrypted_intermediate_key,
+ sizeof(crypt_ftr->scrypted_intermediate_key));
+
+ if (rc) {
+ SLOGE("encrypt_master_key: crypto_scrypt failed");
+ }
+
+ EVP_CIPHER_CTX_cleanup(&e_ctx);
+
+ return 0;
+}
+
+static int decrypt_master_key_aux(const char* passwd, unsigned char* salt,
+ const unsigned char* encrypted_master_key, size_t keysize,
+ unsigned char* decrypted_master_key, kdf_func kdf,
+ void* kdf_params, unsigned char** intermediate_key,
+ size_t* intermediate_key_size) {
+ unsigned char ikey[INTERMEDIATE_BUF_SIZE] = {0};
+ EVP_CIPHER_CTX d_ctx;
+ int decrypted_len, final_len;
+
+ /* Turn the password into an intermediate key and IV that can decrypt the
+ master key */
+ if (kdf(passwd, salt, ikey, kdf_params)) {
+ SLOGE("kdf failed");
+ return -1;
+ }
+
+ /* Initialize the decryption engine */
+ EVP_CIPHER_CTX_init(&d_ctx);
+ if (!EVP_DecryptInit_ex(&d_ctx, EVP_aes_128_cbc(), NULL, ikey,
+ ikey + INTERMEDIATE_KEY_LEN_BYTES)) {
+ return -1;
+ }
+ EVP_CIPHER_CTX_set_padding(&d_ctx, 0); /* Turn off padding as our data is block aligned */
+ /* Decrypt the master key */
+ if (!EVP_DecryptUpdate(&d_ctx, decrypted_master_key, &decrypted_len, encrypted_master_key,
+ keysize)) {
+ return -1;
+ }
+ if (!EVP_DecryptFinal_ex(&d_ctx, decrypted_master_key + decrypted_len, &final_len)) {
+ return -1;
+ }
+
+ if (decrypted_len + final_len != static_cast<int>(keysize)) {
+ return -1;
+ }
+
+ /* Copy intermediate key if needed by params */
+ if (intermediate_key && intermediate_key_size) {
+ *intermediate_key = (unsigned char*)malloc(INTERMEDIATE_KEY_LEN_BYTES);
+ if (*intermediate_key) {
+ memcpy(*intermediate_key, ikey, INTERMEDIATE_KEY_LEN_BYTES);
+ *intermediate_key_size = INTERMEDIATE_KEY_LEN_BYTES;
+ }
+ }
+
+ EVP_CIPHER_CTX_cleanup(&d_ctx);
+
+ return 0;
+}
+
+static void get_kdf_func(struct crypt_mnt_ftr* ftr, kdf_func* kdf, void** kdf_params) {
+ if (ftr->kdf_type == KDF_SCRYPT_KEYMASTER) {
+ *kdf = scrypt_keymaster;
+ *kdf_params = ftr;
+ } else if (ftr->kdf_type == KDF_SCRYPT) {
+ *kdf = scrypt;
+ *kdf_params = ftr;
+ } else {
+ *kdf = pbkdf2;
+ *kdf_params = NULL;
+ }
+}
+
+static int decrypt_master_key(const char* passwd, unsigned char* decrypted_master_key,
+ struct crypt_mnt_ftr* crypt_ftr, unsigned char** intermediate_key,
+ size_t* intermediate_key_size) {
+ kdf_func kdf;
+ void* kdf_params;
+ int ret;
+
+ get_kdf_func(crypt_ftr, &kdf, &kdf_params);
+ ret = decrypt_master_key_aux(passwd, crypt_ftr->salt, crypt_ftr->master_key, crypt_ftr->keysize,
+ decrypted_master_key, kdf, kdf_params, intermediate_key,
+ intermediate_key_size);
+ if (ret != 0) {
+ SLOGW("failure decrypting master key");
+ }
+
+ return ret;
+}
+
+static int create_encrypted_random_key(const char* passwd, unsigned char* master_key,
+ unsigned char* salt, struct crypt_mnt_ftr* crypt_ftr) {
+ unsigned char key_buf[MAX_KEY_LEN];
+
+ /* Get some random bits for a key and salt */
+ if (::ReadRandomBytes(sizeof(key_buf), reinterpret_cast<char*>(key_buf)) != 0) {
+ return -1;
+ }
+ if (::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);
+}
+
+static void ensure_subdirectory_unmounted(const char *prefix) {
+ std::vector<std::string> umount_points;
+ std::unique_ptr<FILE, int (*)(FILE*)> mnts(setmntent("/proc/mounts", "r"), endmntent);
+ if (!mnts) {
+ SLOGW("could not read mount files");
+ return;
+ }
+
+ //Find sudirectory mount point
+ mntent* mentry;
+ std::string top_directory(prefix);
+ if (!android::base::EndsWith(prefix, "/")) {
+ top_directory = top_directory + "/";
+ }
+ while ((mentry = getmntent(mnts.get())) != nullptr) {
+ if (strcmp(mentry->mnt_dir, top_directory.c_str()) == 0) {
+ continue;
+ }
+
+ if (android::base::StartsWith(mentry->mnt_dir, top_directory)) {
+ SLOGW("found sub-directory mount %s - %s\n", prefix, mentry->mnt_dir);
+ umount_points.push_back(mentry->mnt_dir);
+ }
+ }
+
+ //Sort by path length to umount longest path first
+ std::sort(std::begin(umount_points), std::end(umount_points),
+ [](const std::string& s1, const std::string& s2) {return s1.length() > s2.length(); });
+
+ for (std::string& mount_point : umount_points) {
+ umount(mount_point.c_str());
+ SLOGW("umount sub-directory mount %s\n", mount_point.c_str());
+ }
+}
+
+static int wait_and_unmount(const char* mountpoint, bool kill) {
+ int i, err, rc;
+
+ // Subdirectory mount will cause a failure of umount.
+ ensure_subdirectory_unmounted(mountpoint);
+#define WAIT_UNMOUNT_COUNT 20
+
+ /* Now umount the tmpfs filesystem */
+ for (i = 0; i < WAIT_UNMOUNT_COUNT; i++) {
+ if (umount(mountpoint) == 0) {
+ break;
+ }
+
+ if (errno == EINVAL) {
+ /* EINVAL is returned if the directory is not a mountpoint,
+ * i.e. there is no filesystem mounted there. So just get out.
+ */
+ break;
+ }
+
+ err = errno;
+
+ /* If allowed, be increasingly aggressive before the last two retries */
+ if (kill) {
+ if (i == (WAIT_UNMOUNT_COUNT - 3)) {
+ SLOGW("sending SIGHUP to processes with open files\n");
+ android::vold::KillProcessesWithOpenFiles(mountpoint, SIGTERM);
+ } else if (i == (WAIT_UNMOUNT_COUNT - 2)) {
+ SLOGW("sending SIGKILL to processes with open files\n");
+ android::vold::KillProcessesWithOpenFiles(mountpoint, SIGKILL);
+ }
+ }
+
+ sleep(1);
+ }
+
+ if (i < WAIT_UNMOUNT_COUNT) {
+ SLOGD("unmounting %s succeeded\n", mountpoint);
+ rc = 0;
+ } else {
+ android::vold::KillProcessesWithOpenFiles(mountpoint, 0);
+ SLOGE("unmounting %s failed: %s\n", mountpoint, strerror(err));
+ rc = -1;
+ }
+
+ return rc;
+}
+
+static void prep_data_fs(void) {
+ // NOTE: post_fs_data results in init calling back around to vold, so all
+ // callers to this method must be async
+
+ /* Do the prep of the /data filesystem */
+ property_set("vold.post_fs_data_done", "0");
+ property_set("vold.decrypt", "trigger_post_fs_data");
+ SLOGD("Just triggered post_fs_data");
+
+ /* Wait a max of 50 seconds, hopefully it takes much less */
+ while (!android::base::WaitForProperty("vold.post_fs_data_done", "1", std::chrono::seconds(15))) {
+ /* We timed out to prep /data in time. Continue wait. */
+ SLOGE("waited 15s for vold.post_fs_data_done, still waiting...");
+ }
+ SLOGD("post_fs_data done");
+}
+
+static void cryptfs_set_corrupt() {
+ // Mark the footer as bad
+ struct crypt_mnt_ftr crypt_ftr;
+ if (get_crypt_ftr_and_key(&crypt_ftr)) {
+ SLOGE("Failed to get crypto footer - panic");
+ return;
+ }
+
+ crypt_ftr.flags |= CRYPT_DATA_CORRUPT;
+ if (put_crypt_ftr_and_key(&crypt_ftr)) {
+ SLOGE("Failed to set crypto footer - panic");
+ return;
+ }
+}
+
+static void cryptfs_trigger_restart_min_framework() {
+ if (fs_mgr_do_tmpfs_mount(DATA_MNT_POINT)) {
+ SLOGE("Failed to mount tmpfs on data - panic");
+ return;
+ }
+
+ if (property_set("vold.decrypt", "trigger_post_fs_data")) {
+ SLOGE("Failed to trigger post fs data - panic");
+ return;
+ }
+
+ if (property_set("vold.decrypt", "trigger_restart_min_framework")) {
+ SLOGE("Failed to trigger restart min framework - panic");
+ return;
+ }
+}
+
+/* returns < 0 on failure */
+static int cryptfs_restart_internal(int restart_main) {
+ char crypto_blkdev[MAXPATHLEN];
+ int rc = -1;
+ static int restart_successful = 0;
+
+ /* Validate that it's OK to call this routine */
+ if (!master_key_saved) {
+ SLOGE("Encrypted filesystem not validated, aborting");
+ return -1;
+ }
+
+ if (restart_successful) {
+ SLOGE("System already restarted with encrypted disk, aborting");
+ return -1;
+ }
+
+ if (restart_main) {
+ /* Here is where we shut down the framework. The init scripts
+ * start all services in one of 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(::sFsckContext)) {
+ SLOGE("Failed to setexeccon");
+ return -1;
+ }
+ bool needs_cp = ::cp_needsCheckpoint();
+ while ((mount_rc = fs_mgr_do_mount(&fstab_default, DATA_MNT_POINT, crypto_blkdev, 0,
+ needs_cp, false)) != 0) {
+ if (mount_rc == FS_MGR_DOMNT_BUSY) {
+ /* TODO: invoke something similar to
+ Process::killProcessWithOpenFiles(DATA_MNT_POINT,
+ retries > RETRY_MOUNT_ATTEMPT/2 ? 1 : 2 ) */
+ SLOGI("Failed to mount %s because it is busy - waiting", crypto_blkdev);
+ if (--retries) {
+ sleep(RETRY_MOUNT_DELAY_SECONDS);
+ } else {
+ /* Let's hope that a reboot clears away whatever is keeping
+ the mount busy */
+ cryptfs_reboot(RebootType::reboot);
+ }
+ } else {
+ SLOGE("Failed to mount decrypted data");
+ cryptfs_set_corrupt();
+ cryptfs_trigger_restart_min_framework();
+ SLOGI("Started framework to offer wipe");
+ if (setexeccon(NULL)) {
+ SLOGE("Failed to setexeccon");
+ }
+ return -1;
+ }
+ }
+ if (setexeccon(NULL)) {
+ SLOGE("Failed to setexeccon");
+ return -1;
+ }
+
+ /* Create necessary paths on /data */
+ prep_data_fs();
+ property_set("vold.decrypt", "trigger_load_persist_props");
+
+ /* startup service classes main and late_start */
+ property_set("vold.decrypt", "trigger_restart_framework");
+ SLOGD("Just triggered restart_framework\n");
+
+ /* Give it a few moments to get started */
+ sleep(1);
+ }
+
+ if (rc == 0) {
+ restart_successful = 1;
+ }
+
+ return rc;
+}
+
+int cryptfs_restart(void) {
+ SLOGI("cryptfs_restart");
+ if (fscrypt_is_native()) {
+ SLOGE("cryptfs_restart not valid for file encryption:");
+ return -1;
+ }
+
+ /* Call internal implementation forcing a restart of main service group */
+ return cryptfs_restart_internal(1);
+}
+
+static int do_crypto_complete(const char* mount_point) {
+ struct crypt_mnt_ftr crypt_ftr;
+ char encrypted_state[PROPERTY_VALUE_MAX];
+
+ property_get("ro.crypto.state", encrypted_state, "");
+ if (strcmp(encrypted_state, "encrypted")) {
+ SLOGE("not running with encryption, aborting");
+ return CRYPTO_COMPLETE_NOT_ENCRYPTED;
+ }
+
+ // crypto_complete is full disk encrypted status
+ if (fscrypt_is_native()) {
+ return CRYPTO_COMPLETE_NOT_ENCRYPTED;
+ }
+
+ if (get_crypt_ftr_and_key(&crypt_ftr)) {
+ std::string key_loc;
+ get_crypt_info(&key_loc, nullptr);
+
+ /*
+ * Only report this error if key_loc is a file and it exists.
+ * If the device was never encrypted, and /data is not mountable for
+ * some reason, returning 1 should prevent the UI from presenting the
+ * a "enter password" screen, or worse, a "press button to wipe the
+ * device" screen.
+ */
+ if (!key_loc.empty() && key_loc[0] == '/' && (access("key_loc", F_OK) == -1)) {
+ SLOGE("master key file does not exist, aborting");
+ return CRYPTO_COMPLETE_NOT_ENCRYPTED;
+ } else {
+ SLOGE("Error getting crypt footer and key\n");
+ return CRYPTO_COMPLETE_BAD_METADATA;
+ }
+ }
+
+ // Test for possible error flags
+ if (crypt_ftr.flags & CRYPT_ENCRYPTION_IN_PROGRESS) {
+ SLOGE("Encryption process is partway completed\n");
+ return CRYPTO_COMPLETE_PARTIAL;
+ }
+
+ if (crypt_ftr.flags & CRYPT_INCONSISTENT_STATE) {
+ SLOGE("Encryption process was interrupted but cannot continue\n");
+ return CRYPTO_COMPLETE_INCONSISTENT;
+ }
+
+ if (crypt_ftr.flags & CRYPT_DATA_CORRUPT) {
+ SLOGE("Encryption is successful but data is corrupt\n");
+ return CRYPTO_COMPLETE_CORRUPT;
+ }
+
+ /* We passed the test! We shall diminish, and return to the west */
+ return CRYPTO_COMPLETE_ENCRYPTED;
+}
+
+static int test_mount_encrypted_fs(struct crypt_mnt_ftr* crypt_ftr, const char* passwd,
+ const char* mount_point, const char* label) {
+ unsigned char decrypted_master_key[MAX_KEY_LEN];
+ std::string crypto_blkdev;
+ 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,
+ const_cast<char*>(crypto_blkdev.c_str()), 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.c_str());
+
+ /* 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.
+ */
+int cryptfs_setup_ext_volume(const char* label, const char* real_blkdev, const KeyBuffer& key,
+ std::string* out_crypto_blkdev) {
+ auto crypto_type = get_crypto_type();
+ if (key.size() != crypto_type.get_keysize()) {
+ SLOGE("Raw keysize %zu does not match crypt keysize %zu", key.size(),
+ crypto_type.get_keysize());
+ return -1;
+ }
+ uint64_t nr_sec = 0;
+ if (::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 = crypto_type.get_keysize();
+ strlcpy((char*)ext_crypt_ftr.crypto_type_name, crypto_type.get_kernel_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, reinterpret_cast<const unsigned char*>(key.data()),
+ real_blkdev, out_crypto_blkdev, label, flags);
+}
+
+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 get_crypto_type().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 = get_crypto_type().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, const char* crypto_blkdev,
+ const char* real_blkdev, int previously_encrypted_upto) {
+ off64_t cur_encryption_done = 0, tot_encryption_size = 0;
+ int rc = -1;
+
+ /* The size of the userdata partition, and add in the vold volumes below */
+ tot_encryption_size = crypt_ftr->fs_size;
+
+ rc = cryptfs_enable_inplace(crypto_blkdev, real_blkdev, crypt_ftr->fs_size, &cur_encryption_done,
+ tot_encryption_size, previously_encrypted_upto, true);
+
+ if (rc == ENABLE_INPLACE_ERR_DEV) {
+ /* Hack for b/17898962 */
+ SLOGE("cryptfs_enable: crypto block dev failure. Must reboot...\n");
+ cryptfs_reboot(RebootType::reboot);
+ }
+
+ if (!rc) {
+ crypt_ftr->encrypted_upto = cur_encryption_done;
+ }
+
+ if (!rc && crypt_ftr->encrypted_upto == crypt_ftr->fs_size) {
+ /* The inplace routine never actually sets the progress to 100% due
+ * to the round down nature of integer division, so set it here */
+ property_set("vold.encrypt_progress", "100");
+ }
+
+ return rc;
+}
+
+// static int vold_unmountAll(void) {
+// VolumeManager* vm = VolumeManager::Instance();
+// return vm->unmountAll();
+// }
+
+int cryptfs_enable_internal(int crypt_type, const char* passwd, int no_ui) {
+ std::string crypto_blkdev;
+ 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;
+ // std::unique_ptr<android::wakelock::WakeLock> wakeLock = nullptr;
+
+ 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 (::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());
+ // wakeLock = std::make_unique<android::wakelock::WakeLock>(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.
+ */
+ wait_and_unmount(DATA_MNT_POINT, true);
+ 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, get_crypto_type().get_kernel_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);
+ ALOGE("cryptfs_enable_internal\n");
+ 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.c_str(), 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.c_str(), 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.c_str(), 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");
+ // wakeLock.reset(nullptr);
+ 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");
+ }
+ 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");
+ return rc;
+
+error_unencrypted:
+ property_set("vold.encrypt_progress", "error_not_encrypted");
+ 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");
+ return -1;
+}
+
+int cryptfs_enable(int type, const char* passwd, int no_ui) {
+ return cryptfs_enable_internal(type, passwd, no_ui);
+}
+
+int cryptfs_enable_default(int no_ui) {
+ return cryptfs_enable_internal(CRYPT_TYPE_DEFAULT, DEFAULT_PASSWORD, no_ui);
+}
+
+int cryptfs_changepw(int crypt_type, const char* newpw) {
+ if (fscrypt_is_native()) {
+ SLOGE("cryptfs_changepw not valid for file encryption");
+ return -1;
+ }
+
+ struct crypt_mnt_ftr crypt_ftr;
+ int rc;
+
+ /* This is only allowed after we've successfully decrypted the master key */
+ if (!master_key_saved) {
+ SLOGE("Key not saved, aborting");
+ return -1;
+ }
+
+ if (crypt_type < 0 || crypt_type > CRYPT_TYPE_MAX_TYPE) {
+ SLOGE("Invalid crypt_type %d", crypt_type);
+ return -1;
+ }
+
+ /* get key */
+ if (get_crypt_ftr_and_key(&crypt_ftr)) {
+ SLOGE("Error getting crypt footer and key");
+ return -1;
+ }
+
+ crypt_ftr.crypt_type = crypt_type;
+
+ rc = encrypt_master_key(crypt_type == CRYPT_TYPE_DEFAULT ? DEFAULT_PASSWORD : newpw,
+ crypt_ftr.salt, saved_master_key, crypt_ftr.master_key, &crypt_ftr);
+ if (rc) {
+ SLOGE("Encrypt master key failed: %d", rc);
+ return -1;
+ }
+ /* save the key */
+ put_crypt_ftr_and_key(&crypt_ftr);
+
+ return 0;
+}
+
+static unsigned int persist_get_max_entries(int encrypted) {
+ struct crypt_mnt_ftr crypt_ftr;
+ unsigned int dsize;
+
+ /* If encrypted, use the values from the crypt_ftr, otherwise
+ * use the values for the current spec.
+ */
+ if (encrypted) {
+ if (get_crypt_ftr_and_key(&crypt_ftr)) {
+ /* Something is wrong, assume no space for entries */
+ return 0;
+ }
+ dsize = crypt_ftr.persist_data_size;
+ } else {
+ dsize = CRYPT_PERSIST_DATA_SIZE;
+ }
+
+ if (dsize > sizeof(struct crypt_persist_data)) {
+ return (dsize - sizeof(struct crypt_persist_data)) / sizeof(struct crypt_persist_entry);
+ } else {
+ return 0;
+ }
+}
+
+static int persist_get_key(const char* fieldname, char* value) {
+ unsigned int i;
+
+ if (persist_data == NULL) {
+ return -1;
+ }
+ for (i = 0; i < persist_data->persist_valid_entries; i++) {
+ if (!strncmp(persist_data->persist_entry[i].key, fieldname, PROPERTY_KEY_MAX)) {
+ /* We found it! */
+ strlcpy(value, persist_data->persist_entry[i].val, PROPERTY_VALUE_MAX);
+ return 0;
+ }
+ }
+
+ return -1;
+}
+
+static int persist_set_key(const char* fieldname, const char* value, int encrypted) {
+ unsigned int i;
+ unsigned int num;
+ unsigned int max_persistent_entries;
+
+ if (persist_data == NULL) {
+ return -1;
+ }
+
+ max_persistent_entries = persist_get_max_entries(encrypted);
+
+ num = persist_data->persist_valid_entries;
+
+ for (i = 0; i < num; i++) {
+ if (!strncmp(persist_data->persist_entry[i].key, fieldname, PROPERTY_KEY_MAX)) {
+ /* We found an existing entry, update it! */
+ memset(persist_data->persist_entry[i].val, 0, PROPERTY_VALUE_MAX);
+ strlcpy(persist_data->persist_entry[i].val, value, PROPERTY_VALUE_MAX);
+ return 0;
+ }
+ }
+
+ /* We didn't find it, add it to the end, if there is room */
+ if (persist_data->persist_valid_entries < max_persistent_entries) {
+ memset(&persist_data->persist_entry[num], 0, sizeof(struct crypt_persist_entry));
+ strlcpy(persist_data->persist_entry[num].key, fieldname, PROPERTY_KEY_MAX);
+ strlcpy(persist_data->persist_entry[num].val, value, PROPERTY_VALUE_MAX);
+ persist_data->persist_valid_entries++;
+ return 0;
+ }
+
+ return -1;
+}
+
+/**
+ * Test if key is part of the multi-entry (field, index) sequence. Return non-zero if key is in the
+ * sequence and its index is greater than or equal to index. Return 0 otherwise.
+ */
+int match_multi_entry(const char* key, const char* field, unsigned index) {
+ std::string key_ = key;
+ std::string field_ = field;
+
+ std::string parsed_field;
+ unsigned parsed_index;
+
+ std::string::size_type split = key_.find_last_of('_');
+ if (split == std::string::npos) {
+ parsed_field = key_;
+ parsed_index = 0;
+ } else {
+ parsed_field = key_.substr(0, split);
+ parsed_index = std::stoi(key_.substr(split + 1));
+ }
+
+ return parsed_field == field_ && parsed_index >= index;
+}
+
+/*
+ * Delete entry/entries from persist_data. If the entries are part of a multi-segment field, all
+ * remaining entries starting from index will be deleted.
+ * returns PERSIST_DEL_KEY_OK if deletion succeeds,
+ * PERSIST_DEL_KEY_ERROR_NO_FIELD if the field does not exist,
+ * and PERSIST_DEL_KEY_ERROR_OTHER if error occurs.
+ *
+ */
+static int persist_del_keys(const char* fieldname, unsigned index) {
+ unsigned int i;
+ unsigned int j;
+ unsigned int num;
+
+ if (persist_data == NULL) {
+ return PERSIST_DEL_KEY_ERROR_OTHER;
+ }
+
+ num = persist_data->persist_valid_entries;
+
+ j = 0; // points to the end of non-deleted entries.
+ // Filter out to-be-deleted entries in place.
+ for (i = 0; i < num; i++) {
+ if (!match_multi_entry(persist_data->persist_entry[i].key, fieldname, index)) {
+ persist_data->persist_entry[j] = persist_data->persist_entry[i];
+ j++;
+ }
+ }
+
+ if (j < num) {
+ persist_data->persist_valid_entries = j;
+ // Zeroise the remaining entries
+ memset(&persist_data->persist_entry[j], 0, (num - j) * sizeof(struct crypt_persist_entry));
+ return PERSIST_DEL_KEY_OK;
+ } else {
+ // Did not find an entry matching the given fieldname
+ return PERSIST_DEL_KEY_ERROR_NO_FIELD;
+ }
+}
+
+static int persist_count_keys(const char* fieldname) {
+ unsigned int i;
+ unsigned int count;
+
+ if (persist_data == NULL) {
+ return -1;
+ }
+
+ count = 0;
+ for (i = 0; i < persist_data->persist_valid_entries; i++) {
+ if (match_multi_entry(persist_data->persist_entry[i].key, fieldname, 0)) {
+ count++;
+ }
+ }
+
+ return count;
+}
+
+/* Return the value of the specified field. */
+int cryptfs_getfield(const char* fieldname, char* value, int len) {
+ if (fscrypt_is_native()) {
+ SLOGE("Cannot get field when file encrypted");
+ return -1;
+ }
+
+ char temp_value[PROPERTY_VALUE_MAX];
+ /* CRYPTO_GETFIELD_OK is success,
+ * CRYPTO_GETFIELD_ERROR_NO_FIELD is value not set,
+ * CRYPTO_GETFIELD_ERROR_BUF_TOO_SMALL is buffer (as given by len) too small,
+ * CRYPTO_GETFIELD_ERROR_OTHER is any other error
+ */
+ int rc = CRYPTO_GETFIELD_ERROR_OTHER;
+ int i;
+ char temp_field[PROPERTY_KEY_MAX];
+
+ if (persist_data == NULL) {
+ load_persistent_data();
+ if (persist_data == NULL) {
+ SLOGE("Getfield error, cannot load persistent data");
+ goto out;
+ }
+ }
+
+ // Read value from persistent entries. If the original value is split into multiple entries,
+ // stitch them back together.
+ if (!persist_get_key(fieldname, temp_value)) {
+ // We found it, copy it to the caller's buffer and keep going until all entries are read.
+ if (strlcpy(value, temp_value, len) >= (unsigned)len) {
+ // value too small
+ rc = CRYPTO_GETFIELD_ERROR_BUF_TOO_SMALL;
+ goto out;
+ }
+ rc = CRYPTO_GETFIELD_OK;
+
+ for (i = 1; /* break explicitly */; i++) {
+ if (snprintf(temp_field, sizeof(temp_field), "%s_%d", fieldname, i) >=
+ (int)sizeof(temp_field)) {
+ // If the fieldname is very long, we stop as soon as it begins to overflow the
+ // maximum field length. At this point we have in fact fully read out the original
+ // value because cryptfs_setfield would not allow fields with longer names to be
+ // written in the first place.
+ break;
+ }
+ if (!persist_get_key(temp_field, temp_value)) {
+ if (strlcat(value, temp_value, len) >= (unsigned)len) {
+ // value too small.
+ rc = CRYPTO_GETFIELD_ERROR_BUF_TOO_SMALL;
+ goto out;
+ }
+ } else {
+ // Exhaust all entries.
+ break;
+ }
+ }
+ } else {
+ /* Sadness, it's not there. Return the error */
+ rc = CRYPTO_GETFIELD_ERROR_NO_FIELD;
+ }
+
+out:
+ return rc;
+}
+
+/* Set the value of the specified field. */
+int cryptfs_setfield(const char* fieldname, const char* value) {
+ if (fscrypt_is_native()) {
+ SLOGE("Cannot set field when file encrypted");
+ return -1;
+ }
+
+ char encrypted_state[PROPERTY_VALUE_MAX];
+ /* 0 is success, negative values are error */
+ int rc = CRYPTO_SETFIELD_ERROR_OTHER;
+ int encrypted = 0;
+ unsigned int field_id;
+ char temp_field[PROPERTY_KEY_MAX];
+ unsigned int num_entries;
+ unsigned int max_keylen;
+
+ if (persist_data == NULL) {
+ load_persistent_data();
+ if (persist_data == NULL) {
+ SLOGE("Setfield error, cannot load persistent data");
+ goto out;
+ }
+ }
+
+ property_get("ro.crypto.state", encrypted_state, "");
+ if (!strcmp(encrypted_state, "encrypted")) {
+ encrypted = 1;
+ }
+
+ // Compute the number of entries required to store value, each entry can store up to
+ // (PROPERTY_VALUE_MAX - 1) chars
+ if (strlen(value) == 0) {
+ // Empty value also needs one entry to store.
+ num_entries = 1;
+ } else {
+ num_entries = (strlen(value) + (PROPERTY_VALUE_MAX - 1) - 1) / (PROPERTY_VALUE_MAX - 1);
+ }
+
+ max_keylen = strlen(fieldname);
+ if (num_entries > 1) {
+ // Need an extra "_%d" suffix.
+ max_keylen += 1 + log10(num_entries);
+ }
+ if (max_keylen > PROPERTY_KEY_MAX - 1) {
+ rc = CRYPTO_SETFIELD_ERROR_FIELD_TOO_LONG;
+ goto out;
+ }
+
+ // Make sure we have enough space to write the new value
+ if (persist_data->persist_valid_entries + num_entries - persist_count_keys(fieldname) >
+ persist_get_max_entries(encrypted)) {
+ rc = CRYPTO_SETFIELD_ERROR_VALUE_TOO_LONG;
+ goto out;
+ }
+
+ // Now that we know persist_data has enough space for value, let's delete the old field first
+ // to make up space.
+ persist_del_keys(fieldname, 0);
+
+ if (persist_set_key(fieldname, value, encrypted)) {
+ // fail to set key, should not happen as we have already checked the available space
+ SLOGE("persist_set_key() error during setfield()");
+ goto out;
+ }
+
+ for (field_id = 1; field_id < num_entries; field_id++) {
+ snprintf(temp_field, sizeof(temp_field), "%s_%u", fieldname, field_id);
+
+ if (persist_set_key(temp_field, value + field_id * (PROPERTY_VALUE_MAX - 1), encrypted)) {
+ // fail to set key, should not happen as we have already checked the available space.
+ SLOGE("persist_set_key() error during setfield()");
+ goto out;
+ }
+ }
+
+ /* If we are running encrypted, save the persistent data now */
+ if (encrypted) {
+ if (save_persistent_data()) {
+ SLOGE("Setfield error, cannot save persistent data");
+ goto out;
+ }
+ }
+
+ rc = CRYPTO_SETFIELD_OK;
+
+out:
+ return rc;
+}
+
+/* Checks userdata. Attempt to mount the volume if default-
+ * encrypted.
+ * On success trigger next init phase and return 0.
+ * Currently do not handle failure - see TODO below.
+ */
+int cryptfs_mount_default_encrypted(void) {
+ int crypt_type = cryptfs_get_password_type();
+ if (crypt_type < 0 || crypt_type > CRYPT_TYPE_MAX_TYPE) {
+ SLOGE("Bad crypt type - error");
+ } else if (crypt_type != CRYPT_TYPE_DEFAULT) {
+ SLOGD(
+ "Password is not default - "
+ "starting min framework to prompt");
+ property_set("vold.decrypt", "trigger_restart_min_framework");
+ return 0;
+ } else if (cryptfs_check_passwd(DEFAULT_PASSWORD) == 0) {
+ SLOGD("Password is default - restarting filesystem");
+ cryptfs_restart_internal(0);
+ return 0;
+ } else {
+ SLOGE("Encrypted, default crypt type but can't decrypt");
+ }
+
+ /** Corrupt. Allow us to boot into framework, which will detect bad
+ crypto when it calls do_crypto_complete, then do a factory reset
+ */
+ property_set("vold.decrypt", "trigger_restart_min_framework");
+ return 0;
+}
+
+/* Returns type of the password, default, pattern, pin or password.
+ */
+int cryptfs_get_password_type(void) {
+ if (fscrypt_is_native()) {
+ SLOGE("cryptfs_get_password_type not valid for file encryption");
+ return -1;
+ }
+
+ struct crypt_mnt_ftr crypt_ftr;
+
+ if (get_crypt_ftr_and_key(&crypt_ftr)) {
+ SLOGE("Error getting crypt footer and key\n");
+ return -1;
+ }
+
+ if (crypt_ftr.flags & CRYPT_INCONSISTENT_STATE) {
+ return -1;
+ }
+
+ return crypt_ftr.crypt_type;
+}
+
+const char* cryptfs_get_password() {
+ if (fscrypt_is_native()) {
+ SLOGE("cryptfs_get_password not valid for file encryption");
+ return 0;
+ }
+
+ struct timespec now;
+ clock_gettime(CLOCK_BOOTTIME, &now);
+ if (now.tv_sec < password_expiry_time) {
+ return password;
+ } else {
+ cryptfs_clear_password();
+ return 0;
+ }
+}
+
+void cryptfs_clear_password() {
+ 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;
+}