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-rw-r--r--crypto/fde/cryptfs.cpp1763
1 files changed, 1763 insertions, 0 deletions
diff --git a/crypto/fde/cryptfs.cpp b/crypto/fde/cryptfs.cpp
new file mode 100644
index 000000000..83522968b
--- /dev/null
+++ b/crypto/fde/cryptfs.cpp
@@ -0,0 +1,1763 @@
+/*
+ * 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.
+ */
+
+/* TO DO:
+ * 1. Perhaps keep several copies of the encrypted key, in case something
+ * goes horribly wrong?
+ *
+ */
+
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <linux/dm-ioctl.h>
+#include <libgen.h>
+#include <stdlib.h>
+#include <sys/param.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <openssl/evp.h>
+#include <openssl/sha.h>
+#include <errno.h>
+//#include <ext4_utils/ext4_crypt.h>
+//#include <ext4_utils/ext4_utils.h>
+#include <linux/kdev_t.h>
+//#include <fs_mgr.h>
+#include <time.h>
+#include <math.h>
+//#include <selinux/selinux.h>
+#include "cryptfs.h"
+//#include "secontext.h"
+#define LOG_TAG "Cryptfs"
+//#include "cutils/log.h"
+#include "cutils/properties.h"
+//#include "cutils/android_reboot.h"
+//#include "hardware_legacy/power.h"
+//#include <logwrap/logwrap.h>
+//#include "ScryptParameters.h"
+//#include "VolumeManager.h"
+//#include "VoldUtil.h"
+//#include "Ext4Crypt.h"
+//#include "f2fs_sparseblock.h"
+//#include "EncryptInplace.h"
+//#include "Process.h"
+#if TW_KEYMASTER_MAX_API == 3
+#include "../ext4crypt/Keymaster3.h"
+#endif
+#if TW_KEYMASTER_MAX_API == 4
+#include "../ext4crypt/Keymaster4.h"
+#endif
+#if TW_KEYMASTER_MAX_API == 0
+#include <hardware/keymaster.h>
+#else // so far, all trees that have keymaster >= 1 have keymaster 1 support
+#include <stdbool.h>
+#include <openssl/evp.h>
+#include <openssl/sha.h>
+#include <hardware/keymaster0.h>
+#include <hardware/keymaster1.h>
+#endif
+//#include "android-base/properties.h"
+//#include <bootloader_message/bootloader_message.h>
+#ifdef CONFIG_HW_DISK_ENCRYPTION
+#include <cryptfs_hw.h>
+#endif
+extern "C" {
+#include <crypto_scrypt.h>
+}
+#include <string>
+#include <vector>
+
+#define ALOGE(...) fprintf(stdout, "E:" __VA_ARGS__)
+#define SLOGE(...) fprintf(stdout, "E:" __VA_ARGS__)
+#define SLOGW(...) fprintf(stdout, "W:" __VA_ARGS__)
+#define SLOGI(...) fprintf(stdout, "I:" __VA_ARGS__)
+#define SLOGD(...) fprintf(stdout, "D:" __VA_ARGS__)
+
+#define UNUSED __attribute__((unused))
+
+#define DM_CRYPT_BUF_SIZE 4096
+
+#define HASH_COUNT 2000
+
+#ifndef min /* already defined by windows.h */
+#define min(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
+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_HEX_PASSWORD "64656661756c745f70617373776f7264"
+#define DEFAULT_PASSWORD "default_password"
+
+#define CRYPTO_BLOCK_DEVICE "userdata"
+
+#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 KEY_LEN_BYTES 16
+
+#define RETRY_MOUNT_ATTEMPTS 10
+#define RETRY_MOUNT_DELAY_SECONDS 1
+
+#define CREATE_CRYPTO_BLK_DEV_FLAGS_ALLOW_ENCRYPT_OVERRIDE (1)
+
+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;
+
+static int previous_type;
+
+static char key_fname[PROPERTY_VALUE_MAX] = "";
+static char real_blkdev[PROPERTY_VALUE_MAX] = "";
+static char file_system[PROPERTY_VALUE_MAX] = "";
+
+static void get_blkdev_size(int fd, unsigned long *nr_sec)
+{
+ if ( (ioctl(fd, BLKGETSIZE, nr_sec)) == -1) {
+ *nr_sec = 0;
+ }
+}
+
+#if TW_KEYMASTER_MAX_API == 0
+static int keymaster_init(keymaster_device_t **keymaster_dev)
+{
+ int rc;
+
+ const hw_module_t* mod;
+ rc = hw_get_module_by_class(KEYSTORE_HARDWARE_MODULE_ID, NULL, &mod);
+ if (rc) {
+ printf("could not find any keystore module\n");
+ goto out;
+ }
+
+ rc = keymaster_open(mod, keymaster_dev);
+ if (rc) {
+ printf("could not open keymaster device in %s (%s)\n",
+ KEYSTORE_HARDWARE_MODULE_ID, strerror(-rc));
+ goto out;
+ }
+
+ return 0;
+
+out:
+ *keymaster_dev = NULL;
+ return rc;
+}
+#else //TW_KEYMASTER_MAX_API == 0
+static int keymaster_init(keymaster0_device_t **keymaster0_dev,
+ keymaster1_device_t **keymaster1_dev)
+{
+ int rc;
+
+ const hw_module_t* mod;
+ rc = hw_get_module_by_class(KEYSTORE_HARDWARE_MODULE_ID, NULL, &mod);
+ if (rc) {
+ printf("could not find any keystore module\n");
+ goto err;
+ }
+
+ printf("keymaster module name is %s\n", mod->name);
+ printf("keymaster version is %d\n", mod->module_api_version);
+
+ *keymaster0_dev = NULL;
+ *keymaster1_dev = NULL;
+ if (mod->module_api_version == KEYMASTER_MODULE_API_VERSION_1_0) {
+ printf("Found keymaster1 module, using keymaster1 API.\n");
+ rc = keymaster1_open(mod, keymaster1_dev);
+ } else {
+ printf("Found keymaster0 module, using keymaster0 API.\n");
+ rc = keymaster0_open(mod, keymaster0_dev);
+ }
+
+ if (rc) {
+ printf("could not open keymaster device in %s (%s)\n",
+ KEYSTORE_HARDWARE_MODULE_ID, strerror(-rc));
+ goto err;
+ }
+
+ return 0;
+
+err:
+ *keymaster0_dev = NULL;
+ *keymaster1_dev = NULL;
+ return rc;
+}
+#endif //TW_KEYMASTER_MAX_API == 0
+
+#ifdef CONFIG_HW_DISK_ENCRYPTION
+static int scrypt_keymaster(const char *passwd, const unsigned char *salt,
+ unsigned char *ikey, void *params);
+static void convert_key_to_hex_ascii(const unsigned char *master_key,
+ unsigned int keysize, char *master_key_ascii);
+static int test_mount_hw_encrypted_fs(struct crypt_mnt_ftr* crypt_ftr,
+ const char *passwd, const char *mount_point, const char *label);
+int cryptfs_check_passwd_hw(char *passwd);
+int cryptfs_get_master_key(struct crypt_mnt_ftr* ftr, const char* password,
+ unsigned char* master_key);
+
+static void convert_key_to_hex_ascii_for_upgrade(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 ? 0x57 : 0x30);
+
+ nibble = master_key[i] & 0xf;
+ master_key_ascii[a + 1] = nibble + (nibble > 9 ? 0x57 : 0x30);
+ }
+
+ /* Add the null termination */
+ master_key_ascii[a] = '\0';
+}
+
+static int get_keymaster_hw_fde_passwd(const char* passwd, unsigned char* newpw,
+ unsigned char* salt,
+ const struct crypt_mnt_ftr *ftr)
+{
+ /* if newpw updated, return 0
+ * if newpw not updated return -1
+ */
+ int rc = -1;
+
+ if (should_use_keymaster()) {
+ if (scrypt_keymaster(passwd, salt, newpw, (void*)ftr)) {
+ SLOGE("scrypt failed");
+ } else {
+ rc = 0;
+ }
+ }
+
+ return rc;
+}
+
+static int verify_hw_fde_passwd(const char *passwd, struct crypt_mnt_ftr* crypt_ftr)
+{
+ unsigned char newpw[32] = {0};
+ int key_index;
+ SLOGI("starting verify_hw_fde_passwd\n");
+ if (get_keymaster_hw_fde_passwd(passwd, newpw, crypt_ftr->salt, crypt_ftr))
+ key_index = set_hw_device_encryption_key(passwd,
+ (char*) crypt_ftr->crypto_type_name);
+ else
+ key_index = set_hw_device_encryption_key((const char*)newpw,
+ (char*) crypt_ftr->crypto_type_name);
+ return key_index;
+}
+
+static int verify_and_update_hw_fde_passwd(const char *passwd,
+ struct crypt_mnt_ftr* crypt_ftr)
+{
+ char* new_passwd = NULL;
+ unsigned char newpw[32] = {0};
+ int key_index = -1;
+ int passwd_updated = -1;
+ int ascii_passwd_updated = (crypt_ftr->flags & CRYPT_ASCII_PASSWORD_UPDATED);
+
+ key_index = verify_hw_fde_passwd(passwd, crypt_ftr);
+ if (key_index < 0) {
+ ++crypt_ftr->failed_decrypt_count;
+
+ if (ascii_passwd_updated) {
+ SLOGI("Ascii password was updated");
+ } else {
+ /* Code in else part would execute only once:
+ * When device is upgraded from L->M release.
+ * Once upgraded, code flow should never come here.
+ * L release passed actual password in hex, so try with hex
+ * Each nible of passwd was encoded as a byte, so allocate memory
+ * twice of password len plus one more byte for null termination
+ */
+ if (crypt_ftr->crypt_type == CRYPT_TYPE_DEFAULT) {
+ new_passwd = (char*)malloc(strlen(DEFAULT_HEX_PASSWORD) + 1);
+ if (new_passwd == NULL) {
+ SLOGE("System out of memory. Password verification incomplete");
+ goto out;
+ }
+ strlcpy(new_passwd, DEFAULT_HEX_PASSWORD, strlen(DEFAULT_HEX_PASSWORD) + 1);
+ } else {
+ new_passwd = (char*)malloc(strlen(passwd) * 2 + 1);
+ if (new_passwd == NULL) {
+ SLOGE("System out of memory. Password verification incomplete");
+ goto out;
+ }
+ convert_key_to_hex_ascii_for_upgrade((const unsigned char*)passwd,
+ strlen(passwd), new_passwd);
+ }
+ key_index = set_hw_device_encryption_key((const char*)new_passwd,
+ (char*) crypt_ftr->crypto_type_name);
+ if (key_index >=0) {
+ crypt_ftr->failed_decrypt_count = 0;
+ SLOGI("Hex password verified...will try to update with Ascii value");
+ /* Before updating password, tie that with keymaster to tie with ROT */
+
+ if (get_keymaster_hw_fde_passwd(passwd, newpw,
+ crypt_ftr->salt, crypt_ftr)) {
+ passwd_updated = update_hw_device_encryption_key(new_passwd,
+ passwd, (char*)crypt_ftr->crypto_type_name);
+ } else {
+ passwd_updated = update_hw_device_encryption_key(new_passwd,
+ (const char*)newpw, (char*)crypt_ftr->crypto_type_name);
+ }
+
+ if (passwd_updated >= 0) {
+ crypt_ftr->flags |= CRYPT_ASCII_PASSWORD_UPDATED;
+ SLOGI("Ascii password recorded and updated");
+ } else {
+ SLOGI("Passwd verified, could not update...Will try next time");
+ }
+ } else {
+ ++crypt_ftr->failed_decrypt_count;
+ }
+ free(new_passwd);
+ }
+ } else {
+ if (!ascii_passwd_updated)
+ crypt_ftr->flags |= CRYPT_ASCII_PASSWORD_UPDATED;
+ }
+out:
+ // update footer before leaving
+ //put_crypt_ftr_and_key(crypt_ftr);
+ return key_index;
+}
+#endif
+
+void set_partition_data(const char* block_device, const char* key_location, const char* fs)
+{
+ strcpy(key_fname, key_location);
+ strcpy(real_blkdev, block_device);
+ strcpy(file_system, fs);
+}
+
+/* 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)
+{
+ SLOGI("TWRP keymaster max API: %i\n", TW_KEYMASTER_MAX_API);
+ 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_UNPADDED:
+ // This is broken: It produces a message which is shorter than
+ // the public modulus, failing criterion 2.
+ memcpy(to_sign, object, object_size);
+ to_sign_size = object_size;
+ SLOGI("Signing unpadded object\n");
+ break;
+ case KDF_SCRYPT_KEYMASTER_BADLY_PADDED:
+ // This is broken: Since the value of object is uniformly
+ // distributed, it produces a message that is larger than the
+ // public modulus with probability 0.25.
+ memcpy(to_sign, object, min(RSA_KEY_SIZE_BYTES, object_size));
+ SLOGI("Signing end-padded object\n");
+ break;
+ 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, 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;
+ }
+
+ int rc = -1;
+
+#if TW_KEYMASTER_MAX_API >= 1
+ keymaster0_device_t *keymaster0_dev = 0;
+ keymaster1_device_t *keymaster1_dev = 0;
+ if (keymaster_init(&keymaster0_dev, &keymaster1_dev)) {
+#else
+ keymaster_device_t *keymaster0_dev = 0;
+ if (keymaster_init(&keymaster0_dev)) {
+#endif
+ printf("Failed to init keymaster 0/1\n");
+ goto initfail;
+ }
+ if (keymaster0_dev) {
+ keymaster_rsa_sign_params_t params;
+ params.digest_type = DIGEST_NONE;
+ params.padding_type = PADDING_NONE;
+
+ rc = keymaster0_dev->sign_data(keymaster0_dev,
+ &params,
+ ftr->keymaster_blob,
+ ftr->keymaster_blob_size,
+ to_sign,
+ to_sign_size,
+ signature,
+ signature_size);
+ goto out;
+ }
+#if TW_KEYMASTER_MAX_API >= 1
+ else if (keymaster1_dev) {
+ keymaster_key_blob_t key = { ftr->keymaster_blob, ftr->keymaster_blob_size };
+ keymaster_key_param_t params[] = {
+ keymaster_param_enum(KM_TAG_PADDING, KM_PAD_NONE),
+ keymaster_param_enum(KM_TAG_DIGEST, KM_DIGEST_NONE),
+ };
+ keymaster_key_param_set_t param_set = { params, sizeof(params)/sizeof(*params) };
+ keymaster_operation_handle_t op_handle;
+ keymaster_error_t error = keymaster1_dev->begin(keymaster1_dev, KM_PURPOSE_SIGN, &key,
+ &param_set, NULL /* out_params */,
+ &op_handle);
+ if (error == KM_ERROR_KEY_RATE_LIMIT_EXCEEDED) {
+ // Key usage has been rate-limited. Wait a bit and try again.
+ sleep(KEYMASTER_CRYPTFS_RATE_LIMIT);
+ error = keymaster1_dev->begin(keymaster1_dev, KM_PURPOSE_SIGN, &key,
+ &param_set, NULL /* out_params */,
+ &op_handle);
+ }
+ if (error != KM_ERROR_OK) {
+ printf("Error starting keymaster signature transaction: %d\n", error);
+ rc = -1;
+ goto out;
+ }
+
+ keymaster_blob_t input = { to_sign, to_sign_size };
+ size_t input_consumed;
+ error = keymaster1_dev->update(keymaster1_dev, op_handle, NULL /* in_params */,
+ &input, &input_consumed, NULL /* out_params */,
+ NULL /* output */);
+ if (error != KM_ERROR_OK) {
+ printf("Error sending data to keymaster signature transaction: %d\n", error);
+ rc = -1;
+ goto out;
+ }
+ if (input_consumed != to_sign_size) {
+ // This should never happen. If it does, it's a bug in the keymaster implementation.
+ printf("Keymaster update() did not consume all data.\n");
+ keymaster1_dev->abort(keymaster1_dev, op_handle);
+ rc = -1;
+ goto out;
+ }
+
+ keymaster_blob_t tmp_sig;
+ error = keymaster1_dev->finish(keymaster1_dev, op_handle, NULL /* in_params */,
+ NULL /* verify signature */, NULL /* out_params */,
+ &tmp_sig);
+ if (error != KM_ERROR_OK) {
+ printf("Error finishing keymaster signature transaction: %d\n", error);
+ rc = -1;
+ goto out;
+ }
+
+ *signature = (uint8_t*)tmp_sig.data;
+ *signature_size = tmp_sig.data_length;
+ rc = 0;
+ }
+#endif // TW_KEYMASTER_API >= 1
+
+ out:
+#if TW_KEYMASTER_MAX_API >= 1
+ if (keymaster1_dev)
+ keymaster1_close(keymaster1_dev);
+#endif
+ if (keymaster0_dev)
+#if TW_KEYMASTER_MAX_API >= 1
+ keymaster0_close(keymaster0_dev);
+#else
+ keymaster_close(keymaster0_dev);
+#endif
+
+ if (rc == 0)
+ return 0; // otherwise we'll try for a newer keymaster API
+
+initfail:
+#if TW_KEYMASTER_MAX_API == 3
+ return 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,
+ ftr->keymaster_blob, KEYMASTER_BLOB_SIZE, &ftr->keymaster_blob_size);
+#endif //TW_KEYMASTER_MAX_API == 3
+#if TW_KEYMASTER_MAX_API >= 4
+ //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\n");
+ 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\n");
+ return -1;
+ }
+ /*if (put_crypt_ftr_and_key(ftr) != 0) {
+ SLOGE("Failed to write upgraded key to disk");
+ }*/
+ SLOGD("Key upgraded successfully\n");
+ return 0;
+ //}
+#endif
+ return -1;
+}
+
+static void ioctl_init(struct dm_ioctl *io, size_t dataSize, const char *name, unsigned flags)
+{
+ memset(io, 0, dataSize);
+ io->data_size = dataSize;
+ io->data_start = sizeof(struct dm_ioctl);
+ io->version[0] = 4;
+ io->version[1] = 0;
+ io->version[2] = 0;
+ io->flags = flags;
+ if (name) {
+ strlcpy(io->name, name, sizeof(io->name));
+ }
+}
+
+namespace {
+
+struct CryptoType;
+
+// Use to get the CryptoType in use on this device.
+const CryptoType &get_crypto_type();
+
+struct CryptoType {
+ // We should only be constructing CryptoTypes as part of
+ // supported_crypto_types[]. We do it via this pseudo-builder pattern,
+ // which isn't pure or fully protected as a concession to being able to
+ // do it all at compile time. Add new CryptoTypes in
+ // supported_crypto_types[] below.
+ constexpr CryptoType() : CryptoType(nullptr, nullptr, 0xFFFFFFFF) {}
+ constexpr CryptoType set_keysize(uint32_t size) const {
+ return CryptoType(this->property_name, this->crypto_name, size);
+ }
+ constexpr CryptoType set_property_name(const char *property) const {
+ return CryptoType(property, this->crypto_name, this->keysize);
+ }
+ constexpr CryptoType set_crypto_name(const char *crypto) const {
+ return CryptoType(this->property_name, crypto, this->keysize);
+ }
+
+ constexpr const char *get_property_name() const { return property_name; }
+ constexpr const char *get_crypto_name() const { return crypto_name; }
+ constexpr uint32_t get_keysize() const { return keysize; }
+
+ private:
+ const char *property_name;
+ const char *crypto_name;
+ uint32_t keysize;
+
+ constexpr CryptoType(const char *property, const char *crypto,
+ uint32_t ksize)
+ : property_name(property), crypto_name(crypto), keysize(ksize) {}
+ friend const CryptoType &get_crypto_type();
+ static const CryptoType &get_device_crypto_algorithm();
+};
+
+// 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.
+const CryptoType &get_crypto_type() {
+ static CryptoType crypto_type = CryptoType::get_device_crypto_algorithm();
+ return crypto_type;
+}
+
+constexpr CryptoType default_crypto_type = CryptoType()
+ .set_property_name("AES-128-CBC")
+ .set_crypto_name("aes-cbc-essiv:sha256")
+ .set_keysize(16);
+
+constexpr CryptoType supported_crypto_types[] = {
+ default_crypto_type,
+ CryptoType()
+ .set_property_name("Speck128/128-XTS")
+ .set_crypto_name("speck128-xts-plain64")
+ .set_keysize(32),
+ // Add new CryptoTypes here. Order is not important.
+};
+
+
+// ---------- START COMPILE-TIME SANITY CHECK BLOCK -------------------------
+// We confirm all supported_crypto_types have a small enough keysize and
+// had both set_property_name() and set_crypto_name() called.
+
+template <typename T, size_t N>
+constexpr size_t array_length(T (&)[N]) { return N; }
+
+constexpr bool indexOutOfBoundsForCryptoTypes(size_t index) {
+ return (index >= array_length(supported_crypto_types));
+}
+
+constexpr bool isValidCryptoType(const CryptoType &crypto_type) {
+ return ((crypto_type.get_property_name() != nullptr) &&
+ (crypto_type.get_crypto_name() != nullptr) &&
+ (crypto_type.get_keysize() <= MAX_KEY_LEN));
+}
+
+// Note in C++11 that constexpr functions can only have a single line.
+// So our code is a bit convoluted (using recursion instead of a loop),
+// but it's asserting at compile time that all of our key lengths are valid.
+constexpr bool validateSupportedCryptoTypes(size_t index) {
+ return indexOutOfBoundsForCryptoTypes(index) ||
+ (isValidCryptoType(supported_crypto_types[index]) &&
+ validateSupportedCryptoTypes(index + 1));
+}
+
+static_assert(validateSupportedCryptoTypes(0),
+ "We have a CryptoType with keysize > MAX_KEY_LEN or which was "
+ "incompletely constructed.");
+// ---------- END COMPILE-TIME SANITY CHECK BLOCK -------------------------
+
+
+// Don't call this directly, use get_crypto_type(), which caches this result.
+const CryptoType &CryptoType::get_device_crypto_algorithm() {
+ constexpr char CRYPT_ALGO_PROP[] = "ro.crypto.fde_algorithm";
+ char paramstr[PROPERTY_VALUE_MAX];
+
+ property_get(CRYPT_ALGO_PROP, paramstr,
+ default_crypto_type.get_property_name());
+ for (auto const &ctype : supported_crypto_types) {
+ if (strcmp(paramstr, ctype.get_property_name()) == 0) {
+ return ctype;
+ }
+ }
+ ALOGE("Invalid name (%s) for %s. Defaulting to %s\n", paramstr,
+ CRYPT_ALGO_PROP, default_crypto_type.get_property_name());
+ return default_crypto_type;
+}
+
+} // namespace
+
+#define SCRYPT_PROP "ro.crypto.scrypt_params"
+#define SCRYPT_DEFAULTS "15:3:1"
+
+bool parse_scrypt_parameters(const char* paramstr, int *Nf, int *rf, int *pf) {
+ int params[3] = {};
+ char *token;
+ char *saveptr;
+ int i;
+
+ /*
+ * The token we're looking for should be three integers separated by
+ * colons (e.g., "12:8:1"). Scan the property to make sure it matches.
+ */
+ for (i = 0, token = strtok_r(const_cast<char *>(paramstr), ":", &saveptr);
+ token != nullptr && i < 3;
+ i++, token = strtok_r(nullptr, ":", &saveptr)) {
+ char *endptr;
+ params[i] = strtol(token, &endptr, 10);
+
+ /*
+ * Check that there was a valid number and it's 8-bit.
+ */
+ if ((*token == '\0') || (*endptr != '\0') || params[i] < 0 || params[i] > 255) {
+ return false;
+ }
+ }
+ if (token != nullptr) {
+ return false;
+ }
+ *Nf = params[0]; *rf = params[1]; *pf = params[2];
+ return true;
+}
+
+uint32_t cryptfs_get_keysize() {
+ return get_crypto_type().get_keysize();
+}
+
+const char *cryptfs_get_crypto_name() {
+ return get_crypto_type().get_crypto_name();
+}
+
+static int get_crypt_ftr_info(char **metadata_fname, off64_t *off)
+{
+ static int cached_data = 0;
+ static off64_t cached_off = 0;
+ static char cached_metadata_fname[PROPERTY_VALUE_MAX] = "";
+ int fd;
+ //char key_loc[PROPERTY_VALUE_MAX];
+ //char real_blkdev[PROPERTY_VALUE_MAX];
+ int rc = -1;
+
+ if (!cached_data) {
+ //fs_mgr_get_crypt_info(fstab_default, key_loc, real_blkdev, sizeof(key_loc));
+
+ if (!strcmp(key_fname, KEY_IN_FOOTER)) {
+ if ( (fd = open(real_blkdev, O_RDWR|O_CLOEXEC)) < 0) {
+ SLOGE("Cannot open real block device %s\n", real_blkdev);
+ return -1;
+ }
+
+ unsigned long nr_sec = 0;
+ get_blkdev_size(fd, &nr_sec);
+ if (nr_sec != 0) {
+ /* 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, sizeof(cached_metadata_fname));
+ cached_off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET;
+ cached_data = 1;
+ } else {
+ SLOGE("Cannot get size of block device %s\n", real_blkdev);
+ }
+ close(fd);
+ } else {
+ strlcpy(cached_metadata_fname, key_fname, 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;
+}
+
+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);
+ }
+
+ /* Success! */
+ rc = 0;
+
+errout:
+ close(fd);
+ return rc;
+}
+
+int cryptfs_check_footer()
+{
+ int rc = -1;
+ struct crypt_mnt_ftr crypt_ftr;
+
+ rc = get_crypt_ftr_and_key(&crypt_ftr);
+
+ return rc;
+}
+
+/* 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;
+ crypt_params = buffer + sizeof(struct dm_ioctl) + sizeof(struct dm_target_spec);
+ buff_offset = crypt_params - buffer;
+ SLOGI("Extra parameters for dm_crypt: %s\n", extra_params);
+
+#ifdef CONFIG_HW_DISK_ENCRYPTION
+ if(is_hw_disk_encryption((char*)crypt_ftr->crypto_type_name)) {
+ strlcpy(tgt->target_type, "req-crypt",DM_MAX_TYPE_NAME);
+ if (is_ice_enabled())
+ convert_key_to_hex_ascii(master_key, sizeof(int), master_key_ascii);
+ else
+ convert_key_to_hex_ascii(master_key, crypt_ftr->keysize, master_key_ascii);
+ }
+ else {
+ convert_key_to_hex_ascii(master_key, crypt_ftr->keysize, master_key_ascii);
+ strlcpy(tgt->target_type, "crypt", DM_MAX_TYPE_NAME);
+ }
+ snprintf(crypt_params, sizeof(buffer) - buff_offset, "%s %s 0 %s 0 %s 0",
+ crypt_ftr->crypto_type_name, master_key_ascii,
+ real_blk_name, extra_params);
+
+ SLOGI("target_type = %s", tgt->target_type);
+ SLOGI("real_blk_name = %s, extra_params = %s", real_blk_name, extra_params);
+#else
+ convert_key_to_hex_ascii(master_key, crypt_ftr->keysize, master_key_ascii);
+ strlcpy(tgt->target_type, "crypt", DM_MAX_TYPE_NAME);
+ 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);
+#endif
+
+ 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) {
+#ifdef CONFIG_HW_DISK_ENCRYPTION
+ if (! strcmp(v->name, "crypt") || ! strcmp(v->name, "req-crypt")) {
+#else
+ if (! strcmp(v->name, "crypt")) {
+#endif
+ /* 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;
+}
+
+#ifndef CONFIG_HW_DISK_ENCRYPTION
+static std::string extra_params_as_string(const std::vector<std::string>& extra_params_vec) {
+ if (extra_params_vec.empty()) return "";
+ char temp[10];
+ snprintf(temp, sizeof(temp), "%zd", extra_params_vec.size());
+ std::string extra_params = temp; //std::to_string(extra_params_vec.size());
+ for (const auto& p : extra_params_vec) {
+ extra_params.append(" ");
+ extra_params.append(p);
+ }
+ return extra_params;
+}
+#endif
+
+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;
+#ifdef CONFIG_HW_DISK_ENCRYPTION
+ char encrypted_state[PROPERTY_VALUE_MAX] = {0};
+ char progress[PROPERTY_VALUE_MAX] = {0};
+ const char *extra_params;
+#else
+ std::vector<std::string> extra_params_vec;
+#endif
+
+ 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);
+
+#ifdef CONFIG_HW_DISK_ENCRYPTION
+ if(is_hw_disk_encryption((char*)crypt_ftr->crypto_type_name)) {
+ /* Set fde_enabled if either FDE completed or in-progress */
+ property_get("ro.crypto.state", encrypted_state, ""); /* FDE completed */
+ property_get("vold.encrypt_progress", progress, ""); /* FDE in progress */
+ if (!strcmp(encrypted_state, "encrypted") || strcmp(progress, "")) {
+ if (is_ice_enabled()) {
+ if (flags & CREATE_CRYPTO_BLK_DEV_FLAGS_ALLOW_ENCRYPT_OVERRIDE)
+ extra_params = "fde_enabled ice allow_encrypt_override";
+ else
+ extra_params = "fde_enabled ice";
+ } else {
+ if (flags & CREATE_CRYPTO_BLK_DEV_FLAGS_ALLOW_ENCRYPT_OVERRIDE)
+ extra_params = "fde_enabled allow_encrypt_override";
+ else
+ extra_params = "fde_enabled";
+ }
+ } else {
+ if (flags & CREATE_CRYPTO_BLK_DEV_FLAGS_ALLOW_ENCRYPT_OVERRIDE)
+ extra_params = "fde_enabled allow_encrypt_override";
+ else
+ extra_params = "fde_enabled";
+ }
+ } else {
+ extra_params = "";
+ 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))) {
+ if (flags & CREATE_CRYPTO_BLK_DEV_FLAGS_ALLOW_ENCRYPT_OVERRIDE)
+ extra_params = "2 allow_discards allow_encrypt_override";
+ else
+ extra_params = "1 allow_discards";
+ SLOGI("Enabling support for allow_discards in dmcrypt.\n");
+ }
+ }
+ }
+ load_count = load_crypto_mapping_table(crypt_ftr, master_key, real_blk_name, name, fd,
+ extra_params);
+#else
+ 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.push_back(std::string("allow_discards")); // Used to be extra_params_vec.emplace_back("allow_discards"); but this won't compile in 5.1 trees
+ }
+ }
+ if (flags & CREATE_CRYPTO_BLK_DEV_FLAGS_ALLOW_ENCRYPT_OVERRIDE) {
+ extra_params_vec.push_back(std::string("allow_encrypt_override")); // Used to be extra_params_vec.emplace_back("allow_encrypt_override"); but this won't compile in 5.1 trees
+ }
+ load_count = load_crypto_mapping_table(crypt_ftr, master_key, real_blk_name, name, fd,
+ extra_params_as_string(extra_params_vec).c_str());
+#endif
+ 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;
+ }
+
+ /* 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;
+}
+
+int delete_crypto_blk_dev(const char *name)
+{
+ int fd;
+ char buffer[DM_CRYPT_BUF_SIZE];
+ struct dm_ioctl *io;
+ int retval = -1;
+
+ 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);
+ if (ioctl(fd, DM_DEV_REMOVE, io)) {
+ SLOGE("Cannot remove dm-crypt device\n");
+ 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\n");
+
+ /* 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\n");
+
+ 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\n");
+
+ 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("Keymaster 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 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;
+}
+
+#ifdef CONFIG_HW_DISK_ENCRYPTION
+static int test_mount_hw_encrypted_fs(struct crypt_mnt_ftr* crypt_ftr,
+ const char *passwd, const char *mount_point, const char *label)
+{
+ /* Allocate enough space for a 256 bit key, but we may use less */
+ unsigned char decrypted_master_key[32];
+ char crypto_blkdev[MAXPATHLEN];
+ //char real_blkdev[MAXPATHLEN];
+ unsigned int orig_failed_decrypt_count;
+ int rc = 0;
+
+ SLOGD("crypt_ftr->fs_size = %lld\n", crypt_ftr->fs_size);
+ orig_failed_decrypt_count = crypt_ftr->failed_decrypt_count;
+
+ //fs_mgr_get_crypt_info(fstab_default, 0, real_blkdev, sizeof(real_blkdev));
+
+ int key_index = 0;
+ if(is_hw_disk_encryption((char*)crypt_ftr->crypto_type_name)) {
+ key_index = verify_and_update_hw_fde_passwd(passwd, crypt_ftr);
+ if (key_index < 0) {
+ rc = -1;
+ goto errout;
+ }
+ else {
+ if (is_ice_enabled()) {
+#ifndef CONFIG_HW_DISK_ENCRYPT_PERF
+ if (create_crypto_blk_dev(crypt_ftr, (unsigned char*)&key_index,
+ real_blkdev, crypto_blkdev, label, 0)) {
+ SLOGE("Error creating decrypted block device");
+ rc = -1;
+ goto errout;
+ }
+#endif
+ } else {
+ if (create_crypto_blk_dev(crypt_ftr, decrypted_master_key,
+ real_blkdev, crypto_blkdev, label, 0)) {
+ SLOGE("Error creating decrypted block device");
+ rc = -1;
+ goto errout;
+ }
+ }
+ }
+ }
+
+ if (rc == 0) {
+ /* Save the name of the crypto block device
+ * so we can mount it when restarting the framework. */
+#ifdef CONFIG_HW_DISK_ENCRYPT_PERF
+ if (!is_ice_enabled())
+#endif
+ property_set("ro.crypto.fs_crypto_blkdev", crypto_blkdev);
+ master_key_saved = 1;
+ }
+
+ errout:
+ return rc;
+}
+#endif
+
+static int try_mount_multiple_fs(const char *crypto_blkdev,
+ const char *mount_point,
+ const char *file_system)
+{
+ if (!mount(crypto_blkdev, mount_point, file_system, 0, NULL))
+ return 0;
+ if (strcmp(file_system, "ext4") &&
+ !mount(crypto_blkdev, mount_point, "ext4", 0, NULL))
+ return 0;
+ if (strcmp(file_system, "f2fs") &&
+ !mount(crypto_blkdev, mount_point, "f2fs", 0, NULL))
+ return 0;
+ return 1;
+}
+
+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];
+ //char real_blkdev[MAXPATHLEN];
+ char tmp_mount_point[64];
+ unsigned int orig_failed_decrypt_count;
+ int rc;
+ int use_keymaster = 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;
+ }
+ }
+
+ //fs_mgr_get_crypt_info(fstab_default, 0, real_blkdev, sizeof(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, 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 (try_mount_multiple_fs(crypto_blkdev, tmp_mount_point, file_system)) {
+ SLOGE("Error temp mounting decrypted block device\n");
+ delete_crypto_blk_dev(label);
+
+ rc = -1;
+ } else {
+ /* Success! */
+ SLOGI("Password did not match but decrypted drive mounted - continue");
+ umount(tmp_mount_point);
+ rc = 0;
+ }
+ }
+
+ if (rc == 0) {
+ /* 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;
+ }
+
+ 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, int keysize, char* out_crypto_blkdev) {
+ int fd = open(real_blkdev, O_RDONLY|O_CLOEXEC);
+ if (fd == -1) {
+ SLOGE("Failed to open %s: %s", real_blkdev, strerror(errno));
+ return -1;
+ }
+
+ unsigned long nr_sec = 0;
+ get_blkdev_size(fd, &nr_sec);
+ close(fd);
+
+ if (nr_sec == 0) {
+ 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 (e4crypt_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(label);
+}
+
+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;
+}
+
+#ifdef CONFIG_HW_DISK_ENCRYPTION
+int cryptfs_check_passwd_hw(const char* passwd)
+{
+ struct crypt_mnt_ftr crypt_ftr;
+ int rc;
+ unsigned char master_key[KEY_LEN_BYTES];
+ /* get key */
+ if (get_crypt_ftr_and_key(&crypt_ftr)) {
+ SLOGE("Error getting crypt footer and key");
+ return -1;
+ }
+
+ /*
+ * in case of manual encryption (from GUI), the encryption is done with
+ * default password
+ */
+ if (crypt_ftr.flags & CRYPT_FORCE_COMPLETE) {
+ /* compare scrypted_intermediate_key with stored scrypted_intermediate_key
+ * which was created with actual password before reboot.
+ */
+ rc = cryptfs_get_master_key(&crypt_ftr, passwd, master_key);
+ if (rc) {
+ SLOGE("password doesn't match");
+ return rc;
+ }
+
+ rc = test_mount_hw_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;
+ }
+ } else {
+ rc = test_mount_hw_encrypted_fs(&crypt_ftr, passwd,
+ DATA_MNT_POINT, CRYPTO_BLOCK_DEVICE);
+ SLOGE("test mount returned %i\n", rc);
+ }
+
+ return rc;
+}
+#endif
+
+int cryptfs_check_passwd(const char *passwd)
+{
+ /*if (e4crypt_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;
+ }
+
+#ifdef CONFIG_HW_DISK_ENCRYPTION
+ if (is_hw_disk_encryption((char*)crypt_ftr.crypto_type_name))
+ return cryptfs_check_passwd_hw(passwd);
+#endif
+
+ 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;
+ }
+ }
+
+ 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 {
+#ifdef CONFIG_HW_DISK_ENCRYPTION
+ if(is_hw_disk_encryption((char*)crypt_ftr.crypto_type_name)) {
+ if (verify_hw_fde_passwd(passwd, &crypt_ftr) >= 0)
+ rc = 0;
+ else
+ rc = -1;
+ } 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;
+ }
+ }
+#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;
+ }
+#endif
+ }
+
+ return rc;
+}
+
+/* Returns type of the password, default, pattern, pin or password.
+ */
+int cryptfs_get_password_type(void)
+{
+ 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;
+}
+
+int cryptfs_get_master_key(struct crypt_mnt_ftr* ftr, const char* password,
+ unsigned char* master_key)
+{
+ int rc;
+
+ unsigned char* intermediate_key = 0;
+ size_t intermediate_key_size = 0;
+
+ if (password == 0 || *password == 0) {
+ password = DEFAULT_PASSWORD;
+ }
+
+ rc = decrypt_master_key(password, master_key, ftr, &intermediate_key,
+ &intermediate_key_size);
+
+ if (rc) {
+ SLOGE("Can't calculate intermediate key");
+ return rc;
+ }
+
+ int N = 1 << ftr->N_factor;
+ int r = 1 << ftr->r_factor;
+ int p = 1 << ftr->p_factor;
+
+ unsigned char scrypted_intermediate_key[sizeof(ftr->scrypted_intermediate_key)];
+
+ rc = crypto_scrypt(intermediate_key, intermediate_key_size,
+ ftr->salt, sizeof(ftr->salt), N, r, p,
+ scrypted_intermediate_key,
+ sizeof(scrypted_intermediate_key));
+
+ free(intermediate_key);
+
+ if (rc) {
+ SLOGE("Can't scrypt intermediate key");
+ return rc;
+ }
+
+ return memcmp(scrypted_intermediate_key, ftr->scrypted_intermediate_key,
+ intermediate_key_size);
+}
+