diff options
Diffstat (limited to 'crypto/lollipop')
| -rw-r--r-- | crypto/lollipop/Android.mk | 60 | ||||
| -rw-r--r-- | crypto/lollipop/cryptfs.c | 1609 | ||||
| -rw-r--r-- | crypto/lollipop/cryptfs.h | 229 | ||||
| -rw-r--r-- | crypto/lollipop/main.c | 32 |
4 files changed, 1930 insertions, 0 deletions
diff --git a/crypto/lollipop/Android.mk b/crypto/lollipop/Android.mk new file mode 100644 index 000000000..6dc386a29 --- /dev/null +++ b/crypto/lollipop/Android.mk @@ -0,0 +1,60 @@ +LOCAL_PATH := $(call my-dir) +ifeq ($(TW_INCLUDE_CRYPTO), true) +include $(CLEAR_VARS) + +LOCAL_MODULE := libcryptfslollipop +LOCAL_MODULE_TAGS := eng optional +LOCAL_CFLAGS := +LOCAL_SRC_FILES = cryptfs.c +LOCAL_SHARED_LIBRARIES := libcrypto libhardware libcutils +LOCAL_C_INCLUDES := external/openssl/include $(commands_recovery_local_path)/crypto/scrypt/lib/crypto + +ifeq ($(TARGET_HW_DISK_ENCRYPTION),true) + ifeq ($(TARGET_CRYPTFS_HW_PATH),) + LOCAL_C_INCLUDES += device/qcom/common/cryptfs_hw + else + LOCAL_C_INCLUDES += $(TARGET_CRYPTFS_HW_PATH) + endif + LOCAL_SHARED_LIBRARIES += libcryptfs_hw + LOCAL_CFLAGS += -DCONFIG_HW_DISK_ENCRYPTION +endif + +ifneq ($(wildcard hardware/libhardware/include/hardware/keymaster0.h),) + LOCAL_CFLAGS += -DTW_CRYPTO_HAVE_KEYMASTERX + LOCAL_C_INCLUDES += external/boringssl/src/include +endif + +LOCAL_WHOLE_STATIC_LIBRARIES += libscrypttwrp_static + +include $(BUILD_SHARED_LIBRARY) + + + +include $(CLEAR_VARS) +LOCAL_MODULE := twrpdec +LOCAL_MODULE_TAGS := optional +LOCAL_MODULE_CLASS := RECOVERY_EXECUTABLES +LOCAL_MODULE_PATH := $(TARGET_RECOVERY_ROOT_OUT)/sbin +LOCAL_SRC_FILES := main.c cryptfs.c +LOCAL_SHARED_LIBRARIES := libcrypto libhardware libcutils libc +LOCAL_C_INCLUDES := external/openssl/include $(commands_recovery_local_path)/crypto/scrypt/lib/crypto + +ifeq ($(TARGET_HW_DISK_ENCRYPTION),true) + ifeq ($(TARGET_CRYPTFS_HW_PATH),) + LOCAL_C_INCLUDES += device/qcom/common/cryptfs_hw + else + LOCAL_C_INCLUDES += $(TARGET_CRYPTFS_HW_PATH) + endif + LOCAL_SHARED_LIBRARIES += libcryptfs_hw + LOCAL_CFLAGS += -DCONFIG_HW_DISK_ENCRYPTION +endif + +ifneq ($(wildcard hardware/libhardware/include/hardware/keymaster0.h),) + LOCAL_CFLAGS += -DTW_CRYPTO_HAVE_KEYMASTERX + LOCAL_C_INCLUDES += external/boringssl/src/include +endif + +LOCAL_WHOLE_STATIC_LIBRARIES += libscrypttwrp_static +include $(BUILD_EXECUTABLE) + +endif diff --git a/crypto/lollipop/cryptfs.c b/crypto/lollipop/cryptfs.c new file mode 100644 index 000000000..80f433bf6 --- /dev/null +++ b/crypto/lollipop/cryptfs.c @@ -0,0 +1,1609 @@ +/* + * 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 <linux/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 <errno.h> +#include <linux/kdev_t.h> +#include <time.h> +#include "cryptfs.h" +#include "cutils/properties.h" +#include "crypto_scrypt.h" + +#ifndef TW_CRYPTO_HAVE_KEYMASTERX +#include <hardware/keymaster.h> +#else +#include <stdbool.h> +#include <openssl/evp.h> +#include <openssl/sha.h> +#include <hardware/keymaster0.h> +#include <hardware/keymaster1.h> +#endif + +#ifndef min /* already defined by windows.h */ +#define min(a, b) ((a) < (b) ? (a) : (b)) +#endif + +#define UNUSED __attribute__((unused)) + +#define UNUSED __attribute__((unused)) + +#ifdef CONFIG_HW_DISK_ENCRYPTION +#include "cryptfs_hw.h" +#endif + +#define DM_CRYPT_BUF_SIZE 4096 + +#define HASH_COUNT 2000 +#define KEY_LEN_BYTES 16 +#define IV_LEN_BYTES 16 + +#define KEY_IN_FOOTER "footer" + +#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 + +char *me = "cryptfs"; + +static unsigned char saved_master_key[KEY_LEN_BYTES]; +static char *saved_mount_point; +static int master_key_saved = 0; +static struct crypt_persist_data *persist_data = NULL; +static char key_fname[PROPERTY_VALUE_MAX] = ""; +static char real_blkdev[PROPERTY_VALUE_MAX] = ""; +static char file_system[PROPERTY_VALUE_MAX] = ""; + +#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 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)) { + printf("scrypt failed"); + } else { + rc = 0; + } + } + + return rc; +} + +static int verify_hw_fde_passwd(char *passwd, struct crypt_mnt_ftr* crypt_ftr) +{ + unsigned char newpw[32] = {0}; + int key_index; + 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; +} +#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); +} + +#ifndef TW_CRYPTO_HAVE_KEYMASTERX +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; +} + +/* Should we use keymaster? */ +static int keymaster_check_compatibility() +{ + keymaster_device_t *keymaster_dev = 0; + int rc = 0; + + if (keymaster_init(&keymaster_dev)) { + printf("Failed to init keymaster\n"); + rc = -1; + goto out; + } + + printf("keymaster version is %d\n", keymaster_dev->common.module->module_api_version); + +#if (KEYMASTER_HEADER_VERSION >= 3) + if (keymaster_dev->common.module->module_api_version + < KEYMASTER_MODULE_API_VERSION_0_3) { + rc = 0; + goto out; + } + + if (keymaster_dev->flags & KEYMASTER_BLOBS_ARE_STANDALONE) { + rc = 1; + } + +#endif +out: + keymaster_close(keymaster_dev); + return rc; +} + +/* Create a new keymaster key and store it in this footer */ +static int keymaster_create_key(struct crypt_mnt_ftr *ftr) +{ + uint8_t* key = 0; + keymaster_device_t *keymaster_dev = 0; + + if (keymaster_init(&keymaster_dev)) { + printf("Failed to init keymaster\n"); + return -1; + } + + int rc = 0; + + keymaster_rsa_keygen_params_t params; + memset(¶ms, '\0', sizeof(params)); + params.public_exponent = RSA_EXPONENT; + params.modulus_size = RSA_KEY_SIZE; + + size_t key_size; + if (keymaster_dev->generate_keypair(keymaster_dev, TYPE_RSA, ¶ms, + &key, &key_size)) { + printf("Failed to generate keypair\n"); + rc = -1; + goto out; + } + + if (key_size > KEYMASTER_BLOB_SIZE) { + printf("Keymaster key too large for crypto footer\n"); + rc = -1; + goto out; + } + + memcpy(ftr->keymaster_blob, key, key_size); + ftr->keymaster_blob_size = key_size; + +out: + keymaster_close(keymaster_dev); + free(key); + return rc; +} + +/* 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) +{ + int rc = 0; + keymaster_device_t *keymaster_dev = 0; + if (keymaster_init(&keymaster_dev)) { + printf("Failed to init keymaster\n"); + return -1; + } + + /* We currently set the digest type to DIGEST_NONE because it's the + * only supported value for keymaster. A similar issue exists with + * PADDING_NONE. Long term both of these should likely change. + */ + keymaster_rsa_sign_params_t params; + params.digest_type = DIGEST_NONE; + params.padding_type = PADDING_NONE; + + 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; + printf("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)); + printf("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 RSA padding + // function, such as OAEP. + // + // TODO(paullawrence): When keymaster 0.4 is available, change + // this to use the padding options it provides. + memcpy(to_sign + 1, object, min(RSA_KEY_SIZE_BYTES - 1, object_size)); + printf("Signing safely-padded object\n"); + break; + default: + printf("Unknown KDF type %d\n", ftr->kdf_type); + return -1; + } + + rc = keymaster_dev->sign_data(keymaster_dev, + ¶ms, + ftr->keymaster_blob, + ftr->keymaster_blob_size, + to_sign, + to_sign_size, + signature, + signature_size); + + keymaster_close(keymaster_dev); + return rc; +} +#else //#ifndef TW_CRYPTO_HAVE_KEYMASTERX +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; +} + +/* Should we use keymaster? */ +static int keymaster_check_compatibility() +{ + keymaster0_device_t *keymaster0_dev = 0; + keymaster1_device_t *keymaster1_dev = 0; + int rc = 0; + + if (keymaster_init(&keymaster0_dev, &keymaster1_dev)) { + printf("Failed to init keymaster\n"); + rc = -1; + goto out; + } + + if (keymaster1_dev) { + rc = 1; + goto out; + } + + // TODO(swillden): Check to see if there's any reason to require v0.3. I think v0.1 and v0.2 + // should work. + if (keymaster0_dev->common.module->module_api_version + < KEYMASTER_MODULE_API_VERSION_0_3) { + rc = 0; + goto out; + } + + if (!(keymaster0_dev->flags & KEYMASTER_SOFTWARE_ONLY) && + (keymaster0_dev->flags & KEYMASTER_BLOBS_ARE_STANDALONE)) { + rc = 1; + } + +out: + if (keymaster1_dev) { + keymaster1_close(keymaster1_dev); + } + if (keymaster0_dev) { + keymaster0_close(keymaster0_dev); + } + return rc; +} + +/* Create a new keymaster key and store it in this footer */ +static int keymaster_create_key(struct crypt_mnt_ftr *ftr) +{ + uint8_t* key = 0; + keymaster0_device_t *keymaster0_dev = 0; + keymaster1_device_t *keymaster1_dev = 0; + + if (keymaster_init(&keymaster0_dev, &keymaster1_dev)) { + printf("Failed to init keymaster\n"); + return -1; + } + + int rc = 0; + size_t key_size = 0; + if (keymaster1_dev) { + keymaster_key_param_t params[] = { + /* Algorithm & size specifications. Stick with RSA for now. Switch to AES later. */ + keymaster_param_enum(KM_TAG_ALGORITHM, KM_ALGORITHM_RSA), + keymaster_param_int(KM_TAG_KEY_SIZE, RSA_KEY_SIZE), + keymaster_param_long(KM_TAG_RSA_PUBLIC_EXPONENT, RSA_EXPONENT), + + /* The only allowed purpose for this key is signing. */ + keymaster_param_enum(KM_TAG_PURPOSE, KM_PURPOSE_SIGN), + + /* Padding & digest specifications. */ + keymaster_param_enum(KM_TAG_PADDING, KM_PAD_NONE), + keymaster_param_enum(KM_TAG_DIGEST, KM_DIGEST_NONE), + + /* Require that the key be usable in standalone mode. File system isn't available. */ + keymaster_param_enum(KM_TAG_BLOB_USAGE_REQUIREMENTS, KM_BLOB_STANDALONE), + + /* No auth requirements, because cryptfs is not yet integrated with gatekeeper. */ + keymaster_param_bool(KM_TAG_NO_AUTH_REQUIRED), + + /* Rate-limit key usage attempts, to rate-limit brute force */ + keymaster_param_int(KM_TAG_MIN_SECONDS_BETWEEN_OPS, KEYMASTER_CRYPTFS_RATE_LIMIT), + }; + keymaster_key_param_set_t param_set = { params, sizeof(params)/sizeof(*params) }; + keymaster_key_blob_t key_blob; + keymaster_error_t error = keymaster1_dev->generate_key(keymaster1_dev, ¶m_set, + &key_blob, + NULL /* characteristics */); + if (error != KM_ERROR_OK) { + printf("Failed to generate keymaster1 key, error %d\n", error); + rc = -1; + goto out; + } + + key = (uint8_t*)key_blob.key_material; + key_size = key_blob.key_material_size; + } + else if (keymaster0_dev) { + keymaster_rsa_keygen_params_t params; + memset(¶ms, '\0', sizeof(params)); + params.public_exponent = RSA_EXPONENT; + params.modulus_size = RSA_KEY_SIZE; + + if (keymaster0_dev->generate_keypair(keymaster0_dev, TYPE_RSA, ¶ms, + &key, &key_size)) { + printf("Failed to generate keypair\n"); + rc = -1; + goto out; + } + } else { + printf("Cryptfs bug: keymaster_init succeeded but didn't initialize a device\n"); + rc = -1; + goto out; + } + + if (key_size > KEYMASTER_BLOB_SIZE) { + printf("Keymaster key too large for crypto footer\n"); + rc = -1; + goto out; + } + + memcpy(ftr->keymaster_blob, key, key_size); + ftr->keymaster_blob_size = key_size; + +out: + if (keymaster0_dev) + keymaster0_close(keymaster0_dev); + if (keymaster1_dev) + keymaster1_close(keymaster1_dev); + free(key); + return rc; +} + +/* 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) +{ + int rc = 0; + keymaster0_device_t *keymaster0_dev = 0; + keymaster1_device_t *keymaster1_dev = 0; + if (keymaster_init(&keymaster0_dev, &keymaster1_dev)) { + printf("Failed to init keymaster\n"); + rc = -1; + goto out; + } + + 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, min(RSA_KEY_SIZE_BYTES - 1, object_size)); + printf("Signing safely-padded object\n"); + break; + default: + printf("Unknown KDF type %d\n", ftr->kdf_type); + rc = -1; + goto out; + } + + 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, + ¶ms, + ftr->keymaster_blob, + ftr->keymaster_blob_size, + to_sign, + to_sign_size, + signature, + signature_size); + goto out; + } 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, + ¶m_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, + ¶m_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; + } else { + printf("Cryptfs bug: keymaster_init succeded but didn't initialize a device.\n"); + rc = -1; + goto out; + } + + out: + if (keymaster1_dev) + keymaster1_close(keymaster1_dev); + if (keymaster0_dev) + keymaster0_close(keymaster0_dev); + + return rc; +} +#endif //#ifndef TW_CRYPTO_HAVE_KEYMASTERX + +/* 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; + +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) { + strncpy(io->name, name, sizeof(io->name)); + } +} + +/** + * 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) { + const int default_params[] = SCRYPT_DEFAULTS; + int params[] = SCRYPT_DEFAULTS; + char paramstr[PROPERTY_VALUE_MAX]; + char *token; + char *saveptr; + int i; + + property_get(SCRYPT_PROP, paramstr, ""); + if (paramstr[0] != '\0') { + /* + * 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(paramstr, ":", &saveptr); + token != NULL && i < 3; + i++, token = strtok_r(NULL, ":", &saveptr)) { + char *endptr; + params[i] = strtol(token, &endptr, 10); + + /* + * Check that there was a valid number and it's 8-bit. If not, + * break out and the end check will take the default values. + */ + if ((*token == '\0') || (*endptr != '\0') || params[i] < 0 || params[i] > 255) { + break; + } + } + + /* + * If there were not enough tokens or a token was malformed (not an + * integer), it will end up here and the default parameters can be + * taken. + */ + if ((i != 3) || (token != NULL)) { + printf("bad scrypt parameters '%s' should be like '12:8:1'; using defaults\n", paramstr); + memcpy(params, default_params, sizeof(params)); + } + } + + ftr->N_factor = params[0]; + ftr->r_factor = params[1]; + ftr->p_factor = params[2]; +} + +static unsigned int get_blkdev_size(int fd) +{ + unsigned long nr_sec; + + if ( (ioctl(fd, BLKGETSIZE, &nr_sec)) == -1) { + nr_sec = 0; + } + + return (unsigned int) nr_sec; +} + +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; + unsigned int nr_sec; + int rc = -1; + + if (!cached_data) { + printf("get_crypt_ftr_info crypto key location: '%s'\n", key_fname); + if (!strcmp(key_fname, KEY_IN_FOOTER)) { + if ( (fd = open(real_blkdev, O_RDWR)) < 0) { + printf("Cannot open real block device %s\n", real_blkdev); + return -1; + } + + if ((nr_sec = get_blkdev_size(fd))) { + /* 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 { + printf("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 nr_sec, cnt; + off64_t starting_off; + int rc = -1; + char *fname = NULL; + struct stat statbuf; + + if (get_crypt_ftr_info(&fname, &starting_off)) { + printf("Unable to get crypt_ftr_info\n"); + return -1; + } + if (fname[0] != '/') { + printf("Unexpected value for crypto key location\n"); + return -1; + } + if ( (fd = open(fname, O_RDWR)) < 0) { + printf("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)) { + printf("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) { + printf("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)) { + printf("Cannot read real block device footer\n"); + goto errout; + } + + if (crypt_ftr->magic != CRYPT_MNT_MAGIC) { + printf("Bad magic for real block device %s\n", fname); + goto errout; + } + + if (crypt_ftr->major_version != CURRENT_MAJOR_VERSION) { + printf("Cannot understand major version %d real block device footer; expected %d\n", + crypt_ftr->major_version, CURRENT_MAJOR_VERSION); + goto errout; + } + + if (crypt_ftr->minor_version > CURRENT_MINOR_VERSION) { + printf("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 hexdigit (char c) +{ + if (c >= '0' && c <= '9') return c - '0'; + c = tolower(c); + if (c >= 'a' && c <= 'f') return c - 'a' + 10; + return -1; +} + +static unsigned char* convert_hex_ascii_to_key(const char* master_key_ascii, + unsigned int* out_keysize) +{ + unsigned int i; + *out_keysize = 0; + + size_t size = strlen (master_key_ascii); + if (size % 2) { + printf("Trying to convert ascii string of odd length\n"); + return NULL; + } + + unsigned char* master_key = (unsigned char*) malloc(size / 2); + if (master_key == 0) { + printf("Cannot allocate\n"); + return NULL; + } + + for (i = 0; i < size; i += 2) { + int high_nibble = hexdigit (master_key_ascii[i]); + int low_nibble = hexdigit (master_key_ascii[i + 1]); + + if(high_nibble < 0 || low_nibble < 0) { + printf("Invalid hex string\n"); + free (master_key); + return NULL; + } + + master_key[*out_keysize] = high_nibble * 16 + low_nibble; + (*out_keysize)++; + } + + return master_key; +} + +/* 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, + char *extra_params) +{ + char buffer[DM_CRYPT_BUF_SIZE]; + struct dm_ioctl *io; + struct dm_target_spec *tgt; + char *crypt_params; + char master_key_ascii[129]; /* Large enough to hold 512 bit key and null */ + 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); + +#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); + } +#else + convert_key_to_hex_ascii(master_key, crypt_ftr->keysize, master_key_ascii); + strlcpy(tgt->target_type, "crypt", DM_MAX_TYPE_NAME); +#endif + + sprintf(crypt_params, "%s %s 0 %s 0 %s", crypt_ftr->crypto_type_name, + master_key_ascii, real_blk_name, extra_params); + + printf("%s: target_type = %s\n", __func__, tgt->target_type); + printf("%s: real_blk_name = %s, extra_params = %s\n", __func__, real_blk_name, extra_params); + + crypt_params += strlen(crypt_params) + 1; + crypt_params = (char *) (((unsigned long)crypt_params + 7) & ~8); /* Align to an 8 byte boundary */ + tgt->next = crypt_params - buffer; + + for (i = 0; i < TABLE_LOAD_RETRIES; i++) { + if (! ioctl(fd, DM_TABLE_LOAD, io)) { + break; + } + printf("%i\n", errno); + 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; + int flag; + int i; + + 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 (is_hw_fde_enabled()) { + flag = (!strcmp(v->name, "crypt") || !strcmp(v->name, "req-crypt")); + } else { + flag = (!strcmp(v->name, "crypt")); + } + printf("get_dm_crypt_version flag: %i, name: '%s'\n", flag, v->name); + if (flag) { +#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; +} + +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) +{ + char buffer[DM_CRYPT_BUF_SIZE]; + char master_key_ascii[129]; /* Large enough to hold 512 bit key and null */ + char *crypt_params; + struct dm_ioctl *io; + struct dm_target_spec *tgt; + unsigned int minor; + int fd=0; + int i; + int retval = -1; + int version[3]; + char *extra_params; + int load_count; +#ifdef CONFIG_HW_DISK_ENCRYPTION + char encrypted_state[PROPERTY_VALUE_MAX] = {0}; + char progress[PROPERTY_VALUE_MAX] = {0}; +#endif + + if ((fd = open("/dev/device-mapper", O_RDWR)) < 0 ) { + printf("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_CREATE, io)) { + printf("Cannot create dm-crypt device %i\n", 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)) { + printf("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()) + extra_params = "fde_enabled ice"; + else + extra_params = "fde_enabled"; + } else + extra_params = "fde_disabled"; + } 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))) { + extra_params = "1 allow_discards"; + printf("Enabling support for allow_discards in dmcrypt.\n"); + } + } + } +#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))) { + extra_params = "1 allow_discards"; + printf("Enabling support for allow_discards in dmcrypt.\n"); + } + } +#endif + + load_count = load_crypto_mapping_table(crypt_ftr, master_key, real_blk_name, name, + fd, extra_params); + if (load_count < 0) { + printf("Cannot load dm-crypt mapping table.\n"); + + // Remove the dm-crypt device, otherwise it cannot be used later on by other + // processes (eg vold_decrypt) or further testing/debugging in recovery + ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); + if (ioctl(fd, DM_DEV_REMOVE, io)) { + printf("Cannot remove dm-crypt device %i\n", errno); + } + goto errout; + } else if (load_count > 1) { + printf("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)) { + printf("Cannot resume the dm-crypt device\n"); + + // Remove the dm-crypt device, otherwise it cannot be used later on by other + // processes (eg vold_decrypt) or further testing/debugging in recovery + ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); + if (ioctl(fd, DM_DEV_REMOVE, io)) { + printf("Cannot remove dm-crypt device %i\n", errno); + } + goto errout; + } + + /* We made it here with no errors. Woot! */ + retval = 0; + +errout: + close(fd); /* If fd is <0 from a failed open call, it's safe to just ignore the close error */ + + return retval; +} + +int delete_crypto_blk_dev(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)) < 0 ) { + printf("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)) { + printf("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) +{ + printf("Using pbkdf2 for cryptfs KDF\n"); + + /* Turn the password into a key and IV that can decrypt the master key */ + unsigned int keysize; + char* master_key = (char*)convert_hex_ascii_to_key(passwd, &keysize); + if (!master_key) return -1; + PKCS5_PBKDF2_HMAC_SHA1(master_key, keysize, salt, SALT_LEN, + HASH_COUNT, KEY_LEN_BYTES+IV_LEN_BYTES, ikey); + + memset(master_key, 0, keysize); + free (master_key); + return 0; +} + +static int scrypt(const char *passwd, const unsigned char *salt, + unsigned char *ikey, void *params) +{ + printf("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 */ + unsigned int keysize; + unsigned char* master_key = convert_hex_ascii_to_key(passwd, &keysize); + if (!master_key) return -1; + crypto_scrypt(master_key, keysize, salt, SALT_LEN, N, r, p, ikey, + KEY_LEN_BYTES + IV_LEN_BYTES); + + memset(master_key, 0, keysize); + free (master_key); + return 0; +} + +static int scrypt_keymaster(const char *passwd, const unsigned char *salt, + unsigned char *ikey, void *params) +{ + printf("Using scrypt with keymaster for cryptfs KDF\n"); + + int rc; + unsigned int key_size; + 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; + + unsigned char* master_key = convert_hex_ascii_to_key(passwd, &key_size); + if (!master_key) { + printf("Failed to convert passwd from hex, using passwd instead\n"); + master_key = strdup(passwd); + } + + rc = crypto_scrypt(master_key, key_size, salt, SALT_LEN, + N, r, p, ikey, KEY_LEN_BYTES + IV_LEN_BYTES); + memset(master_key, 0, key_size); + free(master_key); + + if (rc) { + printf("scrypt failed\n"); + return -1; + } + + if (keymaster_sign_object(ftr, ikey, KEY_LEN_BYTES + IV_LEN_BYTES, + &signature, &signature_size)) { + printf("Signing failed\n"); + return -1; + } + + rc = crypto_scrypt(signature, signature_size, salt, SALT_LEN, + N, r, p, ikey, KEY_LEN_BYTES + IV_LEN_BYTES); + free(signature); + + if (rc) { + printf("scrypt failed\n"); + return -1; + } + + return 0; +} + +static int decrypt_master_key_aux(char *passwd, unsigned char *salt, + unsigned char *encrypted_master_key, + unsigned char *decrypted_master_key, + kdf_func kdf, void *kdf_params, + unsigned char** intermediate_key, + size_t* intermediate_key_size) +{ + unsigned char ikey[32+32] = { 0 }; /* Big enough to hold a 256 bit key and 256 bit IV */ + 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)) { + printf("kdf failed\n"); + return -1; + } + + /* Initialize the decryption engine */ + if (! EVP_DecryptInit(&d_ctx, EVP_aes_128_cbc(), ikey, ikey+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, KEY_LEN_BYTES)) { + return -1; + } +#ifndef TW_CRYPTO_HAVE_KEYMASTERX + if (! EVP_DecryptFinal(&d_ctx, decrypted_master_key + decrypted_len, &final_len)) { +#else + if (! EVP_DecryptFinal_ex(&d_ctx, decrypted_master_key + decrypted_len, &final_len)) { +#endif + return -1; + } + + if (decrypted_len + final_len != KEY_LEN_BYTES) { + return -1; + } + + /* Copy intermediate key if needed by params */ + if (intermediate_key && intermediate_key_size) { + *intermediate_key = (unsigned char*) malloc(KEY_LEN_BYTES); + if (intermediate_key) { + memcpy(*intermediate_key, ikey, KEY_LEN_BYTES); + *intermediate_key_size = KEY_LEN_BYTES; + } + } + + 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_UNPADDED || + ftr->kdf_type == KDF_SCRYPT_KEYMASTER_BADLY_PADDED || + 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(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, + decrypted_master_key, kdf, kdf_params, + intermediate_key, intermediate_key_size); + if (ret != 0) { + printf("failure decrypting master key\n"); + } + + return ret; +} + +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, + char *passwd, char *mount_point, 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 tmp_mount_point[64]; + int rc = 0; + kdf_func kdf; + void *kdf_params; + int use_keymaster = 0; + int upgrade = 0; + unsigned char* intermediate_key = 0; + size_t intermediate_key_size = 0; + + printf("crypt_ftr->fs_size = %lld\n", crypt_ftr->fs_size); + + if (! (crypt_ftr->flags & CRYPT_MNT_KEY_UNENCRYPTED) ) { + if (decrypt_master_key(passwd, decrypted_master_key, crypt_ftr, + &intermediate_key, &intermediate_key_size)) { + printf("Failed to decrypt master key\n"); + rc = -1; + goto errout; + } + } + +#ifdef CONFIG_HW_DISK_ENCRYPTION + int key_index = 0; + if(is_hw_disk_encryption((char*)crypt_ftr->crypto_type_name)) { + key_index = verify_hw_fde_passwd(passwd, crypt_ftr); + + if (key_index < 0) { + rc = 1; + goto errout; + } + else { + if (is_ice_enabled()) { + if (create_crypto_blk_dev(crypt_ftr, (unsigned char*)&key_index, + real_blkdev, crypto_blkdev, label)) { + printf("Error creating decrypted block device"); + rc = -1; + goto errout; + } + } else { + if (create_crypto_blk_dev(crypt_ftr, decrypted_master_key, + real_blkdev, crypto_blkdev, label)) { + printf("Error creating decrypted block device"); + rc = -1; + goto errout; + } + } + } + } else { + /* in case HW FDE is delivered through OTA and device is already encrypted + * using SW FDE, we should let user continue using SW FDE until userdata is + * wiped. + */ + if (create_crypto_blk_dev(crypt_ftr, decrypted_master_key, + real_blkdev, crypto_blkdev, label)) { + printf("Error creating decrypted block device"); + rc = -1; + goto errout; + } + } +#else + // 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)) { + printf("Error creating decrypted block device\n"); + rc = -1; + goto errout; + } +#endif + + /* Work out if the problem is the password or the data */ + unsigned char scrypted_intermediate_key[sizeof(crypt_ftr-> + scrypted_intermediate_key)]; + int N = 1 << crypt_ftr->N_factor; + int r = 1 << crypt_ftr->r_factor; + int p = 1 << crypt_ftr->p_factor; + + 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) { + printf("Password matches\n"); + rc = 0; + } else { + /* Try mounting the file system anyway, just in case the problem's with + * the footer, not the key. */ + sprintf(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)) { + printf("Error temp mounting decrypted block device '%s'\n", crypto_blkdev); + delete_crypto_blk_dev(label); + rc = 1; + } else { + /* Success! */ + printf("Password did not match but decrypted drive mounted - continue\n"); + umount(tmp_mount_point); + rc = 0; + } + } + + if (rc == 0) { + // Don't increment the failed attempt counter as it doesn't + // make sense to do so in TWRP + + /* 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); + + // TWRP shouldn't change the stored key + } + + errout: + if (intermediate_key) { + memset(intermediate_key, 0, intermediate_key_size); + free(intermediate_key); + } + return rc; +} + +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") ) { + printf("encrypted fs already validated or not running with encryption," + " aborting\n"); + //return -1; + } + + if (get_crypt_ftr_and_key(crypt_ftr)) { + printf("Error getting crypt footer and key\n"); + return -1; + } + + return 0; +} + +int cryptfs_check_footer() +{ + int rc = -1; + struct crypt_mnt_ftr crypt_ftr; + + rc = get_crypt_ftr_and_key(&crypt_ftr); + + return rc; +} + +int cryptfs_check_passwd(char *passwd) +{ + struct crypt_mnt_ftr crypt_ftr; + int rc; + + if (!passwd) { + printf("cryptfs_check_passwd: passwd is NULL!\n"); + return -1; + } + + rc = check_unmounted_and_get_ftr(&crypt_ftr); + if (rc) + return rc; + + rc = test_mount_encrypted_fs(&crypt_ftr, passwd, + DATA_MNT_POINT, "userdata"); + + // try falling back to Lollipop hex passwords + if (rc) { + int hex_pass_len = strlen(passwd) * 2 + 1; + char *hex_passwd = (char *)malloc(hex_pass_len); + if (hex_passwd) { + convert_key_to_hex_ascii((unsigned char *)passwd, + strlen(passwd), hex_passwd); + rc = test_mount_encrypted_fs(&crypt_ftr, hex_passwd, + DATA_MNT_POINT, "userdata"); + memset(hex_passwd, 0, hex_pass_len); + free(hex_passwd); + } + } + + 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)) { + printf("Error getting crypt footer and key\n"); + return -1; + } + + if (crypt_ftr.flags & CRYPT_INCONSISTENT_STATE) { + return -1; + } + + return crypt_ftr.crypt_type; +} + +/* + * 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. + * + * 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) { + printf("Failed to open %s: %s", real_blkdev, strerror(errno)); + return -1; + } + + unsigned long nr_sec = 0; + nr_sec = get_blkdev_size(fd); + close(fd); + + if (nr_sec == 0) { + printf("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 = keysize; + strcpy((char*) ext_crypt_ftr.crypto_type_name, "aes-cbc-essiv:sha256"); + + return create_crypto_blk_dev(&ext_crypt_ftr, key, real_blkdev, + out_crypto_blkdev, label); +} + +/* + * Called by vold when it's asked to unmount an encrypted external + * storage volume. + */ +int cryptfs_revert_ext_volume(const char* label) { + return delete_crypto_blk_dev((char*) label); +} diff --git a/crypto/lollipop/cryptfs.h b/crypto/lollipop/cryptfs.h new file mode 100644 index 000000000..cd07e5af7 --- /dev/null +++ b/crypto/lollipop/cryptfs.h @@ -0,0 +1,229 @@ +/* + * 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. + */ + +/* 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. + */ + +#include <cutils/properties.h> +#include "openssl/sha.h" + +/* The current cryptfs version */ +#define CURRENT_MAJOR_VERSION 1 +#define CURRENT_MINOR_VERSION 3 + +#define CRYPT_FOOTER_OFFSET 0x4000 +#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 */ +#ifdef CONFIG_HW_DISK_ENCRYPTION +/* This flag is used to transition from L->M upgrade. L release passed + * a byte for every nible of user password while M release is passing + * ascii value of user password. + * Random flag value is chosen so that it does not conflict with other use cases + */ +#define CRYPT_ASCII_PASSWORD_UPDATED 0x1000 +#endif +/* 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 + +#define SCRYPT_PROP "ro.crypto.scrypt_params" +#define SCRYPT_DEFAULTS { 15, 3, 1 } + +/* Key Derivation Function algorithms */ +#define KDF_PBKDF2 1 +#define KDF_SCRYPT 2 +/* TODO(paullawrence): Remove KDF_SCRYPT_KEYMASTER_UNPADDED and KDF_SCRYPT_KEYMASTER_BADLY_PADDED + * when it is safe to do so. */ +#define KDF_SCRYPT_KEYMASTER_UNPADDED 3 +#define KDF_SCRYPT_KEYMASTER_BADLY_PADDED 4 +#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 + +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]; +}; + +/* 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]; +}; + +struct volume_info { + unsigned int size; + unsigned int flags; + struct crypt_mnt_ftr crypt_ftr; + char mnt_point[256]; + char blk_dev[256]; + char crypto_blkdev[256]; + char label[256]; +}; +#define VOL_NONREMOVABLE 0x1 +#define VOL_ENCRYPTABLE 0x2 +#define VOL_PRIMARY 0x4 +#define VOL_PROVIDES_ASEC 0x8 + +#define DATA_MNT_POINT "/data" + +/* Return values for cryptfs_crypto_complete */ +#define CRYPTO_COMPLETE_NOT_ENCRYPTED 1 +#define CRYPTO_COMPLETE_ENCRYPTED 0 +#define CRYPTO_COMPLETE_BAD_METADATA -1 +#define CRYPTO_COMPLETE_PARTIAL -2 +#define CRYPTO_COMPLETE_INCONSISTENT -3 +#define CRYPTO_COMPLETE_CORRUPT -4 + +/* Return values for cryptfs_enable_inplace*() */ +#define ENABLE_INPLACE_OK 0 +#define ENABLE_INPLACE_ERR_OTHER -1 +#define ENABLE_INPLACE_ERR_DEV -2 /* crypto_blkdev issue */ + +#ifdef __cplusplus +extern "C" { +#endif + + typedef int (*kdf_func)(const char *passwd, const unsigned char *salt, + unsigned char *ikey, void *params); + + void set_partition_data(const char* block_device, const char* key_location, const char* fs); + int cryptfs_check_footer(); + int cryptfs_check_passwd(char *pw); + int cryptfs_verify_passwd(char *newpw); + int cryptfs_get_password_type(void); + int delete_crypto_blk_dev(char *name); + int cryptfs_setup_ext_volume(const char* label, const char* real_blkdev, + const unsigned char* key, int keysize, char* out_crypto_blkdev); + int cryptfs_revert_ext_volume(const char* label); +#ifdef __cplusplus +} +#endif diff --git a/crypto/lollipop/main.c b/crypto/lollipop/main.c new file mode 100644 index 000000000..232afb959 --- /dev/null +++ b/crypto/lollipop/main.c @@ -0,0 +1,32 @@ +#include <stdio.h> +#include <string.h> +#include <sys/types.h> +#include <linux/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 <errno.h> +#include <linux/kdev_t.h> +#include <time.h> +#include "cryptfs.h" +#include "cutils/properties.h" +#include "crypto_scrypt.h" + +int main() { + set_partition_data("/dev/block/platform/sdhci-tegra.3/by-name/UDA", "/dev/block/platform/sdhci-tegra.3/by-name/MD1", "f2fs"); + //int ret = cryptfs_check_passwd("30303030"); + int ret = cryptfs_check_passwd("0000"); + return 0; +} |