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Diffstat (limited to 'crypto/fde/cryptfs.cpp')
| -rw-r--r-- | crypto/fde/cryptfs.cpp | 1763 |
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, + ¶ms, + 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, + ¶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; + 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); +} + |