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c7a2f934b53b4da016fb2bb02ec7bdd3cc6fa5c0
android_bootable_recovery/crypto/lollipop/cryptfs.c
T
nijel8 2dd66f4962 cryptfs: Fix encryption issue due to stack corruption. 
Ioctl BLKGETSIZE expects pointer to unsigned long as argument.

On 64bit target using pointer to unsigned int can cause stack
corruption due to type mismatch.

props to https://github.com/aopp/android_system_vold/commit/f8b8787317fc94439b63bc891eeda83f7ae2f4f6

Change-Id: I1d76c65e29479c8f0cd44b6892069b21b8249b95
2017-02-19 21:34:12 +01:00

1596 lines
50 KiB
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/*
* 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(&params, '\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, &params,
&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,
&params,
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, &param_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(&params, '\0', sizeof(params));
params.public_exponent = RSA_EXPONENT;
params.modulus_size = RSA_KEY_SIZE;
if (keymaster0_dev->generate_keypair(keymaster0_dev, TYPE_RSA, &params,
&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,
&params,
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,
&param_set, NULL /* out_params */,
&op_handle);
if (error == KM_ERROR_KEY_RATE_LIMIT_EXCEEDED) {
// Key usage has been rate-limited. Wait a bit and try again.
sleep(KEYMASTER_CRYPTFS_RATE_LIMIT);
error = keymaster1_dev->begin(keymaster1_dev, KM_PURPOSE_SIGN, &key,
&param_set, NULL /* out_params */,
&op_handle);
}
if (error != KM_ERROR_OK) {
printf("Error starting keymaster signature transaction: %d\n", error);
rc = -1;
goto out;
}
keymaster_blob_t input = { to_sign, to_sign_size };
size_t input_consumed;
error = keymaster1_dev->update(keymaster1_dev, op_handle, NULL /* in_params */,
&input, &input_consumed, NULL /* out_params */,
NULL /* output */);
if (error != KM_ERROR_OK) {
printf("Error sending data to keymaster signature transaction: %d\n", error);
rc = -1;
goto out;
}
if (input_consumed != to_sign_size) {
// This should never happen. If it does, it's a bug in the keymaster implementation.
printf("Keymaster update() did not consume all data.\n");
keymaster1_dev->abort(keymaster1_dev, op_handle);
rc = -1;
goto out;
}
keymaster_blob_t tmp_sig;
error = keymaster1_dev->finish(keymaster1_dev, op_handle, NULL /* in_params */,
NULL /* verify signature */, NULL /* out_params */,
&tmp_sig);
if (error != KM_ERROR_OK) {
printf("Error finishing keymaster signature transaction: %d\n", error);
rc = -1;
goto out;
}
*signature = (uint8_t*)tmp_sig.data;
*signature_size = tmp_sig.data_length;
} 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");
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");
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);
}
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