avb: add support for named persistent values

AVB 2.0 spec. revision 1.1 introduces support for named persistent values
that must be tamper evident and allows AVB to store arbitrary key-value
pairs [1].

Introduce implementation of two additional AVB operations
read_persistent_value()/write_persistent_value() for retrieving/storing
named persistent values.

Correspondent pull request in the OP-TEE OS project repo [2].

[1]: https://android.googlesource.com/platform/external/avb/+/android-9.0.0_r22
[2]: https://github.com/OP-TEE/optee_os/pull/2699

Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Igor Opaniuk <igor.opaniuk@gmail.com>
This commit is contained in:
Igor Opaniuk 2019-04-09 15:38:14 +02:00 committed by Tom Rini
parent b85d155199
commit fc1fe01b08
7 changed files with 351 additions and 22 deletions

View file

@ -340,6 +340,76 @@ int do_avb_is_unlocked(cmd_tbl_t *cmdtp, int flag,
return CMD_RET_FAILURE;
}
int do_avb_read_pvalue(cmd_tbl_t *cmdtp, int flag, int argc,
char * const argv[])
{
const char *name;
size_t bytes;
size_t bytes_read;
void *buffer;
char *endp;
if (!avb_ops) {
printf("AVB 2.0 is not initialized, run 'avb init' first\n");
return CMD_RET_FAILURE;
}
if (argc != 3)
return CMD_RET_USAGE;
name = argv[1];
bytes = simple_strtoul(argv[2], &endp, 10);
if (*endp && *endp != '\n')
return CMD_RET_USAGE;
buffer = malloc(bytes);
if (!buffer)
return CMD_RET_FAILURE;
if (avb_ops->read_persistent_value(avb_ops, name, bytes, buffer,
&bytes_read) == AVB_IO_RESULT_OK) {
printf("Read %ld bytes, value = %s\n", bytes_read,
(char *)buffer);
free(buffer);
return CMD_RET_SUCCESS;
}
printf("Failed to read persistent value\n");
free(buffer);
return CMD_RET_FAILURE;
}
int do_avb_write_pvalue(cmd_tbl_t *cmdtp, int flag, int argc,
char * const argv[])
{
const char *name;
const char *value;
if (!avb_ops) {
printf("AVB 2.0 is not initialized, run 'avb init' first\n");
return CMD_RET_FAILURE;
}
if (argc != 3)
return CMD_RET_USAGE;
name = argv[1];
value = argv[2];
if (avb_ops->write_persistent_value(avb_ops, name, strlen(value) + 1,
(const uint8_t *)value) ==
AVB_IO_RESULT_OK) {
printf("Wrote %ld bytes\n", strlen(value) + 1);
return CMD_RET_SUCCESS;
}
printf("Failed to write persistent value\n");
return CMD_RET_FAILURE;
}
static cmd_tbl_t cmd_avb[] = {
U_BOOT_CMD_MKENT(init, 2, 0, do_avb_init, "", ""),
U_BOOT_CMD_MKENT(read_rb, 2, 0, do_avb_read_rb, "", ""),
@ -350,6 +420,10 @@ static cmd_tbl_t cmd_avb[] = {
U_BOOT_CMD_MKENT(read_part_hex, 4, 0, do_avb_read_part_hex, "", ""),
U_BOOT_CMD_MKENT(write_part, 5, 0, do_avb_write_part, "", ""),
U_BOOT_CMD_MKENT(verify, 1, 0, do_avb_verify_part, "", ""),
#ifdef CONFIG_OPTEE_TA_AVB
U_BOOT_CMD_MKENT(read_pvalue, 3, 0, do_avb_read_pvalue, "", ""),
U_BOOT_CMD_MKENT(write_pvalue, 3, 0, do_avb_write_pvalue, "", ""),
#endif
};
static int do_avb(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
@ -384,6 +458,10 @@ U_BOOT_CMD(
" partition <partname> and print to stdout\n"
"avb write_part <partname> <offset> <num> <addr> - write <num> bytes to\n"
" <partname> by <offset> using data from <addr>\n"
#ifdef CONFIG_OPTEE_TA_AVB
"avb read_pvalue <name> <bytes> - read a persistent value <name>\n"
"avb write_pvalue <name> <value> - write a persistent value <name>\n"
#endif
"avb verify - run verification process using hash data\n"
" from vbmeta structure\n"
);

View file

@ -647,6 +647,10 @@ static AvbIOResult invoke_func(struct AvbOpsData *ops_data, u32 func,
return AVB_IO_RESULT_OK;
case TEE_ERROR_OUT_OF_MEMORY:
return AVB_IO_RESULT_ERROR_OOM;
case TEE_ERROR_STORAGE_NO_SPACE:
return AVB_IO_RESULT_ERROR_INSUFFICIENT_SPACE;
case TEE_ERROR_ITEM_NOT_FOUND:
return AVB_IO_RESULT_ERROR_NO_SUCH_VALUE;
case TEE_ERROR_TARGET_DEAD:
/*
* The TA has paniced, close the session to reload the TA
@ -847,6 +851,123 @@ static AvbIOResult get_size_of_partition(AvbOps *ops,
return AVB_IO_RESULT_OK;
}
static AvbIOResult read_persistent_value(AvbOps *ops,
const char *name,
size_t buffer_size,
u8 *out_buffer,
size_t *out_num_bytes_read)
{
AvbIOResult rc;
struct tee_shm *shm_name;
struct tee_shm *shm_buf;
struct tee_param param[2];
struct udevice *tee;
size_t name_size = strlen(name) + 1;
if (get_open_session(ops->user_data))
return AVB_IO_RESULT_ERROR_IO;
tee = ((struct AvbOpsData *)ops->user_data)->tee;
rc = tee_shm_alloc(tee, name_size,
TEE_SHM_ALLOC, &shm_name);
if (rc)
return AVB_IO_RESULT_ERROR_OOM;
rc = tee_shm_alloc(tee, buffer_size,
TEE_SHM_ALLOC, &shm_buf);
if (rc) {
rc = AVB_IO_RESULT_ERROR_OOM;
goto free_name;
}
memcpy(shm_name->addr, name, name_size);
memset(param, 0, sizeof(param));
param[0].attr = TEE_PARAM_ATTR_TYPE_MEMREF_INPUT;
param[0].u.memref.shm = shm_name;
param[0].u.memref.size = name_size;
param[1].attr = TEE_PARAM_ATTR_TYPE_MEMREF_INOUT;
param[1].u.memref.shm = shm_buf;
param[1].u.memref.size = buffer_size;
rc = invoke_func(ops->user_data, TA_AVB_CMD_READ_PERSIST_VALUE,
2, param);
if (rc)
goto out;
if (param[1].u.memref.size > buffer_size) {
rc = AVB_IO_RESULT_ERROR_NO_SUCH_VALUE;
goto out;
}
*out_num_bytes_read = param[1].u.memref.size;
memcpy(out_buffer, shm_buf->addr, *out_num_bytes_read);
out:
tee_shm_free(shm_buf);
free_name:
tee_shm_free(shm_name);
return rc;
}
static AvbIOResult write_persistent_value(AvbOps *ops,
const char *name,
size_t value_size,
const u8 *value)
{
AvbIOResult rc;
struct tee_shm *shm_name;
struct tee_shm *shm_buf;
struct tee_param param[2];
struct udevice *tee;
size_t name_size = strlen(name) + 1;
if (get_open_session(ops->user_data))
return AVB_IO_RESULT_ERROR_IO;
tee = ((struct AvbOpsData *)ops->user_data)->tee;
if (!value_size)
return AVB_IO_RESULT_ERROR_NO_SUCH_VALUE;
rc = tee_shm_alloc(tee, name_size,
TEE_SHM_ALLOC, &shm_name);
if (rc)
return AVB_IO_RESULT_ERROR_OOM;
rc = tee_shm_alloc(tee, value_size,
TEE_SHM_ALLOC, &shm_buf);
if (rc) {
rc = AVB_IO_RESULT_ERROR_OOM;
goto free_name;
}
memcpy(shm_name->addr, name, name_size);
memcpy(shm_buf->addr, value, value_size);
memset(param, 0, sizeof(param));
param[0].attr = TEE_PARAM_ATTR_TYPE_MEMREF_INPUT;
param[0].u.memref.shm = shm_name;
param[0].u.memref.size = name_size;
param[1].attr = TEE_PARAM_ATTR_TYPE_MEMREF_INPUT;
param[1].u.memref.shm = shm_buf;
param[1].u.memref.size = value_size;
rc = invoke_func(ops->user_data, TA_AVB_CMD_WRITE_PERSIST_VALUE,
2, param);
if (rc)
goto out;
out:
tee_shm_free(shm_buf);
free_name:
tee_shm_free(shm_name);
return rc;
}
/**
* ============================================================================
* AVB2.0 AvbOps alloc/initialisation/free
@ -870,6 +991,10 @@ AvbOps *avb_ops_alloc(int boot_device)
ops_data->ops.read_is_device_unlocked = read_is_device_unlocked;
ops_data->ops.get_unique_guid_for_partition =
get_unique_guid_for_partition;
#ifdef CONFIG_OPTEE_TA_AVB
ops_data->ops.write_persistent_value = write_persistent_value;
ops_data->ops.read_persistent_value = read_persistent_value;
#endif
ops_data->ops.get_size_of_partition = get_size_of_partition;
ops_data->mmc_dev = boot_device;

View file

@ -14,6 +14,7 @@
* available.
*/
static const u32 pstorage_max = 16;
/**
* struct ta_entry - TA entries
* @uuid: UUID of an emulated TA
@ -24,8 +25,11 @@
*/
struct ta_entry {
struct tee_optee_ta_uuid uuid;
u32 (*open_session)(uint num_params, struct tee_param *params);
u32 (*invoke_func)(u32 func, uint num_params, struct tee_param *params);
u32 (*open_session)(struct udevice *dev, uint num_params,
struct tee_param *params);
u32 (*invoke_func)(struct udevice *dev,
u32 func, uint num_params,
struct tee_param *params);
};
#ifdef CONFIG_OPTEE_TA_AVB
@ -59,10 +63,8 @@ bad_params:
return TEE_ERROR_BAD_PARAMETERS;
}
static u64 ta_avb_rollback_indexes[TA_AVB_MAX_ROLLBACK_LOCATIONS];
static u32 ta_avb_lock_state;
static u32 ta_avb_open_session(uint num_params, struct tee_param *params)
static u32 ta_avb_open_session(struct udevice *dev, uint num_params,
struct tee_param *params)
{
/*
* We don't expect additional parameters when opening a session to
@ -73,12 +75,17 @@ static u32 ta_avb_open_session(uint num_params, struct tee_param *params)
num_params, params);
}
static u32 ta_avb_invoke_func(u32 func, uint num_params,
static u32 ta_avb_invoke_func(struct udevice *dev, u32 func, uint num_params,
struct tee_param *params)
{
struct sandbox_tee_state *state = dev_get_priv(dev);
ENTRY e, *ep;
char *name;
u32 res;
uint slot;
u64 val;
char *value;
u32 value_sz;
switch (func) {
case TA_AVB_CMD_READ_ROLLBACK_INDEX:
@ -91,12 +98,12 @@ static u32 ta_avb_invoke_func(u32 func, uint num_params,
return res;
slot = params[0].u.value.a;
if (slot >= ARRAY_SIZE(ta_avb_rollback_indexes)) {
if (slot >= ARRAY_SIZE(state->ta_avb_rollback_indexes)) {
printf("Rollback index slot out of bounds %u\n", slot);
return TEE_ERROR_BAD_PARAMETERS;
}
val = ta_avb_rollback_indexes[slot];
val = state->ta_avb_rollback_indexes[slot];
params[1].u.value.a = val >> 32;
params[1].u.value.b = val;
return TEE_SUCCESS;
@ -111,16 +118,16 @@ static u32 ta_avb_invoke_func(u32 func, uint num_params,
return res;
slot = params[0].u.value.a;
if (slot >= ARRAY_SIZE(ta_avb_rollback_indexes)) {
if (slot >= ARRAY_SIZE(state->ta_avb_rollback_indexes)) {
printf("Rollback index slot out of bounds %u\n", slot);
return TEE_ERROR_BAD_PARAMETERS;
}
val = (u64)params[1].u.value.a << 32 | params[1].u.value.b;
if (val < ta_avb_rollback_indexes[slot])
if (val < state->ta_avb_rollback_indexes[slot])
return TEE_ERROR_SECURITY;
ta_avb_rollback_indexes[slot] = val;
state->ta_avb_rollback_indexes[slot] = val;
return TEE_SUCCESS;
case TA_AVB_CMD_READ_LOCK_STATE:
@ -132,7 +139,7 @@ static u32 ta_avb_invoke_func(u32 func, uint num_params,
if (res)
return res;
params[0].u.value.a = ta_avb_lock_state;
params[0].u.value.a = state->ta_avb_lock_state;
return TEE_SUCCESS;
case TA_AVB_CMD_WRITE_LOCK_STATE:
@ -144,13 +151,64 @@ static u32 ta_avb_invoke_func(u32 func, uint num_params,
if (res)
return res;
if (ta_avb_lock_state != params[0].u.value.a) {
ta_avb_lock_state = params[0].u.value.a;
memset(ta_avb_rollback_indexes, 0,
sizeof(ta_avb_rollback_indexes));
if (state->ta_avb_lock_state != params[0].u.value.a) {
state->ta_avb_lock_state = params[0].u.value.a;
memset(state->ta_avb_rollback_indexes, 0,
sizeof(state->ta_avb_rollback_indexes));
}
return TEE_SUCCESS;
case TA_AVB_CMD_READ_PERSIST_VALUE:
res = check_params(TEE_PARAM_ATTR_TYPE_MEMREF_INPUT,
TEE_PARAM_ATTR_TYPE_MEMREF_INOUT,
TEE_PARAM_ATTR_TYPE_NONE,
TEE_PARAM_ATTR_TYPE_NONE,
num_params, params);
if (res)
return res;
name = params[0].u.memref.shm->addr;
value = params[1].u.memref.shm->addr;
value_sz = params[1].u.memref.size;
e.key = name;
e.data = NULL;
hsearch_r(e, FIND, &ep, &state->pstorage_htab, 0);
if (!ep)
return TEE_ERROR_ITEM_NOT_FOUND;
value_sz = strlen(ep->data);
memcpy(value, ep->data, value_sz);
return TEE_SUCCESS;
case TA_AVB_CMD_WRITE_PERSIST_VALUE:
res = check_params(TEE_PARAM_ATTR_TYPE_MEMREF_INPUT,
TEE_PARAM_ATTR_TYPE_MEMREF_INPUT,
TEE_PARAM_ATTR_TYPE_NONE,
TEE_PARAM_ATTR_TYPE_NONE,
num_params, params);
if (res)
return res;
name = params[0].u.memref.shm->addr;
value = params[1].u.memref.shm->addr;
value_sz = params[1].u.memref.size;
e.key = name;
e.data = NULL;
hsearch_r(e, FIND, &ep, &state->pstorage_htab, 0);
if (ep)
hdelete_r(e.key, &state->pstorage_htab, 0);
e.key = name;
e.data = value;
hsearch_r(e, ENTER, &ep, &state->pstorage_htab, 0);
if (!ep)
return TEE_ERROR_OUT_OF_MEMORY;
return TEE_SUCCESS;
default:
return TEE_ERROR_NOT_SUPPORTED;
@ -225,7 +283,7 @@ static int sandbox_tee_open_session(struct udevice *dev,
return 0;
}
arg->ret = ta->open_session(num_params, params);
arg->ret = ta->open_session(dev, num_params, params);
arg->ret_origin = TEE_ORIGIN_TRUSTED_APP;
if (!arg->ret) {
@ -261,7 +319,7 @@ static int sandbox_tee_invoke_func(struct udevice *dev,
return -EINVAL;
}
arg->ret = ta->invoke_func(arg->func, num_params, params);
arg->ret = ta->invoke_func(dev, arg->func, num_params, params);
arg->ret_origin = TEE_ORIGIN_TRUSTED_APP;
return 0;
@ -285,6 +343,29 @@ static int sandbox_tee_shm_unregister(struct udevice *dev, struct tee_shm *shm)
return 0;
}
static int sandbox_tee_remove(struct udevice *dev)
{
struct sandbox_tee_state *state = dev_get_priv(dev);
hdestroy_r(&state->pstorage_htab);
return 0;
}
static int sandbox_tee_probe(struct udevice *dev)
{
struct sandbox_tee_state *state = dev_get_priv(dev);
/*
* With this hastable we emulate persistent storage,
* which should contain persistent values
* between different sessions/command invocations.
*/
if (!hcreate_r(pstorage_max, &state->pstorage_htab))
return TEE_ERROR_OUT_OF_MEMORY;
return 0;
}
static const struct tee_driver_ops sandbox_tee_ops = {
.get_version = sandbox_tee_get_version,
.open_session = sandbox_tee_open_session,
@ -305,4 +386,6 @@ U_BOOT_DRIVER(sandbox_tee) = {
.of_match = sandbox_tee_match,
.ops = &sandbox_tee_ops,
.priv_auto_alloc_size = sizeof(struct sandbox_tee_state),
.probe = sandbox_tee_probe,
.remove = sandbox_tee_remove,
};

View file

@ -6,16 +6,25 @@
#ifndef __SANDBOXTEE_H
#define __SANDBOXTEE_H
#include <search.h>
#include <tee/optee_ta_avb.h>
/**
* struct sandbox_tee_state - internal state of the sandbox TEE
* @session: current open session
* @num_shms: number of registered shared memory objects
* @ta: Trusted Application of current session
* @session: current open session
* @num_shms: number of registered shared memory objects
* @ta: Trusted Application of current session
* @ta_avb_rollback_indexes TA avb rollback indexes storage
* @ta_avb_lock_state TA avb lock state storage
* @pstorage_htab named persistent values storage
*/
struct sandbox_tee_state {
u32 session;
int num_shms;
void *ta;
u64 ta_avb_rollback_indexes[TA_AVB_MAX_ROLLBACK_LOCATIONS];
u32 ta_avb_lock_state;
struct hsearch_data pstorage_htab;
};
#endif /*__SANDBOXTEE_H*/

View file

@ -43,7 +43,9 @@
#define TEE_ERROR_COMMUNICATION 0xffff000e
#define TEE_ERROR_SECURITY 0xffff000f
#define TEE_ERROR_OUT_OF_MEMORY 0xffff000c
#define TEE_ERROR_OVERFLOW 0xffff300f
#define TEE_ERROR_TARGET_DEAD 0xffff3024
#define TEE_ERROR_STORAGE_NO_SPACE 0xffff3041
#define TEE_ORIGIN_COMMS 0x00000002
#define TEE_ORIGIN_TEE 0x00000003

View file

@ -45,4 +45,20 @@
*/
#define TA_AVB_CMD_WRITE_LOCK_STATE 3
/*
* Reads a persistent value corresponding to the given name.
*
* in params[0].u.memref: persistent value name
* out params[1].u.memref: read persistent value buffer
*/
#define TA_AVB_CMD_READ_PERSIST_VALUE 4
/*
* Writes a persistent value corresponding to the given name.
*
* in params[0].u.memref: persistent value name
* in params[1].u.memref: persistent value buffer to write
*/
#define TA_AVB_CMD_WRITE_PERSIST_VALUE 5
#endif /* __TA_AVB_H */

View file

@ -116,3 +116,19 @@ def test_avb_mmc_read(u_boot_console):
response = u_boot_console.run_command('cmp 0x%x 0x%x 40' %
(temp_addr, temp_addr2))
assert response.find('64 word')
@pytest.mark.buildconfigspec('cmd_avb')
@pytest.mark.buildconfigspec('optee_ta_avb')
def test_avb_persistent_values(u_boot_console):
"""Test reading/writing persistent storage to avb
"""
response = u_boot_console.run_command('avb init %s' % str(mmc_dev))
assert response == ''
response = u_boot_console.run_command('avb write_pvalue test value_value')
assert response == 'Wrote 12 bytes'
response = u_boot_console.run_command('avb read_pvalue test 12')
assert response == 'Read 12 bytes, value = value_value'