[U-Boot] [PATCH v5 1/1] avb: add support for named persistent values
Igor Opaniuk
igor.opaniuk at linaro.org
Thu Feb 14 12:37:01 UTC 2019
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 at chromium.org>
Signed-off-by: Igor Opaniuk <igor.opaniuk at linaro.org>
---
v5:
- fix failing test on sandbox_flattree target
- keep all defined globally variables in a driver-private data struct, which
permits to probe multiple tee sandbox devices
v4:
- extend tee sandbox tee driver to support persistent values
- fix/re-test avb_persistent test on sandbox configuration
v3:
- fix possible mem lick in avb_read_persistent/avb_write_persistent
- add additional sanity checks
- cover avb read_pvalue/write_pvalue commands with python tests
v2:
- fix output format for avb read_pvalue/write_pvalue commands
- fix issue with named value buffer size
cmd/avb.c | 78 ++++++++++++++++++++++++++++
common/avb_verify.c | 125 +++++++++++++++++++++++++++++++++++++++++++++
drivers/tee/sandbox.c | 121 ++++++++++++++++++++++++++++++++++++-------
include/sandboxtee.h | 15 ++++--
include/tee.h | 2 +
include/tee/optee_ta_avb.h | 16 ++++++
test/py/tests/test_avb.py | 16 ++++++
7 files changed, 351 insertions(+), 22 deletions(-)
diff --git a/cmd/avb.c b/cmd/avb.c
index ff00be4..c5af4a2 100644
--- a/cmd/avb.c
+++ b/cmd/avb.c
@@ -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"
);
diff --git a/common/avb_verify.c b/common/avb_verify.c
index a8c5a3e..32034d9 100644
--- a/common/avb_verify.c
+++ b/common/avb_verify.c
@@ -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;
diff --git a/drivers/tee/sandbox.c b/drivers/tee/sandbox.c
index ccddb03..a136bc9 100644
--- a/drivers/tee/sandbox.c
+++ b/drivers/tee/sandbox.c
@@ -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,
};
diff --git a/include/sandboxtee.h b/include/sandboxtee.h
index 44f653d..419643a 100644
--- a/include/sandboxtee.h
+++ b/include/sandboxtee.h
@@ -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*/
diff --git a/include/tee.h b/include/tee.h
index edd9f9b..02bcd9e 100644
--- a/include/tee.h
+++ b/include/tee.h
@@ -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
diff --git a/include/tee/optee_ta_avb.h b/include/tee/optee_ta_avb.h
index 074386a..949875a 100644
--- a/include/tee/optee_ta_avb.h
+++ b/include/tee/optee_ta_avb.h
@@ -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 */
diff --git a/test/py/tests/test_avb.py b/test/py/tests/test_avb.py
index e70a010..2bb75ed 100644
--- a/test/py/tests/test_avb.py
+++ b/test/py/tests/test_avb.py
@@ -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')
+
+
+ at pytest.mark.buildconfigspec('cmd_avb')
+ at 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'
--
2.7.4
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