a11741f98d
See https://developers.google.com/widevine/drm/client/opk for documentation and an integration guide.
110 lines
4.4 KiB
C
110 lines
4.4 KiB
C
/* Copyright 2021 Google LLC. All Rights Reserved. This file and proprietary
|
|
source code may only be used and distributed under the Widevine
|
|
License Agreement. */
|
|
|
|
#ifndef OEMCRYPTO_TA_WTPI_PERSISTENT_STORAGE_INTERFACE_H_
|
|
#define OEMCRYPTO_TA_WTPI_PERSISTENT_STORAGE_INTERFACE_H_
|
|
|
|
#include "stdint.h"
|
|
|
|
#include "OEMCryptoCENC.h"
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
/** @defgroup persistent Persistent Storage
|
|
*
|
|
* Partners implementing a porting layer may either
|
|
* 1. Implement this wtpi_persistent_storage.h and
|
|
* wtpi_clock_interface_layer2.h, and then use the reference implementation
|
|
* clock_and_gn_layer1.c for the clock and generation interfaces. This is
|
|
* preferred if the hardware secure timer resets to 0 whenever the device is
|
|
* inactive.
|
|
* or
|
|
* 2. Implement both wtpi_clock_interface_layer1.h and
|
|
* wtpi_generation_number_interface.h. This is preferred if the system has a
|
|
* hardware secure wall clock.
|
|
*
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* Prepare to load the stored data. If the data is loaded asynchronously,
|
|
* this should initialize that process so that the next call to
|
|
* WTPI_LoadPersistentData does not block for too long.
|
|
*
|
|
* TODO(b/160022428): define and document "too long".
|
|
*
|
|
* The values should be stored in secure persistent storage. By *persistent* we
|
|
* mean that the value should not be changed by shutting down and later
|
|
* restarting the system. By *secure* we mean that the user should not be able
|
|
* to modify the values.
|
|
*
|
|
* Returns OEMCrypto_SUCCESS on success. On failure, initialization of the TA
|
|
* will fail.
|
|
*/
|
|
OEMCryptoResult WTPI_PrepareStoredPersistentData(void);
|
|
|
|
/**
|
|
* Load the persistent data. This is called once, on first use of the clock or
|
|
* generation number. This is expected to block until a value is available. It
|
|
* is the porting interface's responsibility to fail if this blocks too long. In
|
|
* order to support data layout changes across upgrade, this function should
|
|
* return less data than requested if necessary. If the available data is less
|
|
* than |*data_length|, it should fill |data| with the available data and it
|
|
* should change |*data_length| to be the amount of available data, and it
|
|
* should return OEMCrypto_SUCCESS. If there is more data available than will
|
|
* fit in |data|, then it should return OEMCrypto_ERROR_SHORT_BUFFER.
|
|
*
|
|
* The layer above this function is responsible for handling data format changes
|
|
* and backwards compatibility across upgrades.
|
|
*
|
|
* @retval OEMCrypto_SUCCESS data was loaded.
|
|
* @retval OPK_ERROR_NO_PERSISTENT_DATA No data available.
|
|
* @retval OEMCrypto_ERROR_SHORT_BUFFER more than |data_length| data available.
|
|
*
|
|
* @param[out] data: pointer to persistent data.
|
|
* @param[in/out] data_length: on input, the size of the data buffer, on out
|
|
* the amount of data that was loaded.
|
|
*/
|
|
OEMCryptoResult WTPI_LoadPersistentData(uint8_t* data, size_t* data_length);
|
|
|
|
/**
|
|
* Save the persistent data.
|
|
*
|
|
* If the data is saved asynchronously, then it is OK for the first
|
|
* call to this function to begin a save process and then return
|
|
* OEMCrypto_SUCCESS. Subsequent calls will verify that the previous save has
|
|
* completed successfully. If the previous save resulted in an error, then this
|
|
* call will return an error. If the previous call has not completed, then this
|
|
* call should block until the previous save finishes before initializing a new
|
|
* save. If the previous call was successful, then this call will initialize a
|
|
* new save and return OEMCrypto_SUCCESS. It is the porting interface's
|
|
* responsibility to fail if this blocks too long.
|
|
*
|
|
* If the data is saved synchronously, then this function should attempt to save
|
|
* the generation number and return OEMCrypto_SUCCESS if the save was
|
|
* successful.
|
|
*
|
|
* Returns OEMCrypto_SUCCESS on success. Other return values will fail the
|
|
* current attempt to save the usage table. If a failure actually indicates that
|
|
* the previous save had failed, then the usage table will be saved with a
|
|
* generation number skew of 1. When the usage table is loaded with a generation
|
|
* skew of 1, it will result in a warning, but not a failure.
|
|
*
|
|
*
|
|
* @param[in] data: persistent data.
|
|
* @param[in] data_length: the amount of data to save.
|
|
*/
|
|
OEMCryptoResult WTPI_StorePersistentData(const uint8_t* data,
|
|
size_t data_length);
|
|
|
|
/// @}
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* OEMCRYPTO_TA_WTPI_PERSISTENT_STORAGE_INTERFACE_H_ */
|