| /* |
| * Copyright (C) 2015 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. |
| */ |
| |
| #ifndef ANDROID_HARDWARE_KEYMASTER2_H |
| #define ANDROID_HARDWARE_KEYMASTER2_H |
| |
| #include <hardware/keymaster_common.h> |
| #include <hardware/keymaster_defs.h> |
| |
| __BEGIN_DECLS |
| |
| /** |
| * Keymaster2 device definition |
| */ |
| struct keymaster2_device { |
| /** |
| * Common methods of the keymaster device. This *must* be the first member of |
| * keymaster_device as users of this structure will cast a hw_device_t to |
| * keymaster_device pointer in contexts where it's known the hw_device_t references a |
| * keymaster_device. |
| */ |
| struct hw_device_t common; |
| |
| void* context; |
| |
| /** |
| * See flags defined for keymaster0_devices::flags in keymaster_common.h. Used only for |
| * backward compatibility; keymaster2 hardware devices must set this to zero. |
| */ |
| uint32_t flags; |
| |
| /** |
| * Configures keymaster. This method must be called once after the device is opened and before |
| * it is used. It's used to provide KM_TAG_OS_VERSION and KM_TAG_OS_PATCHLEVEL to keymaster. |
| * Until this method is called, all other methods will return KM_ERROR_KEYMASTER_NOT_CONFIGURED. |
| * The values provided by this method are only accepted by keymaster once per boot. Subsequent |
| * calls will return KM_ERROR_OK, but do nothing. |
| * |
| * If the keymaster implementation is in secure hardware and the OS version and patch level |
| * values provided do not match the values provided to the secure hardware by the bootloader (or |
| * if the bootloader did not provide values), then this method will return |
| * KM_ERROR_INVALID_ARGUMENT, and all other methods will continue returning |
| * KM_ERROR_KEYMASTER_NOT_CONFIGURED. |
| */ |
| keymaster_error_t (*configure)(const struct keymaster2_device* dev, |
| const keymaster_key_param_set_t* params); |
| |
| /** |
| * Adds entropy to the RNG used by keymaster. Entropy added through this method is guaranteed |
| * not to be the only source of entropy used, and the mixing function is required to be secure, |
| * in the sense that if the RNG is seeded (from any source) with any data the attacker cannot |
| * predict (or control), then the RNG output is indistinguishable from random. Thus, if the |
| * entropy from any source is good, the output will be good. |
| * |
| * \param[in] dev The keymaster device structure. |
| * |
| * \param[in] data Random data to be mixed in. |
| * |
| * \param[in] data_length Length of \p data. |
| */ |
| keymaster_error_t (*add_rng_entropy)(const struct keymaster2_device* dev, const uint8_t* data, |
| size_t data_length); |
| |
| /** |
| * Generates a key, or key pair, returning a key blob and/or a description of the key. |
| * |
| * Key generation parameters are defined as keymaster tag/value pairs, provided in \p params. |
| * See keymaster_tag_t for the full list. Some values that are always required for generation |
| * of useful keys are: |
| * |
| * - KM_TAG_ALGORITHM; |
| * - KM_TAG_PURPOSE; and |
| * - (KM_TAG_USER_SECURE_ID and KM_TAG_USER_AUTH_TYPE) or KM_TAG_NO_AUTH_REQUIRED. |
| * |
| * KM_TAG_AUTH_TIMEOUT should generally be specified unless KM_TAG_NO_AUTH_REQUIRED is present, |
| * or the user will have to authenticate for every use. |
| * |
| * KM_TAG_BLOCK_MODE, KM_TAG_PADDING, KM_TAG_MAC_LENGTH and KM_TAG_DIGEST must be specified for |
| * algorithms that require them. |
| * |
| * The following tags may not be specified; their values will be provided by the implementation. |
| * |
| * - KM_TAG_ORIGIN, |
| * - KM_TAG_ROLLBACK_RESISTANT, |
| * - KM_TAG_CREATION_DATETIME |
| * |
| * \param[in] dev The keymaster device structure. |
| * |
| * \param[in] params Array of key generation param |
| * |
| * \param[out] key_blob returns the generated key. \p key_blob must not be NULL. The caller |
| * assumes ownership key_blob->key_material and must free() it. |
| * |
| * \param[out] characteristics returns the characteristics of the key that was, generated, if |
| * non-NULL. If non-NULL, the caller assumes ownership and must deallocate with |
| * keymaster_free_characteristics(). Note that KM_TAG_ROOT_OF_TRUST, KM_TAG_APPLICATION_ID and |
| * KM_TAG_APPLICATION_DATA are never returned. |
| */ |
| keymaster_error_t (*generate_key)(const struct keymaster2_device* dev, |
| const keymaster_key_param_set_t* params, |
| keymaster_key_blob_t* key_blob, |
| keymaster_key_characteristics_t* characteristics); |
| |
| /** |
| * Returns the characteristics of the specified key, or KM_ERROR_INVALID_KEY_BLOB if the |
| * key_blob is invalid (implementations must fully validate the integrity of the key). |
| * client_id and app_data must be the ID and data provided when the key was generated or |
| * imported, or empty if KM_TAG_APPLICATION_ID and/or KM_TAG_APPLICATION_DATA were not provided |
| * during generation. Those values are not included in the returned characteristics. The |
| * caller assumes ownership of the allocated characteristics object, which must be deallocated |
| * with keymaster_free_characteristics(). |
| * |
| * Note that KM_TAG_APPLICATION_ID and KM_TAG_APPLICATION_DATA are never returned. |
| * |
| * \param[in] dev The keymaster device structure. |
| * |
| * \param[in] key_blob The key to retreive characteristics from. |
| * |
| * \param[in] client_id The client ID data, or NULL if none associated. |
| * |
| * \param[in] app_id The app data, or NULL if none associated. |
| * |
| * \param[out] characteristics The key characteristics. Must not be NULL. The caller assumes |
| * ownership of the contents and must deallocate with keymaster_free_characteristics(). |
| */ |
| keymaster_error_t (*get_key_characteristics)(const struct keymaster2_device* dev, |
| const keymaster_key_blob_t* key_blob, |
| const keymaster_blob_t* client_id, |
| const keymaster_blob_t* app_data, |
| keymaster_key_characteristics_t* characteristics); |
| |
| /** |
| * Imports a key, or key pair, returning a key blob and/or a description of the key. |
| * |
| * Most key import parameters are defined as keymaster tag/value pairs, provided in "params". |
| * See keymaster_tag_t for the full list. Values that are always required for import of useful |
| * keys are: |
| * |
| * - KM_TAG_ALGORITHM; |
| * - KM_TAG_PURPOSE; and |
| * - (KM_TAG_USER_SECURE_ID and KM_TAG_USER_AUTH_TYPE) or KM_TAG_NO_AUTH_REQUIRED. |
| * |
| * KM_TAG_AUTH_TIMEOUT should generally be specified. If unspecified, the user will have to |
| * authenticate for every use. |
| * |
| * The following tags will take default values if unspecified: |
| * |
| * - KM_TAG_KEY_SIZE will default to the size of the key provided. |
| * - KM_TAG_RSA_PUBLIC_EXPONENT will default to the value in the key provided (for RSA keys) |
| * |
| * The following tags may not be specified; their values will be provided by the implementation. |
| * |
| * - KM_TAG_ORIGIN, |
| * - KM_TAG_ROLLBACK_RESISTANT, |
| * - KM_TAG_CREATION_DATETIME |
| * |
| * \param[in] dev The keymaster device structure. |
| * |
| * \param[in] params Parameters defining the imported key. |
| * |
| * \param[in] params_count The number of entries in \p params. |
| * |
| * \param[in] key_format specifies the format of the key data in key_data. |
| * |
| * \param[out] key_blob Used to return the opaque key blob. Must be non-NULL. The caller |
| * assumes ownership of the contained key_material. |
| * |
| * \param[out] characteristics Used to return the characteristics of the imported key. May be |
| * NULL, in which case no characteristics will be returned. If non-NULL, the caller assumes |
| * ownership of the contents and must deallocate with keymaster_free_characteristics(). Note |
| * that KM_TAG_APPLICATION_ID and KM_TAG_APPLICATION_DATA are never returned. |
| */ |
| keymaster_error_t (*import_key)(const struct keymaster2_device* dev, |
| const keymaster_key_param_set_t* params, |
| keymaster_key_format_t key_format, |
| const keymaster_blob_t* key_data, |
| keymaster_key_blob_t* key_blob, |
| keymaster_key_characteristics_t* characteristics); |
| |
| /** |
| * Exports a public or symmetric key, returning a byte array in the specified format. |
| * |
| * Note that symmetric key export is allowed only if the key was created with KM_TAG_EXPORTABLE, |
| * and only if all of the requirements for key usage (e.g. authentication) are met. |
| * |
| * \param[in] dev The keymaster device structure. |
| * |
| * \param[in] export_format The format to be used for exporting the key. |
| * |
| * \param[in] key_to_export The key to export. |
| * |
| * \param[in] client_id Client ID blob, which must match the blob provided in |
| * KM_TAG_APPLICATION_ID during key generation (if any). |
| * |
| * \param[in] app_data Appliation data blob, which must match the blob provided in |
| * KM_TAG_APPLICATION_DATA during key generation (if any). |
| * |
| * \param[out] export_data The exported key material. The caller assumes ownership. |
| */ |
| keymaster_error_t (*export_key)(const struct keymaster2_device* dev, |
| keymaster_key_format_t export_format, |
| const keymaster_key_blob_t* key_to_export, |
| const keymaster_blob_t* client_id, |
| const keymaster_blob_t* app_data, |
| keymaster_blob_t* export_data); |
| |
| /** |
| * Generates a signed X.509 certificate chain attesting to the presence of \p key_to_attest in |
| * keymaster (TODO(swillden): Describe certificate contents in more detail). The certificate |
| * will contain an extension with OID 1.3.6.1.4.1.11129.2.1.17 and value defined in |
| * <TODO:swillden -- insert link here> which contains the key description. |
| * |
| * \param[in] dev The keymaster device structure. |
| * |
| * \param[in] key_to_attest The keymaster key for which the attestation certificate will be |
| * generated. |
| * |
| * \param[in] attest_params Parameters defining how to do the attestation. At present the only |
| * parameter is KM_TAG_ALGORITHM, which must be either KM_ALGORITHM_EC or KM_ALGORITHM_RSA. |
| * This selects which of the provisioned attestation keys will be used to sign the certificate. |
| * |
| * \param[out] cert_chain An array of DER-encoded X.509 certificates. The first will be the |
| * certificate for \p key_to_attest. The remaining entries will chain back to the root. The |
| * caller takes ownership and must deallocate with keymaster_free_cert_chain. |
| */ |
| keymaster_error_t (*attest_key)(const struct keymaster2_device* dev, |
| const keymaster_key_blob_t* key_to_attest, |
| const keymaster_key_param_set_t* attest_params, |
| keymaster_cert_chain_t* cert_chain); |
| |
| /** |
| * Upgrades an old key. Keys can become "old" in two ways: Keymaster can be upgraded to a new |
| * version, or the system can be updated to invalidate the OS version and/or patch level. In |
| * either case, attempts to use an old key will result in keymaster returning |
| * KM_ERROR_KEY_REQUIRES_UPGRADE. This method should then be called to upgrade the key. |
| * |
| * \param[in] dev The keymaster device structure. |
| * |
| * \param[in] key_to_upgrade The keymaster key to upgrade. |
| * |
| * \param[in] upgrade_params Parameters needed to complete the upgrade. In particular, |
| * KM_TAG_APPLICATION_ID and KM_TAG_APPLICATION_DATA will be required if they were defined for |
| * the key. |
| * |
| * \param[out] upgraded_key The upgraded key blob. |
| */ |
| keymaster_error_t (*upgrade_key)(const struct keymaster2_device* dev, |
| const keymaster_key_blob_t* key_to_upgrade, |
| const keymaster_key_param_set_t* upgrade_params, |
| keymaster_key_blob_t* upgraded_key); |
| |
| /** |
| * Deletes the key, or key pair, associated with the key blob. After calling this function it |
| * will be impossible to use the key for any other operations. May be applied to keys from |
| * foreign roots of trust (keys not usable under the current root of trust). |
| * |
| * This function is optional and should be set to NULL if it is not implemented. |
| * |
| * \param[in] dev The keymaster device structure. |
| * |
| * \param[in] key The key to be deleted. |
| */ |
| keymaster_error_t (*delete_key)(const struct keymaster2_device* dev, |
| const keymaster_key_blob_t* key); |
| |
| /** |
| * Deletes all keys in the hardware keystore. Used when keystore is reset completely. After |
| * calling this function it will be impossible to use any previously generated or imported key |
| * blobs for any operations. |
| * |
| * This function is optional and should be set to NULL if it is not implemented. |
| * |
| * \param[in] dev The keymaster device structure. |
| */ |
| keymaster_error_t (*delete_all_keys)(const struct keymaster2_device* dev); |
| |
| /** |
| * Begins a cryptographic operation using the specified key. If all is well, begin() will |
| * return KM_ERROR_OK and create an operation handle which must be passed to subsequent calls to |
| * update(), finish() or abort(). |
| * |
| * It is critical that each call to begin() be paired with a subsequent call to finish() or |
| * abort(), to allow the keymaster implementation to clean up any internal operation state. |
| * Failure to do this may leak internal state space or other internal resources and may |
| * eventually cause begin() to return KM_ERROR_TOO_MANY_OPERATIONS when it runs out of space for |
| * operations. Any result other than KM_ERROR_OK from begin(), update() or finish() implicitly |
| * aborts the operation, in which case abort() need not be called (and will return |
| * KM_ERROR_INVALID_OPERATION_HANDLE if called). |
| * |
| * \param[in] dev The keymaster device structure. |
| * |
| * \param[in] purpose The purpose of the operation, one of KM_PURPOSE_ENCRYPT, |
| * KM_PURPOSE_DECRYPT, KM_PURPOSE_SIGN or KM_PURPOSE_VERIFY. Note that for AEAD modes, |
| * encryption and decryption imply signing and verification, respectively, but should be |
| * specified as KM_PURPOSE_ENCRYPT and KM_PURPOSE_DECRYPT. |
| * |
| * \param[in] key The key to be used for the operation. \p key must have a purpose compatible |
| * with \p purpose and all of its usage requirements must be satisfied, or begin() will return |
| * an appropriate error code. |
| * |
| * \param[in] in_params Additional parameters for the operation. This is typically used to |
| * provide authentication data, with KM_TAG_AUTH_TOKEN. If KM_TAG_APPLICATION_ID or |
| * KM_TAG_APPLICATION_DATA were provided during generation, they must be provided here, or the |
| * operation will fail with KM_ERROR_INVALID_KEY_BLOB. For operations that require a nonce or |
| * IV, on keys that were generated with KM_TAG_CALLER_NONCE, in_params may contain a tag |
| * KM_TAG_NONCE. |
| * |
| * \param[out] out_params Output parameters. Used to return additional data from the operation |
| * initialization, notably to return the IV or nonce from operations that generate an IV or |
| * nonce. The caller takes ownership of the output parameters array and must free it with |
| * keymaster_free_param_set(). out_params may be set to NULL if no output parameters are |
| * expected. If out_params is NULL, and output paramaters are generated, begin() will return |
| * KM_ERROR_OUTPUT_PARAMETER_NULL. |
| * |
| * \param[out] operation_handle The newly-created operation handle which must be passed to |
| * update(), finish() or abort(). If operation_handle is NULL, begin() will return |
| * KM_ERROR_OUTPUT_PARAMETER_NULL. |
| */ |
| keymaster_error_t (*begin)(const struct keymaster2_device* dev, keymaster_purpose_t purpose, |
| const keymaster_key_blob_t* key, |
| const keymaster_key_param_set_t* in_params, |
| keymaster_key_param_set_t* out_params, |
| keymaster_operation_handle_t* operation_handle); |
| |
| /** |
| * Provides data to, and possibly receives output from, an ongoing cryptographic operation begun |
| * with begin(). |
| * |
| * If operation_handle is invalid, update() will return KM_ERROR_INVALID_OPERATION_HANDLE. |
| * |
| * update() may not consume all of the data provided in the data buffer. update() will return |
| * the amount consumed in *data_consumed. The caller should provide the unconsumed data in a |
| * subsequent call. |
| * |
| * \param[in] dev The keymaster device structure. |
| * |
| * \param[in] operation_handle The operation handle returned by begin(). |
| * |
| * \param[in] in_params Additional parameters for the operation. For AEAD modes, this is used |
| * to specify KM_TAG_ADDITIONAL_DATA. Note that additional data may be provided in multiple |
| * calls to update(), but only until input data has been provided. |
| * |
| * \param[in] input Data to be processed, per the parameters established in the call to begin(). |
| * Note that update() may or may not consume all of the data provided. See \p input_consumed. |
| * |
| * \param[out] input_consumed Amount of data that was consumed by update(). If this is less |
| * than the amount provided, the caller should provide the remainder in a subsequent call to |
| * update(). |
| * |
| * \param[out] out_params Output parameters. Used to return additional data from the operation |
| * The caller takes ownership of the output parameters array and must free it with |
| * keymaster_free_param_set(). out_params may be set to NULL if no output parameters are |
| * expected. If out_params is NULL, and output paramaters are generated, begin() will return |
| * KM_ERROR_OUTPUT_PARAMETER_NULL. |
| * |
| * \param[out] output The output data, if any. The caller assumes ownership of the allocated |
| * buffer. output must not be NULL. |
| * |
| * Note that update() may not provide any output, in which case output->data_length will be |
| * zero, and output->data may be either NULL or zero-length (so the caller should always free() |
| * it). |
| */ |
| keymaster_error_t (*update)(const struct keymaster2_device* dev, |
| keymaster_operation_handle_t operation_handle, |
| const keymaster_key_param_set_t* in_params, |
| const keymaster_blob_t* input, size_t* input_consumed, |
| keymaster_key_param_set_t* out_params, keymaster_blob_t* output); |
| |
| /** |
| * Finalizes a cryptographic operation begun with begin() and invalidates \p operation_handle. |
| * |
| * \param[in] dev The keymaster device structure. |
| * |
| * \param[in] operation_handle The operation handle returned by begin(). This handle will be |
| * invalidated. |
| * |
| * \param[in] in_params Additional parameters for the operation. For AEAD modes, this is used |
| * to specify KM_TAG_ADDITIONAL_DATA, but only if no input data was provided to update(). |
| * |
| * \param[in] input Data to be processed, per the parameters established in the call to |
| * begin(). finish() must consume all provided data or return KM_ERROR_INVALID_INPUT_LENGTH. |
| * |
| * \param[in] signature The signature to be verified if the purpose specified in the begin() |
| * call was KM_PURPOSE_VERIFY. |
| * |
| * \param[out] output The output data, if any. The caller assumes ownership of the allocated |
| * buffer. |
| * |
| * If the operation being finished is a signature verification or an AEAD-mode decryption and |
| * verification fails then finish() will return KM_ERROR_VERIFICATION_FAILED. |
| */ |
| keymaster_error_t (*finish)(const struct keymaster2_device* dev, |
| keymaster_operation_handle_t operation_handle, |
| const keymaster_key_param_set_t* in_params, |
| const keymaster_blob_t* input, const keymaster_blob_t* signature, |
| keymaster_key_param_set_t* out_params, keymaster_blob_t* output); |
| |
| /** |
| * Aborts a cryptographic operation begun with begin(), freeing all internal resources and |
| * invalidating \p operation_handle. |
| */ |
| keymaster_error_t (*abort)(const struct keymaster2_device* dev, |
| keymaster_operation_handle_t operation_handle); |
| }; |
| typedef struct keymaster2_device keymaster2_device_t; |
| |
| /* Convenience API for opening and closing keymaster devices */ |
| |
| static inline int keymaster2_open(const struct hw_module_t* module, keymaster2_device_t** device) { |
| return module->methods->open(module, KEYSTORE_KEYMASTER, TO_HW_DEVICE_T_OPEN(device)); |
| } |
| |
| static inline int keymaster2_close(keymaster2_device_t* device) { |
| return device->common.close(&device->common); |
| } |
| |
| __END_DECLS |
| |
| #endif // ANDROID_HARDWARE_KEYMASTER2_H |
