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Diffstat (limited to 'include_all/hardware/keymaster2.h')
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diff --git a/include_all/hardware/keymaster2.h b/include_all/hardware/keymaster2.h new file mode 100644 index 00000000..f1993f88 --- /dev/null +++ b/include_all/hardware/keymaster2.h @@ -0,0 +1,432 @@ +/* + * 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 |