/** * \file psa/crypto_types.h * * \brief PSA cryptography module: type aliases. * * \note This file may not be included directly. Applications must * include psa/crypto.h. Drivers must include the appropriate driver * header file. * * This file contains portable definitions of integral types for properties * of cryptographic keys, designations of cryptographic algorithms, and * error codes returned by the library. * * This header file does not declare any function. */ /* * Copyright (C) 2018, ARM Limited, All Rights Reserved * SPDX-License-Identifier: Apache-2.0 * * 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. * * This file is part of mbed TLS (https://tls.mbed.org) */ #ifndef PSA_CRYPTO_TYPES_H #define PSA_CRYPTO_TYPES_H #include <stdint.h> /** \defgroup error Error codes * @{ */ /** * \brief Function return status. * * This is either #PSA_SUCCESS (which is zero), indicating success, * or a small negative value indicating that an error occurred. Errors are * encoded as one of the \c PSA_ERROR_xxx values defined here. */ /* If #PSA_SUCCESS is already defined, it means that #psa_status_t * is also defined in an external header, so prevent its multiple * definition. */ #ifndef PSA_SUCCESS typedef int32_t psa_status_t; #endif /**@}*/ /** \defgroup crypto_types Key and algorithm types * @{ */ /** \brief Encoding of a key type. */ typedef uint16_t psa_key_type_t; /** The type of PSA elliptic curve family identifiers. * * The curve identifier is required to create an ECC key using the * PSA_KEY_TYPE_ECC_KEY_PAIR() or PSA_KEY_TYPE_ECC_PUBLIC_KEY() * macros. * * Values defined by this standard will never be in the range 0x80-0xff. * Vendors who define additional families must use an encoding in this range. */ typedef uint8_t psa_ecc_curve_t; /** The type of PSA Diffie-Hellman group family identifiers. * * The group identifier is required to create an Diffie-Hellman key using the * PSA_KEY_TYPE_DH_KEY_PAIR() or PSA_KEY_TYPE_DH_PUBLIC_KEY() * macros. * * Values defined by this standard will never be in the range 0x80-0xff. * Vendors who define additional families must use an encoding in this range. */ typedef uint8_t psa_dh_group_t; /** \brief Encoding of a cryptographic algorithm. * * For algorithms that can be applied to multiple key types, this type * does not encode the key type. For example, for symmetric ciphers * based on a block cipher, #psa_algorithm_t encodes the block cipher * mode and the padding mode while the block cipher itself is encoded * via #psa_key_type_t. */ typedef uint32_t psa_algorithm_t; /**@}*/ /** \defgroup key_lifetimes Key lifetimes * @{ */ /** Encoding of key lifetimes. * * The lifetime of a key indicates where it is stored and what system actions * may create and destroy it. * * Keys with the lifetime #PSA_KEY_LIFETIME_VOLATILE are automatically * destroyed when the application terminates or on a power reset. * * Keys with a lifetime other than #PSA_KEY_LIFETIME_VOLATILE are said * to be _persistent_. * Persistent keys are preserved if the application or the system restarts. * Persistent keys have a key identifier of type #psa_key_id_t. * The application can call psa_open_key() to open a persistent key that * it created previously. */ typedef uint32_t psa_key_lifetime_t; /** Encoding of identifiers of persistent keys. * * - Applications may freely choose key identifiers in the range * #PSA_KEY_ID_USER_MIN to #PSA_KEY_ID_USER_MAX. * - Implementations may define additional key identifiers in the range * #PSA_KEY_ID_VENDOR_MIN to #PSA_KEY_ID_VENDOR_MAX. * - 0 is reserved as an invalid key identifier. * - Key identifiers outside these ranges are reserved for future use. */ /* Implementation-specific quirk: The Mbed Crypto library can be built as * part of a multi-client service that exposes the PSA Crypto API in each * client and encodes the client identity in the key id argument of functions * such as psa_open_key(). In this build configuration, we define * psa_key_id_t in crypto_platform.h instead of here. */ #if !defined(MBEDTLS_PSA_CRYPTO_KEY_FILE_ID_ENCODES_OWNER) typedef uint32_t psa_key_id_t; #define PSA_KEY_ID_INIT 0 #endif /**@}*/ /** \defgroup policy Key policies * @{ */ /** \brief Encoding of permitted usage on a key. */ typedef uint32_t psa_key_usage_t; /**@}*/ /** \defgroup attributes Key attributes * @{ */ /** The type of a structure containing key attributes. * * This is an opaque structure that can represent the metadata of a key * object. Metadata that can be stored in attributes includes: * - The location of the key in storage, indicated by its key identifier * and its lifetime. * - The key's policy, comprising usage flags and a specification of * the permitted algorithm(s). * - Information about the key itself: the key type and its size. * - Implementations may define additional attributes. * * The actual key material is not considered an attribute of a key. * Key attributes do not contain information that is generally considered * highly confidential. * * An attribute structure can be a simple data structure where each function * `psa_set_key_xxx` sets a field and the corresponding function * `psa_get_key_xxx` retrieves the value of the corresponding field. * However, implementations may report values that are equivalent to the * original one, but have a different encoding. For example, an * implementation may use a more compact representation for types where * many bit-patterns are invalid or not supported, and store all values * that it does not support as a special marker value. In such an * implementation, after setting an invalid value, the corresponding * get function returns an invalid value which may not be the one that * was originally stored. * * An attribute structure may contain references to auxiliary resources, * for example pointers to allocated memory or indirect references to * pre-calculated values. In order to free such resources, the application * must call psa_reset_key_attributes(). As an exception, calling * psa_reset_key_attributes() on an attribute structure is optional if * the structure has only been modified by the following functions * since it was initialized or last reset with psa_reset_key_attributes(): * - psa_set_key_id() * - psa_set_key_lifetime() * - psa_set_key_type() * - psa_set_key_bits() * - psa_set_key_usage_flags() * - psa_set_key_algorithm() * * Before calling any function on a key attribute structure, the application * must initialize it by any of the following means: * - Set the structure to all-bits-zero, for example: * \code * psa_key_attributes_t attributes; * memset(&attributes, 0, sizeof(attributes)); * \endcode * - Initialize the structure to logical zero values, for example: * \code * psa_key_attributes_t attributes = {0}; * \endcode * - Initialize the structure to the initializer #PSA_KEY_ATTRIBUTES_INIT, * for example: * \code * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; * \endcode * - Assign the result of the function psa_key_attributes_init() * to the structure, for example: * \code * psa_key_attributes_t attributes; * attributes = psa_key_attributes_init(); * \endcode * * A freshly initialized attribute structure contains the following * values: * * - lifetime: #PSA_KEY_LIFETIME_VOLATILE. * - key identifier: 0 (which is not a valid key identifier). * - type: \c 0 (meaning that the type is unspecified). * - key size: \c 0 (meaning that the size is unspecified). * - usage flags: \c 0 (which allows no usage except exporting a public key). * - algorithm: \c 0 (which allows no cryptographic usage, but allows * exporting). * * A typical sequence to create a key is as follows: * -# Create and initialize an attribute structure. * -# If the key is persistent, call psa_set_key_id(). * Also call psa_set_key_lifetime() to place the key in a non-default * location. * -# Set the key policy with psa_set_key_usage_flags() and * psa_set_key_algorithm(). * -# Set the key type with psa_set_key_type(). * Skip this step if copying an existing key with psa_copy_key(). * -# When generating a random key with psa_generate_key() or deriving a key * with psa_key_derivation_output_key(), set the desired key size with * psa_set_key_bits(). * -# Call a key creation function: psa_import_key(), psa_generate_key(), * psa_key_derivation_output_key() or psa_copy_key(). This function reads * the attribute structure, creates a key with these attributes, and * outputs a handle to the newly created key. * -# The attribute structure is now no longer necessary. * You may call psa_reset_key_attributes(), although this is optional * with the workflow presented here because the attributes currently * defined in this specification do not require any additional resources * beyond the structure itself. * * A typical sequence to query a key's attributes is as follows: * -# Call psa_get_key_attributes(). * -# Call `psa_get_key_xxx` functions to retrieve the attribute(s) that * you are interested in. * -# Call psa_reset_key_attributes() to free any resources that may be * used by the attribute structure. * * Once a key has been created, it is impossible to change its attributes. */ typedef struct psa_key_attributes_s psa_key_attributes_t; #ifndef __DOXYGEN_ONLY__ #if defined(MBEDTLS_PSA_CRYPTO_SE_C) /* Mbed Crypto defines this type in crypto_types.h because it is also * visible to applications through an implementation-specific extension. * For the PSA Cryptography specification, this type is only visible * via crypto_se_driver.h. */ typedef uint64_t psa_key_slot_number_t; #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ #endif /* !__DOXYGEN_ONLY__ */ /**@}*/ /** \defgroup derivation Key derivation * @{ */ /** \brief Encoding of the step of a key derivation. */ typedef uint16_t psa_key_derivation_step_t; /**@}*/ #endif /* PSA_CRYPTO_TYPES_H */