mbedtls/include/psa/crypto_extra.h
Gilles Peskine e38ab1ac4f Move DSA definitions out of the specification
Move DSA-related key types and algorithms to the
implementation-specific header file. Not that we actually implement
DSA, but with domain parameters, we should be able to.
2019-05-16 19:51:10 +02:00

670 lines
27 KiB
C

/**
* \file psa/crypto_extra.h
*
* \brief PSA cryptography module: Mbed TLS vendor extensions
*
* \note This file may not be included directly. Applications must
* include psa/crypto.h.
*
* This file is reserved for vendor-specific definitions.
*/
/*
* 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_EXTRA_H
#define PSA_CRYPTO_EXTRA_H
#include "mbedtls/platform_util.h"
#ifdef __cplusplus
extern "C" {
#endif
/* UID for secure storage seed */
#define PSA_CRYPTO_ITS_RANDOM_SEED_UID 0xFFFFFF52
/*
* Deprecated PSA Crypto error code definitions
*/
#if !defined(MBEDTLS_DEPRECATED_REMOVED)
#define PSA_ERROR_UNKNOWN_ERROR \
MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( PSA_ERROR_GENERIC_ERROR )
#endif
#if !defined(MBEDTLS_DEPRECATED_REMOVED)
#define PSA_ERROR_OCCUPIED_SLOT \
MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( PSA_ERROR_ALREADY_EXISTS )
#endif
#if !defined(MBEDTLS_DEPRECATED_REMOVED)
#define PSA_ERROR_EMPTY_SLOT \
MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( PSA_ERROR_DOES_NOT_EXIST )
#endif
#if !defined(MBEDTLS_DEPRECATED_REMOVED)
#define PSA_ERROR_INSUFFICIENT_CAPACITY \
MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( PSA_ERROR_INSUFFICIENT_DATA )
#endif
/**
* \brief Library deinitialization.
*
* This function clears all data associated with the PSA layer,
* including the whole key store.
*
* This is an Mbed TLS extension.
*/
void mbedtls_psa_crypto_free( void );
/**
* \brief Inject an initial entropy seed for the random generator into
* secure storage.
*
* This function injects data to be used as a seed for the random generator
* used by the PSA Crypto implementation. On devices that lack a trusted
* entropy source (preferably a hardware random number generator),
* the Mbed PSA Crypto implementation uses this value to seed its
* random generator.
*
* On devices without a trusted entropy source, this function must be
* called exactly once in the lifetime of the device. On devices with
* a trusted entropy source, calling this function is optional.
* In all cases, this function may only be called before calling any
* other function in the PSA Crypto API, including psa_crypto_init().
*
* When this function returns successfully, it populates a file in
* persistent storage. Once the file has been created, this function
* can no longer succeed.
*
* If any error occurs, this function does not change the system state.
* You can call this function again after correcting the reason for the
* error if possible.
*
* \warning This function **can** fail! Callers MUST check the return status.
*
* \warning If you use this function, you should use it as part of a
* factory provisioning process. The value of the injected seed
* is critical to the security of the device. It must be
* *secret*, *unpredictable* and (statistically) *unique per device*.
* You should be generate it randomly using a cryptographically
* secure random generator seeded from trusted entropy sources.
* You should transmit it securely to the device and ensure
* that its value is not leaked or stored anywhere beyond the
* needs of transmitting it from the point of generation to
* the call of this function, and erase all copies of the value
* once this function returns.
*
* This is an Mbed TLS extension.
*
* \note This function is only available on the following platforms:
* * If the compile-time option MBEDTLS_PSA_INJECT_ENTROPY is enabled.
* Note that you must provide compatible implementations of
* mbedtls_nv_seed_read and mbedtls_nv_seed_write.
* * In a client-server integration of PSA Cryptography, on the client side,
* if the server supports this feature.
* \param[in] seed Buffer containing the seed value to inject.
* \param[in] seed_size Size of the \p seed buffer.
* The size of the seed in bytes must be greater
* or equal to both #MBEDTLS_ENTROPY_MIN_PLATFORM
* and #MBEDTLS_ENTROPY_BLOCK_SIZE.
* It must be less or equal to
* #MBEDTLS_ENTROPY_MAX_SEED_SIZE.
*
* \retval #PSA_SUCCESS
* The seed value was injected successfully. The random generator
* of the PSA Crypto implementation is now ready for use.
* You may now call psa_crypto_init() and use the PSA Crypto
* implementation.
* \retval #PSA_ERROR_INVALID_ARGUMENT
* \p seed_size is out of range.
* \retval #PSA_ERROR_STORAGE_FAILURE
* There was a failure reading or writing from storage.
* \retval #PSA_ERROR_NOT_PERMITTED
* The library has already been initialized. It is no longer
* possible to call this function.
*/
psa_status_t mbedtls_psa_inject_entropy(const unsigned char *seed,
size_t seed_size);
/** Set up a key derivation operation.
*
* FIMXE This function is no longer part of the official API. Its prototype
* is only kept around for the sake of tests that haven't been updated yet.
*
* A key derivation algorithm takes three inputs: a secret input \p handle and
* two non-secret inputs \p label and p salt.
* The result of this function is a byte generator which can
* be used to produce keys and other cryptographic material.
*
* The role of \p label and \p salt is as follows:
* - For HKDF (#PSA_ALG_HKDF), \p salt is the salt used in the "extract" step
* and \p label is the info string used in the "expand" step.
*
* \param[in,out] operation The key derivation object to set up. It must
* have been initialized as per the documentation
* for #psa_key_derivation_operation_t and not
* yet be in use.
* \param handle Handle to the secret key.
* \param alg The key derivation algorithm to compute
* (\c PSA_ALG_XXX value such that
* #PSA_ALG_IS_KEY_DERIVATION(\p alg) is true).
* \param[in] salt Salt to use.
* \param salt_length Size of the \p salt buffer in bytes.
* \param[in] label Label to use.
* \param label_length Size of the \p label buffer in bytes.
* \param capacity The maximum number of bytes that the
* operation will be able to provide.
*
* \retval #PSA_SUCCESS
* Success.
* \retval #PSA_ERROR_INVALID_HANDLE
* \retval #PSA_ERROR_EMPTY_SLOT
* \retval #PSA_ERROR_NOT_PERMITTED
* \retval #PSA_ERROR_INVALID_ARGUMENT
* \c key is not compatible with \c alg,
* or \p capacity is too large for the specified algorithm and key.
* \retval #PSA_ERROR_NOT_SUPPORTED
* \c alg is not supported or is not a key derivation algorithm.
* \retval #PSA_ERROR_INSUFFICIENT_MEMORY
* \retval #PSA_ERROR_COMMUNICATION_FAILURE
* \retval #PSA_ERROR_HARDWARE_FAILURE
* \retval #PSA_ERROR_TAMPERING_DETECTED
* \retval #PSA_ERROR_BAD_STATE
* The library has not been previously initialized by psa_crypto_init().
* It is implementation-dependent whether a failure to initialize
* results in this error code.
*/
psa_status_t psa_key_derivation(psa_key_derivation_operation_t *operation,
psa_key_handle_t handle,
psa_algorithm_t alg,
const uint8_t *salt,
size_t salt_length,
const uint8_t *label,
size_t label_length,
size_t capacity);
/* FIXME Deprecated. Remove this as soon as all the tests are updated. */
#define PSA_ALG_SELECT_RAW ((psa_algorithm_t)0x31000001)
/** \defgroup policy Key policies
* @{
*
* The functions in this section are legacy interfaces where the properties
* of a key object are set after allocating a handle, in constrast with the
* preferred interface where key objects are created atomically from
* a structure that represents the properties.
*/
/** \def PSA_KEY_POLICY_INIT
*
* This macro returns a suitable initializer for a key policy object of type
* #psa_key_policy_t.
*/
#ifdef __DOXYGEN_ONLY__
/* This is an example definition for documentation purposes.
* Implementations should define a suitable value in `crypto_struct.h`.
*/
#define PSA_KEY_POLICY_INIT {0}
#endif
/** Return an initial value for a key policy that forbids all usage of the key.
*/
static psa_key_policy_t psa_key_policy_init(void);
/** \brief Set the standard fields of a policy structure.
*
* Note that this function does not make any consistency check of the
* parameters. The values are only checked when applying the policy to
* a key slot with psa_set_key_policy().
*
* \param[in,out] policy The key policy to modify. It must have been
* initialized as per the documentation for
* #psa_key_policy_t.
* \param usage The permitted uses for the key.
* \param alg The algorithm that the key may be used for.
*/
void psa_key_policy_set_usage(psa_key_policy_t *policy,
psa_key_usage_t usage,
psa_algorithm_t alg);
/** \brief Retrieve the usage field of a policy structure.
*
* \param[in] policy The policy object to query.
*
* \return The permitted uses for a key with this policy.
*/
psa_key_usage_t psa_key_policy_get_usage(const psa_key_policy_t *policy);
/** \brief Retrieve the algorithm field of a policy structure.
*
* \param[in] policy The policy object to query.
*
* \return The permitted algorithm for a key with this policy.
*/
psa_algorithm_t psa_key_policy_get_algorithm(const psa_key_policy_t *policy);
/** \brief Set the usage policy on a key slot.
*
* This function must be called on an empty key slot, before importing,
* generating or creating a key in the slot. Changing the policy of an
* existing key is not permitted.
*
* Implementations may set restrictions on supported key policies
* depending on the key type and the key slot.
*
* \param handle Handle to the key whose policy is to be changed.
* \param[in] policy The policy object to query.
*
* \retval #PSA_SUCCESS
* Success.
* If the key is persistent, it is implementation-defined whether
* the policy has been saved to persistent storage. Implementations
* may defer saving the policy until the key material is created.
* \retval #PSA_ERROR_INVALID_HANDLE
* \retval #PSA_ERROR_ALREADY_EXISTS
* \retval #PSA_ERROR_NOT_SUPPORTED
* \retval #PSA_ERROR_INVALID_ARGUMENT
* \retval #PSA_ERROR_COMMUNICATION_FAILURE
* \retval #PSA_ERROR_HARDWARE_FAILURE
* \retval #PSA_ERROR_TAMPERING_DETECTED
* \retval #PSA_ERROR_BAD_STATE
* The library has not been previously initialized by psa_crypto_init().
* It is implementation-dependent whether a failure to initialize
* results in this error code.
*/
psa_status_t psa_set_key_policy(psa_key_handle_t handle,
const psa_key_policy_t *policy);
/** \brief Get the usage policy for a key slot.
*
* \param handle Handle to the key slot whose policy is being queried.
* \param[out] policy On success, the key's policy.
*
* \retval #PSA_SUCCESS
* \retval #PSA_ERROR_INVALID_HANDLE
* \retval #PSA_ERROR_COMMUNICATION_FAILURE
* \retval #PSA_ERROR_HARDWARE_FAILURE
* \retval #PSA_ERROR_TAMPERING_DETECTED
* \retval #PSA_ERROR_BAD_STATE
* The library has not been previously initialized by psa_crypto_init().
* It is implementation-dependent whether a failure to initialize
* results in this error code.
*/
psa_status_t psa_get_key_policy(psa_key_handle_t handle,
psa_key_policy_t *policy);
/**@}*/
/** \defgroup to_handle Key creation to allocated handle
* @{
*
* The functions in this section are legacy interfaces where the properties
* of a key object are set after allocating a handle, in constrast with the
* preferred interface where key objects are created atomically from
* a structure that represents the properties.
*/
/** Create a new persistent key slot.
*
* Create a new persistent key slot and return a handle to it. The handle
* remains valid until the application calls psa_close_key() or terminates.
* The application can open the key again with psa_open_key() until it
* removes the key by calling psa_destroy_key().
*
* \param lifetime The lifetime of the key. This designates a storage
* area where the key material is stored. This must not
* be #PSA_KEY_LIFETIME_VOLATILE.
* \param id The persistent identifier of the key.
* \param[out] handle On success, a handle to the newly created key slot.
* When key material is later created in this key slot,
* it will be saved to the specified persistent location.
*
* \retval #PSA_SUCCESS
* Success. The application can now use the value of `*handle`
* to access the newly allocated key slot.
* \retval #PSA_ERROR_INSUFFICIENT_MEMORY
* \retval #PSA_ERROR_INSUFFICIENT_STORAGE
* \retval #PSA_ERROR_ALREADY_EXISTS
* There is already a key with the identifier \p id in the storage
* area designated by \p lifetime.
* \retval #PSA_ERROR_INVALID_ARGUMENT
* \p lifetime is invalid, for example #PSA_KEY_LIFETIME_VOLATILE.
* \retval #PSA_ERROR_INVALID_ARGUMENT
* \p id is invalid for the specified lifetime.
* \retval #PSA_ERROR_NOT_SUPPORTED
* \p lifetime is not supported.
* \retval #PSA_ERROR_NOT_PERMITTED
* \p lifetime is valid, but the application does not have the
* permission to create a key there.
*/
psa_status_t psa_create_key(psa_key_lifetime_t lifetime,
psa_key_id_t id,
psa_key_handle_t *handle);
/** Allocate a key slot for a transient key, i.e. a key which is only stored
* in volatile memory.
*
* The allocated key slot and its handle remain valid until the
* application calls psa_close_key() or psa_destroy_key() or until the
* application terminates.
*
* \param[out] handle On success, a handle to a volatile key slot.
*
* \retval #PSA_SUCCESS
* Success. The application can now use the value of `*handle`
* to access the newly allocated key slot.
* \retval #PSA_ERROR_INSUFFICIENT_MEMORY
* There was not enough memory, or the maximum number of key slots
* has been reached.
*/
psa_status_t psa_allocate_key(psa_key_handle_t *handle);
/**
* \brief Get basic metadata about a key.
*
* \param handle Handle to the key slot to query.
* \param[out] type On success, the key type (a \c PSA_KEY_TYPE_XXX value).
* This may be a null pointer, in which case the key type
* is not written.
* \param[out] bits On success, the key size in bits.
* This may be a null pointer, in which case the key size
* is not written.
*
* \retval #PSA_SUCCESS
* \retval #PSA_ERROR_INVALID_HANDLE
* \retval #PSA_ERROR_DOES_NOT_EXIST
* The handle is to a key slot which does not contain key material yet.
* \retval #PSA_ERROR_COMMUNICATION_FAILURE
* \retval #PSA_ERROR_HARDWARE_FAILURE
* \retval #PSA_ERROR_TAMPERING_DETECTED
* \retval #PSA_ERROR_BAD_STATE
* The library has not been previously initialized by psa_crypto_init().
* It is implementation-dependent whether a failure to initialize
* results in this error code.
*/
psa_status_t psa_get_key_information(psa_key_handle_t handle,
psa_key_type_t *type,
size_t *bits);
/** \brief Retrieve the lifetime of an open key.
*
* \param handle Handle to query.
* \param[out] lifetime On success, the lifetime value.
*
* \retval #PSA_SUCCESS
* Success.
* \retval #PSA_ERROR_INVALID_HANDLE
* \retval #PSA_ERROR_COMMUNICATION_FAILURE
* \retval #PSA_ERROR_HARDWARE_FAILURE
* \retval #PSA_ERROR_TAMPERING_DETECTED
* \retval #PSA_ERROR_BAD_STATE
* The library has not been previously initialized by psa_crypto_init().
* It is implementation-dependent whether a failure to initialize
* results in this error code.
*/
psa_status_t psa_get_key_lifetime_from_handle(psa_key_handle_t handle,
psa_key_lifetime_t *lifetime);
psa_status_t psa_import_key_to_handle(psa_key_handle_t handle,
psa_key_type_t type,
const uint8_t *data,
size_t data_length);
psa_status_t psa_copy_key_to_handle(psa_key_handle_t source_handle,
psa_key_handle_t target_handle,
const psa_key_policy_t *constraint);
psa_status_t psa_generate_derived_key_to_handle(psa_key_handle_t handle,
psa_key_type_t type,
size_t bits,
psa_key_derivation_operation_t *operation);
psa_status_t psa_generate_random_key_to_handle(psa_key_handle_t handle,
psa_key_type_t type,
size_t bits,
const void *extra,
size_t extra_size);
/**@}*/
/** \addtogroup crypto_types
* @{
*/
/** DSA public key. */
#define PSA_KEY_TYPE_DSA_PUBLIC_KEY ((psa_key_type_t)0x60020000)
/** DSA key pair (private and public key). */
#define PSA_KEY_TYPE_DSA_KEYPAIR ((psa_key_type_t)0x70020000)
/** Whether a key type is an DSA key (pair or public-only). */
#define PSA_KEY_TYPE_IS_DSA(type) \
(PSA_KEY_TYPE_PUBLIC_KEY_OF_KEYPAIR(type) == PSA_KEY_TYPE_DSA_PUBLIC_KEY)
#define PSA_ALG_DSA_BASE ((psa_algorithm_t)0x10040000)
/** DSA signature with hashing.
*
* This is the signature scheme defined by FIPS 186-4,
* with a random per-message secret number (*k*).
*
* \param hash_alg A hash algorithm (\c PSA_ALG_XXX value such that
* #PSA_ALG_IS_HASH(\p hash_alg) is true).
* This includes #PSA_ALG_ANY_HASH
* when specifying the algorithm in a usage policy.
*
* \return The corresponding DSA signature algorithm.
* \return Unspecified if \p hash_alg is not a supported
* hash algorithm.
*/
#define PSA_ALG_DSA(hash_alg) \
(PSA_ALG_DSA_BASE | ((hash_alg) & PSA_ALG_HASH_MASK))
#define PSA_ALG_DETERMINISTIC_DSA_BASE ((psa_algorithm_t)0x10050000)
#define PSA_ALG_DSA_DETERMINISTIC_FLAG ((psa_algorithm_t)0x00010000)
/** Deterministic DSA signature with hashing.
*
* This is the deterministic variant defined by RFC 6979 of
* the signature scheme defined by FIPS 186-4.
*
* \param hash_alg A hash algorithm (\c PSA_ALG_XXX value such that
* #PSA_ALG_IS_HASH(\p hash_alg) is true).
* This includes #PSA_ALG_ANY_HASH
* when specifying the algorithm in a usage policy.
*
* \return The corresponding DSA signature algorithm.
* \return Unspecified if \p hash_alg is not a supported
* hash algorithm.
*/
#define PSA_ALG_DETERMINISTIC_DSA(hash_alg) \
(PSA_ALG_DETERMINISTIC_DSA_BASE | ((hash_alg) & PSA_ALG_HASH_MASK))
#define PSA_ALG_IS_DSA(alg) \
(((alg) & ~PSA_ALG_HASH_MASK & ~PSA_ALG_DSA_DETERMINISTIC_FLAG) == \
PSA_ALG_DSA_BASE)
#define PSA_ALG_DSA_IS_DETERMINISTIC(alg) \
(((alg) & PSA_ALG_DSA_DETERMINISTIC_FLAG) != 0)
#define PSA_ALG_IS_DETERMINISTIC_DSA(alg) \
(PSA_ALG_IS_DSA(alg) && PSA_ALG_DSA_IS_DETERMINISTIC(alg))
#define PSA_ALG_IS_RANDOMIZED_DSA(alg) \
(PSA_ALG_IS_DSA(alg) && !PSA_ALG_DSA_IS_DETERMINISTIC(alg))
/* We need to expand the sample definition of this macro from
* the API definition. */
#undef PSA_ALG_IS_HASH_AND_SIGN
#define PSA_ALG_IS_HASH_AND_SIGN(alg) \
(PSA_ALG_IS_RSA_PSS(alg) || PSA_ALG_IS_RSA_PKCS1V15_SIGN(alg) || \
PSA_ALG_IS_DSA(alg) || PSA_ALG_IS_ECDSA(alg))
/**@}*/
/** \addtogroup attributes
* @{
*/
/** Custom Diffie-Hellman group.
*
* For keys of type #PSA_KEY_TYPE_DH_PUBLIC_KEY(#PSA_DH_GROUP_CUSTOM) or
* #PSA_KEY_TYPE_DH_KEYPAIR(#PSA_DH_GROUP_CUSTOM), the group data comes
* from domain parameters set by psa_set_key_domain_parameters().
*/
/* This value is reserved for private use in the TLS named group registry. */
#define PSA_DH_GROUP_CUSTOM ((psa_dh_group_t) 0x01fc)
/**
* \brief Set domain parameters for a key.
*
* Some key types require additional domain parameters in addition to
* the key type identifier and the key size. Use this function instead
* of psa_set_key_type() when you need to specify domain parameters.
*
* The format for the required domain parameters varies based on the key type.
*
* - For RSA keys (#PSA_KEY_TYPE_RSA_PUBLIC_KEY or #PSA_KEY_TYPE_RSA_KEYPAIR),
* the domain parameter data consists of the public exponent,
* represented as a big-endian integer with no leading zeros.
* This information is used when generating an RSA key pair.
* When importing a key, the public exponent is read from the imported
* key data and the exponent recorded in the attribute structure is ignored.
* As an exception, the public exponent 65537 is represented by an empty
* byte string.
* - For DSA keys (#PSA_KEY_TYPE_DSA_PUBLIC_KEY or #PSA_KEY_TYPE_DSA_KEYPAIR),
* the `Dss-Parms` format as defined by RFC 3279 §2.3.2.
* ```
* Dss-Parms ::= SEQUENCE {
* p INTEGER,
* q INTEGER,
* g INTEGER
* }
* ```
* - For Diffie-Hellman key exchange keys
* (#PSA_KEY_TYPE_DH_PUBLIC_KEY(#PSA_DH_GROUP_CUSTOM) or
* #PSA_KEY_TYPE_DH_KEYPAIR(#PSA_DH_GROUP_CUSTOM)), the
* `DomainParameters` format as defined by RFC 3279 §2.3.3.
* ```
* DomainParameters ::= SEQUENCE {
* p INTEGER, -- odd prime, p=jq +1
* g INTEGER, -- generator, g
* q INTEGER, -- factor of p-1
* j INTEGER OPTIONAL, -- subgroup factor
* validationParms ValidationParms OPTIONAL
* }
* ValidationParms ::= SEQUENCE {
* seed BIT STRING,
* pgenCounter INTEGER
* }
* ```
*
* \note This function may allocate memory or other resources.
* Once you have called this function on an attribute structure,
* you must call psa_reset_key_attributes() to free these resources.
*
* \note This is an experimental extension to the interface. It may change
* in future versions of the library.
*
* \param[in,out] attributes Attribute structure where the specified domain
* parameters will be stored.
* If this function fails, the content of
* \p attributes is not modified.
* \param type Key type (a \c PSA_KEY_TYPE_XXX value).
* \param[in] data Buffer containing the key domain parameters.
* The content of this buffer is interpreted
* according to \p type as described above.
* \param data_length Size of the \p data buffer in bytes.
*
* \retval #PSA_SUCCESS
* \retval #PSA_ERROR_INVALID_ARGUMENT
* \retval #PSA_ERROR_NOT_SUPPORTED
* \retval #PSA_ERROR_INSUFFICIENT_MEMORY
*/
psa_status_t psa_set_key_domain_parameters(psa_key_attributes_t *attributes,
psa_key_type_t type,
const uint8_t *data,
size_t data_length);
/**
* \brief Get domain parameters for a key.
*
* Get the domain parameters for a key with this function, if any. The format
* of the domain parameters written to \p data is specified in the
* documentation for psa_set_key_domain_parameters().
*
* \note This is an experimental extension to the interface. It may change
* in future versions of the library.
*
* \param[in] attributes The key attribute structure to query.
* \param[out] data On success, the key domain parameters.
* \param data_size Size of the \p data buffer in bytes.
* The buffer is guaranteed to be large
* enough if its size in bytes is at least
* the value given by
* PSA_KEY_DOMAIN_PARAMETERS_SIZE().
* \param[out] data_length On success, the number of bytes
* that make up the key domain parameters data.
*
* \retval #PSA_SUCCESS
* \retval #PSA_ERROR_BUFFER_TOO_SMALL
*/
psa_status_t psa_get_key_domain_parameters(
const psa_key_attributes_t *attributes,
uint8_t *data,
size_t data_size,
size_t *data_length);
/** Safe output buffer size for psa_get_key_domain_parameters().
*
* This macro returns a compile-time constant if its arguments are
* compile-time constants.
*
* \warning This function may call its arguments multiple times or
* zero times, so you should not pass arguments that contain
* side effects.
*
* \note This is an experimental extension to the interface. It may change
* in future versions of the library.
*
* \param key_type A supported key type.
* \param key_bits The size of the key in bits.
*
* \return If the parameters are valid and supported, return
* a buffer size in bytes that guarantees that
* psa_get_key_domain_parameters() will not fail with
* #PSA_ERROR_BUFFER_TOO_SMALL.
* If the parameters are a valid combination that is not supported
* by the implementation, this macro either shall return either a
* sensible size or 0.
* If the parameters are not valid, the
* return value is unspecified.
*/
#define PSA_KEY_DOMAIN_PARAMETERS_SIZE(key_type, key_bits) \
(PSA_KEY_TYPE_IS_RSA(key_type) ? sizeof(int) : \
PSA_KEY_TYPE_IS_DH(key_type) ? PSA_DH_KEY_DOMAIN_PARAMETERS_SIZE(key_bits) : \
PSA_KEY_TYPE_IS_DSA(key_type) ? PSA_DSA_KEY_DOMAIN_PARAMETERS_SIZE(key_bits) : \
0)
#define PSA_DH_KEY_DOMAIN_PARAMETERS_SIZE(key_bits) \
(4 + (PSA_BITS_TO_BYTES(key_bits) + 5) * 3 /*without optional parts*/)
#define PSA_DSA_KEY_DOMAIN_PARAMETERS_SIZE(key_bits) \
(4 + (PSA_BITS_TO_BYTES(key_bits) + 5) * 2 /*p, g*/ + 34 /*q*/)
/**@}*/
#ifdef __cplusplus
}
#endif
#endif /* PSA_CRYPTO_EXTRA_H */