mbedtls/include/psa/crypto_se_driver.h
Gilles Peskine f03143a4d1 Change driver key slot numbers to 64 bits
This slightly increases storage requirements, but works in more use
cases. In particular, it allows drivers to treat choose slot numbers
with a monotonic counter that is incremented each time a key is
created, without worrying about overflow in practice.
2019-07-12 23:18:29 +02:00

1055 lines
49 KiB
C

/**
* \file psa/crypto_se_driver.h
* \brief PSA external cryptoprocessor driver module
*
* This header declares types and function signatures for cryptography
* drivers that access key material via opaque references.
* This is meant for cryptoprocessors that have a separate key storage from the
* space in which the PSA Crypto implementation runs, typically secure
* elements (SEs).
*
* This file is part of the PSA Crypto Driver HAL (hardware abstraction layer),
* containing functions for driver developers to implement to enable hardware
* to be called in a standardized way by a PSA Cryptography API
* implementation. The functions comprising the driver HAL, which driver
* authors implement, are not intended to be called by application developers.
*/
/*
* 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.
*/
#ifndef PSA_CRYPTO_SE_DRIVER_H
#define PSA_CRYPTO_SE_DRIVER_H
#include "crypto_driver_common.h"
#ifdef __cplusplus
extern "C" {
#endif
/** An internal designation of a key slot between the core part of the
* PSA Crypto implementation and the driver. The meaning of this value
* is driver-dependent. */
typedef uint64_t psa_key_slot_number_t;
/** \defgroup se_mac Secure Element Message Authentication Codes
* Generation and authentication of Message Authentication Codes (MACs) using
* a secure element can be done either as a single function call (via the
* `psa_drv_se_mac_generate_t` or `psa_drv_se_mac_verify_t` functions), or in
* parts using the following sequence:
* - `psa_drv_se_mac_setup_t`
* - `psa_drv_se_mac_update_t`
* - `psa_drv_se_mac_update_t`
* - ...
* - `psa_drv_se_mac_finish_t` or `psa_drv_se_mac_finish_verify_t`
*
* If a previously started secure element MAC operation needs to be terminated,
* it should be done so by the `psa_drv_se_mac_abort_t`. Failure to do so may
* result in allocated resources not being freed or in other undefined
* behavior.
*/
/**@{*/
/** \brief A function that starts a secure element MAC operation for a PSA
* Crypto Driver implementation
*
* \param[in,out] p_context A structure that will contain the
* hardware-specific MAC context
* \param[in] key_slot The slot of the key to be used for the
* operation
* \param[in] algorithm The algorithm to be used to underly the MAC
* operation
*
* \retval PSA_SUCCESS
* Success.
*/
typedef psa_status_t (*psa_drv_se_mac_setup_t)(void *p_context,
psa_key_slot_number_t key_slot,
psa_algorithm_t algorithm);
/** \brief A function that continues a previously started secure element MAC
* operation
*
* \param[in,out] p_context A hardware-specific structure for the
* previously-established MAC operation to be
* updated
* \param[in] p_input A buffer containing the message to be appended
* to the MAC operation
* \param[in] input_length The size in bytes of the input message buffer
*/
typedef psa_status_t (*psa_drv_se_mac_update_t)(void *p_context,
const uint8_t *p_input,
size_t input_length);
/** \brief a function that completes a previously started secure element MAC
* operation by returning the resulting MAC.
*
* \param[in,out] p_context A hardware-specific structure for the
* previously started MAC operation to be
* finished
* \param[out] p_mac A buffer where the generated MAC will be
* placed
* \param[in] mac_size The size in bytes of the buffer that has been
* allocated for the `output` buffer
* \param[out] p_mac_length After completion, will contain the number of
* bytes placed in the `p_mac` buffer
*
* \retval PSA_SUCCESS
* Success.
*/
typedef psa_status_t (*psa_drv_se_mac_finish_t)(void *p_context,
uint8_t *p_mac,
size_t mac_size,
size_t *p_mac_length);
/** \brief A function that completes a previously started secure element MAC
* operation by comparing the resulting MAC against a provided value
*
* \param[in,out] p_context A hardware-specific structure for the previously
* started MAC operation to be fiinished
* \param[in] p_mac The MAC value against which the resulting MAC will
* be compared against
* \param[in] mac_length The size in bytes of the value stored in `p_mac`
*
* \retval PSA_SUCCESS
* The operation completed successfully and the MACs matched each
* other
* \retval PSA_ERROR_INVALID_SIGNATURE
* The operation completed successfully, but the calculated MAC did
* not match the provided MAC
*/
typedef psa_status_t (*psa_drv_se_mac_finish_verify_t)(void *p_context,
const uint8_t *p_mac,
size_t mac_length);
/** \brief A function that aborts a previous started secure element MAC
* operation
*
* \param[in,out] p_context A hardware-specific structure for the previously
* started MAC operation to be aborted
*/
typedef psa_status_t (*psa_drv_se_mac_abort_t)(void *p_context);
/** \brief A function that performs a secure element MAC operation in one
* command and returns the calculated MAC
*
* \param[in] p_input A buffer containing the message to be MACed
* \param[in] input_length The size in bytes of `p_input`
* \param[in] key_slot The slot of the key to be used
* \param[in] alg The algorithm to be used to underlie the MAC
* operation
* \param[out] p_mac A buffer where the generated MAC will be
* placed
* \param[in] mac_size The size in bytes of the `p_mac` buffer
* \param[out] p_mac_length After completion, will contain the number of
* bytes placed in the `output` buffer
*
* \retval PSA_SUCCESS
* Success.
*/
typedef psa_status_t (*psa_drv_se_mac_generate_t)(const uint8_t *p_input,
size_t input_length,
psa_key_slot_number_t key_slot,
psa_algorithm_t alg,
uint8_t *p_mac,
size_t mac_size,
size_t *p_mac_length);
/** \brief A function that performs a secure element MAC operation in one
* command and compares the resulting MAC against a provided value
*
* \param[in] p_input A buffer containing the message to be MACed
* \param[in] input_length The size in bytes of `input`
* \param[in] key_slot The slot of the key to be used
* \param[in] alg The algorithm to be used to underlie the MAC
* operation
* \param[in] p_mac The MAC value against which the resulting MAC will
* be compared against
* \param[in] mac_length The size in bytes of `mac`
*
* \retval PSA_SUCCESS
* The operation completed successfully and the MACs matched each
* other
* \retval PSA_ERROR_INVALID_SIGNATURE
* The operation completed successfully, but the calculated MAC did
* not match the provided MAC
*/
typedef psa_status_t (*psa_drv_se_mac_verify_t)(const uint8_t *p_input,
size_t input_length,
psa_key_slot_number_t key_slot,
psa_algorithm_t alg,
const uint8_t *p_mac,
size_t mac_length);
/** \brief A struct containing all of the function pointers needed to
* perform secure element MAC operations
*
* PSA Crypto API implementations should populate the table as appropriate
* upon startup.
*
* If one of the functions is not implemented (such as
* `psa_drv_se_mac_generate_t`), it should be set to NULL.
*
* Driver implementers should ensure that they implement all of the functions
* that make sense for their hardware, and that they provide a full solution
* (for example, if they support `p_setup`, they should also support
* `p_update` and at least one of `p_finish` or `p_finish_verify`).
*
*/
typedef struct {
/**The size in bytes of the hardware-specific secure element MAC context
* structure
*/
size_t context_size;
/** Function that performs a MAC setup operation
*/
psa_drv_se_mac_setup_t p_setup;
/** Function that performs a MAC update operation
*/
psa_drv_se_mac_update_t p_update;
/** Function that completes a MAC operation
*/
psa_drv_se_mac_finish_t p_finish;
/** Function that completes a MAC operation with a verify check
*/
psa_drv_se_mac_finish_verify_t p_finish_verify;
/** Function that aborts a previoustly started MAC operation
*/
psa_drv_se_mac_abort_t p_abort;
/** Function that performs a MAC operation in one call
*/
psa_drv_se_mac_generate_t p_mac;
/** Function that performs a MAC and verify operation in one call
*/
psa_drv_se_mac_verify_t p_mac_verify;
} psa_drv_se_mac_t;
/**@}*/
/** \defgroup se_cipher Secure Element Symmetric Ciphers
*
* Encryption and Decryption using secure element keys in block modes other
* than ECB must be done in multiple parts, using the following flow:
* - `psa_drv_se_cipher_setup_t`
* - `psa_drv_se_cipher_set_iv_t` (optional depending upon block mode)
* - `psa_drv_se_cipher_update_t`
* - `psa_drv_se_cipher_update_t`
* - ...
* - `psa_drv_se_cipher_finish_t`
*
* If a previously started secure element Cipher operation needs to be
* terminated, it should be done so by the `psa_drv_se_cipher_abort_t`. Failure
* to do so may result in allocated resources not being freed or in other
* undefined behavior.
*
* In situations where a PSA Cryptographic API implementation is using a block
* mode not-supported by the underlying hardware or driver, it can construct
* the block mode itself, while calling the `psa_drv_se_cipher_ecb_t` function
* for the cipher operations.
*/
/**@{*/
/** \brief A function that provides the cipher setup function for a
* secure element driver
*
* \param[in,out] p_context A structure that will contain the
* hardware-specific cipher context.
* \param[in] key_slot The slot of the key to be used for the
* operation
* \param[in] algorithm The algorithm to be used in the cipher
* operation
* \param[in] direction Indicates whether the operation is an encrypt
* or decrypt
*
* \retval PSA_SUCCESS
* \retval PSA_ERROR_NOT_SUPPORTED
*/
typedef psa_status_t (*psa_drv_se_cipher_setup_t)(void *p_context,
psa_key_slot_number_t key_slot,
psa_algorithm_t algorithm,
psa_encrypt_or_decrypt_t direction);
/** \brief A function that sets the initialization vector (if
* necessary) for an secure element cipher operation
*
* Rationale: The `psa_se_cipher_*` operation in the PSA Cryptographic API has
* two IV functions: one to set the IV, and one to generate it internally. The
* generate function is not necessary for the drivers to implement as the PSA
* Crypto implementation can do the generation using its RNG features.
*
* \param[in,out] p_context A structure that contains the previously set up
* hardware-specific cipher context
* \param[in] p_iv A buffer containing the initialization vector
* \param[in] iv_length The size (in bytes) of the `p_iv` buffer
*
* \retval PSA_SUCCESS
*/
typedef psa_status_t (*psa_drv_se_cipher_set_iv_t)(void *p_context,
const uint8_t *p_iv,
size_t iv_length);
/** \brief A function that continues a previously started secure element cipher
* operation
*
* \param[in,out] p_context A hardware-specific structure for the
* previously started cipher operation
* \param[in] p_input A buffer containing the data to be
* encrypted/decrypted
* \param[in] input_size The size in bytes of the buffer pointed to
* by `p_input`
* \param[out] p_output The caller-allocated buffer where the
* output will be placed
* \param[in] output_size The allocated size in bytes of the
* `p_output` buffer
* \param[out] p_output_length After completion, will contain the number
* of bytes placed in the `p_output` buffer
*
* \retval PSA_SUCCESS
*/
typedef psa_status_t (*psa_drv_se_cipher_update_t)(void *p_context,
const uint8_t *p_input,
size_t input_size,
uint8_t *p_output,
size_t output_size,
size_t *p_output_length);
/** \brief A function that completes a previously started secure element cipher
* operation
*
* \param[in,out] p_context A hardware-specific structure for the
* previously started cipher operation
* \param[out] p_output The caller-allocated buffer where the output
* will be placed
* \param[in] output_size The allocated size in bytes of the `p_output`
* buffer
* \param[out] p_output_length After completion, will contain the number of
* bytes placed in the `p_output` buffer
*
* \retval PSA_SUCCESS
*/
typedef psa_status_t (*psa_drv_se_cipher_finish_t)(void *p_context,
uint8_t *p_output,
size_t output_size,
size_t *p_output_length);
/** \brief A function that aborts a previously started secure element cipher
* operation
*
* \param[in,out] p_context A hardware-specific structure for the
* previously started cipher operation
*/
typedef psa_status_t (*psa_drv_se_cipher_abort_t)(void *p_context);
/** \brief A function that performs the ECB block mode for secure element
* cipher operations
*
* Note: this function should only be used with implementations that do not
* provide a needed higher-level operation.
*
* \param[in] key_slot The slot of the key to be used for the operation
* \param[in] algorithm The algorithm to be used in the cipher operation
* \param[in] direction Indicates whether the operation is an encrypt or
* decrypt
* \param[in] p_input A buffer containing the data to be
* encrypted/decrypted
* \param[in] input_size The size in bytes of the buffer pointed to by
* `p_input`
* \param[out] p_output The caller-allocated buffer where the output will
* be placed
* \param[in] output_size The allocated size in bytes of the `p_output`
* buffer
*
* \retval PSA_SUCCESS
* \retval PSA_ERROR_NOT_SUPPORTED
*/
typedef psa_status_t (*psa_drv_se_cipher_ecb_t)(psa_key_slot_number_t key_slot,
psa_algorithm_t algorithm,
psa_encrypt_or_decrypt_t direction,
const uint8_t *p_input,
size_t input_size,
uint8_t *p_output,
size_t output_size);
/**
* \brief A struct containing all of the function pointers needed to implement
* cipher operations using secure elements.
*
* PSA Crypto API implementations should populate instances of the table as
* appropriate upon startup or at build time.
*
* If one of the functions is not implemented (such as
* `psa_drv_se_cipher_ecb_t`), it should be set to NULL.
*/
typedef struct {
/** The size in bytes of the hardware-specific secure element cipher
* context structure
*/
size_t context_size;
/** Function that performs a cipher setup operation */
psa_drv_se_cipher_setup_t p_setup;
/** Function that sets a cipher IV (if necessary) */
psa_drv_se_cipher_set_iv_t p_set_iv;
/** Function that performs a cipher update operation */
psa_drv_se_cipher_update_t p_update;
/** Function that completes a cipher operation */
psa_drv_se_cipher_finish_t p_finish;
/** Function that aborts a cipher operation */
psa_drv_se_cipher_abort_t p_abort;
/** Function that performs ECB mode for a cipher operation
* (Danger: ECB mode should not be used directly by clients of the PSA
* Crypto Client API)
*/
psa_drv_se_cipher_ecb_t p_ecb;
} psa_drv_se_cipher_t;
/**@}*/
/** \defgroup se_asymmetric Secure Element Asymmetric Cryptography
*
* Since the amount of data that can (or should) be encrypted or signed using
* asymmetric keys is limited by the key size, asymmetric key operations using
* keys in a secure element must be done in single function calls.
*/
/**@{*/
/**
* \brief A function that signs a hash or short message with a private key in
* a secure element
*
* \param[in] key_slot Key slot of an asymmetric key pair
* \param[in] alg A signature algorithm that is compatible
* with the type of `key`
* \param[in] p_hash The hash to sign
* \param[in] hash_length Size of the `p_hash` buffer in bytes
* \param[out] p_signature Buffer where the signature is to be written
* \param[in] signature_size Size of the `p_signature` buffer in bytes
* \param[out] p_signature_length On success, the number of bytes
* that make up the returned signature value
*
* \retval PSA_SUCCESS
*/
typedef psa_status_t (*psa_drv_se_asymmetric_sign_t)(psa_key_slot_number_t key_slot,
psa_algorithm_t alg,
const uint8_t *p_hash,
size_t hash_length,
uint8_t *p_signature,
size_t signature_size,
size_t *p_signature_length);
/**
* \brief A function that verifies the signature a hash or short message using
* an asymmetric public key in a secure element
*
* \param[in] key_slot Key slot of a public key or an asymmetric key
* pair
* \param[in] alg A signature algorithm that is compatible with
* the type of `key`
* \param[in] p_hash The hash whose signature is to be verified
* \param[in] hash_length Size of the `p_hash` buffer in bytes
* \param[in] p_signature Buffer containing the signature to verify
* \param[in] signature_length Size of the `p_signature` buffer in bytes
*
* \retval PSA_SUCCESS
* The signature is valid.
*/
typedef psa_status_t (*psa_drv_se_asymmetric_verify_t)(psa_key_slot_number_t key_slot,
psa_algorithm_t alg,
const uint8_t *p_hash,
size_t hash_length,
const uint8_t *p_signature,
size_t signature_length);
/**
* \brief A function that encrypts a short message with an asymmetric public
* key in a secure element
*
* \param[in] key_slot Key slot of a public key or an asymmetric key
* pair
* \param[in] alg An asymmetric encryption algorithm that is
* compatible with the type of `key`
* \param[in] p_input The message to encrypt
* \param[in] input_length Size of the `p_input` buffer in bytes
* \param[in] p_salt A salt or label, if supported by the
* encryption algorithm
* If the algorithm does not support a
* salt, pass `NULL`.
* If the algorithm supports an optional
* salt and you do not want to pass a salt,
* pass `NULL`.
* For #PSA_ALG_RSA_PKCS1V15_CRYPT, no salt is
* supported.
* \param[in] salt_length Size of the `p_salt` buffer in bytes
* If `p_salt` is `NULL`, pass 0.
* \param[out] p_output Buffer where the encrypted message is to
* be written
* \param[in] output_size Size of the `p_output` buffer in bytes
* \param[out] p_output_length On success, the number of bytes that make up
* the returned output
*
* \retval PSA_SUCCESS
*/
typedef psa_status_t (*psa_drv_se_asymmetric_encrypt_t)(psa_key_slot_number_t key_slot,
psa_algorithm_t alg,
const uint8_t *p_input,
size_t input_length,
const uint8_t *p_salt,
size_t salt_length,
uint8_t *p_output,
size_t output_size,
size_t *p_output_length);
/**
* \brief A function that decrypts a short message with an asymmetric private
* key in a secure element.
*
* \param[in] key_slot Key slot of an asymmetric key pair
* \param[in] alg An asymmetric encryption algorithm that is
* compatible with the type of `key`
* \param[in] p_input The message to decrypt
* \param[in] input_length Size of the `p_input` buffer in bytes
* \param[in] p_salt A salt or label, if supported by the
* encryption algorithm
* If the algorithm does not support a
* salt, pass `NULL`.
* If the algorithm supports an optional
* salt and you do not want to pass a salt,
* pass `NULL`.
* For #PSA_ALG_RSA_PKCS1V15_CRYPT, no salt is
* supported.
* \param[in] salt_length Size of the `p_salt` buffer in bytes
* If `p_salt` is `NULL`, pass 0.
* \param[out] p_output Buffer where the decrypted message is to
* be written
* \param[in] output_size Size of the `p_output` buffer in bytes
* \param[out] p_output_length On success, the number of bytes
* that make up the returned output
*
* \retval PSA_SUCCESS
*/
typedef psa_status_t (*psa_drv_se_asymmetric_decrypt_t)(psa_key_slot_number_t key_slot,
psa_algorithm_t alg,
const uint8_t *p_input,
size_t input_length,
const uint8_t *p_salt,
size_t salt_length,
uint8_t *p_output,
size_t output_size,
size_t *p_output_length);
/**
* \brief A struct containing all of the function pointers needed to implement
* asymmetric cryptographic operations using secure elements.
*
* PSA Crypto API implementations should populate instances of the table as
* appropriate upon startup or at build time.
*
* If one of the functions is not implemented, it should be set to NULL.
*/
typedef struct {
/** Function that performs an asymmetric sign operation */
psa_drv_se_asymmetric_sign_t p_sign;
/** Function that performs an asymmetric verify operation */
psa_drv_se_asymmetric_verify_t p_verify;
/** Function that performs an asymmetric encrypt operation */
psa_drv_se_asymmetric_encrypt_t p_encrypt;
/** Function that performs an asymmetric decrypt operation */
psa_drv_se_asymmetric_decrypt_t p_decrypt;
} psa_drv_se_asymmetric_t;
/**@}*/
/** \defgroup se_aead Secure Element Authenticated Encryption with Additional Data
* Authenticated Encryption with Additional Data (AEAD) operations with secure
* elements must be done in one function call. While this creates a burden for
* implementers as there must be sufficient space in memory for the entire
* message, it prevents decrypted data from being made available before the
* authentication operation is complete and the data is known to be authentic.
*/
/**@{*/
/** \brief A function that performs a secure element authenticated encryption
* operation
*
* \param[in] key_slot Slot containing the key to use.
* \param[in] algorithm The AEAD algorithm to compute
* (\c PSA_ALG_XXX value such that
* #PSA_ALG_IS_AEAD(`alg`) is true)
* \param[in] p_nonce Nonce or IV to use
* \param[in] nonce_length Size of the `p_nonce` buffer in bytes
* \param[in] p_additional_data Additional data that will be
* authenticated but not encrypted
* \param[in] additional_data_length Size of `p_additional_data` in bytes
* \param[in] p_plaintext Data that will be authenticated and
* encrypted
* \param[in] plaintext_length Size of `p_plaintext` in bytes
* \param[out] p_ciphertext Output buffer for the authenticated and
* encrypted data. The additional data is
* not part of this output. For algorithms
* where the encrypted data and the
* authentication tag are defined as
* separate outputs, the authentication
* tag is appended to the encrypted data.
* \param[in] ciphertext_size Size of the `p_ciphertext` buffer in
* bytes
* \param[out] p_ciphertext_length On success, the size of the output in
* the `p_ciphertext` buffer
*
* \retval #PSA_SUCCESS
* Success.
*/
typedef psa_status_t (*psa_drv_se_aead_encrypt_t)(psa_key_slot_number_t key_slot,
psa_algorithm_t algorithm,
const uint8_t *p_nonce,
size_t nonce_length,
const uint8_t *p_additional_data,
size_t additional_data_length,
const uint8_t *p_plaintext,
size_t plaintext_length,
uint8_t *p_ciphertext,
size_t ciphertext_size,
size_t *p_ciphertext_length);
/** A function that peforms a secure element authenticated decryption operation
*
* \param[in] key_slot Slot containing the key to use
* \param[in] algorithm The AEAD algorithm to compute
* (\c PSA_ALG_XXX value such that
* #PSA_ALG_IS_AEAD(`alg`) is true)
* \param[in] p_nonce Nonce or IV to use
* \param[in] nonce_length Size of the `p_nonce` buffer in bytes
* \param[in] p_additional_data Additional data that has been
* authenticated but not encrypted
* \param[in] additional_data_length Size of `p_additional_data` in bytes
* \param[in] p_ciphertext Data that has been authenticated and
* encrypted.
* For algorithms where the encrypted data
* and the authentication tag are defined
* as separate inputs, the buffer must
* contain the encrypted data followed by
* the authentication tag.
* \param[in] ciphertext_length Size of `p_ciphertext` in bytes
* \param[out] p_plaintext Output buffer for the decrypted data
* \param[in] plaintext_size Size of the `p_plaintext` buffer in
* bytes
* \param[out] p_plaintext_length On success, the size of the output in
* the `p_plaintext` buffer
*
* \retval #PSA_SUCCESS
* Success.
*/
typedef psa_status_t (*psa_drv_se_aead_decrypt_t)(psa_key_slot_number_t key_slot,
psa_algorithm_t algorithm,
const uint8_t *p_nonce,
size_t nonce_length,
const uint8_t *p_additional_data,
size_t additional_data_length,
const uint8_t *p_ciphertext,
size_t ciphertext_length,
uint8_t *p_plaintext,
size_t plaintext_size,
size_t *p_plaintext_length);
/**
* \brief A struct containing all of the function pointers needed to implement
* secure element Authenticated Encryption with Additional Data operations
*
* PSA Crypto API implementations should populate instances of the table as
* appropriate upon startup.
*
* If one of the functions is not implemented, it should be set to NULL.
*/
typedef struct {
/** Function that performs the AEAD encrypt operation */
psa_drv_se_aead_encrypt_t p_encrypt;
/** Function that performs the AEAD decrypt operation */
psa_drv_se_aead_decrypt_t p_decrypt;
} psa_drv_se_aead_t;
/**@}*/
/** \defgroup se_key_management Secure Element Key Management
* Currently, key management is limited to importing keys in the clear,
* destroying keys, and exporting keys in the clear.
* Whether a key may be exported is determined by the key policies in place
* on the key slot.
*/
/**@{*/
/** \brief A function that imports a key into a secure element in binary format
*
* This function can support any output from psa_export_key(). Refer to the
* documentation of psa_export_key() for the format for each key type.
*
* \param[in] key_slot Slot where the key will be stored
* This must be a valid slot for a key of the chosen
* type. It must be unoccupied.
* \param[in] lifetime The required lifetime of the key storage
* \param[in] type Key type (a \c PSA_KEY_TYPE_XXX value)
* \param[in] algorithm Key algorithm (a \c PSA_ALG_XXX value)
* \param[in] usage The allowed uses of the key
* \param[in] p_data Buffer containing the key data
* \param[in] data_length Size of the `data` buffer in bytes
*
* \retval #PSA_SUCCESS
* Success.
*/
typedef psa_status_t (*psa_drv_se_import_key_t)(psa_key_slot_number_t key_slot,
psa_key_lifetime_t lifetime,
psa_key_type_t type,
psa_algorithm_t algorithm,
psa_key_usage_t usage,
const uint8_t *p_data,
size_t data_length);
/**
* \brief A function that destroys a secure element key and restore the slot to
* its default state
*
* This function destroys the content of the key from a secure element.
* Implementations shall make a best effort to ensure that any previous content
* of the slot is unrecoverable.
*
* This function returns the specified slot to its default state.
*
* \param[in] key_slot The key slot to erase.
*
* \retval #PSA_SUCCESS
* The slot's content, if any, has been erased.
*/
typedef psa_status_t (*psa_drv_se_destroy_key_t)(psa_key_slot_number_t key_slot);
/**
* \brief A function that exports a secure element key in binary format
*
* The output of this function can be passed to psa_import_key() to
* create an equivalent object.
*
* If a key is created with `psa_import_key()` and then exported with
* this function, it is not guaranteed that the resulting data is
* identical: the implementation may choose a different representation
* of the same key if the format permits it.
*
* This function should generate output in the same format that
* `psa_export_key()` does. Refer to the
* documentation of `psa_export_key()` for the format for each key type.
*
* \param[in] key Slot whose content is to be exported. This must
* be an occupied key slot.
* \param[out] p_data Buffer where the key data is to be written.
* \param[in] data_size Size of the `p_data` buffer in bytes.
* \param[out] p_data_length On success, the number of bytes
* that make up the key data.
*
* \retval #PSA_SUCCESS
* \retval #PSA_ERROR_DOES_NOT_EXIST
* \retval #PSA_ERROR_NOT_PERMITTED
* \retval #PSA_ERROR_NOT_SUPPORTED
* \retval #PSA_ERROR_COMMUNICATION_FAILURE
* \retval #PSA_ERROR_HARDWARE_FAILURE
* \retval #PSA_ERROR_CORRUPTION_DETECTED
*/
typedef psa_status_t (*psa_drv_se_export_key_t)(psa_key_slot_number_t key,
uint8_t *p_data,
size_t data_size,
size_t *p_data_length);
/**
* \brief A function that generates a symmetric or asymmetric key on a secure
* element
*
* If \p type is asymmetric (`#PSA_KEY_TYPE_IS_ASYMMETRIC(\p type) == 1`),
* the public component of the generated key will be placed in `p_pubkey_out`.
* The format of the public key information will match the format specified for
* the psa_export_key() function for the key type.
*
* \param[in] key_slot Slot where the generated key will be placed
* \param[in] type The type of the key to be generated
* \param[in] usage The prescribed usage of the generated key
* Note: Not all Secure Elements support the same
* restrictions that PSA Crypto does (and vice versa).
* Driver developers should endeavor to match the
* usages as close as possible.
* \param[in] bits The size in bits of the key to be generated.
* \param[in] extra Extra parameters for key generation. The
* interpretation of this parameter should match the
* interpretation in the `extra` parameter is the
* `psa_generate_key` function
* \param[in] extra_size The size in bytes of the \p extra buffer
* \param[out] p_pubkey_out The buffer where the public key information will
* be placed
* \param[in] pubkey_out_size The size in bytes of the `p_pubkey_out` buffer
* \param[out] p_pubkey_length Upon successful completion, will contain the
* size of the data placed in `p_pubkey_out`.
*/
typedef psa_status_t (*psa_drv_se_generate_key_t)(psa_key_slot_number_t key_slot,
psa_key_type_t type,
psa_key_usage_t usage,
size_t bits,
const void *extra,
size_t extra_size,
uint8_t *p_pubkey_out,
size_t pubkey_out_size,
size_t *p_pubkey_length);
/**
* \brief A struct containing all of the function pointers needed to for secure
* element key management
*
* PSA Crypto API implementations should populate instances of the table as
* appropriate upon startup or at build time.
*
* If one of the functions is not implemented, it should be set to NULL.
*/
typedef struct {
/** Function that performs a key import operation */
psa_drv_se_import_key_t p_import;
/** Function that performs a generation */
psa_drv_se_generate_key_t p_generate;
/** Function that performs a key destroy operation */
psa_drv_se_destroy_key_t p_destroy;
/** Function that performs a key export operation */
psa_drv_se_export_key_t p_export;
/** Function that performs a public key export operation */
psa_drv_se_export_key_t p_export_public;
} psa_drv_se_key_management_t;
/**@}*/
/** \defgroup driver_derivation Secure Element Key Derivation and Agreement
* Key derivation is the process of generating new key material using an
* existing key and additional parameters, iterating through a basic
* cryptographic function, such as a hash.
* Key agreement is a part of cryptographic protocols that allows two parties
* to agree on the same key value, but starting from different original key
* material.
* The flows are similar, and the PSA Crypto Driver Model uses the same functions
* for both of the flows.
*
* There are two different final functions for the flows,
* `psa_drv_se_key_derivation_derive` and `psa_drv_se_key_derivation_export`.
* `psa_drv_se_key_derivation_derive` is used when the key material should be
* placed in a slot on the hardware and not exposed to the caller.
* `psa_drv_se_key_derivation_export` is used when the key material should be
* returned to the PSA Cryptographic API implementation.
*
* Different key derivation algorithms require a different number of inputs.
* Instead of having an API that takes as input variable length arrays, which
* can be problemmatic to manage on embedded platforms, the inputs are passed
* to the driver via a function, `psa_drv_se_key_derivation_collateral`, that
* is called multiple times with different `collateral_id`s. Thus, for a key
* derivation algorithm that required 3 paramter inputs, the flow would look
* something like:
* ~~~~~~~~~~~~~{.c}
* psa_drv_se_key_derivation_setup(kdf_algorithm, source_key, dest_key_size_bytes);
* psa_drv_se_key_derivation_collateral(kdf_algorithm_collateral_id_0,
* p_collateral_0,
* collateral_0_size);
* psa_drv_se_key_derivation_collateral(kdf_algorithm_collateral_id_1,
* p_collateral_1,
* collateral_1_size);
* psa_drv_se_key_derivation_collateral(kdf_algorithm_collateral_id_2,
* p_collateral_2,
* collateral_2_size);
* psa_drv_se_key_derivation_derive();
* ~~~~~~~~~~~~~
*
* key agreement example:
* ~~~~~~~~~~~~~{.c}
* psa_drv_se_key_derivation_setup(alg, source_key. dest_key_size_bytes);
* psa_drv_se_key_derivation_collateral(DHE_PUBKEY, p_pubkey, pubkey_size);
* psa_drv_se_key_derivation_export(p_session_key,
* session_key_size,
* &session_key_length);
* ~~~~~~~~~~~~~
*/
/**@{*/
/** \brief A function that Sets up a secure element key derivation operation by
* specifying the algorithm and the source key sot
*
* \param[in,out] p_context A hardware-specific structure containing any
* context information for the implementation
* \param[in] kdf_alg The algorithm to be used for the key derivation
* \param[in] source_key The key to be used as the source material for the
* key derivation
*
* \retval PSA_SUCCESS
*/
typedef psa_status_t (*psa_drv_se_key_derivation_setup_t)(void *p_context,
psa_algorithm_t kdf_alg,
psa_key_slot_number_t source_key);
/** \brief A function that provides collateral (parameters) needed for a secure
* element key derivation or key agreement operation
*
* Since many key derivation algorithms require multiple parameters, it is
* expeced that this function may be called multiple times for the same
* operation, each with a different algorithm-specific `collateral_id`
*
* \param[in,out] p_context A hardware-specific structure containing any
* context information for the implementation
* \param[in] collateral_id An ID for the collateral being provided
* \param[in] p_collateral A buffer containing the collateral data
* \param[in] collateral_size The size in bytes of the collateral
*
* \retval PSA_SUCCESS
*/
typedef psa_status_t (*psa_drv_se_key_derivation_collateral_t)(void *p_context,
uint32_t collateral_id,
const uint8_t *p_collateral,
size_t collateral_size);
/** \brief A function that performs the final secure element key derivation
* step and place the generated key material in a slot
*
* \param[in,out] p_context A hardware-specific structure containing any
* context information for the implementation
* \param[in] dest_key The slot where the generated key material
* should be placed
*
* \retval PSA_SUCCESS
*/
typedef psa_status_t (*psa_drv_se_key_derivation_derive_t)(void *p_context,
psa_key_slot_number_t dest_key);
/** \brief A function that performs the final step of a secure element key
* agreement and place the generated key material in a buffer
*
* \param[out] p_output Buffer in which to place the generated key
* material
* \param[in] output_size The size in bytes of `p_output`
* \param[out] p_output_length Upon success, contains the number of bytes of
* key material placed in `p_output`
*
* \retval PSA_SUCCESS
*/
typedef psa_status_t (*psa_drv_se_key_derivation_export_t)(void *p_context,
uint8_t *p_output,
size_t output_size,
size_t *p_output_length);
/**
* \brief A struct containing all of the function pointers needed to for secure
* element key derivation and agreement
*
* PSA Crypto API implementations should populate instances of the table as
* appropriate upon startup.
*
* If one of the functions is not implemented, it should be set to NULL.
*/
typedef struct {
/** The driver-specific size of the key derivation context */
size_t context_size;
/** Function that performs a key derivation setup */
psa_drv_se_key_derivation_setup_t p_setup;
/** Function that sets key derivation collateral */
psa_drv_se_key_derivation_collateral_t p_collateral;
/** Function that performs a final key derivation step */
psa_drv_se_key_derivation_derive_t p_derive;
/** Function that perforsm a final key derivation or agreement and
* exports the key */
psa_drv_se_key_derivation_export_t p_export;
} psa_drv_se_key_derivation_t;
/**@}*/
/** \defgroup se_registration Secure element driver registration
*/
/**@{*/
/** A structure containing pointers to all the entry points of a
* secure element driver.
*
* Future versions of this specification may add extra substructures at
* the end of this structure.
*/
typedef struct {
/** The version of the driver HAL that this driver implements.
* This is a protection against loading driver binaries built against
* a different version of this specification.
* Use #PSA_DRV_SE_HAL_VERSION.
*/
uint32_t hal_version;
const psa_drv_se_key_management_t *key_management;
const psa_drv_se_mac_t *mac;
const psa_drv_se_cipher_t *cipher;
const psa_drv_se_aead_t *aead;
const psa_drv_se_asymmetric_t *asymmetric;
const psa_drv_se_key_derivation_t *derivation;
} psa_drv_se_t;
/** The current version of the secure element driver HAL.
*/
/* 0.0.0 patchlevel 5 */
#define PSA_DRV_SE_HAL_VERSION 0x00000005
/** Register an external cryptoprocessor (secure element) driver.
*
* This function is only intended to be used by driver code, not by
* application code. In implementations with separation between the
* PSA cryptography module and applications, this function should
* only be available to callers that run in the same memory space as
* the cryptography module, and should not be exposed to applications
* running in a different memory space.
*
* This function may be called before psa_crypto_init(). It is
* implementation-defined whether this function may be called
* after psa_crypto_init().
*
* \note Implementations store metadata about keys including the lifetime
* value. Therefore, from one instantiation of the PSA Cryptography
* library to the next one, if there is a key in storage with a certain
* lifetime value, you must always register the same driver (or an
* updated version that communicates with the same secure element)
* with the same lifetime value.
*
* \param lifetime The lifetime value through which this driver will
* be exposed to applications.
* The values #PSA_KEY_LIFETIME_VOLATILE and
* #PSA_KEY_LIFETIME_PERSISTENT are reserved and
* may not be used for drivers. Implementations
* may reserve other values.
* \param[in] methods The method table of the driver. This structure must
* remain valid for as long as the cryptography
* module keeps running. It is typically a global
* constant.
*
* \return PSA_SUCCESS
* The driver was successfully registered. Applications can now
* use \p lifetime to access keys through the methods passed to
* this function.
* \return PSA_ERROR_BAD_STATE
* This function was called after the initialization of the
* cryptography module, and this implementation does not support
* driver registration at this stage.
* \return PSA_ERROR_ALREADY_EXISTS
* There is already a registered driver for this value of \p lifetime.
* \return PSA_ERROR_INVALID_ARGUMENT
* \p lifetime is a reserved value.
* \return PSA_ERROR_NOT_SUPPORTED
* `methods->hal_version` is not supported by this implementation.
* \return PSA_ERROR_INSUFFICIENT_MEMORY
* \return PSA_ERROR_NOT_PERMITTED
*/
psa_status_t psa_register_se_driver(
psa_key_lifetime_t lifetime,
const psa_drv_se_t *methods);
/**@}*/
#ifdef __cplusplus
}
#endif
#endif /* PSA_CRYPTO_SE_DRIVER_H */