mbedtls/include/psa/crypto_se_driver.h
Gilles Peskine ae9964d3ef Add validate_slot_number method to SE drivers
Pave the way for allowing the application to choose the slot number in
a secure element, rather than always letting the driver choose.
2019-08-08 11:02:30 +02:00

1295 lines
61 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
/** \defgroup se_init Secure element driver initialization
*/
/**@{*/
/** \brief Driver context structure
*
* Driver functions receive a pointer to this structure.
* Each registered driver has one instance of this structure.
*
* Implementations must include the fields specified here and
* may include other fields.
*/
typedef struct {
/** A read-only pointer to the driver's persistent data.
*
* Drivers typically use this persistent data to keep track of
* which slot numbers are available. This is only a guideline:
* drivers may use the persistent data for any purpose, keeping
* in mind the restrictions on when the persistent data is saved
* to storage: the persistent data is only saved after calling
* certain functions that receive a writable pointer to the
* persistent data.
*
* The core allocates a memory buffer for the persistent data.
* The pointer is guaranteed to be suitably aligned for any data type,
* like a pointer returned by `malloc` (but the core can use any
* method to allocate the buffer, not necessarily `malloc`).
*
* The size of this buffer is in the \c persistent_data_size field of
* this structure.
*
* Before the driver is initialized for the first time, the content of
* the persistent data is all-bits-zero. After a driver upgrade, if the
* size of the persistent data has increased, the original data is padded
* on the right with zeros; if the size has decreased, the original data
* is truncated to the new size.
*
* This pointer is to read-only data. Only a few driver functions are
* allowed to modify the persistent data. These functions receive a
* writable pointer. These functions are:
* - psa_drv_se_t::p_init
* - psa_drv_se_key_management_t::p_allocate
* - psa_drv_se_key_management_t::p_destroy
*
* The PSA Cryptography core saves the persistent data from one
* session to the next. It does this before returning from API functions
* that call a driver method that is allowed to modify the persistent
* data, specifically:
* - psa_crypto_init() causes a call to psa_drv_se_t::p_init, and may call
* psa_drv_se_key_management_t::p_destroy to complete an action
* that was interrupted by a power failure.
* - Key creation functions cause a call to
* psa_drv_se_key_management_t::p_allocate, and may cause a call to
* psa_drv_se_key_management_t::p_destroy in case an error occurs.
* - psa_destroy_key() causes a call to
* psa_drv_se_key_management_t::p_destroy.
*/
const void *const persistent_data;
/** The size of \c persistent_data in bytes.
*
* This is always equal to the value of the `persistent_data_size` field
* of the ::psa_drv_se_t structure when the driver is registered.
*/
const size_t persistent_data_size;
/** Driver transient data.
*
* The core initializes this value to 0 and does not read or modify it
* afterwards. The driver may store whatever it wants in this field.
*/
uintptr_t transient_data;
} psa_drv_se_context_t;
/** \brief A driver initialization function.
*
* \param[in,out] drv_context The driver context structure.
* \param[in,out] persistent_data A pointer to the persistent data
* that allows writing.
* \param lifetime The lifetime value for which this driver
* is registered.
*
* \retval #PSA_SUCCESS
* The driver is operational.
* The core will update the persistent data in storage.
* \return
* Any other return value prevents the driver from being used in
* this session.
* The core will NOT update the persistent data in storage.
*/
typedef psa_status_t (*psa_drv_se_init_t)(psa_drv_se_context_t *drv_context,
void *persistent_data,
psa_key_lifetime_t lifetime);
#if defined(__DOXYGEN_ONLY__) || !defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* Mbed Crypto with secure element support enabled 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. */
/** 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;
#endif /* __DOXYGEN_ONLY__ || !MBEDTLS_PSA_CRYPTO_SE_C */
/**@}*/
/** \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] drv_context The driver context structure.
* \param[in,out] op_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)(psa_drv_se_context_t *drv_context,
void *op_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] op_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 *op_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] op_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 *op_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] op_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 *op_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] op_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 *op_context);
/** \brief A function that performs a secure element MAC operation in one
* command and returns the calculated MAC
*
* \param[in,out] drv_context The driver context structure.
* \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)(psa_drv_se_context_t *drv_context,
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,out] drv_context The driver context structure.
* \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)(psa_drv_se_context_t *drv_context,
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] drv_context The driver context structure.
* \param[in,out] op_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)(psa_drv_se_context_t *drv_context,
void *op_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] op_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 *op_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] op_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 *op_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] op_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 *op_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] op_context A hardware-specific structure for the
* previously started cipher operation
*/
typedef psa_status_t (*psa_drv_se_cipher_abort_t)(void *op_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,out] drv_context The driver context structure.
* \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_drv_se_context_t *drv_context,
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,out] drv_context The driver context structure.
* \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_drv_se_context_t *drv_context,
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,out] drv_context The driver context structure.
* \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_drv_se_context_t *drv_context,
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,out] drv_context The driver context structure.
* \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_drv_se_context_t *drv_context,
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,out] drv_context The driver context structure.
* \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_drv_se_context_t *drv_context,
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,out] drv_context The driver context structure.
* \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_drv_se_context_t *drv_context,
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,out] drv_context The driver context structure.
* \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_drv_se_context_t *drv_context,
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 allocates a slot for a key.
*
* \param[in,out] drv_context The driver context structure.
* \param[in,out] persistent_data A pointer to the persistent data
* that allows writing.
* \param[in] attributes Attributes of the key.
* \param[out] 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.
*
* \retval #PSA_SUCCESS
* Success.
* The core will record \c *key_slot as the key slot where the key
* is stored and will update the persistent data in storage.
* \retval #PSA_ERROR_NOT_SUPPORTED
* \retval #PSA_ERROR_INSUFFICIENT_STORAGE
*/
typedef psa_status_t (*psa_drv_se_allocate_key_t)(
psa_drv_se_context_t *drv_context,
void *persistent_data,
const psa_key_attributes_t *attributes,
psa_key_slot_number_t *key_slot);
/** \brief A function that determines whether a slot number is valid
* for a key.
*
* \param[in,out] drv_context The driver context structure.
* \param[in] attributes Attributes of the key.
* \param[in] key_slot Slot where the key is to be stored.
*
* \retval #PSA_SUCCESS
* The given slot number is valid for a key with the given
* attributes.
* \retval #PSA_ERROR_INVALID_ARGUMENT
* The given slot number is not valid for a key with the
* given attributes. This includes the case where the slot
* number is not valid at all.
* \retval #PSA_ERROR_ALREADY_EXISTS
* There is already a key with the specified slot number.
* Drivers may choose to return this error from the key
* creation function instead.
*/
typedef psa_status_t (*psa_drv_se_validate_slot_number_t)(
psa_drv_se_context_t *drv_context,
const psa_key_attributes_t *attributes,
psa_key_slot_number_t 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,out] drv_context The driver context structure.
* \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
* \param[out] bits On success, the key size in bits. The driver
* must determine this value after parsing the
* key according to the key type.
* This value is not used if the function fails.
*
* \retval #PSA_SUCCESS
* Success.
*/
typedef psa_status_t (*psa_drv_se_import_key_t)(psa_drv_se_context_t *drv_context,
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,
size_t *bits);
/**
* \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,out] drv_context The driver context structure.
* \param[in,out] persistent_data A pointer to the persistent data
* that allows writing.
* \param 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_drv_se_context_t *drv_context,
void *persistent_data,
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,out] drv_context The driver context structure.
* \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_drv_se_context_t *drv_context,
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,out] drv_context The driver context structure.
* \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_drv_se_context_t *drv_context,
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 allocates a slot for a key.
*
* The core calls this function to determine a slot number, then
* calls the actual creation function (such as
* psa_drv_se_key_management_t::p_import or
* psa_drv_se_key_management_t::p_generate).
*
* If this function succeeds, the next call that the core makes to the
* driver is either the creation function or
* psa_drv_se_key_management_t::p_destroy. Note that
* if the platform is reset after this function returns, the core
* may either subsequently call
* psa_drv_se_key_management_t::p_destroy or may behave as if the
* last call to this function had not taken place.
*/
psa_drv_se_allocate_key_t p_allocate;
/** Function that checks the validity of a slot for a key.
*
* The core calls this function instead of
* psa_drv_se_key_management_t::p_allocate to create
* a key in a specific slot. It then calls the actual creation function
* (such as psa_drv_se_key_management_t::p_import or
* psa_drv_se_key_management_t::p_generate) or
* psa_drv_se_key_management_t::p_destroy.
*/
psa_drv_se_validate_slot_number_t p_validate_slot_number;
/** 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] drv_context The driver context structure.
* \param[in,out] op_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)(psa_drv_se_context_t *drv_context,
void *op_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] op_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 *op_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] op_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 *op_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 *op_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;
/** The size of the driver's persistent data in bytes.
*
* This can be 0 if the driver does not need persistent data.
*
* See the documentation of psa_drv_se_context_t::persistent_data
* for more information about why and how a driver can use
* persistent data.
*/
size_t persistent_data_size;
/** The driver initialization function.
*
* This function is called once during the initialization of the
* PSA Cryptography subsystem, before any other function of the
* driver is called. If this function returns a failure status,
* the driver will be unusable, at least until the next system reset.
*
* If this field is \c NULL, it is equivalent to a function that does
* nothing and returns #PSA_SUCCESS.
*/
psa_drv_se_init_t p_init;
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 */