Encryption and Decryption using secure element keys in block modes other than ECB must be done in multiple parts, using the following flow:
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.
Data Structures | |
struct | psa_drv_se_cipher_t |
A struct containing all of the function pointers needed to implement cipher operations using secure elements. More... | |
Typedefs | |
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) |
A function that provides the cipher setup function for a secure element driver. | |
typedef psa_status_t(* | psa_drv_se_cipher_set_iv_t) (void *op_context, const uint8_t *p_iv, size_t iv_length) |
A function that sets the initialization vector (if necessary) for an secure element cipher operation. | |
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) |
A function that continues a previously started secure element cipher operation. | |
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) |
A function that completes a previously started secure element cipher operation. | |
typedef psa_status_t(* | psa_drv_se_cipher_abort_t) (void *op_context) |
A function that aborts a previously started secure element cipher operation. | |
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) |
A function that performs the ECB block mode for secure element cipher operations. | |
typedef psa_status_t(* psa_drv_se_cipher_abort_t) (void *op_context) |
A function that aborts a previously started secure element cipher operation.
op_context | A hardware-specific structure for the previously started cipher operation |
Definition at line 475 of file psa_crypto_se_driver.h.
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) |
A function that performs the ECB block mode for secure element cipher operations.
drv_context | The driver context structure. |
key_slot | The slot of the key to be used for the operation |
algorithm | The algorithm to be used in the cipher operation |
direction | Indicates whether the operation is an encrypt or decrypt |
p_input | A buffer containing the data to be encrypted/decrypted |
input_size | The size in bytes of the buffer pointed to by input |
p_output | The caller-allocated buffer where the output will be placed |
output_size | The allocated size in bytes of the output buffer |
Definition at line 501 of file psa_crypto_se_driver.h.
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) |
A function that completes a previously started secure element cipher operation.
op_context | A hardware-specific structure for the previously started cipher operation |
p_output | The caller-allocated buffer where the output will be placed |
output_size | The allocated size in bytes of the p_output buffer |
p_output_length | After completion, will contain the number of bytes placed in the p_output buffer |
Definition at line 463 of file psa_crypto_se_driver.h.
typedef psa_status_t(* psa_drv_se_cipher_set_iv_t) (void *op_context, const uint8_t *p_iv, size_t iv_length) |
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.
op_context | A structure that contains the previously set up hardware-specific cipher context |
p_iv | A buffer containing the initialization vector |
iv_length | The size (in bytes) of the p_iv buffer |
Definition at line 418 of file psa_crypto_se_driver.h.
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) |
A function that provides the cipher setup function for a secure element driver.
drv_context | The driver context structure. |
op_context | A structure that will contain the hardware-specific cipher context. |
key_slot | The slot of the key to be used for the operation |
algorithm | The algorithm to be used in the cipher operation |
direction | Indicates whether the operation is an encrypt or decrypt |
Definition at line 396 of file psa_crypto_se_driver.h.
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) |
A function that continues a previously started secure element cipher operation.
op_context | A hardware-specific structure for the previously started cipher operation |
p_input | A buffer containing the data to be encrypted/decrypted |
input_size | The size in bytes of the buffer pointed to by p_input |
p_output | The caller-allocated buffer where the output will be placed |
output_size | The allocated size in bytes of the p_output buffer |
p_output_length | After completion, will contain the number of bytes placed in the p_output buffer |
Definition at line 441 of file psa_crypto_se_driver.h.