cracen_decapsulate()

psa_status_t cracen_decapsulate	(	const psa_key_attributes_t *	attributes,
		const uint8_t *	key,
		size_t	key_length,
		psa_algorithm_t	alg,
		const uint8_t *	ciphertext,
		size_t	ciphertext_length,
		const psa_key_attributes_t *	output_attributes,
		uint8_t *	output_key,
		size_t	output_key_size,
		size_t *	output_key_length )

#include <cracen_psa_key_encapsulation.h>

Use a private key to decapsulate a shared secret key from a ciphertext.

Note

ML-KEM uses implicit rejection: an invalid ciphertext does not fail the operation, it yields a shared secret key that differs from the one the peer encapsulated.

Parameters

[in]	attributes	Key attributes of the decapsulation (private) key.
[in]	key	Key material of the decapsulation key.
[in]	key_length	Size of the decapsulation key in bytes.
[in]	alg	Key encapsulation algorithm.
[in]	ciphertext	Buffer containing the ciphertext produced by the peer.
[in]	ciphertext_length	Size of the ciphertext in bytes.
[in]	output_attributes	Key attributes of the shared secret key to produce.
[out]	output_key	Buffer where the shared secret key is to be written.
[in]	output_key_size	Size of the output key buffer in bytes.
[out]	output_key_length	On success, the number of bytes that make up the shared secret key.

Return values

PSA_SUCCESS	The operation completed successfully.
PSA_ERROR_NOT_SUPPORTED	The algorithm or the key type is not supported.
PSA_ERROR_INVALID_ARGUMENT	Invalid parameters.
PSA_ERROR_BUFFER_TOO_SMALL	The output buffer is too small.