kmac_kdf.h File Reference

(dbfdd20677)

KMAC-KDF operations for the OpenTitan cryptography library. More...

#include "datatypes.h"

Go to the source code of this file.

Functions
otcrypto_status_t	otcrypto_kmac_kdf (const otcrypto_blinded_key_t key_derivation_key, const otcrypto_const_byte_buf_t label, const otcrypto_const_byte_buf_t context, otcrypto_blinded_key_t *output_key_material)
	Performs KMAC-KDF as specified in NIST SP 800-108r1. More...

Detailed Description

KMAC-KDF operations for the OpenTitan cryptography library.

Definition in file kmac_kdf.h.

Function Documentation

otcrypto_kmac_kdf()

otcrypto_status_t otcrypto_kmac_kdf	(	const otcrypto_blinded_key_t	key_derivation_key,
		const otcrypto_const_byte_buf_t	label,
		const otcrypto_const_byte_buf_t	context,
		otcrypto_blinded_key_t *	output_key_material
	)

Performs KMAC-KDF as specified in NIST SP 800-108r1.

KMAC-KDF can use either KMAC128 or KMAC256; which one is determined by the key mode in the configuration of key_derivation_key.

Because of limitations on the KMAC hardware, labels longer than 32 bytes are not supported.

The caller should allocate and partially populate the output_key_material blinded key struct, including populating the key configuration and allocating space for the keyblob. The configuration may not indicate a hardware-backed key and must indicate a symmetric mode. The allocated keyblob length for the output key should be twice the unmasked key length indicated in its key configuration, rounded up to the nearest 32-bit word. The value in the checksum field of the blinded key struct will be populated by the key derivation function.

Parameters

	key_derivation_key	Blinded key derivation key.
	kmac_mode	Either KMAC128 or KMAC256 as PRF.
	label	Label string (optional, may be empty).
	context	Context string (optional, may be empty).
[out]	output_key_material	Blinded output key material.

Returns

Result of the key derivation operation.

Definition at line 17 of file kmac_kdf.c.