hkdf.h File Reference

HMAC-based key derivation function based on ASCON-HMAC. More...

#include <stddef.h>

Go to the source code of this file.

Classes
struct	ascon_hkdf_state_t
	State for incremental generation of key material from ASCON-HKDF. More...
struct	ascon_hkdfa_state_t
	State for incremental generation of key material from ASCON-HKDFA. More...

Macros
#define	ASCON_HKDF_OUTPUT_SIZE   32
	Default output block size for ASCON-HKDF and ASCON-HKDFA. Key material is generated in blocks of this size. More...

Functions
int	ascon_hkdf (unsigned char *out, size_t outlen, const unsigned char *key, size_t keylen, const unsigned char *salt, size_t saltlen, const unsigned char *info, size_t infolen)
	Derives key material using ASCON-HKDF. More...
void	ascon_hkdf_extract (ascon_hkdf_state_t *state, const unsigned char *key, size_t keylen, const unsigned char *salt, size_t saltlen)
	Extracts entropy from a key and salt for ASCON-HKDF. More...
int	ascon_hkdf_expand (ascon_hkdf_state_t *state, const unsigned char *info, size_t infolen, unsigned char *out, size_t outlen)
	Expands key material using a ASCON-HKDF state. More...
void	ascon_hkdf_free (ascon_hkdf_state_t *state)
	Frees all sensitive material in a ASCON-HKDF state. More...
int	ascon_hkdfa (unsigned char *out, size_t outlen, const unsigned char *key, size_t keylen, const unsigned char *salt, size_t saltlen, const unsigned char *info, size_t infolen)
	Derives key material using ASCON-HKDFA. More...
void	ascon_hkdfa_extract (ascon_hkdfa_state_t *state, const unsigned char *key, size_t keylen, const unsigned char *salt, size_t saltlen)
	Extracts entropy from a key and salt for ASCON-HKDFA. More...
int	ascon_hkdfa_expand (ascon_hkdfa_state_t *state, const unsigned char *info, size_t infolen, unsigned char *out, size_t outlen)
	Expands key material using a ASCON-HKDFA state. More...
void	ascon_hkdfa_free (ascon_hkdfa_state_t *state)
	Frees all sensitive material in a ASCON-HKDFA state. More...

Detailed Description

HMAC-based key derivation function based on ASCON-HMAC.

Reference: https://tools.ietf.org/html/rfc5869

Definition in file hkdf.h.

Macro Definition Documentation

ASCON_HKDF_OUTPUT_SIZE

#define ASCON_HKDF_OUTPUT_SIZE   32

Default output block size for ASCON-HKDF and ASCON-HKDFA. Key material is generated in blocks of this size.

Definition at line 43 of file hkdf.h.

Function Documentation

ascon_hkdf()

int ascon_hkdf	(	unsigned char *	out,
		size_t	outlen,
		const unsigned char *	key,
		size_t	keylen,
		const unsigned char *	salt,
		size_t	saltlen,
		const unsigned char *	info,
		size_t	infolen
	)

Derives key material using ASCON-HKDF.

Parameters

out	Points to the output buffer to receive the key material.
outlen	Number of bytes of key material to generate, maximum of ASCON_HKDF_OUTPUT_SIZE * 255 bytes.
key	Points to the bytes of the key.
keylen	Number of bytes in the key.
salt	Points to the bytes of the salt.
saltlen	Number of bytes in the salt.
info	Points to the bytes of the informational data.
infolen	Number of bytes in the informational data.

Returns

Zero on success or -1 if outlen is out of range.

See also

ascon_hkdf_extract(), ascon_hkdf_expand()

ascon_hkdf_expand()

int ascon_hkdf_expand	(	ascon_hkdf_state_t *	state,
		const unsigned char *	info,
		size_t	infolen,
		unsigned char *	out,
		size_t	outlen
	)

Expands key material using a ASCON-HKDF state.

Parameters

state	HKDF state to use to expand key material.
info	Points to the bytes of the informational data.
infolen	Number of bytes in the informational data.
out	Points to the output buffer to receive the key material.
outlen	Number of bytes of key material to generate.

Returns

Zero on success or -1 if too many bytes have been generated so far. There is a limit of ASCON_HKDF_OUTPUT_SIZE * 255 bytes.

ascon_hkdf_extract()

void ascon_hkdf_extract	(	ascon_hkdf_state_t *	state,
		const unsigned char *	key,
		size_t	keylen,
		const unsigned char *	salt,
		size_t	saltlen
	)

Extracts entropy from a key and salt for ASCON-HKDF.

Parameters

state	HKDF state to be initialized.
key	Points to the bytes of the key.
keylen	Number of bytes in the key.
salt	Points to the bytes of the salt.
saltlen	Number of bytes in the salt.

See also

ascon_hkdf_expand(), ascon_hkdf()

ascon_hkdf_free()

void ascon_hkdf_free

(

ascon_hkdf_state_t *

state

)

Frees all sensitive material in a ASCON-HKDF state.

Parameters

state

Points to the HKDF state.

ascon_hkdfa()

int ascon_hkdfa	(	unsigned char *	out,
		size_t	outlen,
		const unsigned char *	key,
		size_t	keylen,
		const unsigned char *	salt,
		size_t	saltlen,
		const unsigned char *	info,
		size_t	infolen
	)

Derives key material using ASCON-HKDFA.

Parameters

out	Points to the output buffer to receive the key material.
outlen	Number of bytes of key material to generate, maximum of ASCON_HKDF_OUTPUT_SIZE * 255 bytes.
key	Points to the bytes of the key.
keylen	Number of bytes in the key.
salt	Points to the bytes of the salt.
saltlen	Number of bytes in the salt.
info	Points to the bytes of the informational data.
infolen	Number of bytes in the informational data.

Returns

Zero on success or -1 if outlen is out of range.

See also

ascon_hkdfa_extract(), ascon_hkdfa_expand()

ascon_hkdfa_expand()

int ascon_hkdfa_expand	(	ascon_hkdfa_state_t *	state,
		const unsigned char *	info,
		size_t	infolen,
		unsigned char *	out,
		size_t	outlen
	)

Expands key material using a ASCON-HKDFA state.

Parameters

state	HKDF state to use to expand key material.
info	Points to the bytes of the informational data.
infolen	Number of bytes in the informational data.
out	Points to the output buffer to receive the key material.
outlen	Number of bytes of key material to generate.

Returns

Zero on success or -1 if too many bytes have been generated so far. There is a limit of ASCON_HKDF_OUTPUT_SIZE * 255 bytes.

ascon_hkdfa_extract()

void ascon_hkdfa_extract	(	ascon_hkdfa_state_t *	state,
		const unsigned char *	key,
		size_t	keylen,
		const unsigned char *	salt,
		size_t	saltlen
	)

Extracts entropy from a key and salt for ASCON-HKDFA.

Parameters

state	HKDF state to be initialized.
key	Points to the bytes of the key.
keylen	Number of bytes in the key.
salt	Points to the bytes of the salt.
saltlen	Number of bytes in the salt.

See also

ascon_hkdfa_expand(), ascon_hkdfa()

ascon_hkdfa_free()

void ascon_hkdfa_free

(

ascon_hkdfa_state_t *

state

)

Frees all sensitive material in a ASCON-HKDFA state.

Parameters

state

Points to the HKDF state.