sparkle-hkdf.h File Reference

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

#include <stddef.h>

Go to the source code of this file.

Data Structures
struct	esch_256_hkdf_state_t
	State for incremental generation of key material from Esch256-HKDF. More...
struct	esch_384_hkdf_state_t
	State for incremental generation of key material from Esch384-HKDF. More...

Macros
#define	ESCH_256_HKDF_OUTPUT_SIZE   32
	Default output block size for Ecsh256-HKDF. Key material is generated in blocks of this size.
#define	ESCH_384_HKDF_OUTPUT_SIZE   48
	Default output block size for Ecsh384-HKDF. Key material is generated in blocks of this size.

Functions
int	esch_256_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 Esch256-HKDF. More...
void	esch_256_hkdf_extract (esch_256_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 Esch256-HKDF. More...
int	esch_256_hkdf_expand (esch_256_hkdf_state_t *state, const unsigned char *info, size_t infolen, unsigned char *out, size_t outlen)
	Expands key material using a Esch256-HKDF state. More...
void	esch_256_hkdf_free (esch_256_hkdf_state_t *state)
	Frees all sensitive material in a Esch256-HKDF state. More...
int	esch_384_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 Esch384-HKDF. More...
void	esch_384_hkdf_extract (esch_384_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 Esch384-HKDF. More...
int	esch_384_hkdf_expand (esch_384_hkdf_state_t *state, const unsigned char *info, size_t infolen, unsigned char *out, size_t outlen)
	Expands key material using a Esch384-HKDF state. More...
void	esch_384_hkdf_free (esch_384_hkdf_state_t *state)
	Frees all sensitive material in a Esch384-HKDF state. More...

Detailed Description

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

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

Function Documentation

int esch_256_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 Esch256-HKDF.

Parameters

out	Points to the output buffer to receive the key material.
outlen	Number of bytes of key material to generate, maximum of ESCH_256_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

esch_256_hkdf_extract(), esch_256_hkdf_expand()

int esch_256_hkdf_expand	(	esch_256_hkdf_state_t *	state,
		const unsigned char *	info,
		size_t	infolen,
		unsigned char *	out,
		size_t	outlen
	)

Expands key material using a Esch256-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 ESCH_256_HKDF_OUTPUT_SIZE * 255 bytes.

void esch_256_hkdf_extract	(	esch_256_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 Esch256-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

esch_256_hkdf_expand(), esch_256_hkdf()

void esch_256_hkdf_free

(

esch_256_hkdf_state_t *

state

)

Frees all sensitive material in a Esch256-HKDF state.

Parameters

state

Points to the HKDF state.

int esch_384_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 Esch384-HKDF.

Parameters

out	Points to the output buffer to receive the key material.
outlen	Number of bytes of key material to generate, maximum of ESCH_384_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

esch_384_hkdf_extract(), esch_384_hkdf_expand()

int esch_384_hkdf_expand	(	esch_384_hkdf_state_t *	state,
		const unsigned char *	info,
		size_t	infolen,
		unsigned char *	out,
		size_t	outlen
	)

Expands key material using a Esch384-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 ESCH_384_HKDF_OUTPUT_SIZE * 255 bytes.

void esch_384_hkdf_extract	(	esch_384_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 Esch384-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

esch_384_hkdf_expand(), esch_384_hkdf()

void esch_384_hkdf_free

(

esch_384_hkdf_state_t *

state

)

Frees all sensitive material in a Esch384-HKDF state.

Parameters

state

Points to the HKDF state.