sha256.h File Reference

SHA256 hash implementation and interface functions. More...

Go to the source code of this file.

Defines
#define	SHA256_MAC_LEN   32
Functions
void	hmac_sha256_vector (const u8 *key, size_t key_len, size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
	HMAC-SHA256 over data vector (RFC 2104)
void	hmac_sha256 (const u8 *key, size_t key_len, const u8 *data, size_t data_len, u8 *mac)
	HMAC-SHA256 over data buffer (RFC 2104)
void	sha256_prf (const u8 *key, size_t key_len, const char *label, const u8 *data, size_t data_len, u8 *buf, size_t buf_len)
	SHA256-based Pseudo-Random Function (IEEE 802.11r, 8.5.1.5.2)
void	tls_prf_sha256 (const u8 *secret, size_t secret_len, const char *label, const u8 *seed, size_t seed_len, u8 *out, size_t outlen)
	Pseudo-Random Function for TLS v1.2 (P_SHA256, RFC 5246)

---

Detailed Description

SHA256 hash implementation and interface functions.

Copyright

Copyright (c) 2003-2011, Jouni Malinen <j@w1.fi>

This software may be distributed under the terms of the BSD license. See README for more details.

---

Function Documentation

void hmac_sha256	(	const u8 *	key,
		size_t	key_len,
		const u8 *	data,
		size_t	data_len,
		u8 *	mac
	)

HMAC-SHA256 over data buffer (RFC 2104)

Parameters:

key	Key for HMAC operations
key_len	Length of the key in bytes
data	Pointers to the data area
data_len	Length of the data area
mac	Buffer for the hash (20 bytes)

void hmac_sha256_vector	(	const u8 *	key,
		size_t	key_len,
		size_t	num_elem,
		const u8 *	addr[],
		const size_t *	len,
		u8 *	mac
	)

HMAC-SHA256 over data vector (RFC 2104)

Parameters:

key	Key for HMAC operations
key_len	Length of the key in bytes
num_elem	Number of elements in the data vector
addr	Pointers to the data areas
len	Lengths of the data blocks
mac	Buffer for the hash (32 bytes)

void sha256_prf	(	const u8 *	key,
		size_t	key_len,
		const char *	label,
		const u8 *	data,
		size_t	data_len,
		u8 *	buf,
		size_t	buf_len
	)

SHA256-based Pseudo-Random Function (IEEE 802.11r, 8.5.1.5.2)

Parameters:

key	Key for PRF
key_len	Length of the key in bytes
label	A unique label for each purpose of the PRF
data	Extra data to bind into the key
data_len	Length of the data
buf	Buffer for the generated pseudo-random key
buf_len	Number of bytes of key to generate

This function is used to derive new, cryptographically separate keys from a given key.

void tls_prf_sha256	(	const u8 *	secret,
		size_t	secret_len,
		const char *	label,
		const u8 *	seed,
		size_t	seed_len,
		u8 *	out,
		size_t	outlen
	)

Pseudo-Random Function for TLS v1.2 (P_SHA256, RFC 5246)

Parameters:

secret	Key for PRF
secret_len	Length of the key in bytes
label	A unique label for each purpose of the PRF
seed	Seed value to bind into the key
seed_len	Length of the seed
out	Buffer for the generated pseudo-random key
outlen	Number of bytes of key to generate

Returns:

0 on success, -1 on failure.

This function is used to derive new, cryptographically separate keys from a given key in TLS. This PRF is defined in RFC 2246, Chapter 5.