apr_siphash.h File Reference

APR-UTIL siphash library "SipHash-c-d is a family of pseudorandom functions (a.k.a. keyed hash functions) optimized for speed on short messages", designed by Jean-Philippe Aumasson and Daniel J. Bernstein. It generates a 64bit hash (or MAC) from the message and a 128bit key. See http://cr.yp.to/siphash/siphash-20120620.pdf for the details, c is the number of compression rounds, d the number of finalization rounds; we also define fast implementations for c = 2 with d = 4 (aka siphash-2-4), and c = 4 with d = 8 (aka siphash-4-8), as recommended parameters per the authors. More...

#include "apr.h"

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Macros
#define	APR_SIPHASH_DSIZE   8
#define	APR_SIPHASH_KSIZE   16

Functions
apr_uint64_t	apr_siphash (const void *src, apr_size_t len, const unsigned char key[APR_SIPHASH_KSIZE], unsigned int c, unsigned int d)
	Computes SipHash-c-d, producing a 64bit (APR_SIPHASH_DSIZE) hash from a message and a 128bit (APR_SIPHASH_KSIZE) secret key. More...
void	apr_siphash_auth (unsigned char out[APR_SIPHASH_DSIZE], const void *src, apr_size_t len, const unsigned char key[APR_SIPHASH_KSIZE], unsigned int c, unsigned int d)
	Computes SipHash-c-d, producing a 64bit (APR_SIPHASH_DSIZE) hash from a message and a 128bit (APR_SIPHASH_KSIZE) secret key, into a possibly unaligned buffer (using the little endian representation as defined by the authors for interoperabilty) usable as a MAC. More...
apr_uint64_t	apr_siphash24 (const void *src, apr_size_t len, const unsigned char key[APR_SIPHASH_KSIZE])
	Computes SipHash-2-4, producing a 64bit (APR_SIPHASH_DSIZE) hash from a message and a 128bit (APR_SIPHASH_KSIZE) secret key. More...
void	apr_siphash24_auth (unsigned char out[APR_SIPHASH_DSIZE], const void *src, apr_size_t len, const unsigned char key[APR_SIPHASH_KSIZE])
	Computes SipHash-2-4, producing a 64bit (APR_SIPHASH_DSIZE) hash from a message and a 128bit (APR_SIPHASH_KSIZE) secret key, into a possibly unaligned buffer (using the little endian representation as defined by the authors for interoperabilty) usable as a MAC. More...
apr_uint64_t	apr_siphash48 (const void *src, apr_size_t len, const unsigned char key[APR_SIPHASH_KSIZE])
	Computes SipHash-4-8, producing a 64bit (APR_SIPHASH_DSIZE) hash from a message and a 128bit (APR_SIPHASH_KSIZE) secret key. More...
void	apr_siphash48_auth (unsigned char out[APR_SIPHASH_DSIZE], const void *src, apr_size_t len, const unsigned char key[APR_SIPHASH_KSIZE])
	Computes SipHash-4-8, producing a 64bit (APR_SIPHASH_DSIZE) hash from a message and a 128bit (APR_SIPHASH_KSIZE) secret key, into a possibly unaligned buffer (using the little endian representation as defined by the authors for interoperabilty) usable as a MAC. More...

Detailed Description

APR-UTIL siphash library "SipHash-c-d is a family of pseudorandom functions (a.k.a. keyed hash functions) optimized for speed on short messages", designed by Jean-Philippe Aumasson and Daniel J. Bernstein. It generates a 64bit hash (or MAC) from the message and a 128bit key. See http://cr.yp.to/siphash/siphash-20120620.pdf for the details, c is the number of compression rounds, d the number of finalization rounds; we also define fast implementations for c = 2 with d = 4 (aka siphash-2-4), and c = 4 with d = 8 (aka siphash-4-8), as recommended parameters per the authors.

Macro Definition Documentation

APR_SIPHASH_DSIZE

#define APR_SIPHASH_DSIZE   8

size of the siphash digest

APR_SIPHASH_KSIZE

#define APR_SIPHASH_KSIZE   16

size of the siphash key

Function Documentation

apr_siphash()

apr_uint64_t apr_siphash	(	const void *	src,
		apr_size_t	len,
		const unsigned char	key[APR_SIPHASH_KSIZE],
		unsigned int	c,
		unsigned int	d
	)

Computes SipHash-c-d, producing a 64bit (APR_SIPHASH_DSIZE) hash from a message and a 128bit (APR_SIPHASH_KSIZE) secret key.

Parameters

src	The message
len	The length of the message
key	The secret key
c	The number of compression rounds
d	The number of finalization rounds

Returns

The hash value as a 64bit unsigned integer

apr_siphash24()

apr_uint64_t apr_siphash24	(	const void *	src,
		apr_size_t	len,
		const unsigned char	key[APR_SIPHASH_KSIZE]
	)

Computes SipHash-2-4, producing a 64bit (APR_SIPHASH_DSIZE) hash from a message and a 128bit (APR_SIPHASH_KSIZE) secret key.

Parameters

src	The message to hash
len	The length of the message
key	The secret key

Returns

The hash value as a 64bit unsigned integer

apr_siphash24_auth()

void apr_siphash24_auth	(	unsigned char	out[APR_SIPHASH_DSIZE],
		const void *	src,
		apr_size_t	len,
		const unsigned char	key[APR_SIPHASH_KSIZE]
	)

Computes SipHash-2-4, producing a 64bit (APR_SIPHASH_DSIZE) hash from a message and a 128bit (APR_SIPHASH_KSIZE) secret key, into a possibly unaligned buffer (using the little endian representation as defined by the authors for interoperabilty) usable as a MAC.

Parameters

out	The output buffer (or MAC)
src	The message
len	The length of the message
key	The secret key

Returns

The hash value as a 64bit unsigned integer

apr_siphash48()

apr_uint64_t apr_siphash48	(	const void *	src,
		apr_size_t	len,
		const unsigned char	key[APR_SIPHASH_KSIZE]
	)

Computes SipHash-4-8, producing a 64bit (APR_SIPHASH_DSIZE) hash from a message and a 128bit (APR_SIPHASH_KSIZE) secret key.

Parameters

src	The message
len	The length of the message
key	The secret key

Returns

The hash value as a 64bit unsigned integer

apr_siphash48_auth()

void apr_siphash48_auth	(	unsigned char	out[APR_SIPHASH_DSIZE],
		const void *	src,
		apr_size_t	len,
		const unsigned char	key[APR_SIPHASH_KSIZE]
	)

Computes SipHash-4-8, producing a 64bit (APR_SIPHASH_DSIZE) hash from a message and a 128bit (APR_SIPHASH_KSIZE) secret key, into a possibly unaligned buffer (using the little endian representation as defined by the authors for interoperabilty) usable as a MAC.

Parameters

out	The output buffer (or MAC)
src	The message
len	The length of the message
key	The secret key

Returns

The hash value as a 64bit unsigned integer

apr_siphash_auth()

void apr_siphash_auth	(	unsigned char	out[APR_SIPHASH_DSIZE],
		const void *	src,
		apr_size_t	len,
		const unsigned char	key[APR_SIPHASH_KSIZE],
		unsigned int	c,
		unsigned int	d
	)

Computes SipHash-c-d, producing a 64bit (APR_SIPHASH_DSIZE) hash from a message and a 128bit (APR_SIPHASH_KSIZE) secret key, into a possibly unaligned buffer (using the little endian representation as defined by the authors for interoperabilty) usable as a MAC.

Parameters

out	The output buffer (or MAC)
src	The message
len	The length of the message
key	The secret key
c	The number of compression rounds
d	The number of finalization rounds

Returns

The hash value as a 64bit unsigned integer