GSM A5 ciphering algorithm

Files
file	a5.h
	Osmocom GSM A5 ciphering algorithm header.

Functions
static uint32_t	osmo_a5_fn_count (uint32_t fn)
	Converts a frame number into the 22 bit number used in A5/x. More...
int	osmo_a5 (int n, const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul)
	Main method to generate a A5/x cipher stream. More...
void	osmo_a5_1 (const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul) OSMO_DEPRECATED("Use generic osmo_a5() instead")
void	osmo_a5_2 (const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul) OSMO_DEPRECATED("Use generic osmo_a5() instead")

Detailed Description

Function Documentation

int osmo_a5	(	int	n,
		const uint8_t *	key,
		uint32_t	fn,
		ubit_t *	dl,
		ubit_t *	ul
	)

Main method to generate a A5/x cipher stream.

Parameters

[in]	n	Which A5/x method to use
[in]	key	8 or 16 (for a5/4) byte array for the key (as received from the SIM)
[in]	fn	Frame number
[out]	dl	Pointer to array of ubits to return Downlink cipher stream
[out]	ul	Pointer to array of ubits to return Uplink cipher stream

Returns

0 for success, -ENOTSUP for invalid cipher selection.

Currently A5/[0-4] are supported. Either (or both) of dl/ul can be NULL if not needed.

References _a5_1(), _a5_2(), _a5_3(), _a5_4(), and ENOTSUP.

Referenced by osmo_a5_1(), osmo_a5_2(), and osmo_a5_fn_count().

void osmo_a5_1	(	const uint8_t *	key,
		uint32_t	fn,
		ubit_t *	dl,
		ubit_t *	ul
	)

References osmo_a5().

Referenced by osmo_a5_fn_count().

void osmo_a5_2	(	const uint8_t *	key,
		uint32_t	fn,
		ubit_t *	dl,
		ubit_t *	ul
	)

References osmo_a5().

Referenced by osmo_a5_fn_count().

static uint32_t osmo_a5_fn_count ( uint32_t  fn )

inlinestatic

Converts a frame number into the 22 bit number used in A5/x.

Parameters

[in]

fn

The true framenumber

Returns

22 bit word

References osmo_a5(), osmo_a5_1(), osmo_a5_2(), OSMO_DEPRECATED, t1, t2, and t3.

Referenced by _a5_1(), _a5_2(), and _a5_4().