Osmocom Authentication Protocol

The Osmocom Authentication Protocol (OAP) is a way to use the 3GPP AKA (Authentication and Key Agreement) as cryptographic authentication mechanism in other protocols that don't provide cryptographic authentication. More...

Files
file	oap.h
file	oap.c
	Osmocom Authentication Protocol.

Data Structures
struct	osmo_oap_message
	Parsed/decoded OAP protocol message. More...

Enumerations
enum	osmo_oap_iei {   OAP_CAUSE_IE = 0x02 ,   OAP_RAND_IE = 0x20 ,   OAP_AUTN_IE = 0x23 ,   OAP_XRES_IE = 0x24 ,   OAP_AUTS_IE = 0x25 ,   OAP_CLIENT_ID_IE = 0x30 }
	Information Element Identifiers for OAP IEs. More...
enum	osmo_oap_message_type {   OAP_MSGT_REGISTER_REQUEST = 0b00000100 ,   OAP_MSGT_REGISTER_ERROR = 0b00000101 ,   OAP_MSGT_REGISTER_RESULT = 0b00000110 ,   OAP_MSGT_CHALLENGE_REQUEST = 0b00001000 ,   OAP_MSGT_CHALLENGE_ERROR = 0b00001001 ,   OAP_MSGT_CHALLENGE_RESULT = 0b00001010 ,   OAP_MSGT_SYNC_REQUEST = 0b00001100 ,   OAP_MSGT_SYNC_ERROR = 0b00001101 ,   OAP_MSGT_SYNC_RESULT = 0b00001110 }
	OAP message types. More...

Functions
int	osmo_oap_decode (struct osmo_oap_message *oap_msg, const uint8_t *const_data, size_t data_len)
	Decode OAP message data. More...
void	osmo_oap_encode (struct msgb *msg, const struct osmo_oap_message *oap_msg)
	Compose OAP message data. More...

Detailed Description

The Osmocom Authentication Protocol (OAP) is a way to use the 3GPP AKA (Authentication and Key Agreement) as cryptographic authentication mechanism in other protocols that don't provide cryptographic authentication.

Enumeration Type Documentation

osmo_oap_iei

enum osmo_oap_iei

Information Element Identifiers for OAP IEs.

They match osmo_gsup_iei (so far).

Enumerator
OAP_CAUSE_IE
OAP_RAND_IE
OAP_AUTN_IE
OAP_XRES_IE
OAP_AUTS_IE
OAP_CLIENT_ID_IE

osmo_oap_message_type

enum osmo_oap_message_type

OAP message types.

Enumerator
OAP_MSGT_REGISTER_REQUEST
OAP_MSGT_REGISTER_ERROR
OAP_MSGT_REGISTER_RESULT
OAP_MSGT_CHALLENGE_REQUEST
OAP_MSGT_CHALLENGE_ERROR
OAP_MSGT_CHALLENGE_RESULT
OAP_MSGT_SYNC_REQUEST
OAP_MSGT_SYNC_ERROR
OAP_MSGT_SYNC_RESULT

Function Documentation

osmo_oap_decode()

int osmo_oap_decode	(	struct osmo_oap_message *	oap_msg,
		const uint8_t *	const_data,
		size_t	data_len
	)

Decode OAP message data.

Parameters

[out]	oap_msg	Parsed data is written to this instance.
[in]	data	Pointer to the data buffer containing the OAP message.
[in]	data_len	Length of the OAP message data.

Returns

0 on success, a negative cause value on failure.

References osmo_oap_message::autn, osmo_oap_message::autn_present, osmo_oap_message::auts, osmo_oap_message::auts_present, osmo_oap_message::cause, osmo_oap_message::client_id, data, DLOAP, GMM_CAUSE_INV_MAND_INFO, GMM_CAUSE_PROTO_ERR_UNSPEC, iei, LOGL_ERROR, LOGL_NOTICE, LOGP, osmo_oap_message::message_type, OAP_AUTN_IE, OAP_AUTS_IE, OAP_CAUSE_IE, OAP_CLIENT_ID_IE, OAP_RAND_IE, OAP_XRES_IE, osmo_decode_big_endian(), osmo_shift_tlv(), osmo_shift_v_fixed(), osmo_oap_message::rand, osmo_oap_message::rand_present, osmo_oap_message::xres, and osmo_oap_message::xres_present.

Referenced by osmo_oap_client_handle().

osmo_oap_encode()

void osmo_oap_encode	(	struct msgb *	msg,
		const struct osmo_oap_message *	oap_msg
	)

Compose OAP message data.

Parameters

[out]	msg	OAP message data is appended to this message buffer.
[in]	oap_msg	Elements to encode in the message data.

References osmo_oap_message::autn, osmo_oap_message::autn_present, osmo_oap_message::auts, osmo_oap_message::auts_present, osmo_oap_message::cause, osmo_oap_message::client_id, osmo_oap_message::message_type, msg, msgb_tlv_put(), msgb_v_put(), OAP_AUTN_IE, OAP_AUTS_IE, OAP_CAUSE_IE, OAP_CLIENT_ID_IE, OAP_RAND_IE, OAP_XRES_IE, OSMO_ASSERT, osmo_encode_big_endian(), osmo_oap_message::rand, osmo_oap_message::rand_present, osmo_oap_message::xres, and osmo_oap_message::xres_present.

Referenced by osmo_oap_client_encoded().