wpa_common.c File Reference

WPA/RSN - Shared functions for supplicant and authenticator. More...

#include "includes.h"
#include "common.h"
#include "crypto/md5.h"
#include "crypto/sha1.h"
#include "crypto/sha256.h"
#include "crypto/sha384.h"
#include "crypto/aes_wrap.h"
#include "crypto/crypto.h"
#include "ieee802_11_defs.h"
#include "defs.h"
#include "wpa_common.h"

Functions
unsigned int	wpa_mic_len (int akmp)
int	wpa_eapol_key_mic (const u8 *key, size_t key_len, int akmp, int ver, const u8 *buf, size_t len, u8 *mic)
	Calculate EAPOL-Key MIC. More...
int	wpa_pmk_to_ptk (const u8 *pmk, size_t pmk_len, const char *label, const u8 *addr1, const u8 *addr2, const u8 *nonce1, const u8 *nonce2, struct wpa_ptk *ptk, int akmp, int cipher)
	Calculate PTK from PMK, addresses, and nonces. More...
int	wpa_cipher_valid_group (int cipher)
int	wpa_parse_wpa_ie_rsn (const u8 *rsn_ie, size_t rsn_ie_len, struct wpa_ie_data *data)
	Parse RSN IE. More...
int	wpa_parse_wpa_ie_wpa (const u8 *wpa_ie, size_t wpa_ie_len, struct wpa_ie_data *data)
void	rsn_pmkid (const u8 *pmk, size_t pmk_len, const u8 *aa, const u8 *spa, u8 *pmkid, int use_sha256)
	Calculate PMK identifier. More...
const char *	wpa_cipher_txt (int cipher)
	Convert cipher suite to a text string. More...
const char *	wpa_key_mgmt_txt (int key_mgmt, int proto)
	Convert key management suite to a text string. More...
u32	wpa_akm_to_suite (int akm)
int	wpa_compare_rsn_ie (int ft_initial_assoc, const u8 *ie1, size_t ie1len, const u8 *ie2, size_t ie2len)
int	wpa_cipher_key_len (int cipher)
int	wpa_cipher_rsc_len (int cipher)
int	wpa_cipher_to_alg (int cipher)
int	wpa_cipher_valid_pairwise (int cipher)
u32	wpa_cipher_to_suite (int proto, int cipher)
int	rsn_cipher_put_suites (u8 *start, int ciphers)
int	wpa_cipher_put_suites (u8 *start, int ciphers)
int	wpa_pick_pairwise_cipher (int ciphers, int none_allowed)
int	wpa_pick_group_cipher (int ciphers)
int	wpa_parse_cipher (const char *value)
int	wpa_write_ciphers (char *start, char *end, int ciphers, const char *delim)
int	wpa_select_ap_group_cipher (int wpa, int wpa_pairwise, int rsn_pairwise)

Detailed Description

WPA/RSN - Shared functions for supplicant and authenticator.

Function Documentation

void rsn_pmkid	(	const u8 *	pmk,
		size_t	pmk_len,
		const u8 *	aa,
		const u8 *	spa,
		u8 *	pmkid,
		int	use_sha256
	)

Calculate PMK identifier.

Parameters

pmk	Pairwise master key
pmk_len	Length of pmk in bytes
aa	Authenticator address
spa	Supplicant address
pmkid	Buffer for PMKID
use_sha256	Whether to use SHA256-based KDF

IEEE Std 802.11i-2004 - 8.5.1.2 Pairwise key hierarchy PMKID = HMAC-SHA1-128(PMK, "PMK Name" || AA || SPA)

const char* wpa_cipher_txt

(

int

cipher

)

Convert cipher suite to a text string.

Parameters

cipher

Cipher suite (WPA_CIPHER_* enum)

Returns

Pointer to a text string of the cipher suite name

int wpa_eapol_key_mic	(	const u8 *	key,
		size_t	key_len,
		int	akmp,
		int	ver,
		const u8 *	buf,
		size_t	len,
		u8 *	mic
	)

Calculate EAPOL-Key MIC.

Parameters

key	EAPOL-Key Key Confirmation Key (KCK)
key_len	KCK length in octets
akmp	WPA_KEY_MGMT_* used in key derivation
ver	Key descriptor version (WPA_KEY_INFO_TYPE_*)
buf	Pointer to the beginning of the EAPOL header (version field)
len	Length of the EAPOL frame (from EAPOL header to the end of the frame)
mic	Pointer to the buffer to which the EAPOL-Key MIC is written

Returns

0 on success, -1 on failure

Calculate EAPOL-Key MIC for an EAPOL-Key packet. The EAPOL-Key MIC field has to be cleared (all zeroes) when calling this function.

Note: 'IEEE Std 802.11i-2004 - 8.5.2 EAPOL-Key frames' has an error in the description of the Key MIC calculation. It includes packet data from the beginning of the EAPOL-Key header, not EAPOL header. This incorrect change happened during final editing of the standard and the correct behavior is defined in the last draft (IEEE 802.11i/D10).

const char* wpa_key_mgmt_txt	(	int	key_mgmt,
		int	proto
	)

Convert key management suite to a text string.

Parameters

key_mgmt	Key management suite (WPA_KEY_MGMT_* enum)
proto	WPA/WPA2 version (WPA_PROTO_*)

Returns

Pointer to a text string of the key management suite name

int wpa_parse_wpa_ie_rsn	(	const u8 *	rsn_ie,
		size_t	rsn_ie_len,
		struct wpa_ie_data *	data
	)

Parse RSN IE.

Parameters

rsn_ie	Buffer containing RSN IE
rsn_ie_len	RSN IE buffer length (including IE number and length octets)
data	Pointer to structure that will be filled in with parsed data

Returns

0 on success, <0 on failure

int wpa_pmk_to_ptk	(	const u8 *	pmk,
		size_t	pmk_len,
		const char *	label,
		const u8 *	addr1,
		const u8 *	addr2,
		const u8 *	nonce1,
		const u8 *	nonce2,
		struct wpa_ptk *	ptk,
		int	akmp,
		int	cipher
	)

Calculate PTK from PMK, addresses, and nonces.

Parameters

pmk	Pairwise master key
pmk_len	Length of PMK
label	Label to use in derivation
addr1	AA or SA
addr2	SA or AA
nonce1	ANonce or SNonce
nonce2	SNonce or ANonce
ptk	Buffer for pairwise transient key
akmp	Negotiated AKM
cipher	Negotiated pairwise cipher

Returns

0 on success, -1 on failure

IEEE Std 802.11i-2004 - 8.5.1.2 Pairwise key hierarchy PTK = PRF-X(PMK, "Pairwise key expansion", Min(AA, SA) || Max(AA, SA) || Min(ANonce, SNonce) || Max(ANonce, SNonce))

STK = PRF-X(SMK, "Peer key expansion", Min(MAC_I, MAC_P) || Max(MAC_I, MAC_P) || Min(INonce, PNonce) || Max(INonce, PNonce))