sec80211.h File Reference

Definitions for general secured-network routines. More...

#include <ipxe/net80211.h>
#include <errno.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER)
int	sec80211_detect (struct io_buffer *iob, enum net80211_security_proto *secprot, enum net80211_crypto_alg *crypt)
	Detect the cryptosystem and handshaking protocol used by an 802.11 network.
int	sec80211_detect_ie (int is_rsn, u8 *start, u8 *end, enum net80211_security_proto *secprot, enum net80211_crypto_alg *crypt)
	Find the RSN or WPA information element in the provided beacon frame.
u8 *	sec80211_find_rsn (union ieee80211_ie *ie, void *ie_end, int *is_rsn, u8 **end)
int	sec80211_install (struct net80211_crypto **which, enum net80211_crypto_alg crypt, const void *key, int len, const void *rsc)
	Install 802.11 cryptosystem.
u32	sec80211_rsn_get_crypto_desc (enum net80211_crypto_alg crypt, int rsnie)
	Determine RSN descriptor for specified net80211 cryptosystem number.
u32	sec80211_rsn_get_akm_desc (enum net80211_security_proto secprot, int rsnie)
	Determine RSN descriptor for specified net80211 handshaker number.
enum net80211_crypto_alg	sec80211_rsn_get_net80211_crypt (u32 desc)
	Determine net80211 cryptosystem number from RSN descriptor.

Detailed Description

Definitions for general secured-network routines.

Definition in file sec80211.h.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER

)

References end, start, and u8.

sec80211_detect()

int sec80211_detect	(	struct io_buffer *	iob,
		enum net80211_security_proto *	secprot,
		enum net80211_crypto_alg *	crypt )

Detect the cryptosystem and handshaking protocol used by an 802.11 network.

@v iob I/O buffer containing beacon frame @ret secprot Security handshaking protocol used by network @ret crypt Cryptosystem used by network @ret rc Return status code

This function uses weak linkage, as it must be called from generic contexts but should only be linked in if some encryption is supported; you must test its address against NULL before calling it. If it does not exist, any network with the PRIVACY bit set in beacon->capab should be considered unknown.

Definition at line 407 of file sec80211.c.

{
        struct ieee80211_frame *hdr = iob->data;
        struct ieee80211_beacon *beacon =
                ( struct ieee80211_beacon * ) hdr->data;
        u8 *rsn, *rsn_end;
        int is_rsn, rc;
 
        *crypt = NET80211_CRYPT_UNKNOWN;
        *secprot = NET80211_SECPROT_UNKNOWN;
 
        /* Find RSN or WPA IE */
        if ( ! ( rsn = sec80211_find_rsn ( beacon->info_element, iob->tail,
                                           &is_rsn, &rsn_end ) ) ) {
                /* No security IE at all; either WEP or no security. */
                *secprot = NET80211_SECPROT_NONE;
 
                if ( beacon->capability & IEEE80211_CAPAB_PRIVACY )
                        *crypt = NET80211_CRYPT_WEP;
                else
                        *crypt = NET80211_CRYPT_NONE;
 
                return 0;
        }
 
        /* Determine type of security */
        if ( ( rc = sec80211_detect_ie ( is_rsn, rsn, rsn_end, secprot,
                                         crypt ) ) == 0 )
                return 0;
 
        /* If we get here, the RSN IE was invalid */
 
        *crypt = NET80211_CRYPT_UNKNOWN;
        *secprot = NET80211_SECPROT_UNKNOWN;
        DBG ( "Failed to handle RSN IE:\n" );
        DBG_HD ( rsn, rsn_end - rsn );
        return rc;
}

References io_buffer::data, DBG, DBG_HD, hdr, ieee80211_beacon, IEEE80211_CAPAB_PRIVACY, NET80211_CRYPT_NONE, NET80211_CRYPT_UNKNOWN, NET80211_CRYPT_WEP, NET80211_SECPROT_NONE, NET80211_SECPROT_UNKNOWN, rc, sec80211_detect_ie(), sec80211_find_rsn(), io_buffer::tail, and u8.

sec80211_detect_ie()

int sec80211_detect_ie	(	int	is_rsn,
		u8 *	start,
		u8 *	end,
		enum net80211_security_proto *	secprot,
		enum net80211_crypto_alg *	crypt )

Find the RSN or WPA information element in the provided beacon frame.

Parameters

ie	Pointer to first information element to check
ie_end	Pointer to end of information element space

Return values

is_rsn	TRUE if returned IE is RSN, FALSE if it's WPA
end	Pointer to byte immediately after last byte of data
data	Pointer to first byte of data (the `version' field)

If both an RSN and a WPA information element are found, this function will return the first one seen, which by ordering rules should always prefer the newer RSN IE.

If no RSN or WPA infomration element is found, returns NULL and leaves is_rsn and end in an undefined state.

This function will not return a pointer to an information element that states it extends past the tail of the io_buffer, or whose version field is incorrect. */ u8 * sec80211_find_rsn ( union ieee80211_ie *ie, void *ie_end, int *is_rsn, u8 **end ) { u8 *rsn = NULL;

if ( ! ieee80211_ie_bound ( ie, ie_end ) ) return NULL;

while ( ie ) { if ( ie->id == IEEE80211_IE_VENDOR && ie->vendor.oui == IEEE80211_WPA_OUI_VEN ) { DBG ( "RSN detect: old-style WPA IE found\n" ); rsn = &ie->vendor.data[0]; end = rsn + ie->len - 4; is_rsn = 0; } else if ( ie->id == IEEE80211_IE_RSN ) { DBG ( "RSN detect: 802.11i RSN IE found\n" ); rsn = ( u8 * ) &ie->rsn.version; end = rsn + ie->len; is_rsn = 1; }

if ( rsn && ( *end > ( u8 * ) ie_end || rsn >= *end || ( u16 * ) rsn != IEEE80211_RSN_VERSION ) ) { DBG ( "RSN detect: malformed RSN IE or unknown " "version, keep trying\n" ); rsn = NULL; }

if ( rsn ) break;

ie = ieee80211_next_ie ( ie, ie_end ); }

if ( ! ie ) { DBG ( "RSN detect: no RSN IE found\n" ); return NULL; }

return rsn; }

/** Detect crypto and AKM types from RSN information element

@v is_rsn If TRUE, IE is a new-style RSN information element @v start Pointer to first byte of version field @v end Pointer to first byte not in the RSN IE @ret secprot Security handshaking protocol used by network @ret crypt Cryptosystem used by network @ret rc Return status code

If the IE cannot be parsed, returns an error indication and leaves secprot and crypt unchanged.

Definition at line 341 of file sec80211.c.

{
        enum net80211_security_proto sp;
        enum net80211_crypto_alg cr;
        struct descriptor_map *map;
        u8 *rsn = start;
 
        /* Set some defaults */
        cr = ( is_rsn ? NET80211_CRYPT_CCMP : NET80211_CRYPT_TKIP );
        sp = NET80211_SECPROT_EAP;
 
        rsn += 2;               /* version - already checked */
        rsn += 4;               /* group cipher - we don't use it here */
 
        if ( rsn >= end )
                goto done;
 
        /* Pick crypto algorithm */
        map = rsn_pick_desc ( &rsn, end, rsn_cipher_map,
                              table_start ( NET80211_CRYPTOS ),
                              table_end ( NET80211_CRYPTOS ) );
        if ( ! map )
                goto invalid_rsn;
 
        cr = map->net80211_type;
 
        if ( rsn >= end )
                goto done;
 
        /* Pick handshaking algorithm */
        map = rsn_pick_desc ( &rsn, end, rsn_akm_map,
                              table_start ( NET80211_HANDSHAKERS ),
                              table_end ( NET80211_HANDSHAKERS ) );
        if ( ! map )
                goto invalid_rsn;
 
        sp = map->net80211_type;
 
 done:
        DBG ( "RSN detect: OK, crypto type %d, secprot type %d\n", cr, sp );
        *secprot = sp;
        *crypt = cr;
        return 0;
 
 invalid_rsn:
        DBG ( "RSN detect: invalid RSN IE\n" );
        return -EINVAL;
}

References cr, DBG, done, EINVAL, end, map, NET80211_CRYPT_CCMP, NET80211_CRYPT_TKIP, NET80211_CRYPTOS, NET80211_HANDSHAKERS, NET80211_SECPROT_EAP, rsn_akm_map, rsn_cipher_map, rsn_pick_desc(), sp, start, table_end, table_start, and u8.

Referenced by sec80211_detect(), and wpa_handle_3_of_4().

sec80211_find_rsn()

u8 * sec80211_find_rsn	(	union ieee80211_ie *	ie,
		void *	ie_end,
		int *	is_rsn,
		u8 **	end )

References desc, end, key, len, rsc, u32, and u8.

Referenced by rsn_pick_desc(), sec80211_detect(), wpa_handle_3_of_4(), wpa_make_rsn_ie(), and wpa_start().

sec80211_install()

int sec80211_install	(	struct net80211_crypto **	which,
		enum net80211_crypto_alg	crypt,
		const void *	key,
		int	len,
		const void *	rsc )

Install 802.11 cryptosystem.

Parameters

which	Pointer to the cryptosystem structure to install in
crypt	Cryptosystem ID number
key	Encryption key to use
len	Length of encryption key
rsc	Initial receive sequence counter, if applicable

Return values

rc	Return status code

The encryption key will not be accessed via the provided pointer after this function returns, so you may keep it on the stack.

which must point to either dev->crypto (for the normal case of installing a unicast cryptosystem) or dev->gcrypto (to install a cryptosystem that will be used only for decrypting group-source frames).

Definition at line 114 of file sec80211.c.

{
        struct net80211_crypto *crypto = *which;
        struct net80211_crypto *tbl_crypto;
 
        /* Remove old crypto if it exists */
        free ( *which );
        *which = NULL;
 
        if ( crypt == NET80211_CRYPT_NONE ) {
                DBG ( "802.11-Sec not installing null cryptography\n" );
                return 0;
        }
 
        /* Find cryptosystem to use */
        for_each_table_entry ( tbl_crypto, NET80211_CRYPTOS ) {
                if ( tbl_crypto->algorithm == crypt ) {
                        crypto = zalloc ( sizeof ( *crypto ) +
                                          tbl_crypto->priv_len );
                        if ( ! crypto ) {
                                DBG ( "802.11-Sec out of memory\n" );
                                return -ENOMEM;
                        }
 
                        memcpy ( crypto, tbl_crypto, sizeof ( *crypto ) );
                        crypto->priv = ( ( void * ) crypto +
                                         sizeof ( *crypto ) );
                        break;
                }
        }
 
        if ( ! crypto ) {
                DBG ( "802.11-Sec no support for cryptosystem %d\n", crypt );
                return -ENOTSUP_CRYPT ( crypt );
        }
 
        *which = crypto;
 
        DBG ( "802.11-Sec installing cryptosystem %d as %p with key of "
              "length %d\n", crypt, crypto, len );
 
        return crypto->init ( crypto, key, len, rsc );
}

References net80211_crypto::algorithm, DBG, ENOMEM, ENOTSUP_CRYPT, for_each_table_entry, free, net80211_crypto::init, key, len, memcpy(), NET80211_CRYPT_NONE, NET80211_CRYPTOS, NULL, net80211_crypto::priv, net80211_crypto::priv_len, rsc, and zalloc().

Referenced by trivial_init(), wpa_install_gtk(), and wpa_install_ptk().

sec80211_rsn_get_crypto_desc()

u32 sec80211_rsn_get_crypto_desc	(	enum net80211_crypto_alg	crypt,
		int	rsnie )

Determine RSN descriptor for specified net80211 cryptosystem number.

@v crypt Cryptosystem number @v rsnie Whether to return a new-format (RSN IE) descriptor @ret desc RSN descriptor

If rsnie is false, returns an old-format (WPA vendor IE) descriptor.

Definition at line 482 of file sec80211.c.

{
        return rsn_get_desc ( crypt, rsnie, rsn_cipher_map );
}

References rsn_cipher_map, rsn_get_desc(), and u32.

Referenced by wpa_make_rsn_ie().

sec80211_rsn_get_akm_desc()

u32 sec80211_rsn_get_akm_desc	(	enum net80211_security_proto	secprot,
		int	rsnie )

Determine RSN descriptor for specified net80211 handshaker number.

@v secprot Handshaker number @v rsnie Whether to return a new-format (RSN IE) descriptor @ret desc RSN descriptor

If rsnie is false, returns an old-format (WPA vendor IE) descriptor.

Definition at line 497 of file sec80211.c.

{
        return rsn_get_desc ( secprot, rsnie, rsn_akm_map );
}

References rsn_akm_map, rsn_get_desc(), and u32.

Referenced by wpa_make_rsn_ie().

sec80211_rsn_get_net80211_crypt()

enum net80211_crypto_alg sec80211_rsn_get_net80211_crypt

(

u32

desc

)

Determine net80211 cryptosystem number from RSN descriptor.

@v desc RSN descriptor @ret crypt net80211 cryptosystem enumeration value

Definition at line 509 of file sec80211.c.

{
        struct descriptor_map *map = rsn_cipher_map;
 
        for ( ; map->oui_type != END_MAGIC; map++ ) {
                if ( map->oui_type == ( desc & OUI_TYPE_MASK ) )
                        break;
        }
 
        return map->net80211_type;
}

References desc, END_MAGIC, map, OUI_TYPE_MASK, rsn_cipher_map, and u32.

Referenced by wpa_handle_3_of_4(), and wpa_make_rsn_ie().