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-rw-r--r--gpxe/src/net/80211/wpa.c973
1 files changed, 973 insertions, 0 deletions
diff --git a/gpxe/src/net/80211/wpa.c b/gpxe/src/net/80211/wpa.c
new file mode 100644
index 00000000..9bac8fe7
--- /dev/null
+++ b/gpxe/src/net/80211/wpa.c
@@ -0,0 +1,973 @@
+/*
+ * Copyright (c) 2009 Joshua Oreman <oremanj@rwcr.net>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <gpxe/net80211.h>
+#include <gpxe/sec80211.h>
+#include <gpxe/wpa.h>
+#include <gpxe/eapol.h>
+#include <gpxe/crypto.h>
+#include <gpxe/arc4.h>
+#include <gpxe/crc32.h>
+#include <gpxe/sha1.h>
+#include <gpxe/hmac.h>
+#include <gpxe/list.h>
+#include <gpxe/ethernet.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+/** @file
+ *
+ * Handler for the aspects of WPA handshaking that are independent of
+ * 802.1X/PSK or TKIP/CCMP; this mostly involves the 4-Way Handshake.
+ */
+
+/** List of WPA contexts in active use. */
+struct list_head wpa_contexts = LIST_HEAD_INIT ( wpa_contexts );
+
+
+/**
+ * Return an error code and deauthenticate
+ *
+ * @v ctx WPA common context
+ * @v rc Return status code
+ * @ret rc The passed return status code
+ */
+static int wpa_fail ( struct wpa_common_ctx *ctx, int rc )
+{
+ net80211_deauthenticate ( ctx->dev, rc );
+ return rc;
+}
+
+
+/**
+ * Find a cryptosystem handler structure from a crypto ID
+ *
+ * @v crypt Cryptosystem ID
+ * @ret crypto Cryptosystem handler structure
+ *
+ * If support for @a crypt is not compiled in to gPXE, or if @a crypt
+ * is NET80211_CRYPT_UNKNOWN, returns @c NULL.
+ */
+static struct net80211_crypto *
+wpa_find_cryptosystem ( enum net80211_crypto_alg crypt )
+{
+ struct net80211_crypto *crypto;
+
+ for_each_table_entry ( crypto, NET80211_CRYPTOS ) {
+ if ( crypto->algorithm == crypt )
+ return crypto;
+ }
+
+ return NULL;
+}
+
+
+/**
+ * Find WPA key integrity and encryption handler from key version field
+ *
+ * @v ver Version bits of EAPOL-Key info field
+ * @ret kie Key integrity and encryption handler
+ */
+struct wpa_kie * wpa_find_kie ( int version )
+{
+ struct wpa_kie *kie;
+
+ for_each_table_entry ( kie, WPA_KIES ) {
+ if ( kie->version == version )
+ return kie;
+ }
+
+ return NULL;
+}
+
+
+/**
+ * Construct RSN or WPA information element
+ *
+ * @v dev 802.11 device
+ * @ret ie_ret RSN or WPA information element
+ * @ret rc Return status code
+ *
+ * This function allocates, fills, and returns a RSN or WPA
+ * information element suitable for including in an association
+ * request frame to the network identified by @c dev->associating.
+ * If it is impossible to construct an information element consistent
+ * with gPXE's capabilities that is compatible with that network, or
+ * if none should be sent because that network's beacon included no
+ * security information, returns an error indication and leaves
+ * @a ie_ret unchanged.
+ *
+ * The returned IE will be of the same type (RSN or WPA) as was
+ * included in the beacon for the network it is destined for.
+ */
+int wpa_make_rsn_ie ( struct net80211_device *dev, union ieee80211_ie **ie_ret )
+{
+ u8 *rsn, *rsn_end;
+ int is_rsn;
+ u32 group_cipher;
+ enum net80211_crypto_alg gcrypt;
+ int ie_len;
+ u8 *iep;
+ struct ieee80211_ie_rsn *ie;
+ struct ieee80211_frame *hdr;
+ struct ieee80211_beacon *beacon;
+
+ if ( ! dev->associating ) {
+ DBG ( "WPA: Can't make RSN IE for a non-associating device\n" );
+ return -EINVAL;
+ }
+
+ hdr = dev->associating->beacon->data;
+ beacon = ( struct ieee80211_beacon * ) hdr->data;
+ rsn = sec80211_find_rsn ( beacon->info_element,
+ dev->associating->beacon->tail, &is_rsn,
+ &rsn_end );
+ if ( ! rsn ) {
+ DBG ( "WPA: Can't make RSN IE when we didn't get one\n" );
+ return -EINVAL;
+ }
+
+ rsn += 2; /* skip version */
+ group_cipher = *( u32 * ) rsn;
+ gcrypt = sec80211_rsn_get_net80211_crypt ( group_cipher );
+
+ if ( ! wpa_find_cryptosystem ( gcrypt ) ||
+ ! wpa_find_cryptosystem ( dev->associating->crypto ) ) {
+ DBG ( "WPA: No support for (GC:%d, PC:%d)\n",
+ gcrypt, dev->associating->crypto );
+ return -ENOTSUP;
+ }
+
+ /* Everything looks good - make our IE. */
+
+ /* WPA IEs need 4 more bytes for the OUI+type */
+ ie_len = ieee80211_rsn_size ( 1, 1, 0, is_rsn ) + ( 4 * ! is_rsn );
+ iep = malloc ( ie_len );
+ if ( ! iep )
+ return -ENOMEM;
+
+ *ie_ret = ( union ieee80211_ie * ) iep;
+
+ /* Store ID and length bytes. */
+ *iep++ = ( is_rsn ? IEEE80211_IE_RSN : IEEE80211_IE_VENDOR );
+ *iep++ = ie_len - 2;
+
+ /* Store OUI+type for WPA IEs. */
+ if ( ! is_rsn ) {
+ *( u32 * ) iep = IEEE80211_WPA_OUI_VEN;
+ iep += 4;
+ }
+
+ /* If this is a WPA IE, the id and len bytes in the
+ ieee80211_ie_rsn structure will not be valid, but by doing
+ the cast we can fill all the other fields much more
+ readily. */
+
+ ie = ( struct ieee80211_ie_rsn * ) ( iep - 2 );
+ ie->version = IEEE80211_RSN_VERSION;
+ ie->group_cipher = group_cipher;
+ ie->pairwise_count = 1;
+ ie->pairwise_cipher[0] =
+ sec80211_rsn_get_crypto_desc ( dev->associating->crypto,
+ is_rsn );
+ ie->akm_count = 1;
+ ie->akm_list[0] =
+ sec80211_rsn_get_akm_desc ( dev->associating->handshaking,
+ is_rsn );
+ if ( is_rsn ) {
+ ie->rsn_capab = 0;
+ ie->pmkid_count = 0;
+ }
+
+ return 0;
+}
+
+
+/**
+ * Set up generic WPA support to handle 4-Way Handshake
+ *
+ * @v dev 802.11 device
+ * @v ctx WPA common context
+ * @v pmk Pairwise Master Key to use for session
+ * @v pmk_len Length of PMK, almost always 32
+ * @ret rc Return status code
+ */
+int wpa_start ( struct net80211_device *dev, struct wpa_common_ctx *ctx,
+ const void *pmk, size_t pmk_len )
+{
+ struct io_buffer *iob;
+ struct ieee80211_frame *hdr;
+ struct ieee80211_beacon *beacon;
+ u8 *ap_rsn_ie = NULL, *ap_rsn_ie_end;
+
+ if ( ! dev->rsn_ie || ! dev->associating )
+ return -EINVAL;
+
+ ctx->dev = dev;
+ memcpy ( ctx->pmk, pmk, ctx->pmk_len = pmk_len );
+ ctx->state = WPA_READY;
+ ctx->replay = ~0ULL;
+
+ iob = dev->associating->beacon;
+ hdr = iob->data;
+ beacon = ( struct ieee80211_beacon * ) hdr->data;
+ ap_rsn_ie = sec80211_find_rsn ( beacon->info_element, iob->tail,
+ &ctx->ap_rsn_is_rsn, &ap_rsn_ie_end );
+ if ( ap_rsn_ie ) {
+ ctx->ap_rsn_ie = malloc ( ap_rsn_ie_end - ap_rsn_ie );
+ if ( ! ctx->ap_rsn_ie )
+ return -ENOMEM;
+ memcpy ( ctx->ap_rsn_ie, ap_rsn_ie, ap_rsn_ie_end - ap_rsn_ie );
+ ctx->ap_rsn_ie_len = ap_rsn_ie_end - ap_rsn_ie;
+ } else {
+ return -ENOENT;
+ }
+
+ ctx->crypt = dev->associating->crypto;
+ ctx->gcrypt = NET80211_CRYPT_UNKNOWN;
+
+ list_add_tail ( &ctx->list, &wpa_contexts );
+ return 0;
+}
+
+
+/**
+ * Disable handling of received WPA handshake frames
+ *
+ * @v dev 802.11 device
+ */
+void wpa_stop ( struct net80211_device *dev )
+{
+ struct wpa_common_ctx *ctx, *tmp;
+
+ list_for_each_entry_safe ( ctx, tmp, &wpa_contexts, list ) {
+ if ( ctx->dev == dev ) {
+ free ( ctx->ap_rsn_ie );
+ ctx->ap_rsn_ie = NULL;
+ list_del ( &ctx->list );
+ }
+ }
+}
+
+
+/**
+ * Check PMKID consistency
+ *
+ * @v ctx WPA common context
+ * @v pmkid PMKID to check against (16 bytes long)
+ * @ret rc Zero if they match, or a negative error code if not
+ */
+int wpa_check_pmkid ( struct wpa_common_ctx *ctx, const u8 *pmkid )
+{
+ u8 sha1_ctx[SHA1_CTX_SIZE];
+ u8 my_pmkid[SHA1_SIZE];
+ u8 pmk[ctx->pmk_len];
+ size_t pmk_len;
+ struct {
+ char name[8];
+ u8 aa[ETH_ALEN];
+ u8 spa[ETH_ALEN];
+ } __attribute__ (( packed )) pmkid_data;
+
+ memcpy ( pmk, ctx->pmk, ctx->pmk_len );
+ pmk_len = ctx->pmk_len;
+
+ memcpy ( pmkid_data.name, "PMK Name", 8 );
+ memcpy ( pmkid_data.aa, ctx->dev->bssid, ETH_ALEN );
+ memcpy ( pmkid_data.spa, ctx->dev->netdev->ll_addr, ETH_ALEN );
+
+ hmac_init ( &sha1_algorithm, sha1_ctx, pmk, &pmk_len );
+ hmac_update ( &sha1_algorithm, sha1_ctx, &pmkid_data,
+ sizeof ( pmkid_data ) );
+ hmac_final ( &sha1_algorithm, sha1_ctx, pmk, &pmk_len, my_pmkid );
+
+ if ( memcmp ( my_pmkid, pmkid, WPA_PMKID_LEN ) != 0 )
+ return -EACCES;
+
+ return 0;
+}
+
+
+/**
+ * Derive pairwise transient key
+ *
+ * @v ctx WPA common context
+ */
+static void wpa_derive_ptk ( struct wpa_common_ctx *ctx )
+{
+ struct {
+ u8 mac1[ETH_ALEN];
+ u8 mac2[ETH_ALEN];
+ u8 nonce1[WPA_NONCE_LEN];
+ u8 nonce2[WPA_NONCE_LEN];
+ } __attribute__ (( packed )) ptk_data;
+
+ /* The addresses and nonces are stored in numerical order (!) */
+
+ if ( memcmp ( ctx->dev->netdev->ll_addr, ctx->dev->bssid,
+ ETH_ALEN ) < 0 ) {
+ memcpy ( ptk_data.mac1, ctx->dev->netdev->ll_addr, ETH_ALEN );
+ memcpy ( ptk_data.mac2, ctx->dev->bssid, ETH_ALEN );
+ } else {
+ memcpy ( ptk_data.mac1, ctx->dev->bssid, ETH_ALEN );
+ memcpy ( ptk_data.mac2, ctx->dev->netdev->ll_addr, ETH_ALEN );
+ }
+
+ if ( memcmp ( ctx->Anonce, ctx->Snonce, WPA_NONCE_LEN ) < 0 ) {
+ memcpy ( ptk_data.nonce1, ctx->Anonce, WPA_NONCE_LEN );
+ memcpy ( ptk_data.nonce2, ctx->Snonce, WPA_NONCE_LEN );
+ } else {
+ memcpy ( ptk_data.nonce1, ctx->Snonce, WPA_NONCE_LEN );
+ memcpy ( ptk_data.nonce2, ctx->Anonce, WPA_NONCE_LEN );
+ }
+
+ DBGC2 ( ctx, "WPA %p A1 %s, A2 %s\n", ctx, eth_ntoa ( ptk_data.mac1 ),
+ eth_ntoa ( ptk_data.mac2 ) );
+ DBGC2 ( ctx, "WPA %p Nonce1, Nonce2:\n", ctx );
+ DBGC2_HD ( ctx, ptk_data.nonce1, WPA_NONCE_LEN );
+ DBGC2_HD ( ctx, ptk_data.nonce2, WPA_NONCE_LEN );
+
+ prf_sha1 ( ctx->pmk, ctx->pmk_len,
+ "Pairwise key expansion",
+ &ptk_data, sizeof ( ptk_data ),
+ &ctx->ptk, sizeof ( ctx->ptk ) );
+
+ DBGC2 ( ctx, "WPA %p PTK:\n", ctx );
+ DBGC2_HD ( ctx, &ctx->ptk, sizeof ( ctx->ptk ) );
+}
+
+
+/**
+ * Install pairwise transient key
+ *
+ * @v ctx WPA common context
+ * @v len Key length (16 for CCMP, 32 for TKIP)
+ * @ret rc Return status code
+ */
+static inline int wpa_install_ptk ( struct wpa_common_ctx *ctx, int len )
+{
+ DBGC ( ctx, "WPA %p: installing %d-byte pairwise transient key\n",
+ ctx, len );
+ DBGC2_HD ( ctx, &ctx->ptk.tk, len );
+
+ return sec80211_install ( &ctx->dev->crypto, ctx->crypt,
+ &ctx->ptk.tk, len, NULL );
+}
+
+/**
+ * Install group transient key
+ *
+ * @v ctx WPA common context
+ * @v len Key length (16 for CCMP, 32 for TKIP)
+ * @v rsc Receive sequence counter field in EAPOL-Key packet
+ * @ret rc Return status code
+ */
+static inline int wpa_install_gtk ( struct wpa_common_ctx *ctx, int len,
+ const void *rsc )
+{
+ DBGC ( ctx, "WPA %p: installing %d-byte group transient key\n",
+ ctx, len );
+ DBGC2_HD ( ctx, &ctx->gtk.tk, len );
+
+ return sec80211_install ( &ctx->dev->gcrypto, ctx->gcrypt,
+ &ctx->gtk.tk, len, rsc );
+}
+
+/**
+ * Search for group transient key, and install it if found
+ *
+ * @v ctx WPA common context
+ * @v ie Pointer to first IE in key data field
+ * @v ie_end Pointer to first byte not in key data field
+ * @v rsc Receive sequence counter field in EAPOL-Key packet
+ * @ret rc Return status code
+ */
+static int wpa_maybe_install_gtk ( struct wpa_common_ctx *ctx,
+ union ieee80211_ie *ie, void *ie_end,
+ const void *rsc )
+{
+ struct wpa_kde *kde;
+
+ if ( ! ieee80211_ie_bound ( ie, ie_end ) )
+ return -ENOENT;
+
+ while ( ie ) {
+ if ( ie->id == IEEE80211_IE_VENDOR &&
+ ie->vendor.oui == WPA_KDE_GTK )
+ break;
+
+ ie = ieee80211_next_ie ( ie, ie_end );
+ }
+
+ if ( ! ie )
+ return -ENOENT;
+
+ if ( ie->len - 6u > sizeof ( ctx->gtk.tk ) ) {
+ DBGC ( ctx, "WPA %p: GTK KDE is too long (%d bytes, max %d)\n",
+ ctx, ie->len - 4, sizeof ( ctx->gtk.tk ) );
+ return -EINVAL;
+ }
+
+ /* XXX We ignore key ID for now. */
+ kde = ( struct wpa_kde * ) ie;
+ memcpy ( &ctx->gtk.tk, &kde->gtk_encap.gtk, kde->len - 6 );
+
+ return wpa_install_gtk ( ctx, kde->len - 6, rsc );
+}
+
+
+/**
+ * Allocate I/O buffer for construction of outgoing EAPOL-Key frame
+ *
+ * @v kdlen Maximum number of bytes in the Key Data field
+ * @ret iob Newly allocated I/O buffer
+ *
+ * The returned buffer will have space reserved for the link-layer and
+ * EAPOL headers, and will have @c iob->tail pointing to the start of
+ * the Key Data field. Thus, it is necessary to use iob_put() in
+ * filling the Key Data.
+ */
+static struct io_buffer * wpa_alloc_frame ( int kdlen )
+{
+ struct io_buffer *ret = alloc_iob ( sizeof ( struct eapol_key_pkt ) +
+ kdlen + EAPOL_HDR_LEN +
+ MAX_LL_HEADER_LEN );
+ if ( ! ret )
+ return NULL;
+
+ iob_reserve ( ret, MAX_LL_HEADER_LEN + EAPOL_HDR_LEN );
+ memset ( iob_put ( ret, sizeof ( struct eapol_key_pkt ) ), 0,
+ sizeof ( struct eapol_key_pkt ) );
+
+ return ret;
+}
+
+
+/**
+ * Send EAPOL-Key packet
+ *
+ * @v iob I/O buffer, with sufficient headroom for headers
+ * @v dev 802.11 device
+ * @v kie Key integrity and encryption handler
+ * @v is_rsn If TRUE, handshake uses new RSN format
+ * @ret rc Return status code
+ *
+ * If a KIE is specified, the MIC will be filled in before transmission.
+ */
+static int wpa_send_eapol ( struct io_buffer *iob, struct wpa_common_ctx *ctx,
+ struct wpa_kie *kie )
+{
+ struct eapol_key_pkt *pkt = iob->data;
+ struct eapol_frame *eapol = iob_push ( iob, EAPOL_HDR_LEN );
+
+ pkt->info = htons ( pkt->info );
+ pkt->keysize = htons ( pkt->keysize );
+ pkt->datalen = htons ( pkt->datalen );
+ pkt->replay = cpu_to_be64 ( pkt->replay );
+ eapol->version = EAPOL_THIS_VERSION;
+ eapol->type = EAPOL_TYPE_KEY;
+ eapol->length = htons ( iob->tail - iob->data - sizeof ( *eapol ) );
+
+ memset ( pkt->mic, 0, sizeof ( pkt->mic ) );
+ if ( kie )
+ kie->mic ( &ctx->ptk.kck, eapol, EAPOL_HDR_LEN +
+ sizeof ( *pkt ) + ntohs ( pkt->datalen ),
+ pkt->mic );
+
+ return net_tx ( iob, ctx->dev->netdev, &eapol_protocol,
+ ctx->dev->bssid );
+}
+
+
+/**
+ * Send second frame in 4-Way Handshake
+ *
+ * @v ctx WPA common context
+ * @v pkt First frame, to which this is a reply
+ * @v is_rsn If TRUE, handshake uses new RSN format
+ * @v kie Key integrity and encryption handler
+ * @ret rc Return status code
+ */
+static int wpa_send_2_of_4 ( struct wpa_common_ctx *ctx,
+ struct eapol_key_pkt *pkt, int is_rsn,
+ struct wpa_kie *kie )
+{
+ struct io_buffer *iob = wpa_alloc_frame ( ctx->dev->rsn_ie->len + 2 );
+ struct eapol_key_pkt *npkt;
+
+ if ( ! iob )
+ return -ENOMEM;
+
+ npkt = iob->data;
+ memcpy ( npkt, pkt, sizeof ( *pkt ) );
+ npkt->info &= ~EAPOL_KEY_INFO_KEY_ACK;
+ npkt->info |= EAPOL_KEY_INFO_KEY_MIC;
+ if ( is_rsn )
+ npkt->keysize = 0;
+ memcpy ( npkt->nonce, ctx->Snonce, sizeof ( npkt->nonce ) );
+ npkt->datalen = ctx->dev->rsn_ie->len + 2;
+ memcpy ( iob_put ( iob, npkt->datalen ), ctx->dev->rsn_ie,
+ npkt->datalen );
+
+ DBGC ( ctx, "WPA %p: sending 2/4\n", ctx );
+
+ return wpa_send_eapol ( iob, ctx, kie );
+}
+
+
+/**
+ * Handle receipt of first frame in 4-Way Handshake
+ *
+ * @v ctx WPA common context
+ * @v pkt EAPOL-Key packet
+ * @v is_rsn If TRUE, frame uses new RSN format
+ * @v kie Key integrity and encryption handler
+ * @ret rc Return status code
+ */
+static int wpa_handle_1_of_4 ( struct wpa_common_ctx *ctx,
+ struct eapol_key_pkt *pkt, int is_rsn,
+ struct wpa_kie *kie )
+{
+ int rc;
+
+ if ( ctx->state == WPA_WAITING )
+ return -EINVAL;
+
+ ctx->state = WPA_WORKING;
+ memcpy ( ctx->Anonce, pkt->nonce, sizeof ( ctx->Anonce ) );
+ if ( ! ctx->have_Snonce ) {
+ get_random_bytes ( ctx->Snonce, sizeof ( ctx->Snonce ) );
+ ctx->have_Snonce = 1;
+ }
+
+ if ( is_rsn && pkt->datalen ) {
+ union ieee80211_ie *ie = ( union ieee80211_ie * ) pkt->data;
+ void *ie_end = pkt->data + pkt->datalen;
+
+ if ( ! ieee80211_ie_bound ( ie, ie_end ) ) {
+ DBGC ( ctx, "WPA %p: malformed PMKID KDE\n", ctx );
+ return wpa_fail ( ctx, -EINVAL );
+ }
+
+ while ( ie ) {
+ if ( ie->id == IEEE80211_IE_VENDOR &&
+ ie->vendor.oui == WPA_KDE_PMKID ) {
+ rc = wpa_check_pmkid ( ctx, ie->vendor.data );
+ if ( rc < 0 ) {
+ DBGC ( ctx, "WPA %p ALERT: PMKID "
+ "mismatch in 1/4\n", ctx );
+ return wpa_fail ( ctx, rc );
+ }
+ }
+
+ ie = ieee80211_next_ie ( ie, ie_end );
+ }
+ }
+
+ DBGC ( ctx, "WPA %p: received 1/4, looks OK\n", ctx );
+
+ wpa_derive_ptk ( ctx );
+
+ return wpa_send_2_of_4 ( ctx, pkt, is_rsn, kie );
+}
+
+
+/**
+ * Send fourth frame in 4-Way Handshake, or second in Group Key Handshake
+ *
+ * @v ctx WPA common context
+ * @v pkt EAPOL-Key packet for frame to which we're replying
+ * @v is_rsn If TRUE, frame uses new RSN format
+ * @v kie Key integrity and encryption handler
+ * @ret rc Return status code
+ */
+static int wpa_send_final ( struct wpa_common_ctx *ctx,
+ struct eapol_key_pkt *pkt, int is_rsn,
+ struct wpa_kie *kie )
+{
+ struct io_buffer *iob = wpa_alloc_frame ( 0 );
+ struct eapol_key_pkt *npkt;
+
+ if ( ! iob )
+ return -ENOMEM;
+
+ npkt = iob->data;
+ memcpy ( npkt, pkt, sizeof ( *pkt ) );
+ npkt->info &= ~( EAPOL_KEY_INFO_KEY_ACK | EAPOL_KEY_INFO_INSTALL |
+ EAPOL_KEY_INFO_KEY_ENC );
+ if ( is_rsn )
+ npkt->keysize = 0;
+ memset ( npkt->nonce, 0, sizeof ( npkt->nonce ) );
+ memset ( npkt->iv, 0, sizeof ( npkt->iv ) );
+ npkt->datalen = 0;
+
+ if ( npkt->info & EAPOL_KEY_INFO_TYPE )
+ DBGC ( ctx, "WPA %p: sending 4/4\n", ctx );
+ else
+ DBGC ( ctx, "WPA %p: sending 2/2\n", ctx );
+
+ return wpa_send_eapol ( iob, ctx, kie );
+
+}
+
+
+/**
+ * Handle receipt of third frame in 4-Way Handshake
+ *
+ * @v ctx WPA common context
+ * @v pkt EAPOL-Key packet
+ * @v is_rsn If TRUE, frame uses new RSN format
+ * @v kie Key integrity and encryption handler
+ * @ret rc Return status code
+ */
+static int wpa_handle_3_of_4 ( struct wpa_common_ctx *ctx,
+ struct eapol_key_pkt *pkt, int is_rsn,
+ struct wpa_kie *kie )
+{
+ int rc;
+ u8 *this_rsn, *this_rsn_end;
+ u8 *new_rsn, *new_rsn_end;
+ int this_is_rsn, new_is_rsn;
+
+ if ( ctx->state == WPA_WAITING )
+ return -EINVAL;
+
+ ctx->state = WPA_WORKING;
+
+ /* Check nonce */
+ if ( memcmp ( ctx->Anonce, pkt->nonce, WPA_NONCE_LEN ) != 0 ) {
+ DBGC ( ctx, "WPA %p ALERT: nonce mismatch in 3/4\n", ctx );
+ return wpa_fail ( ctx, -EACCES );
+ }
+
+ /* Check RSN IE */
+ this_rsn = sec80211_find_rsn ( ( union ieee80211_ie * ) pkt->data,
+ pkt->data + pkt->datalen,
+ &this_is_rsn, &this_rsn_end );
+ if ( this_rsn )
+ new_rsn = sec80211_find_rsn ( ( union ieee80211_ie * )
+ this_rsn_end,
+ pkt->data + pkt->datalen,
+ &new_is_rsn, &new_rsn_end );
+ else
+ new_rsn = NULL;
+
+ if ( ! ctx->ap_rsn_ie || ! this_rsn ||
+ ctx->ap_rsn_ie_len != ( this_rsn_end - this_rsn ) ||
+ ctx->ap_rsn_is_rsn != this_is_rsn ||
+ memcmp ( ctx->ap_rsn_ie, this_rsn, ctx->ap_rsn_ie_len ) != 0 ) {
+ DBGC ( ctx, "WPA %p ALERT: RSN mismatch in 3/4\n", ctx );
+ DBGC2 ( ctx, "WPA %p RSNs (in 3/4, in beacon):\n", ctx );
+ DBGC2_HD ( ctx, this_rsn, this_rsn_end - this_rsn );
+ DBGC2_HD ( ctx, ctx->ap_rsn_ie, ctx->ap_rsn_ie_len );
+ return wpa_fail ( ctx, -EACCES );
+ }
+
+ /* Don't switch if they just supplied both styles of IE
+ simultaneously; we need two RSN IEs or two WPA IEs to
+ switch ciphers. They'll be immediately consecutive because
+ of ordering guarantees. */
+ if ( new_rsn && this_is_rsn == new_is_rsn ) {
+ struct net80211_wlan *assoc = ctx->dev->associating;
+ DBGC ( ctx, "WPA %p: accommodating bait-and-switch tactics\n",
+ ctx );
+ DBGC2 ( ctx, "WPA %p RSNs (in 3/4+beacon, new in 3/4):\n",
+ ctx );
+ DBGC2_HD ( ctx, this_rsn, this_rsn_end - this_rsn );
+ DBGC2_HD ( ctx, new_rsn, new_rsn_end - new_rsn );
+
+ if ( ( rc = sec80211_detect_ie ( new_is_rsn, new_rsn,
+ new_rsn_end,
+ &assoc->handshaking,
+ &assoc->crypto ) ) != 0 )
+ DBGC ( ctx, "WPA %p: bait-and-switch invalid, staying "
+ "with original request\n", ctx );
+ } else {
+ new_rsn = this_rsn;
+ new_is_rsn = this_is_rsn;
+ new_rsn_end = this_rsn_end;
+ }
+
+ /* Grab group cryptosystem ID */
+ ctx->gcrypt = sec80211_rsn_get_net80211_crypt ( *( u32 * )
+ ( new_rsn + 2 ) );
+
+ /* Check for a GTK, if info field is encrypted */
+ if ( pkt->info & EAPOL_KEY_INFO_KEY_ENC ) {
+ rc = wpa_maybe_install_gtk ( ctx,
+ ( union ieee80211_ie * ) pkt->data,
+ pkt->data + pkt->datalen,
+ pkt->rsc );
+ if ( rc < 0 ) {
+ DBGC ( ctx, "WPA %p did not install GTK in 3/4: %s\n",
+ ctx, strerror ( rc ) );
+ if ( rc != -ENOENT )
+ return wpa_fail ( ctx, rc );
+ }
+ }
+
+ DBGC ( ctx, "WPA %p: received 3/4, looks OK\n", ctx );
+
+ /* Send final message */
+ rc = wpa_send_final ( ctx, pkt, is_rsn, kie );
+ if ( rc < 0 )
+ return wpa_fail ( ctx, rc );
+
+ /* Install PTK */
+ rc = wpa_install_ptk ( ctx, pkt->keysize );
+ if ( rc < 0 ) {
+ DBGC ( ctx, "WPA %p failed to install PTK: %s\n", ctx,
+ strerror ( rc ) );
+ return wpa_fail ( ctx, rc );
+ }
+
+ /* Mark us as needing a new Snonce if we rekey */
+ ctx->have_Snonce = 0;
+
+ /* Done! */
+ ctx->state = WPA_SUCCESS;
+ return 0;
+}
+
+
+/**
+ * Handle receipt of first frame in Group Key Handshake
+ *
+ * @v ctx WPA common context
+ * @v pkt EAPOL-Key packet
+ * @v is_rsn If TRUE, frame uses new RSN format
+ * @v kie Key integrity and encryption handler
+ * @ret rc Return status code
+ */
+static int wpa_handle_1_of_2 ( struct wpa_common_ctx *ctx,
+ struct eapol_key_pkt *pkt, int is_rsn,
+ struct wpa_kie *kie )
+{
+ int rc;
+
+ /*
+ * WPA and RSN do this completely differently.
+ *
+ * The idea of encoding the GTK (or PMKID, or various other
+ * things) into a KDE that looks like an information element
+ * is an RSN innovation; old WPA code never encapsulates
+ * things like that. If it looks like an info element, it
+ * really is (for the WPA IE check in frames 2/4 and 3/4). The
+ * "key data encrypted" bit in the info field is also specific
+ * to RSN.
+ *
+ * So from an old WPA host, 3/4 does not contain an
+ * encapsulated GTK. The first frame of the GK handshake
+ * contains it, encrypted, but without a KDE wrapper, and with
+ * the key ID field (which gPXE doesn't use) shoved away in
+ * the reserved bits in the info field, and the TxRx bit
+ * stealing the Install bit's spot.
+ */
+
+ if ( is_rsn && ( pkt->info & EAPOL_KEY_INFO_KEY_ENC ) ) {
+ rc = wpa_maybe_install_gtk ( ctx,
+ ( union ieee80211_ie * ) pkt->data,
+ pkt->data + pkt->datalen,
+ pkt->rsc );
+ if ( rc < 0 ) {
+ DBGC ( ctx, "WPA %p: failed to install GTK in 1/2: "
+ "%s\n", ctx, strerror ( rc ) );
+ return wpa_fail ( ctx, rc );
+ }
+ } else {
+ rc = kie->decrypt ( &ctx->ptk.kek, pkt->iv, pkt->data,
+ &pkt->datalen );
+ if ( rc < 0 ) {
+ DBGC ( ctx, "WPA %p: failed to decrypt GTK: %s\n",
+ ctx, strerror ( rc ) );
+ return rc; /* non-fatal */
+ }
+ if ( pkt->datalen > sizeof ( ctx->gtk.tk ) ) {
+ DBGC ( ctx, "WPA %p: too much GTK data (%d > %d)\n",
+ ctx, pkt->datalen, sizeof ( ctx->gtk.tk ) );
+ return wpa_fail ( ctx, -EINVAL );
+ }
+
+ memcpy ( &ctx->gtk.tk, pkt->data, pkt->datalen );
+ wpa_install_gtk ( ctx, pkt->datalen, pkt->rsc );
+ }
+
+ DBGC ( ctx, "WPA %p: received 1/2, looks OK\n", ctx );
+
+ return wpa_send_final ( ctx, pkt, is_rsn, kie );
+}
+
+
+/**
+ * Handle receipt of EAPOL-Key frame for WPA
+ *
+ * @v iob I/O buffer
+ * @v netdev Network device
+ * @v ll_source Source link-layer address
+ */
+static int eapol_key_rx ( struct io_buffer *iob, struct net_device *netdev,
+ const void *ll_source )
+{
+ struct net80211_device *dev = net80211_get ( netdev );
+ struct eapol_key_pkt *pkt = iob->data;
+ int is_rsn, found_ctx;
+ struct wpa_common_ctx *ctx;
+ int rc = 0;
+ struct wpa_kie *kie;
+ u8 their_mic[16], our_mic[16];
+
+ if ( pkt->type != EAPOL_KEY_TYPE_WPA &&
+ pkt->type != EAPOL_KEY_TYPE_RSN ) {
+ DBG ( "EAPOL-Key: packet not of 802.11 type\n" );
+ rc = -EINVAL;
+ goto drop;
+ }
+
+ is_rsn = ( pkt->type == EAPOL_KEY_TYPE_RSN );
+
+ if ( ! dev ) {
+ DBG ( "EAPOL-Key: packet not from 802.11\n" );
+ rc = -EINVAL;
+ goto drop;
+ }
+
+ if ( memcmp ( dev->bssid, ll_source, ETH_ALEN ) != 0 ) {
+ DBG ( "EAPOL-Key: packet not from associated AP\n" );
+ rc = -EINVAL;
+ goto drop;
+ }
+
+ if ( ! ( ntohs ( pkt->info ) & EAPOL_KEY_INFO_KEY_ACK ) ) {
+ DBG ( "EAPOL-Key: packet sent in wrong direction\n" );
+ rc = -EINVAL;
+ goto drop;
+ }
+
+ found_ctx = 0;
+ list_for_each_entry ( ctx, &wpa_contexts, list ) {
+ if ( ctx->dev == dev ) {
+ found_ctx = 1;
+ break;
+ }
+ }
+
+ if ( ! found_ctx ) {
+ DBG ( "EAPOL-Key: no WPA context to handle packet for %p\n",
+ dev );
+ rc = -ENOENT;
+ goto drop;
+ }
+
+ if ( ( void * ) ( pkt + 1 ) + ntohs ( pkt->datalen ) > iob->tail ) {
+ DBGC ( ctx, "WPA %p: packet truncated (has %d extra bytes, "
+ "states %d)\n", ctx, iob->tail - ( void * ) ( pkt + 1 ),
+ ntohs ( pkt->datalen ) );
+ rc = -EINVAL;
+ goto drop;
+ }
+
+ /* Get a handle on key integrity/encryption handler */
+ kie = wpa_find_kie ( ntohs ( pkt->info ) & EAPOL_KEY_INFO_VERSION );
+ if ( ! kie ) {
+ DBGC ( ctx, "WPA %p: no support for packet version %d\n", ctx,
+ ntohs ( pkt->info ) & EAPOL_KEY_INFO_VERSION );
+ rc = wpa_fail ( ctx, -ENOTSUP );
+ goto drop;
+ }
+
+ /* Check MIC */
+ if ( ntohs ( pkt->info ) & EAPOL_KEY_INFO_KEY_MIC ) {
+ memcpy ( their_mic, pkt->mic, sizeof ( pkt->mic ) );
+ memset ( pkt->mic, 0, sizeof ( pkt->mic ) );
+ kie->mic ( &ctx->ptk.kck, ( void * ) pkt - EAPOL_HDR_LEN,
+ EAPOL_HDR_LEN + sizeof ( *pkt ) +
+ ntohs ( pkt->datalen ), our_mic );
+ DBGC2 ( ctx, "WPA %p MIC comparison (theirs, ours):\n", ctx );
+ DBGC2_HD ( ctx, their_mic, 16 );
+ DBGC2_HD ( ctx, our_mic, 16 );
+ if ( memcmp ( their_mic, our_mic, sizeof ( pkt->mic ) ) != 0 ) {
+ DBGC ( ctx, "WPA %p: EAPOL MIC failure\n", ctx );
+ goto drop;
+ }
+ }
+
+ /* Fix byte order to local */
+ pkt->info = ntohs ( pkt->info );
+ pkt->keysize = ntohs ( pkt->keysize );
+ pkt->datalen = ntohs ( pkt->datalen );
+ pkt->replay = be64_to_cpu ( pkt->replay );
+
+ /* Check replay counter */
+ if ( ctx->replay != ~0ULL && ctx->replay >= pkt->replay ) {
+ DBGC ( ctx, "WPA %p ALERT: Replay detected! "
+ "(%08x:%08x >= %08x:%08x)\n", ctx,
+ ( u32 ) ( ctx->replay >> 32 ), ( u32 ) ctx->replay,
+ ( u32 ) ( pkt->replay >> 32 ), ( u32 ) pkt->replay );
+ rc = 0; /* ignore without error */
+ goto drop;
+ }
+ ctx->replay = pkt->replay;
+
+ /* Decrypt key data */
+ if ( pkt->info & EAPOL_KEY_INFO_KEY_ENC ) {
+ rc = kie->decrypt ( &ctx->ptk.kek, pkt->iv, pkt->data,
+ &pkt->datalen );
+ if ( rc < 0 ) {
+ DBGC ( ctx, "WPA %p: failed to decrypt packet: %s\n",
+ ctx, strerror ( rc ) );
+ goto drop;
+ }
+ }
+
+ /* Hand it off to appropriate handler */
+ switch ( pkt->info & ( EAPOL_KEY_INFO_TYPE |
+ EAPOL_KEY_INFO_KEY_MIC ) ) {
+ case EAPOL_KEY_TYPE_PTK:
+ rc = wpa_handle_1_of_4 ( ctx, pkt, is_rsn, kie );
+ break;
+
+ case EAPOL_KEY_TYPE_PTK | EAPOL_KEY_INFO_KEY_MIC:
+ rc = wpa_handle_3_of_4 ( ctx, pkt, is_rsn, kie );
+ break;
+
+ case EAPOL_KEY_TYPE_GTK | EAPOL_KEY_INFO_KEY_MIC:
+ rc = wpa_handle_1_of_2 ( ctx, pkt, is_rsn, kie );
+ break;
+
+ default:
+ DBGC ( ctx, "WPA %p: Invalid combination of key flags %04x\n",
+ ctx, pkt->info );
+ rc = -EINVAL;
+ break;
+ }
+
+ drop:
+ free_iob ( iob );
+ return rc;
+}
+
+struct eapol_handler eapol_key_handler __eapol_handler = {
+ .type = EAPOL_TYPE_KEY,
+ .rx = eapol_key_rx,
+};
+
+/* WPA always needs EAPOL in order to be useful */
+REQUIRE_OBJECT ( eapol );