peerkey.c

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/*
 * WPA Supplicant - PeerKey for Direct Link Setup (DLS)
 * Copyright (c) 2006-2008, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#ifdef CONFIG_PEERKEY

#include "common.h"
#include "eloop.h"
#include "crypto/sha1.h"
#include "crypto/sha256.h"
#include "common/ieee802_11_defs.h"
#include "wpa.h"
#include "wpa_i.h"
#include "wpa_ie.h"
#include "peerkey.h"


static u8 * wpa_add_ie(u8 *pos, const u8 *ie, size_t ie_len)
{
        os_memcpy(pos, ie, ie_len);
        return pos + ie_len;
}


static u8 * wpa_add_kde(u8 *pos, u32 kde, const u8 *data, size_t data_len)
{
        *pos++ = WLAN_EID_VENDOR_SPECIFIC;
        *pos++ = RSN_SELECTOR_LEN + data_len;
        RSN_SELECTOR_PUT(pos, kde);
        pos += RSN_SELECTOR_LEN;
        os_memcpy(pos, data, data_len);
        pos += data_len;
        return pos;
}


static void wpa_supplicant_smk_timeout(void *eloop_ctx, void *timeout_ctx)
{
#if 0
        struct wpa_sm *sm = eloop_ctx;
        struct wpa_peerkey *peerkey = timeout_ctx;
#endif
        /* TODO: time out SMK and any STK that was generated using this SMK */
}


static void wpa_supplicant_peerkey_free(struct wpa_sm *sm,
                                        struct wpa_peerkey *peerkey)
{
        eloop_cancel_timeout(wpa_supplicant_smk_timeout, sm, peerkey);
        os_free(peerkey);
}


static int wpa_supplicant_send_smk_error(struct wpa_sm *sm, const u8 *dst,
                                         const u8 *peer,
                                         u16 mui, u16 error_type, int ver)
{
        size_t rlen;
        struct wpa_eapol_key *err;
        struct rsn_error_kde error;
        u8 *rbuf, *pos;
        size_t kde_len;
        u16 key_info;

        kde_len = 2 + RSN_SELECTOR_LEN + sizeof(error);
        if (peer)
                kde_len += 2 + RSN_SELECTOR_LEN + ETH_ALEN;

        rbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY,
                                  NULL, sizeof(*err) + kde_len, &rlen,
                                  (void *) &err);
        if (rbuf == NULL)
                return -1;

        err->type = EAPOL_KEY_TYPE_RSN;
        key_info = ver | WPA_KEY_INFO_SMK_MESSAGE | WPA_KEY_INFO_MIC |
                WPA_KEY_INFO_SECURE | WPA_KEY_INFO_ERROR |
                WPA_KEY_INFO_REQUEST;
        WPA_PUT_BE16(err->key_info, key_info);
        WPA_PUT_BE16(err->key_length, 0);
        os_memcpy(err->replay_counter, sm->request_counter,
                  WPA_REPLAY_COUNTER_LEN);
        inc_byte_array(sm->request_counter, WPA_REPLAY_COUNTER_LEN);

        WPA_PUT_BE16(err->key_data_length, (u16) kde_len);
        pos = (u8 *) (err + 1);

        if (peer) {
                /* Peer MAC Address KDE */
                pos = wpa_add_kde(pos, RSN_KEY_DATA_MAC_ADDR, peer, ETH_ALEN);
        }

        /* Error KDE */
        error.mui = host_to_be16(mui);
        error.error_type = host_to_be16(error_type);
        wpa_add_kde(pos, RSN_KEY_DATA_ERROR, (u8 *) &error, sizeof(error));

        if (peer) {
                wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key SMK Error (peer "
                           MACSTR " mui %d error_type %d)",
                           MAC2STR(peer), mui, error_type);
        } else {
                wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key SMK Error "
                           "(mui %d error_type %d)", mui, error_type);
        }

        wpa_eapol_key_send(sm, sm->ptk.kck, ver, dst, ETH_P_EAPOL,
                           rbuf, rlen, err->key_mic);

        return 0;
}


static int wpa_supplicant_send_smk_m3(struct wpa_sm *sm,
                                      const unsigned char *src_addr,
                                      const struct wpa_eapol_key *key,
                                      int ver, struct wpa_peerkey *peerkey)
{
        size_t rlen;
        struct wpa_eapol_key *reply;
        u8 *rbuf, *pos;
        size_t kde_len;
        u16 key_info;

        /* KDEs: Peer RSN IE, Initiator MAC Address, Initiator Nonce */
        kde_len = peerkey->rsnie_p_len +
                2 + RSN_SELECTOR_LEN + ETH_ALEN +
                2 + RSN_SELECTOR_LEN + WPA_NONCE_LEN;

        rbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY,
                                  NULL, sizeof(*reply) + kde_len, &rlen,
                                  (void *) &reply);
        if (rbuf == NULL)
                return -1;

        reply->type = EAPOL_KEY_TYPE_RSN;
        key_info = ver | WPA_KEY_INFO_SMK_MESSAGE | WPA_KEY_INFO_MIC |
                WPA_KEY_INFO_SECURE;
        WPA_PUT_BE16(reply->key_info, key_info);
        WPA_PUT_BE16(reply->key_length, 0);
        os_memcpy(reply->replay_counter, key->replay_counter,
                  WPA_REPLAY_COUNTER_LEN);

        os_memcpy(reply->key_nonce, peerkey->pnonce, WPA_NONCE_LEN);

        WPA_PUT_BE16(reply->key_data_length, (u16) kde_len);
        pos = (u8 *) (reply + 1);

        /* Peer RSN IE */
        pos = wpa_add_ie(pos, peerkey->rsnie_p, peerkey->rsnie_p_len);

        /* Initiator MAC Address KDE */
        pos = wpa_add_kde(pos, RSN_KEY_DATA_MAC_ADDR, peerkey->addr, ETH_ALEN);

        /* Initiator Nonce */
        wpa_add_kde(pos, RSN_KEY_DATA_NONCE, peerkey->inonce, WPA_NONCE_LEN);

        wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key SMK M3");
        wpa_eapol_key_send(sm, sm->ptk.kck, ver, src_addr, ETH_P_EAPOL,
                           rbuf, rlen, reply->key_mic);

        return 0;
}


static int wpa_supplicant_process_smk_m2(
        struct wpa_sm *sm, const unsigned char *src_addr,
        const struct wpa_eapol_key *key, size_t extra_len, int ver)
{
        struct wpa_peerkey *peerkey;
        struct wpa_eapol_ie_parse kde;
        struct wpa_ie_data ie;
        int cipher;
        struct rsn_ie_hdr *hdr;
        u8 *pos;

        wpa_printf(MSG_DEBUG, "RSN: Received SMK M2");

        if (!sm->peerkey_enabled || sm->proto != WPA_PROTO_RSN) {
                wpa_printf(MSG_INFO, "RSN: SMK handshake not allowed for "
                           "the current network");
                return -1;
        }

        if (wpa_supplicant_parse_ies((const u8 *) (key + 1), extra_len, &kde) <
            0) {
                wpa_printf(MSG_INFO, "RSN: Failed to parse KDEs in SMK M2");
                return -1;
        }

        if (kde.rsn_ie == NULL || kde.mac_addr == NULL ||
            kde.mac_addr_len < ETH_ALEN) {
                wpa_printf(MSG_INFO, "RSN: No RSN IE or MAC address KDE in "
                           "SMK M2");
                return -1;
        }

        wpa_printf(MSG_DEBUG, "RSN: SMK M2 - SMK initiator " MACSTR,
                   MAC2STR(kde.mac_addr));

        if (kde.rsn_ie_len > PEERKEY_MAX_IE_LEN) {
                wpa_printf(MSG_INFO, "RSN: Too long Initiator RSN IE in SMK "
                           "M2");
                return -1;
        }

        if (wpa_parse_wpa_ie_rsn(kde.rsn_ie, kde.rsn_ie_len, &ie) < 0) {
                wpa_printf(MSG_INFO, "RSN: Failed to parse RSN IE in SMK M2");
                return -1;
        }

        cipher = ie.pairwise_cipher & sm->allowed_pairwise_cipher;
        if (cipher & WPA_CIPHER_CCMP) {
                wpa_printf(MSG_DEBUG, "RSN: Using CCMP for PeerKey");
                cipher = WPA_CIPHER_CCMP;
        } else if (cipher & WPA_CIPHER_TKIP) {
                wpa_printf(MSG_DEBUG, "RSN: Using TKIP for PeerKey");
                cipher = WPA_CIPHER_TKIP;
        } else {
                wpa_printf(MSG_INFO, "RSN: No acceptable cipher in SMK M2");
                wpa_supplicant_send_smk_error(sm, src_addr, kde.mac_addr,
                                              STK_MUI_SMK, STK_ERR_CPHR_NS,
                                              ver);
                return -1;
        }

        /* TODO: find existing entry and if found, use that instead of adding
         * a new one; how to handle the case where both ends initiate at the
         * same time? */
        peerkey = os_zalloc(sizeof(*peerkey));
        if (peerkey == NULL)
                return -1;
        os_memcpy(peerkey->addr, kde.mac_addr, ETH_ALEN);
        os_memcpy(peerkey->inonce, key->key_nonce, WPA_NONCE_LEN);
        os_memcpy(peerkey->rsnie_i, kde.rsn_ie, kde.rsn_ie_len);
        peerkey->rsnie_i_len = kde.rsn_ie_len;
        peerkey->cipher = cipher;
#ifdef CONFIG_IEEE80211W
        if (ie.key_mgmt & (WPA_KEY_MGMT_IEEE8021X_SHA256 |
                           WPA_KEY_MGMT_PSK_SHA256))
                peerkey->use_sha256 = 1;
#endif /* CONFIG_IEEE80211W */

        if (os_get_random(peerkey->pnonce, WPA_NONCE_LEN)) {
                wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
                        "WPA: Failed to get random data for PNonce");
                wpa_supplicant_peerkey_free(sm, peerkey);
                return -1;
        }

        hdr = (struct rsn_ie_hdr *) peerkey->rsnie_p;
        hdr->elem_id = WLAN_EID_RSN;
        WPA_PUT_LE16(hdr->version, RSN_VERSION);
        pos = (u8 *) (hdr + 1);
        /* Group Suite can be anything for SMK RSN IE; receiver will just
         * ignore it. */
        RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
        pos += RSN_SELECTOR_LEN;
        /* Include only the selected cipher in pairwise cipher suite */
        WPA_PUT_LE16(pos, 1);
        pos += 2;
        if (cipher == WPA_CIPHER_CCMP)
                RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
        else if (cipher == WPA_CIPHER_TKIP)
                RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
        pos += RSN_SELECTOR_LEN;

        hdr->len = (pos - peerkey->rsnie_p) - 2;
        peerkey->rsnie_p_len = pos - peerkey->rsnie_p;
        wpa_hexdump(MSG_DEBUG, "WPA: RSN IE for SMK handshake",
                    peerkey->rsnie_p, peerkey->rsnie_p_len);

        wpa_supplicant_send_smk_m3(sm, src_addr, key, ver, peerkey);

        peerkey->next = sm->peerkey;
        sm->peerkey = peerkey;

        return 0;
}


static void rsn_smkid(const u8 *smk, const u8 *pnonce, const u8 *mac_p,
                      const u8 *inonce, const u8 *mac_i, u8 *smkid,
                      int use_sha256)
{
        char *title = "SMK Name";
        const u8 *addr[5];
        const size_t len[5] = { 8, WPA_NONCE_LEN, ETH_ALEN, WPA_NONCE_LEN,
                                ETH_ALEN };
        unsigned char hash[SHA256_MAC_LEN];

        addr[0] = (u8 *) title;
        addr[1] = pnonce;
        addr[2] = mac_p;
        addr[3] = inonce;
        addr[4] = mac_i;

#ifdef CONFIG_IEEE80211W
        if (use_sha256)
                hmac_sha256_vector(smk, PMK_LEN, 5, addr, len, hash);
        else
#endif /* CONFIG_IEEE80211W */
                hmac_sha1_vector(smk, PMK_LEN, 5, addr, len, hash);
        os_memcpy(smkid, hash, PMKID_LEN);
}


static void wpa_supplicant_send_stk_1_of_4(struct wpa_sm *sm,
                                           struct wpa_peerkey *peerkey)
{
        size_t mlen;
        struct wpa_eapol_key *msg;
        u8 *mbuf;
        size_t kde_len;
        u16 key_info, ver;

        kde_len = 2 + RSN_SELECTOR_LEN + PMKID_LEN;

        mbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY, NULL,
                                  sizeof(*msg) + kde_len, &mlen,
                                  (void *) &msg);
        if (mbuf == NULL)
                return;

        msg->type = EAPOL_KEY_TYPE_RSN;

        if (peerkey->cipher == WPA_CIPHER_CCMP)
                ver = WPA_KEY_INFO_TYPE_HMAC_SHA1_AES;
        else
                ver = WPA_KEY_INFO_TYPE_HMAC_MD5_RC4;

        key_info = ver | WPA_KEY_INFO_KEY_TYPE | WPA_KEY_INFO_ACK;
        WPA_PUT_BE16(msg->key_info, key_info);

        if (peerkey->cipher == WPA_CIPHER_CCMP)
                WPA_PUT_BE16(msg->key_length, 16);
        else
                WPA_PUT_BE16(msg->key_length, 32);

        os_memcpy(msg->replay_counter, peerkey->replay_counter,
                  WPA_REPLAY_COUNTER_LEN);
        inc_byte_array(peerkey->replay_counter, WPA_REPLAY_COUNTER_LEN);

        WPA_PUT_BE16(msg->key_data_length, kde_len);
        wpa_add_kde((u8 *) (msg + 1), RSN_KEY_DATA_PMKID,
                    peerkey->smkid, PMKID_LEN);

        if (os_get_random(peerkey->inonce, WPA_NONCE_LEN)) {
                wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
                        "RSN: Failed to get random data for INonce (STK)");
                os_free(mbuf);
                return;
        }
        wpa_hexdump(MSG_DEBUG, "RSN: INonce for STK 4-Way Handshake",
                    peerkey->inonce, WPA_NONCE_LEN);
        os_memcpy(msg->key_nonce, peerkey->inonce, WPA_NONCE_LEN);

        wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key STK 1/4 to " MACSTR,
                   MAC2STR(peerkey->addr));
        wpa_eapol_key_send(sm, NULL, ver, peerkey->addr, ETH_P_EAPOL,
                           mbuf, mlen, NULL);
}


static void wpa_supplicant_send_stk_3_of_4(struct wpa_sm *sm,
                                           struct wpa_peerkey *peerkey)
{
        size_t mlen;
        struct wpa_eapol_key *msg;
        u8 *mbuf, *pos;
        size_t kde_len;
        u16 key_info, ver;
        be32 lifetime;

        kde_len = peerkey->rsnie_i_len +
                2 + RSN_SELECTOR_LEN + sizeof(lifetime);

        mbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY, NULL,
                                  sizeof(*msg) + kde_len, &mlen,
                                  (void *) &msg);
        if (mbuf == NULL)
                return;

        msg->type = EAPOL_KEY_TYPE_RSN;

        if (peerkey->cipher == WPA_CIPHER_CCMP)
                ver = WPA_KEY_INFO_TYPE_HMAC_SHA1_AES;
        else
                ver = WPA_KEY_INFO_TYPE_HMAC_MD5_RC4;

        key_info = ver | WPA_KEY_INFO_KEY_TYPE | WPA_KEY_INFO_ACK |
                WPA_KEY_INFO_MIC | WPA_KEY_INFO_SECURE;
        WPA_PUT_BE16(msg->key_info, key_info);

        if (peerkey->cipher == WPA_CIPHER_CCMP)
                WPA_PUT_BE16(msg->key_length, 16);
        else
                WPA_PUT_BE16(msg->key_length, 32);

        os_memcpy(msg->replay_counter, peerkey->replay_counter,
                  WPA_REPLAY_COUNTER_LEN);
        inc_byte_array(peerkey->replay_counter, WPA_REPLAY_COUNTER_LEN);

        WPA_PUT_BE16(msg->key_data_length, kde_len);
        pos = (u8 *) (msg + 1);
        pos = wpa_add_ie(pos, peerkey->rsnie_i, peerkey->rsnie_i_len);
        lifetime = host_to_be32(peerkey->lifetime);
        wpa_add_kde(pos, RSN_KEY_DATA_LIFETIME,
                    (u8 *) &lifetime, sizeof(lifetime));

        os_memcpy(msg->key_nonce, peerkey->inonce, WPA_NONCE_LEN);

        wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key STK 3/4 to " MACSTR,
                   MAC2STR(peerkey->addr));
        wpa_eapol_key_send(sm, peerkey->stk.kck, ver, peerkey->addr,
                           ETH_P_EAPOL, mbuf, mlen, msg->key_mic);
}


static int wpa_supplicant_process_smk_m4(struct wpa_peerkey *peerkey,
                                         struct wpa_eapol_ie_parse *kde)
{
        wpa_printf(MSG_DEBUG, "RSN: Received SMK M4 (Initiator " MACSTR ")",
                   MAC2STR(kde->mac_addr));

        if (os_memcmp(kde->smk + PMK_LEN, peerkey->pnonce, WPA_NONCE_LEN) != 0)
        {
                wpa_printf(MSG_INFO, "RSN: PNonce in SMK KDE does not "
                           "match with the one used in SMK M3");
                return -1;
        }

        if (os_memcmp(kde->nonce, peerkey->inonce, WPA_NONCE_LEN) != 0) {
                wpa_printf(MSG_INFO, "RSN: INonce in SMK M4 did not "
                           "match with the one received in SMK M2");
                return -1;
        }

        return 0;
}


static int wpa_supplicant_process_smk_m5(struct wpa_sm *sm,
                                         const unsigned char *src_addr,
                                         const struct wpa_eapol_key *key,
                                         int ver,
                                         struct wpa_peerkey *peerkey,
                                         struct wpa_eapol_ie_parse *kde)
{
        int cipher;
        struct wpa_ie_data ie;

        wpa_printf(MSG_DEBUG, "RSN: Received SMK M5 (Peer " MACSTR ")",
                   MAC2STR(kde->mac_addr));
        if (kde->rsn_ie == NULL || kde->rsn_ie_len > PEERKEY_MAX_IE_LEN ||
            wpa_parse_wpa_ie_rsn(kde->rsn_ie, kde->rsn_ie_len, &ie) < 0) {
                wpa_printf(MSG_INFO, "RSN: No RSN IE in SMK M5");
                /* TODO: abort negotiation */
                return -1;
        }

        if (os_memcmp(key->key_nonce, peerkey->inonce, WPA_NONCE_LEN) != 0) {
                wpa_printf(MSG_INFO, "RSN: Key Nonce in SMK M5 does "
                           "not match with INonce used in SMK M1");
                return -1;
        }

        if (os_memcmp(kde->smk + PMK_LEN, peerkey->inonce, WPA_NONCE_LEN) != 0)
        {
                wpa_printf(MSG_INFO, "RSN: INonce in SMK KDE does not "
                           "match with the one used in SMK M1");
                return -1;
        }

        os_memcpy(peerkey->rsnie_p, kde->rsn_ie, kde->rsn_ie_len);
        peerkey->rsnie_p_len = kde->rsn_ie_len;
        os_memcpy(peerkey->pnonce, kde->nonce, WPA_NONCE_LEN);

        cipher = ie.pairwise_cipher & sm->allowed_pairwise_cipher;
        if (cipher & WPA_CIPHER_CCMP) {
                wpa_printf(MSG_DEBUG, "RSN: Using CCMP for PeerKey");
                peerkey->cipher = WPA_CIPHER_CCMP;
        } else if (cipher & WPA_CIPHER_TKIP) {
                wpa_printf(MSG_DEBUG, "RSN: Using TKIP for PeerKey");
                peerkey->cipher = WPA_CIPHER_TKIP;
        } else {
                wpa_printf(MSG_INFO, "RSN: SMK Peer STA " MACSTR " selected "
                           "unacceptable cipher", MAC2STR(kde->mac_addr));
                wpa_supplicant_send_smk_error(sm, src_addr, kde->mac_addr,
                                              STK_MUI_SMK, STK_ERR_CPHR_NS,
                                              ver);
                /* TODO: abort negotiation */
                return -1;
        }

        return 0;
}


static int wpa_supplicant_process_smk_m45(
        struct wpa_sm *sm, const unsigned char *src_addr,
        const struct wpa_eapol_key *key, size_t extra_len, int ver)
{
        struct wpa_peerkey *peerkey;
        struct wpa_eapol_ie_parse kde;
        u32 lifetime;
        struct os_time now;

        if (!sm->peerkey_enabled || sm->proto != WPA_PROTO_RSN) {
                wpa_printf(MSG_DEBUG, "RSN: SMK handshake not allowed for "
                           "the current network");
                return -1;
        }

        if (wpa_supplicant_parse_ies((const u8 *) (key + 1), extra_len, &kde) <
            0) {
                wpa_printf(MSG_INFO, "RSN: Failed to parse KDEs in SMK M4/M5");
                return -1;
        }

        if (kde.mac_addr == NULL || kde.mac_addr_len < ETH_ALEN ||
            kde.nonce == NULL || kde.nonce_len < WPA_NONCE_LEN ||
            kde.smk == NULL || kde.smk_len < PMK_LEN + WPA_NONCE_LEN ||
            kde.lifetime == NULL || kde.lifetime_len < 4) {
                wpa_printf(MSG_INFO, "RSN: No MAC Address, Nonce, SMK, or "
                           "Lifetime KDE in SMK M4/M5");
                return -1;
        }

        for (peerkey = sm->peerkey; peerkey; peerkey = peerkey->next) {
                if (os_memcmp(peerkey->addr, kde.mac_addr, ETH_ALEN) == 0 &&
                    os_memcmp(peerkey->initiator ? peerkey->inonce :
                           peerkey->pnonce,
                           key->key_nonce, WPA_NONCE_LEN) == 0)
                        break;
        }
        if (peerkey == NULL) {
                wpa_printf(MSG_INFO, "RSN: No matching SMK handshake found "
                           "for SMK M4/M5: peer " MACSTR,
                           MAC2STR(kde.mac_addr));
                return -1;
        }

        if (peerkey->initiator) {
                if (wpa_supplicant_process_smk_m5(sm, src_addr, key, ver,
                                                  peerkey, &kde) < 0)
                        return -1;
        } else {
                if (wpa_supplicant_process_smk_m4(peerkey, &kde) < 0)
                        return -1;
        }

        os_memcpy(peerkey->smk, kde.smk, PMK_LEN);
        peerkey->smk_complete = 1;
        wpa_hexdump_key(MSG_DEBUG, "RSN: SMK", peerkey->smk, PMK_LEN);
        lifetime = WPA_GET_BE32(kde.lifetime);
        wpa_printf(MSG_DEBUG, "RSN: SMK lifetime %u seconds", lifetime);
        if (lifetime > 1000000000)
                lifetime = 1000000000; /* avoid overflowing expiration time */
        peerkey->lifetime = lifetime;
        os_get_time(&now);
        peerkey->expiration = now.sec + lifetime;
        eloop_register_timeout(lifetime, 0, wpa_supplicant_smk_timeout,
                               sm, peerkey);

        if (peerkey->initiator) {
                rsn_smkid(peerkey->smk, peerkey->pnonce, peerkey->addr,
                          peerkey->inonce, sm->own_addr, peerkey->smkid,
                          peerkey->use_sha256);
                wpa_supplicant_send_stk_1_of_4(sm, peerkey);
        } else {
                rsn_smkid(peerkey->smk, peerkey->pnonce, sm->own_addr,
                          peerkey->inonce, peerkey->addr, peerkey->smkid,
                          peerkey->use_sha256);
        }
        wpa_hexdump(MSG_DEBUG, "RSN: SMKID", peerkey->smkid, PMKID_LEN);

        return 0;
}


static int wpa_supplicant_process_smk_error(
        struct wpa_sm *sm, const unsigned char *src_addr,
        const struct wpa_eapol_key *key, size_t extra_len)
{
        struct wpa_eapol_ie_parse kde;
        struct rsn_error_kde error;
        u8 peer[ETH_ALEN];
        u16 error_type;

        wpa_printf(MSG_DEBUG, "RSN: Received SMK Error");

        if (!sm->peerkey_enabled || sm->proto != WPA_PROTO_RSN) {
                wpa_printf(MSG_DEBUG, "RSN: SMK handshake not allowed for "
                           "the current network");
                return -1;
        }

        if (wpa_supplicant_parse_ies((const u8 *) (key + 1), extra_len, &kde) <
            0) {
                wpa_printf(MSG_INFO, "RSN: Failed to parse KDEs in SMK Error");
                return -1;
        }

        if (kde.error == NULL || kde.error_len < sizeof(error)) {
                wpa_printf(MSG_INFO, "RSN: No Error KDE in SMK Error");
                return -1;
        }

        if (kde.mac_addr && kde.mac_addr_len >= ETH_ALEN)
                os_memcpy(peer, kde.mac_addr, ETH_ALEN);
        else
                os_memset(peer, 0, ETH_ALEN);
        os_memcpy(&error, kde.error, sizeof(error));
        error_type = be_to_host16(error.error_type);
        wpa_msg(sm->ctx->msg_ctx, MSG_INFO,
                "RSN: SMK Error KDE received: MUI %d error_type %d peer "
                MACSTR,
                be_to_host16(error.mui), error_type,
                MAC2STR(peer));

        if (kde.mac_addr &&
            (error_type == STK_ERR_STA_NR || error_type == STK_ERR_STA_NRSN ||
             error_type == STK_ERR_CPHR_NS)) {
                struct wpa_peerkey *peerkey;

                for (peerkey = sm->peerkey; peerkey; peerkey = peerkey->next) {
                        if (os_memcmp(peerkey->addr, kde.mac_addr, ETH_ALEN) ==
                            0)
                                break;
                }
                if (peerkey == NULL) {
                        wpa_printf(MSG_DEBUG, "RSN: No matching SMK handshake "
                                   "found for SMK Error");
                        return -1;
                }
                /* TODO: abort SMK/STK handshake and remove all related keys */
        }

        return 0;
}


static void wpa_supplicant_process_stk_1_of_4(struct wpa_sm *sm,
                                              struct wpa_peerkey *peerkey,
                                              const struct wpa_eapol_key *key,
                                              u16 ver)
{
        struct wpa_eapol_ie_parse ie;
        const u8 *kde;
        size_t len, kde_buf_len;
        struct wpa_ptk *stk;
        u8 buf[8], *kde_buf, *pos;
        be32 lifetime;

        wpa_printf(MSG_DEBUG, "RSN: RX message 1 of STK 4-Way Handshake from "
                   MACSTR " (ver=%d)", MAC2STR(peerkey->addr), ver);

        os_memset(&ie, 0, sizeof(ie));

        /* RSN: msg 1/4 should contain SMKID for the selected SMK */
        kde = (const u8 *) (key + 1);
        len = WPA_GET_BE16(key->key_data_length);
        wpa_hexdump(MSG_DEBUG, "RSN: msg 1/4 key data", kde, len);
        if (wpa_supplicant_parse_ies(kde, len, &ie) < 0 || ie.pmkid == NULL) {
                wpa_printf(MSG_DEBUG, "RSN: No SMKID in STK 1/4");
                return;
        }
        if (os_memcmp(ie.pmkid, peerkey->smkid, PMKID_LEN) != 0) {
                wpa_hexdump(MSG_DEBUG, "RSN: Unknown SMKID in STK 1/4",
                            ie.pmkid, PMKID_LEN);
                return;
        }

        if (os_get_random(peerkey->pnonce, WPA_NONCE_LEN)) {
                wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
                        "RSN: Failed to get random data for PNonce");
                return;
        }
        wpa_hexdump(MSG_DEBUG, "WPA: Renewed PNonce",
                    peerkey->pnonce, WPA_NONCE_LEN);

        /* Calculate STK which will be stored as a temporary STK until it has
         * been verified when processing message 3/4. */
        stk = &peerkey->tstk;
        wpa_pmk_to_ptk(peerkey->smk, PMK_LEN, "Peer key expansion",
                       sm->own_addr, peerkey->addr,
                       peerkey->pnonce, key->key_nonce,
                       (u8 *) stk, sizeof(*stk),
                       peerkey->use_sha256);
        /* Supplicant: swap tx/rx Mic keys */
        os_memcpy(buf, stk->u.auth.tx_mic_key, 8);
        os_memcpy(stk->u.auth.tx_mic_key, stk->u.auth.rx_mic_key, 8);
        os_memcpy(stk->u.auth.rx_mic_key, buf, 8);
        peerkey->tstk_set = 1;

        kde_buf_len = peerkey->rsnie_p_len +
                2 + RSN_SELECTOR_LEN + sizeof(lifetime) +
                2 + RSN_SELECTOR_LEN + PMKID_LEN;
        kde_buf = os_malloc(kde_buf_len);
        if (kde_buf == NULL)
                return;
        pos = kde_buf;
        pos = wpa_add_ie(pos, peerkey->rsnie_p, peerkey->rsnie_p_len);
        lifetime = host_to_be32(peerkey->lifetime);
        pos = wpa_add_kde(pos, RSN_KEY_DATA_LIFETIME,
                          (u8 *) &lifetime, sizeof(lifetime));
        wpa_add_kde(pos, RSN_KEY_DATA_PMKID, peerkey->smkid, PMKID_LEN);

        if (wpa_supplicant_send_2_of_4(sm, peerkey->addr, key, ver,
                                       peerkey->pnonce, kde_buf, kde_buf_len,
                                       stk)) {
                os_free(kde_buf);
                return;
        }
        os_free(kde_buf);

        os_memcpy(peerkey->inonce, key->key_nonce, WPA_NONCE_LEN);
}


static void wpa_supplicant_update_smk_lifetime(struct wpa_sm *sm,
                                               struct wpa_peerkey *peerkey,
                                               struct wpa_eapol_ie_parse *kde)
{
        u32 lifetime;
        struct os_time now;

        if (kde->lifetime == NULL || kde->lifetime_len < sizeof(lifetime))
                return;

        lifetime = WPA_GET_BE32(kde->lifetime);

        if (lifetime >= peerkey->lifetime) {
                wpa_printf(MSG_DEBUG, "RSN: Peer used SMK lifetime %u seconds "
                           "which is larger than or equal to own value %u "
                           "seconds - ignored", lifetime, peerkey->lifetime);
                return;
        }

        wpa_printf(MSG_DEBUG, "RSN: Peer used shorter SMK lifetime %u seconds "
                   "(own was %u seconds) - updated",
                   lifetime, peerkey->lifetime);
        peerkey->lifetime = lifetime;

        os_get_time(&now);
        peerkey->expiration = now.sec + lifetime;
        eloop_cancel_timeout(wpa_supplicant_smk_timeout, sm, peerkey);
        eloop_register_timeout(lifetime, 0, wpa_supplicant_smk_timeout,
                               sm, peerkey);
}


static void wpa_supplicant_process_stk_2_of_4(struct wpa_sm *sm,
                                              struct wpa_peerkey *peerkey,
                                              const struct wpa_eapol_key *key,
                                              u16 ver)
{
        struct wpa_eapol_ie_parse kde;
        const u8 *keydata;
        size_t len;

        wpa_printf(MSG_DEBUG, "RSN: RX message 2 of STK 4-Way Handshake from "
                   MACSTR " (ver=%d)", MAC2STR(peerkey->addr), ver);

        os_memset(&kde, 0, sizeof(kde));

        /* RSN: msg 2/4 should contain SMKID for the selected SMK and RSN IE
         * from the peer. It may also include Lifetime KDE. */
        keydata = (const u8 *) (key + 1);
        len = WPA_GET_BE16(key->key_data_length);
        wpa_hexdump(MSG_DEBUG, "RSN: msg 2/4 key data", keydata, len);
        if (wpa_supplicant_parse_ies(keydata, len, &kde) < 0 ||
            kde.pmkid == NULL || kde.rsn_ie == NULL) {
                wpa_printf(MSG_DEBUG, "RSN: No SMKID or RSN IE in STK 2/4");
                return;
        }

        if (os_memcmp(kde.pmkid, peerkey->smkid, PMKID_LEN) != 0) {
                wpa_hexdump(MSG_DEBUG, "RSN: Unknown SMKID in STK 2/4",
                            kde.pmkid, PMKID_LEN);
                return;
        }

        if (kde.rsn_ie_len != peerkey->rsnie_p_len ||
            os_memcmp(kde.rsn_ie, peerkey->rsnie_p, kde.rsn_ie_len) != 0) {
                wpa_printf(MSG_INFO, "RSN: Peer RSN IE in SMK and STK "
                           "handshakes did not match");
                wpa_hexdump(MSG_DEBUG, "RSN: Peer RSN IE in SMK handshake",
                            peerkey->rsnie_p, peerkey->rsnie_p_len);
                wpa_hexdump(MSG_DEBUG, "RSN: Peer RSN IE in STK handshake",
                            kde.rsn_ie, kde.rsn_ie_len);
                return;
        }

        wpa_supplicant_update_smk_lifetime(sm, peerkey, &kde);

        wpa_supplicant_send_stk_3_of_4(sm, peerkey);
        os_memcpy(peerkey->pnonce, key->key_nonce, WPA_NONCE_LEN);
}


static void wpa_supplicant_process_stk_3_of_4(struct wpa_sm *sm,
                                              struct wpa_peerkey *peerkey,
                                              const struct wpa_eapol_key *key,
                                              u16 ver)
{
        struct wpa_eapol_ie_parse kde;
        const u8 *keydata;
        size_t len, key_len;
        const u8 *_key;
        u8 key_buf[32], rsc[6];

        wpa_printf(MSG_DEBUG, "RSN: RX message 3 of STK 4-Way Handshake from "
                   MACSTR " (ver=%d)", MAC2STR(peerkey->addr), ver);

        os_memset(&kde, 0, sizeof(kde));

        /* RSN: msg 3/4 should contain Initiator RSN IE. It may also include
         * Lifetime KDE. */
        keydata = (const u8 *) (key + 1);
        len = WPA_GET_BE16(key->key_data_length);
        wpa_hexdump(MSG_DEBUG, "RSN: msg 3/4 key data", keydata, len);
        if (wpa_supplicant_parse_ies(keydata, len, &kde) < 0) {
                wpa_printf(MSG_DEBUG, "RSN: Failed to parse key data in "
                           "STK 3/4");
                return;
        }

        if (kde.rsn_ie_len != peerkey->rsnie_i_len ||
            os_memcmp(kde.rsn_ie, peerkey->rsnie_i, kde.rsn_ie_len) != 0) {
                wpa_printf(MSG_INFO, "RSN: Initiator RSN IE in SMK and STK "
                           "handshakes did not match");
                wpa_hexdump(MSG_DEBUG, "RSN: Initiator RSN IE in SMK "
                            "handshake",
                            peerkey->rsnie_i, peerkey->rsnie_i_len);
                wpa_hexdump(MSG_DEBUG, "RSN: Initiator RSN IE in STK "
                            "handshake",
                            kde.rsn_ie, kde.rsn_ie_len);
                return;
        }

        if (os_memcmp(peerkey->inonce, key->key_nonce, WPA_NONCE_LEN) != 0) {
                wpa_printf(MSG_WARNING, "RSN: INonce from message 1 of STK "
                           "4-Way Handshake differs from 3 of STK 4-Way "
                           "Handshake - drop packet (src=" MACSTR ")",
                           MAC2STR(peerkey->addr));
                return;
        }

        wpa_supplicant_update_smk_lifetime(sm, peerkey, &kde);

        if (wpa_supplicant_send_4_of_4(sm, peerkey->addr, key, ver,
                                       WPA_GET_BE16(key->key_info),
                                       NULL, 0, &peerkey->stk))
                return;

        _key = (u8 *) peerkey->stk.tk1;
        if (peerkey->cipher == WPA_CIPHER_TKIP) {
                /* Swap Tx/Rx keys for Michael MIC */
                os_memcpy(key_buf, _key, 16);
                os_memcpy(key_buf + 16, peerkey->stk.u.auth.rx_mic_key, 8);
                os_memcpy(key_buf + 24, peerkey->stk.u.auth.tx_mic_key, 8);
                _key = key_buf;
                key_len = 32;
        } else
                key_len = 16;

        os_memset(rsc, 0, 6);
        if (wpa_sm_set_key(sm, peerkey->cipher, peerkey->addr, 0, 1,
                           rsc, sizeof(rsc), _key, key_len) < 0) {
                wpa_printf(MSG_WARNING, "RSN: Failed to set STK to the "
                           "driver.");
                return;
        }
}


static void wpa_supplicant_process_stk_4_of_4(struct wpa_sm *sm,
                                              struct wpa_peerkey *peerkey,
                                              const struct wpa_eapol_key *key,
                                              u16 ver)
{
        u8 rsc[6];

        wpa_printf(MSG_DEBUG, "RSN: RX message 4 of STK 4-Way Handshake from "
                   MACSTR " (ver=%d)", MAC2STR(peerkey->addr), ver);

        os_memset(rsc, 0, 6);
        if (wpa_sm_set_key(sm, peerkey->cipher, peerkey->addr, 0, 1,
                           rsc, sizeof(rsc), (u8 *) peerkey->stk.tk1,
                           peerkey->cipher == WPA_CIPHER_TKIP ? 32 : 16) < 0) {
                wpa_printf(MSG_WARNING, "RSN: Failed to set STK to the "
                           "driver.");
                return;
        }
}


int peerkey_verify_eapol_key_mic(struct wpa_sm *sm,
                                 struct wpa_peerkey *peerkey,
                                 struct wpa_eapol_key *key, u16 ver,
                                 const u8 *buf, size_t len)
{
        u8 mic[16];
        int ok = 0;

        if (peerkey->initiator && !peerkey->stk_set) {
                wpa_pmk_to_ptk(peerkey->smk, PMK_LEN, "Peer key expansion",
                               sm->own_addr, peerkey->addr,
                               peerkey->inonce, key->key_nonce,
                               (u8 *) &peerkey->stk, sizeof(peerkey->stk),
                               peerkey->use_sha256);
                peerkey->stk_set = 1;
        }

        os_memcpy(mic, key->key_mic, 16);
        if (peerkey->tstk_set) {
                os_memset(key->key_mic, 0, 16);
                wpa_eapol_key_mic(peerkey->tstk.kck, ver, buf, len,
                                  key->key_mic);
                if (os_memcmp(mic, key->key_mic, 16) != 0) {
                        wpa_printf(MSG_WARNING, "RSN: Invalid EAPOL-Key MIC "
                                   "when using TSTK - ignoring TSTK");
                } else {
                        ok = 1;
                        peerkey->tstk_set = 0;
                        peerkey->stk_set = 1;
                        os_memcpy(&peerkey->stk, &peerkey->tstk,
                                  sizeof(peerkey->stk));
                }
        }

        if (!ok && peerkey->stk_set) {
                os_memset(key->key_mic, 0, 16);
                wpa_eapol_key_mic(peerkey->stk.kck, ver, buf, len,
                                  key->key_mic);
                if (os_memcmp(mic, key->key_mic, 16) != 0) {
                        wpa_printf(MSG_WARNING, "RSN: Invalid EAPOL-Key MIC "
                                   "- dropping packet");
                        return -1;
                }
                ok = 1;
        }

        if (!ok) {
                wpa_printf(MSG_WARNING, "RSN: Could not verify EAPOL-Key MIC "
                           "- dropping packet");
                return -1;
        }

        os_memcpy(peerkey->replay_counter, key->replay_counter,
                  WPA_REPLAY_COUNTER_LEN);
        peerkey->replay_counter_set = 1;
        return 0;
}


int wpa_sm_stkstart(struct wpa_sm *sm, const u8 *peer)
{
        size_t rlen, kde_len;
        struct wpa_eapol_key *req;
        int key_info, ver;
        u8 bssid[ETH_ALEN], *rbuf, *pos, *count_pos;
        u16 count;
        struct rsn_ie_hdr *hdr;
        struct wpa_peerkey *peerkey;
        struct wpa_ie_data ie;

        if (sm->proto != WPA_PROTO_RSN || !sm->ptk_set || !sm->peerkey_enabled)
                return -1;

        if (sm->ap_rsn_ie &&
            wpa_parse_wpa_ie_rsn(sm->ap_rsn_ie, sm->ap_rsn_ie_len, &ie) == 0 &&
            !(ie.capabilities & WPA_CAPABILITY_PEERKEY_ENABLED)) {
                wpa_printf(MSG_DEBUG, "RSN: Current AP does not support STK");
                return -1;
        }

        if (sm->pairwise_cipher == WPA_CIPHER_CCMP)
                ver = WPA_KEY_INFO_TYPE_HMAC_SHA1_AES;
        else
                ver = WPA_KEY_INFO_TYPE_HMAC_MD5_RC4;

        if (wpa_sm_get_bssid(sm, bssid) < 0) {
                wpa_printf(MSG_WARNING, "Failed to read BSSID for EAPOL-Key "
                           "SMK M1");
                return -1;
        }

        /* TODO: find existing entry and if found, use that instead of adding
         * a new one */
        peerkey = os_zalloc(sizeof(*peerkey));
        if (peerkey == NULL)
                return -1;
        peerkey->initiator = 1;
        os_memcpy(peerkey->addr, peer, ETH_ALEN);
#ifdef CONFIG_IEEE80211W
        if (wpa_key_mgmt_sha256(sm->key_mgmt))
                peerkey->use_sha256 = 1;
#endif /* CONFIG_IEEE80211W */

        /* SMK M1:
         * EAPOL-Key(S=1, M=1, A=0, I=0, K=0, SM=1, KeyRSC=0, Nonce=INonce,
         *           MIC=MIC, DataKDs=(RSNIE_I, MAC_P KDE))
         */

        hdr = (struct rsn_ie_hdr *) peerkey->rsnie_i;
        hdr->elem_id = WLAN_EID_RSN;
        WPA_PUT_LE16(hdr->version, RSN_VERSION);
        pos = (u8 *) (hdr + 1);
        /* Group Suite can be anything for SMK RSN IE; receiver will just
         * ignore it. */
        RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
        pos += RSN_SELECTOR_LEN;
        count_pos = pos;
        pos += 2;

        count = 0;
        if (sm->allowed_pairwise_cipher & WPA_CIPHER_CCMP) {
                RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
                pos += RSN_SELECTOR_LEN;
                count++;
        }
        if (sm->allowed_pairwise_cipher & WPA_CIPHER_TKIP) {
                RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
                pos += RSN_SELECTOR_LEN;
                count++;
        }
        WPA_PUT_LE16(count_pos, count);

        hdr->len = (pos - peerkey->rsnie_i) - 2;
        peerkey->rsnie_i_len = pos - peerkey->rsnie_i;
        wpa_hexdump(MSG_DEBUG, "WPA: RSN IE for SMK handshake",
                    peerkey->rsnie_i, peerkey->rsnie_i_len);

        kde_len = peerkey->rsnie_i_len + 2 + RSN_SELECTOR_LEN + ETH_ALEN;

        rbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY, NULL,
                                  sizeof(*req) + kde_len, &rlen,
                                  (void *) &req);
        if (rbuf == NULL) {
                wpa_supplicant_peerkey_free(sm, peerkey);
                return -1;
        }

        req->type = EAPOL_KEY_TYPE_RSN;
        key_info = WPA_KEY_INFO_SMK_MESSAGE | WPA_KEY_INFO_MIC |
                WPA_KEY_INFO_SECURE | WPA_KEY_INFO_REQUEST | ver;
        WPA_PUT_BE16(req->key_info, key_info);
        WPA_PUT_BE16(req->key_length, 0);
        os_memcpy(req->replay_counter, sm->request_counter,
                  WPA_REPLAY_COUNTER_LEN);
        inc_byte_array(sm->request_counter, WPA_REPLAY_COUNTER_LEN);

        if (os_get_random(peerkey->inonce, WPA_NONCE_LEN)) {
                wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
                        "WPA: Failed to get random data for INonce");
                os_free(rbuf);
                wpa_supplicant_peerkey_free(sm, peerkey);
                return -1;
        }
        os_memcpy(req->key_nonce, peerkey->inonce, WPA_NONCE_LEN);
        wpa_hexdump(MSG_DEBUG, "WPA: INonce for SMK handshake",
                    req->key_nonce, WPA_NONCE_LEN);

        WPA_PUT_BE16(req->key_data_length, (u16) kde_len);
        pos = (u8 *) (req + 1);

        /* Initiator RSN IE */
        pos = wpa_add_ie(pos, peerkey->rsnie_i, peerkey->rsnie_i_len);
        /* Peer MAC address KDE */
        wpa_add_kde(pos, RSN_KEY_DATA_MAC_ADDR, peer, ETH_ALEN);

        wpa_printf(MSG_INFO, "RSN: Sending EAPOL-Key SMK M1 Request (peer "
                   MACSTR ")", MAC2STR(peer));
        wpa_eapol_key_send(sm, sm->ptk.kck, ver, bssid, ETH_P_EAPOL,
                           rbuf, rlen, req->key_mic);

        peerkey->next = sm->peerkey;
        sm->peerkey = peerkey;

        return 0;
}


void peerkey_deinit(struct wpa_sm *sm)
{
        struct wpa_peerkey *prev, *peerkey = sm->peerkey;
        while (peerkey) {
                prev = peerkey;
                peerkey = peerkey->next;
                os_free(prev);
        }
}


void peerkey_rx_eapol_4way(struct wpa_sm *sm, struct wpa_peerkey *peerkey,
                           struct wpa_eapol_key *key, u16 key_info, u16 ver)
{
        if ((key_info & (WPA_KEY_INFO_MIC | WPA_KEY_INFO_ACK)) ==
            (WPA_KEY_INFO_MIC | WPA_KEY_INFO_ACK)) {
                /* 3/4 STK 4-Way Handshake */
                wpa_supplicant_process_stk_3_of_4(sm, peerkey, key, ver);
        } else if (key_info & WPA_KEY_INFO_ACK) {
                /* 1/4 STK 4-Way Handshake */
                wpa_supplicant_process_stk_1_of_4(sm, peerkey, key, ver);
        } else if (key_info & WPA_KEY_INFO_SECURE) {
                /* 4/4 STK 4-Way Handshake */
                wpa_supplicant_process_stk_4_of_4(sm, peerkey, key, ver);
        } else {
                /* 2/4 STK 4-Way Handshake */
                wpa_supplicant_process_stk_2_of_4(sm, peerkey, key, ver);
        }
}


void peerkey_rx_eapol_smk(struct wpa_sm *sm, const u8 *src_addr,
                          struct wpa_eapol_key *key, size_t extra_len,
                          u16 key_info, u16 ver)
{
        if (key_info & WPA_KEY_INFO_ERROR) {
                /* SMK Error */
                wpa_supplicant_process_smk_error(sm, src_addr, key, extra_len);
        } else if (key_info & WPA_KEY_INFO_ACK) {
                /* SMK M2 */
                wpa_supplicant_process_smk_m2(sm, src_addr, key, extra_len,
                                              ver);
        } else {
                /* SMK M4 or M5 */
                wpa_supplicant_process_smk_m45(sm, src_addr, key, extra_len,
                                               ver);
        }
}

#endif /* CONFIG_PEERKEY */