eap_ttls.c

Go to the documentation of this file.

/*
 * EAP peer method: EAP-TTLS (RFC 5281)
 * Copyright (c) 2004-2008, 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"

#include "common.h"
#include "crypto/ms_funcs.h"
#include "crypto/sha1.h"
#include "crypto/tls.h"
#include "eap_common/chap.h"
#include "eap_common/eap_ttls.h"
#include "mschapv2.h"
#include "eap_i.h"
#include "eap_tls_common.h"
#include "eap_config.h"


/* Maximum supported TTLS version
 * 0 = RFC 5281
 * 1 = draft-funk-eap-ttls-v1-00.txt
 */
#ifndef EAP_TTLS_VERSION
#define EAP_TTLS_VERSION 0 /* TTLSv1 implementation is not yet complete */
#endif /* EAP_TTLS_VERSION */


#define MSCHAPV2_KEY_LEN 16
#define MSCHAPV2_NT_RESPONSE_LEN 24


static void eap_ttls_deinit(struct eap_sm *sm, void *priv);


struct eap_ttls_data {
        struct eap_ssl_data ssl;
        int ssl_initialized;

        int ttls_version, force_ttls_version;

        const struct eap_method *phase2_method;
        void *phase2_priv;
        int phase2_success;
        int phase2_start;

        enum phase2_types {
                EAP_TTLS_PHASE2_EAP,
                EAP_TTLS_PHASE2_MSCHAPV2,
                EAP_TTLS_PHASE2_MSCHAP,
                EAP_TTLS_PHASE2_PAP,
                EAP_TTLS_PHASE2_CHAP
        } phase2_type;
        struct eap_method_type phase2_eap_type;
        struct eap_method_type *phase2_eap_types;
        size_t num_phase2_eap_types;

        u8 auth_response[MSCHAPV2_AUTH_RESPONSE_LEN];
        int auth_response_valid;
        u8 master_key[MSCHAPV2_MASTER_KEY_LEN]; /* MSCHAPv2 master key */
        u8 ident;
        int resuming; /* starting a resumed session */
        int reauth; /* reauthentication */
        u8 *key_data;

        struct wpabuf *pending_phase2_req;

#ifdef EAP_TNC
        int ready_for_tnc;
        int tnc_started;
#endif /* EAP_TNC */
};


static void * eap_ttls_init(struct eap_sm *sm)
{
        struct eap_ttls_data *data;
        struct eap_peer_config *config = eap_get_config(sm);
        char *selected;

        data = os_zalloc(sizeof(*data));
        if (data == NULL)
                return NULL;
        data->ttls_version = EAP_TTLS_VERSION;
        data->force_ttls_version = -1;
        selected = "EAP";
        data->phase2_type = EAP_TTLS_PHASE2_EAP;

#if EAP_TTLS_VERSION > 0
        if (config && config->phase1) {
                const char *pos = os_strstr(config->phase1, "ttlsver=");
                if (pos) {
                        data->force_ttls_version = atoi(pos + 8);
                        data->ttls_version = data->force_ttls_version;
                        wpa_printf(MSG_DEBUG, "EAP-TTLS: Forced TTLS version "
                                   "%d", data->force_ttls_version);
                }
        }
#endif /* EAP_TTLS_VERSION */

        if (config && config->phase2) {
                if (os_strstr(config->phase2, "autheap=")) {
                        selected = "EAP";
                        data->phase2_type = EAP_TTLS_PHASE2_EAP;
                } else if (os_strstr(config->phase2, "auth=MSCHAPV2")) {
                        selected = "MSCHAPV2";
                        data->phase2_type = EAP_TTLS_PHASE2_MSCHAPV2;
                } else if (os_strstr(config->phase2, "auth=MSCHAP")) {
                        selected = "MSCHAP";
                        data->phase2_type = EAP_TTLS_PHASE2_MSCHAP;
                } else if (os_strstr(config->phase2, "auth=PAP")) {
                        selected = "PAP";
                        data->phase2_type = EAP_TTLS_PHASE2_PAP;
                } else if (os_strstr(config->phase2, "auth=CHAP")) {
                        selected = "CHAP";
                        data->phase2_type = EAP_TTLS_PHASE2_CHAP;
                }
        }
        wpa_printf(MSG_DEBUG, "EAP-TTLS: Phase2 type: %s", selected);

        if (data->phase2_type == EAP_TTLS_PHASE2_EAP) {
                if (eap_peer_select_phase2_methods(config, "autheap=",
                                                   &data->phase2_eap_types,
                                                   &data->num_phase2_eap_types)
                    < 0) {
                        eap_ttls_deinit(sm, data);
                        return NULL;
                }

                data->phase2_eap_type.vendor = EAP_VENDOR_IETF;
                data->phase2_eap_type.method = EAP_TYPE_NONE;
        }

#if EAP_TTLS_VERSION > 0
        if (!(tls_capabilities(sm->ssl_ctx) & TLS_CAPABILITY_IA) &&
            data->ttls_version > 0) {
                if (data->force_ttls_version > 0) {
                        wpa_printf(MSG_INFO, "EAP-TTLS: Forced TTLSv%d and "
                                   "TLS library does not support TLS/IA.",
                                   data->force_ttls_version);
                        eap_ttls_deinit(sm, data);
                        return NULL;
                }
                data->ttls_version = 0;
        }
#endif /* EAP_TTLS_VERSION */

        return data;
}


static void eap_ttls_phase2_eap_deinit(struct eap_sm *sm,
                                       struct eap_ttls_data *data)
{
        if (data->phase2_priv && data->phase2_method) {
                data->phase2_method->deinit(sm, data->phase2_priv);
                data->phase2_method = NULL;
                data->phase2_priv = NULL;
        }
}


static void eap_ttls_deinit(struct eap_sm *sm, void *priv)
{
        struct eap_ttls_data *data = priv;
        if (data == NULL)
                return;
        eap_ttls_phase2_eap_deinit(sm, data);
        os_free(data->phase2_eap_types);
        if (data->ssl_initialized)
                eap_peer_tls_ssl_deinit(sm, &data->ssl);
        os_free(data->key_data);
        wpabuf_free(data->pending_phase2_req);
        os_free(data);
}


static u8 * eap_ttls_avp_hdr(u8 *avphdr, u32 avp_code, u32 vendor_id,
                             int mandatory, size_t len)
{
        struct ttls_avp_vendor *avp;
        u8 flags;
        size_t hdrlen;

        avp = (struct ttls_avp_vendor *) avphdr;
        flags = mandatory ? AVP_FLAGS_MANDATORY : 0;
        if (vendor_id) {
                flags |= AVP_FLAGS_VENDOR;
                hdrlen = sizeof(*avp);
                avp->vendor_id = host_to_be32(vendor_id);
        } else {
                hdrlen = sizeof(struct ttls_avp);
        }

        avp->avp_code = host_to_be32(avp_code);
        avp->avp_length = host_to_be32((flags << 24) | (hdrlen + len));

        return avphdr + hdrlen;
}


static u8 * eap_ttls_avp_add(u8 *start, u8 *avphdr, u32 avp_code,
                             u32 vendor_id, int mandatory,
                             const u8 *data, size_t len)
{
        u8 *pos;
        pos = eap_ttls_avp_hdr(avphdr, avp_code, vendor_id, mandatory, len);
        os_memcpy(pos, data, len);
        pos += len;
        AVP_PAD(start, pos);
        return pos;
}


static int eap_ttls_avp_encapsulate(struct wpabuf **resp, u32 avp_code,
                                    int mandatory)
{
        struct wpabuf *msg;
        u8 *avp, *pos;

        msg = wpabuf_alloc(sizeof(struct ttls_avp) + wpabuf_len(*resp) + 4);
        if (msg == NULL) {
                wpabuf_free(*resp);
                *resp = NULL;
                return -1;
        }

        avp = wpabuf_mhead(msg);
        pos = eap_ttls_avp_hdr(avp, avp_code, 0, mandatory, wpabuf_len(*resp));
        os_memcpy(pos, wpabuf_head(*resp), wpabuf_len(*resp));
        pos += wpabuf_len(*resp);
        AVP_PAD(avp, pos);
        wpabuf_free(*resp);
        wpabuf_put(msg, pos - avp);
        *resp = msg;
        return 0;
}


#if EAP_TTLS_VERSION > 0
static int eap_ttls_ia_permute_inner_secret(struct eap_sm *sm,
                                            struct eap_ttls_data *data,
                                            const u8 *key, size_t key_len)
{
        u8 *buf;
        size_t buf_len;
        int ret;

        if (key) {
                buf_len = 2 + key_len;
                buf = os_malloc(buf_len);
                if (buf == NULL)
                        return -1;
                WPA_PUT_BE16(buf, key_len);
                os_memcpy(buf + 2, key, key_len);
        } else {
                buf = NULL;
                buf_len = 0;
        }

        wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: Session keys for TLS/IA inner "
                        "secret permutation", buf, buf_len);
        ret = tls_connection_ia_permute_inner_secret(sm->ssl_ctx,
                                                     data->ssl.conn,
                                                     buf, buf_len);
        os_free(buf);

        return ret;
}
#endif /* EAP_TTLS_VERSION */


static int eap_ttls_v0_derive_key(struct eap_sm *sm,
                                  struct eap_ttls_data *data)
{
        os_free(data->key_data);
        data->key_data = eap_peer_tls_derive_key(sm, &data->ssl,
                                                 "ttls keying material",
                                                 EAP_TLS_KEY_LEN);
        if (!data->key_data) {
                wpa_printf(MSG_INFO, "EAP-TTLS: Failed to derive key");
                return -1;
        }

        wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: Derived key",
                        data->key_data, EAP_TLS_KEY_LEN);

        return 0;
}


#if EAP_TTLS_VERSION > 0
static int eap_ttls_v1_derive_key(struct eap_sm *sm,
                                  struct eap_ttls_data *data)
{
        struct tls_keys keys;
        u8 *rnd;

        os_free(data->key_data);
        data->key_data = NULL;

        os_memset(&keys, 0, sizeof(keys));
        if (tls_connection_get_keys(sm->ssl_ctx, data->ssl.conn, &keys) ||
            keys.client_random == NULL || keys.server_random == NULL ||
            keys.inner_secret == NULL) {
                wpa_printf(MSG_INFO, "EAP-TTLS: Could not get inner secret, "
                           "client random, or server random to derive keying "
                           "material");
                return -1;
        }

        rnd = os_malloc(keys.client_random_len + keys.server_random_len);
        data->key_data = os_malloc(EAP_TLS_KEY_LEN);
        if (rnd == NULL || data->key_data == NULL) {
                wpa_printf(MSG_INFO, "EAP-TTLS: No memory for key derivation");
                os_free(rnd);
                os_free(data->key_data);
                data->key_data = NULL;
                return -1;
        }
        os_memcpy(rnd, keys.client_random, keys.client_random_len);
        os_memcpy(rnd + keys.client_random_len, keys.server_random,
                  keys.server_random_len);

        if (tls_prf(keys.inner_secret, keys.inner_secret_len,
                    "ttls v1 keying material", rnd, keys.client_random_len +
                    keys.server_random_len, data->key_data, EAP_TLS_KEY_LEN)) {
                wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to derive key");
                os_free(rnd);
                os_free(data->key_data);
                data->key_data = NULL;
                return -1;
        }

        wpa_hexdump(MSG_DEBUG, "EAP-TTLS: client/server random",
                    rnd, keys.client_random_len + keys.server_random_len);
        wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: TLS/IA inner secret",
                        keys.inner_secret, keys.inner_secret_len);

        os_free(rnd);

        wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: Derived key",
                        data->key_data, EAP_TLS_KEY_LEN);

        return 0;
}
#endif /* EAP_TTLS_VERSION */


static u8 * eap_ttls_implicit_challenge(struct eap_sm *sm,
                                        struct eap_ttls_data *data, size_t len)
{
#if EAP_TTLS_VERSION > 0
        struct tls_keys keys;
        u8 *challenge, *rnd;
#endif /* EAP_TTLS_VERSION */

        if (data->ttls_version == 0) {
                return eap_peer_tls_derive_key(sm, &data->ssl,
                                               "ttls challenge", len);
        }

#if EAP_TTLS_VERSION > 0

        os_memset(&keys, 0, sizeof(keys));
        if (tls_connection_get_keys(sm->ssl_ctx, data->ssl.conn, &keys) ||
            keys.client_random == NULL || keys.server_random == NULL ||
            keys.inner_secret == NULL) {
                wpa_printf(MSG_INFO, "EAP-TTLS: Could not get inner secret, "
                           "client random, or server random to derive "
                           "implicit challenge");
                return NULL;
        }

        rnd = os_malloc(keys.client_random_len + keys.server_random_len);
        challenge = os_malloc(len);
        if (rnd == NULL || challenge == NULL) {
                wpa_printf(MSG_INFO, "EAP-TTLS: No memory for implicit "
                           "challenge derivation");
                os_free(rnd);
                os_free(challenge);
                return NULL;
        }
        os_memcpy(rnd, keys.server_random, keys.server_random_len);
        os_memcpy(rnd + keys.server_random_len, keys.client_random,
                  keys.client_random_len);

        if (tls_prf(keys.inner_secret, keys.inner_secret_len,
                    "inner application challenge", rnd,
                    keys.client_random_len + keys.server_random_len,
                    challenge, len)) {
                wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to derive implicit "
                           "challenge");
                os_free(rnd);
                os_free(challenge);
                return NULL;
        }

        os_free(rnd);

        wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: Derived implicit challenge",
                        challenge, len);

        return challenge;

#else /* EAP_TTLS_VERSION */

        return NULL;

#endif /* EAP_TTLS_VERSION */
}


static void eap_ttlsv1_phase2_eap_finish(struct eap_sm *sm,
                                         struct eap_ttls_data *data,
                                         struct eap_method_ret *ret)
{
#if EAP_TTLS_VERSION > 0
        if (data->ttls_version > 0) {
                const struct eap_method *m = data->phase2_method;
                void *priv = data->phase2_priv;

                /* TTLSv1 requires TLS/IA FinalPhaseFinished */
                if (ret->decision == DECISION_UNCOND_SUCC)
                        ret->decision = DECISION_COND_SUCC;
                ret->methodState = METHOD_CONT;

                if (ret->decision == DECISION_COND_SUCC &&
                    m->isKeyAvailable && m->getKey &&
                    m->isKeyAvailable(sm, priv)) {
                        u8 *key;
                        size_t key_len;
                        key = m->getKey(sm, priv, &key_len);
                        if (key) {
                                eap_ttls_ia_permute_inner_secret(
                                        sm, data, key, key_len);
                                os_free(key);
                        }
                }
        }
#endif /* EAP_TTLS_VERSION */
}


static void eap_ttls_phase2_select_eap_method(struct eap_ttls_data *data,
                                              u8 method)
{
        size_t i;
        for (i = 0; i < data->num_phase2_eap_types; i++) {
                if (data->phase2_eap_types[i].vendor != EAP_VENDOR_IETF ||
                    data->phase2_eap_types[i].method != method)
                        continue;

                data->phase2_eap_type.vendor =
                        data->phase2_eap_types[i].vendor;
                data->phase2_eap_type.method =
                        data->phase2_eap_types[i].method;
                wpa_printf(MSG_DEBUG, "EAP-TTLS: Selected "
                           "Phase 2 EAP vendor %d method %d",
                           data->phase2_eap_type.vendor,
                           data->phase2_eap_type.method);
                break;
        }
}


static int eap_ttls_phase2_eap_process(struct eap_sm *sm,
                                       struct eap_ttls_data *data,
                                       struct eap_method_ret *ret,
                                       struct eap_hdr *hdr, size_t len,
                                       struct wpabuf **resp)
{
        struct wpabuf msg;
        struct eap_method_ret iret;

        os_memset(&iret, 0, sizeof(iret));
        wpabuf_set(&msg, hdr, len);
        *resp = data->phase2_method->process(sm, data->phase2_priv, &iret,
                                             &msg);
        if ((iret.methodState == METHOD_DONE ||
             iret.methodState == METHOD_MAY_CONT) &&
            (iret.decision == DECISION_UNCOND_SUCC ||
             iret.decision == DECISION_COND_SUCC ||
             iret.decision == DECISION_FAIL)) {
                ret->methodState = iret.methodState;
                ret->decision = iret.decision;
        }
        eap_ttlsv1_phase2_eap_finish(sm, data, ret);

        return 0;
}


static int eap_ttls_phase2_request_eap_method(struct eap_sm *sm,
                                              struct eap_ttls_data *data,
                                              struct eap_method_ret *ret,
                                              struct eap_hdr *hdr, size_t len,
                                              u8 method, struct wpabuf **resp)
{
#ifdef EAP_TNC
        if (data->tnc_started && data->phase2_method &&
            data->phase2_priv && method == EAP_TYPE_TNC &&
            data->phase2_eap_type.method == EAP_TYPE_TNC)
                return eap_ttls_phase2_eap_process(sm, data, ret, hdr, len,
                                                   resp);

        if (data->ready_for_tnc && !data->tnc_started &&
            method == EAP_TYPE_TNC) {
                wpa_printf(MSG_DEBUG, "EAP-TTLS: Start TNC after completed "
                           "EAP method");
                data->tnc_started = 1;
        }

        if (data->tnc_started) {
                if (data->phase2_eap_type.vendor != EAP_VENDOR_IETF ||
                    data->phase2_eap_type.method == EAP_TYPE_TNC) {
                        wpa_printf(MSG_DEBUG, "EAP-TTLS: Unexpected EAP "
                                   "type %d for TNC", method);
                        return -1;
                }

                data->phase2_eap_type.vendor = EAP_VENDOR_IETF;
                data->phase2_eap_type.method = method;
                wpa_printf(MSG_DEBUG, "EAP-TTLS: Selected "
                           "Phase 2 EAP vendor %d method %d (TNC)",
                           data->phase2_eap_type.vendor,
                           data->phase2_eap_type.method);

                if (data->phase2_type == EAP_TTLS_PHASE2_EAP)
                        eap_ttls_phase2_eap_deinit(sm, data);
        }
#endif /* EAP_TNC */

        if (data->phase2_eap_type.vendor == EAP_VENDOR_IETF &&
            data->phase2_eap_type.method == EAP_TYPE_NONE)
                eap_ttls_phase2_select_eap_method(data, method);

        if (method != data->phase2_eap_type.method || method == EAP_TYPE_NONE)
        {
                if (eap_peer_tls_phase2_nak(data->phase2_eap_types,
                                            data->num_phase2_eap_types,
                                            hdr, resp))
                        return -1;
                return 0;
        }

        if (data->phase2_priv == NULL) {
                data->phase2_method = eap_peer_get_eap_method(
                        EAP_VENDOR_IETF, method);
                if (data->phase2_method) {
                        sm->init_phase2 = 1;
                        data->phase2_priv = data->phase2_method->init(sm);
                        sm->init_phase2 = 0;
                }
        }
        if (data->phase2_priv == NULL || data->phase2_method == NULL) {
                wpa_printf(MSG_INFO, "EAP-TTLS: failed to initialize "
                           "Phase 2 EAP method %d", method);
                return -1;
        }

        return eap_ttls_phase2_eap_process(sm, data, ret, hdr, len, resp);
}


static int eap_ttls_phase2_request_eap(struct eap_sm *sm,
                                       struct eap_ttls_data *data,
                                       struct eap_method_ret *ret,
                                       struct eap_hdr *hdr,
                                       struct wpabuf **resp)
{
        size_t len = be_to_host16(hdr->length);
        u8 *pos;
        struct eap_peer_config *config = eap_get_config(sm);

        if (len <= sizeof(struct eap_hdr)) {
                wpa_printf(MSG_INFO, "EAP-TTLS: too short "
                           "Phase 2 request (len=%lu)", (unsigned long) len);
                return -1;
        }
        pos = (u8 *) (hdr + 1);
        wpa_printf(MSG_DEBUG, "EAP-TTLS: Phase 2 EAP Request: type=%d", *pos);
        switch (*pos) {
        case EAP_TYPE_IDENTITY:
                *resp = eap_sm_buildIdentity(sm, hdr->identifier, 1);
                break;
        default:
                if (eap_ttls_phase2_request_eap_method(sm, data, ret, hdr, len,
                                                       *pos, resp) < 0)
                        return -1;
                break;
        }

        if (*resp == NULL &&
            (config->pending_req_identity || config->pending_req_password ||
             config->pending_req_otp)) {
                return 0;
        }

        if (*resp == NULL)
                return -1;

        wpa_hexdump_buf(MSG_DEBUG, "EAP-TTLS: AVP encapsulate EAP Response",
                        *resp);
        return eap_ttls_avp_encapsulate(resp, RADIUS_ATTR_EAP_MESSAGE, 1);
}


static void eap_ttlsv1_permute_inner(struct eap_sm *sm,
                                     struct eap_ttls_data *data)
{
#if EAP_TTLS_VERSION > 0
        u8 session_key[2 * MSCHAPV2_KEY_LEN];

        if (data->ttls_version == 0)
                return;

        get_asymetric_start_key(data->master_key, session_key,
                                MSCHAPV2_KEY_LEN, 0, 0);
        get_asymetric_start_key(data->master_key,
                                session_key + MSCHAPV2_KEY_LEN,
                                MSCHAPV2_KEY_LEN, 1, 0);
        eap_ttls_ia_permute_inner_secret(sm, data, session_key,
                                         sizeof(session_key));
#endif /* EAP_TTLS_VERSION */
}


static int eap_ttls_phase2_request_mschapv2(struct eap_sm *sm,
                                            struct eap_ttls_data *data,
                                            struct eap_method_ret *ret,
                                            struct wpabuf **resp)
{
        struct wpabuf *msg;
        u8 *buf, *pos, *challenge, *peer_challenge;
        const u8 *identity, *password;
        size_t identity_len, password_len;
        int pwhash;

        wpa_printf(MSG_DEBUG, "EAP-TTLS: Phase 2 MSCHAPV2 Request");

        identity = eap_get_config_identity(sm, &identity_len);
        password = eap_get_config_password2(sm, &password_len, &pwhash);
        if (identity == NULL || password == NULL)
                return -1;

        msg = wpabuf_alloc(identity_len + 1000);
        if (msg == NULL) {
                wpa_printf(MSG_ERROR,
                           "EAP-TTLS/MSCHAPV2: Failed to allocate memory");
                return -1;
        }
        pos = buf = wpabuf_mhead(msg);

        /* User-Name */
        pos = eap_ttls_avp_add(buf, pos, RADIUS_ATTR_USER_NAME, 0, 1,
                               identity, identity_len);

        /* MS-CHAP-Challenge */
        challenge = eap_ttls_implicit_challenge(
                sm, data, EAP_TTLS_MSCHAPV2_CHALLENGE_LEN + 1);
        if (challenge == NULL) {
                wpabuf_free(msg);
                wpa_printf(MSG_ERROR, "EAP-TTLS/MSCHAPV2: Failed to derive "
                           "implicit challenge");
                return -1;
        }
        peer_challenge = challenge + 1 + EAP_TTLS_MSCHAPV2_CHALLENGE_LEN;

        pos = eap_ttls_avp_add(buf, pos, RADIUS_ATTR_MS_CHAP_CHALLENGE,
                               RADIUS_VENDOR_ID_MICROSOFT, 1,
                               challenge, EAP_TTLS_MSCHAPV2_CHALLENGE_LEN);

        /* MS-CHAP2-Response */
        pos = eap_ttls_avp_hdr(pos, RADIUS_ATTR_MS_CHAP2_RESPONSE,
                               RADIUS_VENDOR_ID_MICROSOFT, 1,
                               EAP_TTLS_MSCHAPV2_RESPONSE_LEN);
        data->ident = challenge[EAP_TTLS_MSCHAPV2_CHALLENGE_LEN];
        *pos++ = data->ident;
        *pos++ = 0; /* Flags */
        os_memcpy(pos, peer_challenge, EAP_TTLS_MSCHAPV2_CHALLENGE_LEN);
        pos += EAP_TTLS_MSCHAPV2_CHALLENGE_LEN;
        os_memset(pos, 0, 8); /* Reserved, must be zero */
        pos += 8;
        if (mschapv2_derive_response(identity, identity_len, password,
                                     password_len, pwhash, challenge,
                                     peer_challenge, pos, data->auth_response,
                                     data->master_key)) {
                wpabuf_free(msg);
                wpa_printf(MSG_ERROR, "EAP-TTLS/MSCHAPV2: Failed to derive "
                           "response");
                return -1;
        }
        data->auth_response_valid = 1;

        eap_ttlsv1_permute_inner(sm, data);

        pos += 24;
        os_free(challenge);
        AVP_PAD(buf, pos);

        wpabuf_put(msg, pos - buf);
        *resp = msg;

        if (sm->workaround && data->ttls_version == 0) {
                /* At least FreeRADIUS seems to be terminating
                 * EAP-TTLS/MSHCAPV2 without the expected MS-CHAP-v2 Success
                 * packet. */
                wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: EAP workaround - "
                           "allow success without tunneled response");
                ret->methodState = METHOD_MAY_CONT;
                ret->decision = DECISION_COND_SUCC;
        }

        return 0;
}


static int eap_ttls_phase2_request_mschap(struct eap_sm *sm,
                                          struct eap_ttls_data *data,
                                          struct eap_method_ret *ret,
                                          struct wpabuf **resp)
{
        struct wpabuf *msg;
        u8 *buf, *pos, *challenge;
        const u8 *identity, *password;
        size_t identity_len, password_len;
        int pwhash;

        wpa_printf(MSG_DEBUG, "EAP-TTLS: Phase 2 MSCHAP Request");

        identity = eap_get_config_identity(sm, &identity_len);
        password = eap_get_config_password2(sm, &password_len, &pwhash);
        if (identity == NULL || password == NULL)
                return -1;

        msg = wpabuf_alloc(identity_len + 1000);
        if (msg == NULL) {
                wpa_printf(MSG_ERROR,
                           "EAP-TTLS/MSCHAP: Failed to allocate memory");
                return -1;
        }
        pos = buf = wpabuf_mhead(msg);

        /* User-Name */
        pos = eap_ttls_avp_add(buf, pos, RADIUS_ATTR_USER_NAME, 0, 1,
                               identity, identity_len);

        /* MS-CHAP-Challenge */
        challenge = eap_ttls_implicit_challenge(
                sm, data, EAP_TTLS_MSCHAP_CHALLENGE_LEN + 1);
        if (challenge == NULL) {
                wpabuf_free(msg);
                wpa_printf(MSG_ERROR, "EAP-TTLS/MSCHAP: Failed to derive "
                           "implicit challenge");
                return -1;
        }

        pos = eap_ttls_avp_add(buf, pos, RADIUS_ATTR_MS_CHAP_CHALLENGE,
                               RADIUS_VENDOR_ID_MICROSOFT, 1,
                               challenge, EAP_TTLS_MSCHAP_CHALLENGE_LEN);

        /* MS-CHAP-Response */
        pos = eap_ttls_avp_hdr(pos, RADIUS_ATTR_MS_CHAP_RESPONSE,
                               RADIUS_VENDOR_ID_MICROSOFT, 1,
                               EAP_TTLS_MSCHAP_RESPONSE_LEN);
        data->ident = challenge[EAP_TTLS_MSCHAP_CHALLENGE_LEN];
        *pos++ = data->ident;
        *pos++ = 1; /* Flags: Use NT style passwords */
        os_memset(pos, 0, 24); /* LM-Response */
        pos += 24;
        if (pwhash) {
                challenge_response(challenge, password, pos); /* NT-Response */
                wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: MSCHAP password hash",
                                password, 16);
        } else {
                nt_challenge_response(challenge, password, password_len,
                                      pos); /* NT-Response */
                wpa_hexdump_ascii_key(MSG_DEBUG, "EAP-TTLS: MSCHAP password",
                                      password, password_len);
        }
        wpa_hexdump(MSG_DEBUG, "EAP-TTLS: MSCHAP implicit challenge",
                    challenge, EAP_TTLS_MSCHAP_CHALLENGE_LEN);
        wpa_hexdump(MSG_DEBUG, "EAP-TTLS: MSCHAP response", pos, 24);
        pos += 24;
        os_free(challenge);
        AVP_PAD(buf, pos);

        wpabuf_put(msg, pos - buf);
        *resp = msg;

        if (data->ttls_version > 0) {
                /* EAP-TTLSv1 uses TLS/IA FinalPhaseFinished to report success,
                 * so do not allow connection to be terminated yet. */
                ret->methodState = METHOD_CONT;
                ret->decision = DECISION_COND_SUCC;
        } else {
                /* EAP-TTLS/MSCHAP does not provide tunneled success
                 * notification, so assume that Phase2 succeeds. */
                ret->methodState = METHOD_DONE;
                ret->decision = DECISION_COND_SUCC;
        }

        return 0;
}


static int eap_ttls_phase2_request_pap(struct eap_sm *sm,
                                       struct eap_ttls_data *data,
                                       struct eap_method_ret *ret,
                                       struct wpabuf **resp)
{
        struct wpabuf *msg;
        u8 *buf, *pos;
        size_t pad;
        const u8 *identity, *password;
        size_t identity_len, password_len;

        wpa_printf(MSG_DEBUG, "EAP-TTLS: Phase 2 PAP Request");

        identity = eap_get_config_identity(sm, &identity_len);
        password = eap_get_config_password(sm, &password_len);
        if (identity == NULL || password == NULL)
                return -1;

        msg = wpabuf_alloc(identity_len + password_len + 100);
        if (msg == NULL) {
                wpa_printf(MSG_ERROR,
                           "EAP-TTLS/PAP: Failed to allocate memory");
                return -1;
        }
        pos = buf = wpabuf_mhead(msg);

        /* User-Name */
        pos = eap_ttls_avp_add(buf, pos, RADIUS_ATTR_USER_NAME, 0, 1,
                               identity, identity_len);

        /* User-Password; in RADIUS, this is encrypted, but EAP-TTLS encrypts
         * the data, so no separate encryption is used in the AVP itself.
         * However, the password is padded to obfuscate its length. */
        pad = password_len == 0 ? 16 : (16 - (password_len & 15)) & 15;
        pos = eap_ttls_avp_hdr(pos, RADIUS_ATTR_USER_PASSWORD, 0, 1,
                               password_len + pad);
        os_memcpy(pos, password, password_len);
        pos += password_len;
        os_memset(pos, 0, pad);
        pos += pad;
        AVP_PAD(buf, pos);

        wpabuf_put(msg, pos - buf);
        *resp = msg;

        if (data->ttls_version > 0) {
                /* EAP-TTLSv1 uses TLS/IA FinalPhaseFinished to report success,
                 * so do not allow connection to be terminated yet. */
                ret->methodState = METHOD_CONT;
                ret->decision = DECISION_COND_SUCC;
        } else {
                /* EAP-TTLS/PAP does not provide tunneled success notification,
                 * so assume that Phase2 succeeds. */
                ret->methodState = METHOD_DONE;
                ret->decision = DECISION_COND_SUCC;
        }

        return 0;
}


static int eap_ttls_phase2_request_chap(struct eap_sm *sm,
                                        struct eap_ttls_data *data,
                                        struct eap_method_ret *ret,
                                        struct wpabuf **resp)
{
        struct wpabuf *msg;
        u8 *buf, *pos, *challenge;
        const u8 *identity, *password;
        size_t identity_len, password_len;

        wpa_printf(MSG_DEBUG, "EAP-TTLS: Phase 2 CHAP Request");

        identity = eap_get_config_identity(sm, &identity_len);
        password = eap_get_config_password(sm, &password_len);
        if (identity == NULL || password == NULL)
                return -1;

        msg = wpabuf_alloc(identity_len + 1000);
        if (msg == NULL) {
                wpa_printf(MSG_ERROR,
                           "EAP-TTLS/CHAP: Failed to allocate memory");
                return -1;
        }
        pos = buf = wpabuf_mhead(msg);

        /* User-Name */
        pos = eap_ttls_avp_add(buf, pos, RADIUS_ATTR_USER_NAME, 0, 1,
                               identity, identity_len);

        /* CHAP-Challenge */
        challenge = eap_ttls_implicit_challenge(
                sm, data, EAP_TTLS_CHAP_CHALLENGE_LEN + 1);
        if (challenge == NULL) {
                wpabuf_free(msg);
                wpa_printf(MSG_ERROR, "EAP-TTLS/CHAP: Failed to derive "
                           "implicit challenge");
                return -1;
        }

        pos = eap_ttls_avp_add(buf, pos, RADIUS_ATTR_CHAP_CHALLENGE, 0, 1,
                               challenge, EAP_TTLS_CHAP_CHALLENGE_LEN);

        /* CHAP-Password */
        pos = eap_ttls_avp_hdr(pos, RADIUS_ATTR_CHAP_PASSWORD, 0, 1,
                               1 + EAP_TTLS_CHAP_PASSWORD_LEN);
        data->ident = challenge[EAP_TTLS_CHAP_CHALLENGE_LEN];
        *pos++ = data->ident;

        /* MD5(Ident + Password + Challenge) */
        chap_md5(data->ident, password, password_len, challenge,
                 EAP_TTLS_CHAP_CHALLENGE_LEN, pos);

        wpa_hexdump_ascii(MSG_DEBUG, "EAP-TTLS: CHAP username",
                          identity, identity_len);
        wpa_hexdump_ascii_key(MSG_DEBUG, "EAP-TTLS: CHAP password",
                              password, password_len);
        wpa_hexdump(MSG_DEBUG, "EAP-TTLS: CHAP implicit challenge",
                    challenge, EAP_TTLS_CHAP_CHALLENGE_LEN);
        wpa_hexdump(MSG_DEBUG, "EAP-TTLS: CHAP password",
                    pos, EAP_TTLS_CHAP_PASSWORD_LEN);
        pos += EAP_TTLS_CHAP_PASSWORD_LEN;
        os_free(challenge);
        AVP_PAD(buf, pos);

        wpabuf_put(msg, pos - buf);
        *resp = msg;

        if (data->ttls_version > 0) {
                /* EAP-TTLSv1 uses TLS/IA FinalPhaseFinished to report success,
                 * so do not allow connection to be terminated yet. */
                ret->methodState = METHOD_CONT;
                ret->decision = DECISION_COND_SUCC;
        } else {
                /* EAP-TTLS/CHAP does not provide tunneled success
                 * notification, so assume that Phase2 succeeds. */
                ret->methodState = METHOD_DONE;
                ret->decision = DECISION_COND_SUCC;
        }

        return 0;
}


static int eap_ttls_phase2_request(struct eap_sm *sm,
                                   struct eap_ttls_data *data,
                                   struct eap_method_ret *ret,
                                   struct eap_hdr *hdr,
                                   struct wpabuf **resp)
{
        int res = 0;
        size_t len;
        enum phase2_types phase2_type = data->phase2_type;

#ifdef EAP_TNC
        if (data->tnc_started) {
                wpa_printf(MSG_DEBUG, "EAP-TTLS: Processing TNC");
                phase2_type = EAP_TTLS_PHASE2_EAP;
        }
#endif /* EAP_TNC */

        if (phase2_type == EAP_TTLS_PHASE2_MSCHAPV2 ||
            phase2_type == EAP_TTLS_PHASE2_MSCHAP ||
            phase2_type == EAP_TTLS_PHASE2_PAP ||
            phase2_type == EAP_TTLS_PHASE2_CHAP) {
                if (eap_get_config_identity(sm, &len) == NULL) {
                        wpa_printf(MSG_INFO,
                                   "EAP-TTLS: Identity not configured");
                        eap_sm_request_identity(sm);
                        if (eap_get_config_password(sm, &len) == NULL)
                                eap_sm_request_password(sm);
                        return 0;
                }

                if (eap_get_config_password(sm, &len) == NULL) {
                        wpa_printf(MSG_INFO,
                                   "EAP-TTLS: Password not configured");
                        eap_sm_request_password(sm);
                        return 0;
                }
        }

        switch (phase2_type) {
        case EAP_TTLS_PHASE2_EAP:
                res = eap_ttls_phase2_request_eap(sm, data, ret, hdr, resp);
                break;
        case EAP_TTLS_PHASE2_MSCHAPV2:
                res = eap_ttls_phase2_request_mschapv2(sm, data, ret, resp);
                break;
        case EAP_TTLS_PHASE2_MSCHAP:
                res = eap_ttls_phase2_request_mschap(sm, data, ret, resp);
                break;
        case EAP_TTLS_PHASE2_PAP:
                res = eap_ttls_phase2_request_pap(sm, data, ret, resp);
                break;
        case EAP_TTLS_PHASE2_CHAP:
                res = eap_ttls_phase2_request_chap(sm, data, ret, resp);
                break;
        default:
                wpa_printf(MSG_ERROR, "EAP-TTLS: Phase 2 - Unknown");
                res = -1;
                break;
        }

        if (res < 0) {
                ret->methodState = METHOD_DONE;
                ret->decision = DECISION_FAIL;
        }

        return res;
}


#if EAP_TTLS_VERSION > 0
static struct wpabuf * eap_ttls_build_phase_finished(
        struct eap_sm *sm, struct eap_ttls_data *data, int id, int final)
{
        struct wpabuf *req, *buf;

        buf = tls_connection_ia_send_phase_finished(sm->ssl_ctx,
                                                    data->ssl.conn,
                                                    final);
        if (buf == NULL)
                return NULL;

        req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TTLS,
                            1 + wpabuf_len(buf),
                            EAP_CODE_RESPONSE, id);
        if (req == NULL) {
                wpabuf_free(buf);
                return NULL;
        }

        wpabuf_put_u8(req, data->ttls_version);
        wpabuf_put_buf(req, buf);
        wpabuf_free(buf);
        eap_update_len(req);

        return req;
}
#endif /* EAP_TTLS_VERSION */


struct ttls_parse_avp {
        u8 *mschapv2;
        u8 *eapdata;
        size_t eap_len;
        int mschapv2_error;
};


static int eap_ttls_parse_attr_eap(const u8 *dpos, size_t dlen,
                                   struct ttls_parse_avp *parse)
{
        wpa_printf(MSG_DEBUG, "EAP-TTLS: AVP - EAP Message");
        if (parse->eapdata == NULL) {
                parse->eapdata = os_malloc(dlen);
                if (parse->eapdata == NULL) {
                        wpa_printf(MSG_WARNING, "EAP-TTLS: Failed to allocate "
                                   "memory for Phase 2 EAP data");
                        return -1;
                }
                os_memcpy(parse->eapdata, dpos, dlen);
                parse->eap_len = dlen;
        } else {
                u8 *neweap = os_realloc(parse->eapdata, parse->eap_len + dlen);
                if (neweap == NULL) {
                        wpa_printf(MSG_WARNING, "EAP-TTLS: Failed to allocate "
                                   "memory for Phase 2 EAP data");
                        return -1;
                }
                os_memcpy(neweap + parse->eap_len, dpos, dlen);
                parse->eapdata = neweap;
                parse->eap_len += dlen;
        }

        return 0;
}


static int eap_ttls_parse_avp(u8 *pos, size_t left,
                              struct ttls_parse_avp *parse)
{
        struct ttls_avp *avp;
        u32 avp_code, avp_length, vendor_id = 0;
        u8 avp_flags, *dpos;
        size_t dlen;

        avp = (struct ttls_avp *) pos;
        avp_code = be_to_host32(avp->avp_code);
        avp_length = be_to_host32(avp->avp_length);
        avp_flags = (avp_length >> 24) & 0xff;
        avp_length &= 0xffffff;
        wpa_printf(MSG_DEBUG, "EAP-TTLS: AVP: code=%d flags=0x%02x "
                   "length=%d", (int) avp_code, avp_flags,
                   (int) avp_length);

        if (avp_length > left) {
                wpa_printf(MSG_WARNING, "EAP-TTLS: AVP overflow "
                           "(len=%d, left=%lu) - dropped",
                           (int) avp_length, (unsigned long) left);
                return -1;
        }

        if (avp_length < sizeof(*avp)) {
                wpa_printf(MSG_WARNING, "EAP-TTLS: Invalid AVP length %d",
                           avp_length);
                return -1;
        }

        dpos = (u8 *) (avp + 1);
        dlen = avp_length - sizeof(*avp);
        if (avp_flags & AVP_FLAGS_VENDOR) {
                if (dlen < 4) {
                        wpa_printf(MSG_WARNING, "EAP-TTLS: Vendor AVP "
                                   "underflow");
                        return -1;
                }
                vendor_id = WPA_GET_BE32(dpos);
                wpa_printf(MSG_DEBUG, "EAP-TTLS: AVP vendor_id %d",
                           (int) vendor_id);
                dpos += 4;
                dlen -= 4;
        }

        wpa_hexdump(MSG_DEBUG, "EAP-TTLS: AVP data", dpos, dlen);

        if (vendor_id == 0 && avp_code == RADIUS_ATTR_EAP_MESSAGE) {
                if (eap_ttls_parse_attr_eap(dpos, dlen, parse) < 0)
                        return -1;
        } else if (vendor_id == 0 && avp_code == RADIUS_ATTR_REPLY_MESSAGE) {
                /* This is an optional message that can be displayed to
                 * the user. */
                wpa_hexdump_ascii(MSG_DEBUG, "EAP-TTLS: AVP - Reply-Message",
                                  dpos, dlen);
        } else if (vendor_id == RADIUS_VENDOR_ID_MICROSOFT &&
                   avp_code == RADIUS_ATTR_MS_CHAP2_SUCCESS) {
                wpa_hexdump_ascii(MSG_DEBUG, "EAP-TTLS: MS-CHAP2-Success",
                                  dpos, dlen);
                if (dlen != 43) {
                        wpa_printf(MSG_WARNING, "EAP-TTLS: Unexpected "
                                   "MS-CHAP2-Success length "
                                   "(len=%lu, expected 43)",
                                   (unsigned long) dlen);
                        return -1;
                }
                parse->mschapv2 = dpos;
        } else if (vendor_id == RADIUS_VENDOR_ID_MICROSOFT &&
                   avp_code == RADIUS_ATTR_MS_CHAP_ERROR) {
                wpa_hexdump_ascii(MSG_DEBUG, "EAP-TTLS: MS-CHAP-Error",
                                  dpos, dlen);
                parse->mschapv2_error = 1;
        } else if (avp_flags & AVP_FLAGS_MANDATORY) {
                wpa_printf(MSG_WARNING, "EAP-TTLS: Unsupported mandatory AVP "
                           "code %d vendor_id %d - dropped",
                           (int) avp_code, (int) vendor_id);
                return -1;
        } else {
                wpa_printf(MSG_DEBUG, "EAP-TTLS: Ignoring unsupported AVP "
                           "code %d vendor_id %d",
                           (int) avp_code, (int) vendor_id);
        }

        return avp_length;
}


static int eap_ttls_parse_avps(struct wpabuf *in_decrypted,
                               struct ttls_parse_avp *parse)
{
        u8 *pos;
        size_t left, pad;
        int avp_length;

        pos = wpabuf_mhead(in_decrypted);
        left = wpabuf_len(in_decrypted);
        wpa_hexdump(MSG_DEBUG, "EAP-TTLS: Decrypted Phase 2 AVPs", pos, left);
        if (left < sizeof(struct ttls_avp)) {
                wpa_printf(MSG_WARNING, "EAP-TTLS: Too short Phase 2 AVP frame"
                           " len=%lu expected %lu or more - dropped",
                           (unsigned long) left,
                           (unsigned long) sizeof(struct ttls_avp));
                return -1;
        }

        /* Parse AVPs */
        os_memset(parse, 0, sizeof(*parse));

        while (left > 0) {
                avp_length = eap_ttls_parse_avp(pos, left, parse);
                if (avp_length < 0)
                        return -1;

                pad = (4 - (avp_length & 3)) & 3;
                pos += avp_length + pad;
                if (left < avp_length + pad)
                        left = 0;
                else
                        left -= avp_length + pad;
        }

        return 0;
}


static u8 * eap_ttls_fake_identity_request(void)
{
        struct eap_hdr *hdr;
        u8 *buf;

        wpa_printf(MSG_DEBUG, "EAP-TTLS: empty data in beginning of "
                   "Phase 2 - use fake EAP-Request Identity");
        buf = os_malloc(sizeof(*hdr) + 1);
        if (buf == NULL) {
                wpa_printf(MSG_WARNING, "EAP-TTLS: failed to allocate "
                           "memory for fake EAP-Identity Request");
                return NULL;
        }

        hdr = (struct eap_hdr *) buf;
        hdr->code = EAP_CODE_REQUEST;
        hdr->identifier = 0;
        hdr->length = host_to_be16(sizeof(*hdr) + 1);
        buf[sizeof(*hdr)] = EAP_TYPE_IDENTITY;

        return buf;
}


static int eap_ttls_encrypt_response(struct eap_sm *sm,
                                     struct eap_ttls_data *data,
                                     struct wpabuf *resp, u8 identifier,
                                     struct wpabuf **out_data)
{
        if (resp == NULL)
                return 0;

        wpa_hexdump_buf_key(MSG_DEBUG, "EAP-TTLS: Encrypting Phase 2 data",
                            resp);
        if (eap_peer_tls_encrypt(sm, &data->ssl, EAP_TYPE_TTLS,
                                 data->ttls_version, identifier,
                                 resp, out_data)) {
                wpa_printf(MSG_INFO, "EAP-TTLS: Failed to encrypt a Phase 2 "
                           "frame");
                return -1;
        }
        wpabuf_free(resp);

        return 0;
}


static int eap_ttls_process_phase2_eap(struct eap_sm *sm,
                                       struct eap_ttls_data *data,
                                       struct eap_method_ret *ret,
                                       struct ttls_parse_avp *parse,
                                       struct wpabuf **resp)
{
        struct eap_hdr *hdr;
        size_t len;

        if (parse->eapdata == NULL) {
                wpa_printf(MSG_WARNING, "EAP-TTLS: No EAP Message in the "
                           "packet - dropped");
                return -1;
        }

        wpa_hexdump(MSG_DEBUG, "EAP-TTLS: Phase 2 EAP",
                    parse->eapdata, parse->eap_len);
        hdr = (struct eap_hdr *) parse->eapdata;

        if (parse->eap_len < sizeof(*hdr)) {
                wpa_printf(MSG_WARNING, "EAP-TTLS: Too short Phase 2 EAP "
                           "frame (len=%lu, expected %lu or more) - dropped",
                           (unsigned long) parse->eap_len,
                           (unsigned long) sizeof(*hdr));
                return -1;
        }
        len = be_to_host16(hdr->length);
        if (len > parse->eap_len) {
                wpa_printf(MSG_INFO, "EAP-TTLS: Length mismatch in Phase 2 "
                           "EAP frame (EAP hdr len=%lu, EAP data len in "
                           "AVP=%lu)",
                           (unsigned long) len,
                           (unsigned long) parse->eap_len);
                return -1;
        }
        wpa_printf(MSG_DEBUG, "EAP-TTLS: received Phase 2: code=%d "
                   "identifier=%d length=%lu",
                   hdr->code, hdr->identifier, (unsigned long) len);
        switch (hdr->code) {
        case EAP_CODE_REQUEST:
                if (eap_ttls_phase2_request(sm, data, ret, hdr, resp)) {
                        wpa_printf(MSG_INFO, "EAP-TTLS: Phase2 Request "
                                   "processing failed");
                        return -1;
                }
                break;
        default:
                wpa_printf(MSG_INFO, "EAP-TTLS: Unexpected code=%d in "
                           "Phase 2 EAP header", hdr->code);
                return -1;
        }

        return 0;
}


static int eap_ttls_process_phase2_mschapv2(struct eap_sm *sm,
                                            struct eap_ttls_data *data,
                                            struct eap_method_ret *ret,
                                            struct ttls_parse_avp *parse)
{
        if (parse->mschapv2_error) {
                wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Received "
                           "MS-CHAP-Error - failed");
                ret->methodState = METHOD_DONE;
                ret->decision = DECISION_FAIL;
                /* Reply with empty data to ACK error */
                return 1;
        }

        if (parse->mschapv2 == NULL) {
#ifdef EAP_TNC
                if (data->phase2_success && parse->eapdata) {
                        /*
                         * Allow EAP-TNC to be started after successfully
                         * completed MSCHAPV2.
                         */
                        return 1;
                }
#endif /* EAP_TNC */
                wpa_printf(MSG_WARNING, "EAP-TTLS: no MS-CHAP2-Success AVP "
                           "received for Phase2 MSCHAPV2");
                return -1;
        }
        if (parse->mschapv2[0] != data->ident) {
                wpa_printf(MSG_WARNING, "EAP-TTLS: Ident mismatch for Phase 2 "
                           "MSCHAPV2 (received Ident 0x%02x, expected 0x%02x)",
                           parse->mschapv2[0], data->ident);
                return -1;
        }
        if (!data->auth_response_valid ||
            mschapv2_verify_auth_response(data->auth_response,
                                          parse->mschapv2 + 1, 42)) {
                wpa_printf(MSG_WARNING, "EAP-TTLS: Invalid authenticator "
                           "response in Phase 2 MSCHAPV2 success request");
                return -1;
        }

        wpa_printf(MSG_INFO, "EAP-TTLS: Phase 2 MSCHAPV2 "
                   "authentication succeeded");
        if (data->ttls_version > 0) {
                /*
                 * EAP-TTLSv1 uses TLS/IA FinalPhaseFinished to report
                 * success, so do not allow connection to be terminated
                 * yet.
                 */
                ret->methodState = METHOD_CONT;
                ret->decision = DECISION_COND_SUCC;
        } else {
                ret->methodState = METHOD_DONE;
                ret->decision = DECISION_UNCOND_SUCC;
                data->phase2_success = 1;
        }

        /*
         * Reply with empty data; authentication server will reply
         * with EAP-Success after this.
         */
        return 1;
}


#ifdef EAP_TNC
static int eap_ttls_process_tnc_start(struct eap_sm *sm,
                                      struct eap_ttls_data *data,
                                      struct eap_method_ret *ret,
                                      struct ttls_parse_avp *parse,
                                      struct wpabuf **resp)
{
        /* TNC uses inner EAP method after non-EAP TTLS phase 2. */
        if (parse->eapdata == NULL) {
                wpa_printf(MSG_INFO, "EAP-TTLS: Phase 2 received "
                           "unexpected tunneled data (no EAP)");
                return -1;
        }

        if (!data->ready_for_tnc) {
                wpa_printf(MSG_INFO, "EAP-TTLS: Phase 2 received "
                           "EAP after non-EAP, but not ready for TNC");
                return -1;
        }

        wpa_printf(MSG_DEBUG, "EAP-TTLS: Start TNC after completed "
                   "non-EAP method");
        data->tnc_started = 1;

        if (eap_ttls_process_phase2_eap(sm, data, ret, parse, resp) < 0)
                return -1;

        return 0;
}
#endif /* EAP_TNC */


static int eap_ttls_process_decrypted(struct eap_sm *sm,
                                      struct eap_ttls_data *data,
                                      struct eap_method_ret *ret,
                                      u8 identifier,
                                      struct ttls_parse_avp *parse,
                                      struct wpabuf *in_decrypted,
                                      struct wpabuf **out_data)
{
        struct wpabuf *resp = NULL;
        struct eap_peer_config *config = eap_get_config(sm);
        int res;
        enum phase2_types phase2_type = data->phase2_type;

#ifdef EAP_TNC
        if (data->tnc_started)
                phase2_type = EAP_TTLS_PHASE2_EAP;
#endif /* EAP_TNC */

        switch (phase2_type) {
        case EAP_TTLS_PHASE2_EAP:
                if (eap_ttls_process_phase2_eap(sm, data, ret, parse, &resp) <
                    0)
                        return -1;
                break;
        case EAP_TTLS_PHASE2_MSCHAPV2:
                res = eap_ttls_process_phase2_mschapv2(sm, data, ret, parse);
#ifdef EAP_TNC
                if (res == 1 && parse->eapdata && data->phase2_success) {
                        /*
                         * TNC may be required as the next
                         * authentication method within the tunnel.
                         */
                        ret->methodState = METHOD_MAY_CONT;
                        data->ready_for_tnc = 1;
                        if (eap_ttls_process_tnc_start(sm, data, ret, parse,
                                                       &resp) == 0)
                                break;
                }
#endif /* EAP_TNC */
                return res;
        case EAP_TTLS_PHASE2_MSCHAP:
        case EAP_TTLS_PHASE2_PAP:
        case EAP_TTLS_PHASE2_CHAP:
#ifdef EAP_TNC
                if (eap_ttls_process_tnc_start(sm, data, ret, parse, &resp) <
                    0)
                        return -1;
                break;
#else /* EAP_TNC */
                /* EAP-TTLS/{MSCHAP,PAP,CHAP} should not send any TLS tunneled
                 * requests to the supplicant */
                wpa_printf(MSG_INFO, "EAP-TTLS: Phase 2 received unexpected "
                           "tunneled data");
                return -1;
#endif /* EAP_TNC */
        }

        if (resp) {
                if (eap_ttls_encrypt_response(sm, data, resp, identifier,
                                              out_data) < 0)
                        return -1;
        } else if (config->pending_req_identity ||
                   config->pending_req_password ||
                   config->pending_req_otp ||
                   config->pending_req_new_password) {
                wpabuf_free(data->pending_phase2_req);
                data->pending_phase2_req = wpabuf_dup(in_decrypted);
        }

        return 0;
}


#if EAP_TTLS_VERSION > 0
static void eap_ttls_final_phase_finished(struct eap_sm *sm,
                                          struct eap_ttls_data *data,
                                          struct eap_method_ret *ret,
                                          u8 identifier,
                                          struct wpabuf **out_data)
{
        wpa_printf(MSG_DEBUG, "EAP-TTLS: FinalPhaseFinished received");
        wpa_printf(MSG_INFO, "EAP-TTLS: TLS/IA authentication succeeded");
        ret->methodState = METHOD_DONE;
        ret->decision = DECISION_UNCOND_SUCC;
        data->phase2_success = 1;
        *out_data = eap_ttls_build_phase_finished(sm, data, identifier, 1);
        eap_ttls_v1_derive_key(sm, data);
}
#endif /* EAP_TTLS_VERSION */


static int eap_ttls_implicit_identity_request(struct eap_sm *sm,
                                              struct eap_ttls_data *data,
                                              struct eap_method_ret *ret,
                                              u8 identifier,
                                              struct wpabuf **out_data)
{
        int retval = 0;
        struct eap_hdr *hdr;
        struct wpabuf *resp;

        hdr = (struct eap_hdr *) eap_ttls_fake_identity_request();
        if (hdr == NULL) {
                ret->methodState = METHOD_DONE;
                ret->decision = DECISION_FAIL;
                return -1;
        }

        resp = NULL;
        if (eap_ttls_phase2_request(sm, data, ret, hdr, &resp)) {
                wpa_printf(MSG_INFO, "EAP-TTLS: Phase2 Request "
                           "processing failed");
                retval = -1;
        } else {
                retval = eap_ttls_encrypt_response(sm, data, resp, identifier,
                                                   out_data);
        }

        os_free(hdr);

        if (retval < 0) {
                ret->methodState = METHOD_DONE;
                ret->decision = DECISION_FAIL;
        }

        return retval;
}


static int eap_ttls_phase2_start(struct eap_sm *sm, struct eap_ttls_data *data,
                                 struct eap_method_ret *ret, u8 identifier,
                                 struct wpabuf **out_data)
{
        data->phase2_start = 0;

        /*
         * EAP-TTLS does not use Phase2 on fast re-auth; this must be done only
         * if TLS part was indeed resuming a previous session. Most
         * Authentication Servers terminate EAP-TTLS before reaching this
         * point, but some do not. Make wpa_supplicant stop phase 2 here, if
         * needed.
         */
        if (data->reauth &&
            tls_connection_resumed(sm->ssl_ctx, data->ssl.conn)) {
                wpa_printf(MSG_DEBUG, "EAP-TTLS: Session resumption - "
                           "skip phase 2");
                *out_data = eap_peer_tls_build_ack(identifier, EAP_TYPE_TTLS,
                                                   data->ttls_version);
                ret->methodState = METHOD_DONE;
                ret->decision = DECISION_UNCOND_SUCC;
                data->phase2_success = 1;
                return 0;
        }

        return eap_ttls_implicit_identity_request(sm, data, ret, identifier,
                                                  out_data);
}


static int eap_ttls_decrypt(struct eap_sm *sm, struct eap_ttls_data *data,
                            struct eap_method_ret *ret, u8 identifier,
                            const struct wpabuf *in_data,
                            struct wpabuf **out_data)
{
        struct wpabuf *in_decrypted = NULL;
        int retval = 0;
        struct ttls_parse_avp parse;

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

        wpa_printf(MSG_DEBUG, "EAP-TTLS: received %lu bytes encrypted data for"
                   " Phase 2",
                   in_data ? (unsigned long) wpabuf_len(in_data) : 0);

        if (data->pending_phase2_req) {
                wpa_printf(MSG_DEBUG, "EAP-TTLS: Pending Phase 2 request - "
                           "skip decryption and use old data");
                /* Clear TLS reassembly state. */
                eap_peer_tls_reset_input(&data->ssl);

                in_decrypted = data->pending_phase2_req;
                data->pending_phase2_req = NULL;
                if (wpabuf_len(in_decrypted) == 0) {
                        wpabuf_free(in_decrypted);
                        return eap_ttls_implicit_identity_request(
                                sm, data, ret, identifier, out_data);
                }
                goto continue_req;
        }

        if ((in_data == NULL || wpabuf_len(in_data) == 0) &&
            data->phase2_start) {
                return eap_ttls_phase2_start(sm, data, ret, identifier,
                                             out_data);
        }

        if (in_data == NULL || wpabuf_len(in_data) == 0) {
                /* Received TLS ACK - requesting more fragments */
                return eap_peer_tls_encrypt(sm, &data->ssl, EAP_TYPE_TTLS,
                                            data->ttls_version,
                                            identifier, NULL, out_data);
        }

        retval = eap_peer_tls_decrypt(sm, &data->ssl, in_data, &in_decrypted);
        if (retval)
                goto done;

#if EAP_TTLS_VERSION > 0
        if (data->ttls_version > 0 &&
            (in_decrypted == NULL || wpabuf_len(in_decrypted) == 0) &&
            tls_connection_ia_final_phase_finished(sm->ssl_ctx,
                                                   data->ssl.conn)) {
                eap_ttls_final_phase_finished(sm, data, ret, identifier,
                                              out_data);
                goto done;
        }
#endif /* EAP_TTLS_VERSION */

continue_req:
        data->phase2_start = 0;

        if (eap_ttls_parse_avps(in_decrypted, &parse) < 0) {
                retval = -1;
                goto done;
        }

        retval = eap_ttls_process_decrypted(sm, data, ret, identifier,
                                            &parse, in_decrypted, out_data);

done:
        wpabuf_free(in_decrypted);
        os_free(parse.eapdata);

        if (retval < 0) {
                ret->methodState = METHOD_DONE;
                ret->decision = DECISION_FAIL;
        }

        return retval;
}


static int eap_ttls_process_start(struct eap_sm *sm,
                                  struct eap_ttls_data *data, u8 flags,
                                  struct eap_method_ret *ret)
{
        struct eap_peer_config *config = eap_get_config(sm);

        wpa_printf(MSG_DEBUG, "EAP-TTLS: Start (server ver=%d, own ver=%d)",
                   flags & EAP_TLS_VERSION_MASK, data->ttls_version);
#if EAP_TTLS_VERSION > 0
        if ((flags & EAP_TLS_VERSION_MASK) < data->ttls_version)
                data->ttls_version = flags & EAP_TLS_VERSION_MASK;
        if (data->force_ttls_version >= 0 &&
            data->force_ttls_version != data->ttls_version) {
                wpa_printf(MSG_WARNING, "EAP-TTLS: Failed to select "
                           "forced TTLS version %d",
                           data->force_ttls_version);
                ret->methodState = METHOD_DONE;
                ret->decision = DECISION_FAIL;
                ret->allowNotifications = FALSE;
                return -1;
        }
        wpa_printf(MSG_DEBUG, "EAP-TTLS: Using TTLS version %d",
                   data->ttls_version);

        if (data->ttls_version > 0)
                data->ssl.tls_ia = 1;
#endif /* EAP_TTLS_VERSION */
        if (!data->ssl_initialized &&
            eap_peer_tls_ssl_init(sm, &data->ssl, config)) {
                wpa_printf(MSG_INFO, "EAP-TTLS: Failed to initialize SSL.");
                return -1;
        }
        data->ssl_initialized = 1;

        wpa_printf(MSG_DEBUG, "EAP-TTLS: Start");

        return 0;
}


static int eap_ttls_process_handshake(struct eap_sm *sm,
                                      struct eap_ttls_data *data,
                                      struct eap_method_ret *ret,
                                      u8 identifier,
                                      const u8 *in_data, size_t in_len,
                                      struct wpabuf **out_data)
{
        int res;

        res = eap_peer_tls_process_helper(sm, &data->ssl, EAP_TYPE_TTLS,
                                          data->ttls_version, identifier,
                                          in_data, in_len, out_data);

        if (tls_connection_established(sm->ssl_ctx, data->ssl.conn)) {
                wpa_printf(MSG_DEBUG, "EAP-TTLS: TLS done, proceed to "
                           "Phase 2");
                if (data->resuming) {
                        wpa_printf(MSG_DEBUG, "EAP-TTLS: fast reauth - may "
                                   "skip Phase 2");
                        ret->decision = DECISION_COND_SUCC;
                        ret->methodState = METHOD_MAY_CONT;
                }
                data->phase2_start = 1;
                if (data->ttls_version == 0)
                        eap_ttls_v0_derive_key(sm, data);

                if (*out_data == NULL || wpabuf_len(*out_data) == 0) {
                        if (eap_ttls_decrypt(sm, data, ret, identifier,
                                             NULL, out_data)) {
                                wpa_printf(MSG_WARNING, "EAP-TTLS: "
                                           "failed to process early "
                                           "start for Phase 2");
                        }
                        res = 0;
                }
                data->resuming = 0;
        }

        if (res == 2) {
                struct wpabuf msg;
                /*
                 * Application data included in the handshake message.
                 */
                wpabuf_free(data->pending_phase2_req);
                data->pending_phase2_req = *out_data;
                *out_data = NULL;
                wpabuf_set(&msg, in_data, in_len);
                res = eap_ttls_decrypt(sm, data, ret, identifier, &msg,
                                       out_data);
        }

        return res;
}


static void eap_ttls_check_auth_status(struct eap_sm *sm, 
                                       struct eap_ttls_data *data,
                                       struct eap_method_ret *ret)
{
        if (data->ttls_version == 0 && ret->methodState == METHOD_DONE) {
                ret->allowNotifications = FALSE;
                if (ret->decision == DECISION_UNCOND_SUCC ||
                    ret->decision == DECISION_COND_SUCC) {
                        wpa_printf(MSG_DEBUG, "EAP-TTLS: Authentication "
                                   "completed successfully");
                        data->phase2_success = 1;
#ifdef EAP_TNC
                        if (!data->ready_for_tnc && !data->tnc_started) {
                                /*
                                 * TNC may be required as the next
                                 * authentication method within the tunnel.
                                 */
                                ret->methodState = METHOD_MAY_CONT;
                                data->ready_for_tnc = 1;
                        }
#endif /* EAP_TNC */
                }
        } else if (data->ttls_version == 0 &&
                   ret->methodState == METHOD_MAY_CONT &&
                   (ret->decision == DECISION_UNCOND_SUCC ||
                    ret->decision == DECISION_COND_SUCC)) {
                        wpa_printf(MSG_DEBUG, "EAP-TTLS: Authentication "
                                   "completed successfully (MAY_CONT)");
                        data->phase2_success = 1;
        }
}


static struct wpabuf * eap_ttls_process(struct eap_sm *sm, void *priv,
                                        struct eap_method_ret *ret,
                                        const struct wpabuf *reqData)
{
        size_t left;
        int res;
        u8 flags, id;
        struct wpabuf *resp;
        const u8 *pos;
        struct eap_ttls_data *data = priv;

        pos = eap_peer_tls_process_init(sm, &data->ssl, EAP_TYPE_TTLS, ret,
                                        reqData, &left, &flags);
        if (pos == NULL)
                return NULL;
        id = eap_get_id(reqData);

        if (flags & EAP_TLS_FLAGS_START) {
                if (eap_ttls_process_start(sm, data, flags, ret) < 0)
                        return NULL;

                /* RFC 5281, Ch. 9.2:
                 * "This packet MAY contain additional information in the form
                 * of AVPs, which may provide useful hints to the client"
                 * For now, ignore any potential extra data.
                 */
                left = 0;
        } else if (!data->ssl_initialized) {
                wpa_printf(MSG_DEBUG, "EAP-TTLS: First message did not "
                           "include Start flag");
                ret->methodState = METHOD_DONE;
                ret->decision = DECISION_FAIL;
                ret->allowNotifications = FALSE;
                return NULL;
        }

        resp = NULL;
        if (tls_connection_established(sm->ssl_ctx, data->ssl.conn) &&
            !data->resuming) {
                struct wpabuf msg;
                wpabuf_set(&msg, pos, left);
                res = eap_ttls_decrypt(sm, data, ret, id, &msg, &resp);
        } else {
                res = eap_ttls_process_handshake(sm, data, ret, id,
                                                 pos, left, &resp);
        }

        eap_ttls_check_auth_status(sm, data, ret);

        /* FIX: what about res == -1? Could just move all error processing into
         * the other functions and get rid of this res==1 case here. */
        if (res == 1) {
                wpabuf_free(resp);
                return eap_peer_tls_build_ack(id, EAP_TYPE_TTLS,
                                              data->ttls_version);
        }
        return resp;
}


static Boolean eap_ttls_has_reauth_data(struct eap_sm *sm, void *priv)
{
        struct eap_ttls_data *data = priv;
        return tls_connection_established(sm->ssl_ctx, data->ssl.conn) &&
                data->phase2_success;
}


static void eap_ttls_deinit_for_reauth(struct eap_sm *sm, void *priv)
{
        struct eap_ttls_data *data = priv;
        wpabuf_free(data->pending_phase2_req);
        data->pending_phase2_req = NULL;
#ifdef EAP_TNC
        data->ready_for_tnc = 0;
        data->tnc_started = 0;
#endif /* EAP_TNC */
}


static void * eap_ttls_init_for_reauth(struct eap_sm *sm, void *priv)
{
        struct eap_ttls_data *data = priv;
        os_free(data->key_data);
        data->key_data = NULL;
        if (eap_peer_tls_reauth_init(sm, &data->ssl)) {
                os_free(data);
                return NULL;
        }
        if (data->phase2_priv && data->phase2_method &&
            data->phase2_method->init_for_reauth)
                data->phase2_method->init_for_reauth(sm, data->phase2_priv);
        data->phase2_start = 0;
        data->phase2_success = 0;
        data->resuming = 1;
        data->reauth = 1;
        return priv;
}


static int eap_ttls_get_status(struct eap_sm *sm, void *priv, char *buf,
                               size_t buflen, int verbose)
{
        struct eap_ttls_data *data = priv;
        int len, ret;

        len = eap_peer_tls_status(sm, &data->ssl, buf, buflen, verbose);
        ret = os_snprintf(buf + len, buflen - len,
                          "EAP-TTLSv%d Phase2 method=",
                          data->ttls_version);
        if (ret < 0 || (size_t) ret >= buflen - len)
                return len;
        len += ret;
        switch (data->phase2_type) {
        case EAP_TTLS_PHASE2_EAP:
                ret = os_snprintf(buf + len, buflen - len, "EAP-%s\n",
                                  data->phase2_method ?
                                  data->phase2_method->name : "?");
                break;
        case EAP_TTLS_PHASE2_MSCHAPV2:
                ret = os_snprintf(buf + len, buflen - len, "MSCHAPV2\n");
                break;
        case EAP_TTLS_PHASE2_MSCHAP:
                ret = os_snprintf(buf + len, buflen - len, "MSCHAP\n");
                break;
        case EAP_TTLS_PHASE2_PAP:
                ret = os_snprintf(buf + len, buflen - len, "PAP\n");
                break;
        case EAP_TTLS_PHASE2_CHAP:
                ret = os_snprintf(buf + len, buflen - len, "CHAP\n");
                break;
        default:
                ret = 0;
                break;
        }
        if (ret < 0 || (size_t) ret >= buflen - len)
                return len;
        len += ret;

        return len;
}


static Boolean eap_ttls_isKeyAvailable(struct eap_sm *sm, void *priv)
{
        struct eap_ttls_data *data = priv;
        return data->key_data != NULL && data->phase2_success;
}


static u8 * eap_ttls_getKey(struct eap_sm *sm, void *priv, size_t *len)
{
        struct eap_ttls_data *data = priv;
        u8 *key;

        if (data->key_data == NULL || !data->phase2_success)
                return NULL;

        key = os_malloc(EAP_TLS_KEY_LEN);
        if (key == NULL)
                return NULL;

        *len = EAP_TLS_KEY_LEN;
        os_memcpy(key, data->key_data, EAP_TLS_KEY_LEN);

        return key;
}


int eap_peer_ttls_register(void)
{
        struct eap_method *eap;
        int ret;

        eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
                                    EAP_VENDOR_IETF, EAP_TYPE_TTLS, "TTLS");
        if (eap == NULL)
                return -1;

        eap->init = eap_ttls_init;
        eap->deinit = eap_ttls_deinit;
        eap->process = eap_ttls_process;
        eap->isKeyAvailable = eap_ttls_isKeyAvailable;
        eap->getKey = eap_ttls_getKey;
        eap->get_status = eap_ttls_get_status;
        eap->has_reauth_data = eap_ttls_has_reauth_data;
        eap->deinit_for_reauth = eap_ttls_deinit_for_reauth;
        eap->init_for_reauth = eap_ttls_init_for_reauth;

        ret = eap_peer_method_register(eap);
        if (ret)
                eap_peer_method_free(eap);
        return ret;
}