src/eap_peer/eap_tls.c

   1 /*
   2  * EAP peer method: EAP-TLS (RFC 2716)
   3  * Copyright (c) 2004-2008, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16
  17 #include "common.h"
  18 #include "crypto/tls.h"
  19 #include "eap_i.h"
  20 #include "eap_tls_common.h"
  21 #include "eap_config.h"
  22
  23
  24 static void eap_tls_deinit(struct eap_sm *sm, void *priv);
  25
  26
  27 struct eap_tls_data {
  28         struct eap_ssl_data ssl;
  29         u8 *key_data;
  30 };
  31
  32
  33 static void * eap_tls_init(struct eap_sm *sm)
  34 {
  35         struct eap_tls_data *data;
  36         struct eap_peer_config *config = eap_get_config(sm);
  37         if (config == NULL ||
  38             ((sm->init_phase2 ? config->private_key2 : config->private_key)
  39              == NULL &&
  40              (sm->init_phase2 ? config->engine2 : config->engine) == 0)) {
  41                 wpa_printf(MSG_INFO, "EAP-TLS: Private key not configured");
  42                 return NULL;
  43         }
  44
  45         data = os_zalloc(sizeof(*data));
  46         if (data == NULL)
  47                 return NULL;
  48
  49         if (eap_peer_tls_ssl_init(sm, &data->ssl, config)) {
  50                 wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
  51                 eap_tls_deinit(sm, data);
  52                 if (config->engine) {
  53                         wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting Smartcard "
  54                                    "PIN");
  55                         eap_sm_request_pin(sm);
  56                         sm->ignore = TRUE;
  57                 } else if (config->private_key && !config->private_key_passwd)
  58                 {
  59                         wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting private "
  60                                    "key passphrase");
  61                         eap_sm_request_passphrase(sm);
  62                         sm->ignore = TRUE;
  63                 }
  64                 return NULL;
  65         }
  66
  67         return data;
  68 }
  69
  70
  71 static void eap_tls_deinit(struct eap_sm *sm, void *priv)
  72 {
  73         struct eap_tls_data *data = priv;
  74         if (data == NULL)
  75                 return;
  76         eap_peer_tls_ssl_deinit(sm, &data->ssl);
  77         os_free(data->key_data);
  78         os_free(data);
  79 }
  80
  81
  82 static struct wpabuf * eap_tls_failure(struct eap_sm *sm,
  83                                        struct eap_tls_data *data,
  84                                        struct eap_method_ret *ret, int res,
  85                                        struct wpabuf *resp, u8 id)
  86 {
  87         wpa_printf(MSG_DEBUG, "EAP-TLS: TLS processing failed");
  88
  89         ret->methodState = METHOD_DONE;
  90         ret->decision = DECISION_FAIL;
  91
  92         if (res == -1) {
  93                 struct eap_peer_config *config = eap_get_config(sm);
  94                 if (config) {
  95                         /*
  96                          * The TLS handshake failed. So better forget the old
  97                          * PIN. It may be wrong, we cannot be sure but trying
  98                          * the wrong one again might block it on the card--so
  99                          * better ask the user again.
 100                          */
 101                         os_free(config->pin);
 102                         config->pin = NULL;
 103                 }
 104         }
 105
 106         if (resp) {
 107                 /*
 108                  * This is likely an alert message, so send it instead of just
 109                  * ACKing the error.
 110                  */
 111                 return resp;
 112         }
 113
 114         return eap_peer_tls_build_ack(id, EAP_TYPE_TLS, 0);
 115 }
 116
 117
 118 static void eap_tls_success(struct eap_sm *sm, struct eap_tls_data *data,
 119                             struct eap_method_ret *ret)
 120 {
 121         wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
 122
 123         ret->methodState = METHOD_DONE;
 124         ret->decision = DECISION_UNCOND_SUCC;
 125
 126         os_free(data->key_data);
 127         data->key_data = eap_peer_tls_derive_key(sm, &data->ssl,
 128                                                  "client EAP encryption",
 129                                                  EAP_TLS_KEY_LEN +
 130                                                  EAP_EMSK_LEN);
 131         if (data->key_data) {
 132                 wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived key",
 133                                 data->key_data, EAP_TLS_KEY_LEN);
 134                 wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived EMSK",
 135                                 data->key_data + EAP_TLS_KEY_LEN,
 136                                 EAP_EMSK_LEN);
 137         } else {
 138                 wpa_printf(MSG_INFO, "EAP-TLS: Failed to derive key");
 139         }
 140 }
 141
 142
 143 static struct wpabuf * eap_tls_process(struct eap_sm *sm, void *priv,
 144                                        struct eap_method_ret *ret,
 145                                        const struct wpabuf *reqData)
 146 {
 147         size_t left;
 148         int res;
 149         struct wpabuf *resp;
 150         u8 flags, id;
 151         const u8 *pos;
 152         struct eap_tls_data *data = priv;
 153
 154         pos = eap_peer_tls_process_init(sm, &data->ssl, EAP_TYPE_TLS, ret,
 155                                         reqData, &left, &flags);
 156         if (pos == NULL)
 157                 return NULL;
 158         id = eap_get_id(reqData);
 159
 160         if (flags & EAP_TLS_FLAGS_START) {
 161                 wpa_printf(MSG_DEBUG, "EAP-TLS: Start");
 162                 left = 0; /* make sure that this frame is empty, even though it
 163                            * should always be, anyway */
 164         }
 165
 166         resp = NULL;
 167         res = eap_peer_tls_process_helper(sm, &data->ssl, EAP_TYPE_TLS, 0, id,
 168                                           pos, left, &resp);
 169
 170         if (res < 0) {
 171                 return eap_tls_failure(sm, data, ret, res, resp, id);
 172         }
 173
 174         if (tls_connection_established(sm->ssl_ctx, data->ssl.conn))
 175                 eap_tls_success(sm, data, ret);
 176
 177         if (res == 1) {
 178                 wpabuf_free(resp);
 179                 return eap_peer_tls_build_ack(id, EAP_TYPE_TLS, 0);
 180         }
 181
 182         return resp;
 183 }
 184
 185
 186 static Boolean eap_tls_has_reauth_data(struct eap_sm *sm, void *priv)
 187 {
 188         struct eap_tls_data *data = priv;
 189         return tls_connection_established(sm->ssl_ctx, data->ssl.conn);
 190 }
 191
 192
 193 static void eap_tls_deinit_for_reauth(struct eap_sm *sm, void *priv)
 194 {
 195 }
 196
 197
 198 static void * eap_tls_init_for_reauth(struct eap_sm *sm, void *priv)
 199 {
 200         struct eap_tls_data *data = priv;
 201         os_free(data->key_data);
 202         data->key_data = NULL;
 203         if (eap_peer_tls_reauth_init(sm, &data->ssl)) {
 204                 os_free(data);
 205                 return NULL;
 206         }
 207         return priv;
 208 }
 209
 210
 211 static int eap_tls_get_status(struct eap_sm *sm, void *priv, char *buf,
 212                               size_t buflen, int verbose)
 213 {
 214         struct eap_tls_data *data = priv;
 215         return eap_peer_tls_status(sm, &data->ssl, buf, buflen, verbose);
 216 }
 217
 218
 219 static Boolean eap_tls_isKeyAvailable(struct eap_sm *sm, void *priv)
 220 {
 221         struct eap_tls_data *data = priv;
 222         return data->key_data != NULL;
 223 }
 224
 225
 226 static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
 227 {
 228         struct eap_tls_data *data = priv;
 229         u8 *key;
 230
 231         if (data->key_data == NULL)
 232                 return NULL;
 233
 234         key = os_malloc(EAP_TLS_KEY_LEN);
 235         if (key == NULL)
 236                 return NULL;
 237
 238         *len = EAP_TLS_KEY_LEN;
 239         os_memcpy(key, data->key_data, EAP_TLS_KEY_LEN);
 240
 241         return key;
 242 }
 243
 244
 245 static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
 246 {
 247         struct eap_tls_data *data = priv;
 248         u8 *key;
 249
 250         if (data->key_data == NULL)
 251                 return NULL;
 252
 253         key = os_malloc(EAP_EMSK_LEN);
 254         if (key == NULL)
 255                 return NULL;
 256
 257         *len = EAP_EMSK_LEN;
 258         os_memcpy(key, data->key_data + EAP_TLS_KEY_LEN, EAP_EMSK_LEN);
 259
 260         return key;
 261 }
 262
 263
 264 int eap_peer_tls_register(void)
 265 {
 266         struct eap_method *eap;
 267         int ret;
 268
 269         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 270                                     EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
 271         if (eap == NULL)
 272                 return -1;
 273
 274         eap->init = eap_tls_init;
 275         eap->deinit = eap_tls_deinit;
 276         eap->process = eap_tls_process;
 277         eap->isKeyAvailable = eap_tls_isKeyAvailable;
 278         eap->getKey = eap_tls_getKey;
 279         eap->get_status = eap_tls_get_status;
 280         eap->has_reauth_data = eap_tls_has_reauth_data;
 281         eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
 282         eap->init_for_reauth = eap_tls_init_for_reauth;
 283         eap->get_emsk = eap_tls_get_emsk;
 284
 285         ret = eap_peer_method_register(eap);
 286         if (ret)
 287                 eap_peer_method_free(eap);
 288         return ret;
 289 }