www.project-moonshot.org Git - mech_eap.orig/blob - src/wps/wps_attr_process.c

   1 /*
   2  * Wi-Fi Protected Setup - attribute processing
   3  * Copyright (c) 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/sha256.h"
  19 #include "wps_i.h"
  20
  21
  22 int wps_process_authenticator(struct wps_data *wps, const u8 *authenticator,
  23                               const struct wpabuf *msg)
  24 {
  25         u8 hash[SHA256_MAC_LEN];
  26         const u8 *addr[2];
  27         size_t len[2];
  28
  29         if (authenticator == NULL) {
  30                 wpa_printf(MSG_DEBUG, "WPS: No Authenticator attribute "
  31                            "included");
  32                 return -1;
  33         }
  34
  35         if (wps->last_msg == NULL) {
  36                 wpa_printf(MSG_DEBUG, "WPS: Last message not available for "
  37                            "validating authenticator");
  38                 return -1;
  39         }
  40
  41         /* Authenticator = HMAC-SHA256_AuthKey(M_prev || M_curr*)
  42          * (M_curr* is M_curr without the Authenticator attribute)
  43          */
  44         addr[0] = wpabuf_head(wps->last_msg);
  45         len[0] = wpabuf_len(wps->last_msg);
  46         addr[1] = wpabuf_head(msg);
  47         len[1] = wpabuf_len(msg) - 4 - WPS_AUTHENTICATOR_LEN;
  48         hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 2, addr, len, hash);
  49
  50         if (os_memcmp(hash, authenticator, WPS_AUTHENTICATOR_LEN) != 0) {
  51                 wpa_printf(MSG_DEBUG, "WPS: Incorrect Authenticator");
  52                 return -1;
  53         }
  54
  55         return 0;
  56 }
  57
  58
  59 int wps_process_key_wrap_auth(struct wps_data *wps, struct wpabuf *msg,
  60                               const u8 *key_wrap_auth)
  61 {
  62         u8 hash[SHA256_MAC_LEN];
  63         const u8 *head;
  64         size_t len;
  65
  66         if (key_wrap_auth == NULL) {
  67                 wpa_printf(MSG_DEBUG, "WPS: No KWA in decrypted attribute");
  68                 return -1;
  69         }
  70
  71         head = wpabuf_head(msg);
  72         len = wpabuf_len(msg) - 4 - WPS_KWA_LEN;
  73         if (head + len != key_wrap_auth - 4) {
  74                 wpa_printf(MSG_DEBUG, "WPS: KWA not in the end of the "
  75                            "decrypted attribute");
  76                 return -1;
  77         }
  78
  79         hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, head, len, hash);
  80         if (os_memcmp(hash, key_wrap_auth, WPS_KWA_LEN) != 0) {
  81                 wpa_printf(MSG_DEBUG, "WPS: Invalid KWA");
  82                 return -1;
  83         }
  84
  85         return 0;
  86 }
  87
  88
  89 static int wps_process_cred_network_idx(struct wps_credential *cred,
  90                                         const u8 *idx)
  91 {
  92         if (idx == NULL) {
  93                 wpa_printf(MSG_DEBUG, "WPS: Credential did not include "
  94                            "Network Index");
  95                 return -1;
  96         }
  97
  98         wpa_printf(MSG_DEBUG, "WPS: Network Index: %d", *idx);
  99
 100         return 0;
 101 }
 102
 103
 104 static int wps_process_cred_ssid(struct wps_credential *cred, const u8 *ssid,
 105                                  size_t ssid_len)
 106 {
 107         if (ssid == NULL) {
 108                 wpa_printf(MSG_DEBUG, "WPS: Credential did not include SSID");
 109                 return -1;
 110         }
 111
 112         /* Remove zero-padding since some Registrar implementations seem to use
 113          * hardcoded 32-octet length for this attribute */
 114         while (ssid_len > 0 && ssid[ssid_len - 1] == 0)
 115                 ssid_len--;
 116
 117         wpa_hexdump_ascii(MSG_DEBUG, "WPS: SSID", ssid, ssid_len);
 118         if (ssid_len <= sizeof(cred->ssid)) {
 119                 os_memcpy(cred->ssid, ssid, ssid_len);
 120                 cred->ssid_len = ssid_len;
 121         }
 122
 123         return 0;
 124 }
 125
 126
 127 static int wps_process_cred_auth_type(struct wps_credential *cred,
 128                                       const u8 *auth_type)
 129 {
 130         if (auth_type == NULL) {
 131                 wpa_printf(MSG_DEBUG, "WPS: Credential did not include "
 132                            "Authentication Type");
 133                 return -1;
 134         }
 135
 136         cred->auth_type = WPA_GET_BE16(auth_type);
 137         wpa_printf(MSG_DEBUG, "WPS: Authentication Type: 0x%x",
 138                    cred->auth_type);
 139
 140         return 0;
 141 }
 142
 143
 144 static int wps_process_cred_encr_type(struct wps_credential *cred,
 145                                       const u8 *encr_type)
 146 {
 147         if (encr_type == NULL) {
 148                 wpa_printf(MSG_DEBUG, "WPS: Credential did not include "
 149                            "Encryption Type");
 150                 return -1;
 151         }
 152
 153         cred->encr_type = WPA_GET_BE16(encr_type);
 154         wpa_printf(MSG_DEBUG, "WPS: Encryption Type: 0x%x",
 155                    cred->encr_type);
 156
 157         return 0;
 158 }
 159
 160
 161 static int wps_process_cred_network_key_idx(struct wps_credential *cred,
 162                                             const u8 *key_idx)
 163 {
 164         if (key_idx == NULL)
 165                 return 0; /* optional attribute */
 166
 167         wpa_printf(MSG_DEBUG, "WPS: Network Key Index: %d", *key_idx);
 168         cred->key_idx = *key_idx;
 169
 170         return 0;
 171 }
 172
 173
 174 static int wps_process_cred_network_key(struct wps_credential *cred,
 175                                         const u8 *key, size_t key_len)
 176 {
 177         if (key == NULL) {
 178                 wpa_printf(MSG_DEBUG, "WPS: Credential did not include "
 179                            "Network Key");
 180                 if (cred->auth_type == WPS_AUTH_OPEN &&
 181                     cred->encr_type == WPS_ENCR_NONE) {
 182                         wpa_printf(MSG_DEBUG, "WPS: Workaround - Allow "
 183                                    "missing mandatory Network Key attribute "
 184                                    "for open network");
 185                         return 0;
 186                 }
 187                 return -1;
 188         }
 189
 190         wpa_hexdump_key(MSG_DEBUG, "WPS: Network Key", key, key_len);
 191         if (key_len <= sizeof(cred->key)) {
 192                 os_memcpy(cred->key, key, key_len);
 193                 cred->key_len = key_len;
 194         }
 195
 196         return 0;
 197 }
 198
 199
 200 static int wps_process_cred_mac_addr(struct wps_credential *cred,
 201                                      const u8 *mac_addr)
 202 {
 203         if (mac_addr == NULL) {
 204                 wpa_printf(MSG_DEBUG, "WPS: Credential did not include "
 205                            "MAC Address");
 206                 return -1;
 207         }
 208
 209         wpa_printf(MSG_DEBUG, "WPS: MAC Address " MACSTR, MAC2STR(mac_addr));
 210         os_memcpy(cred->mac_addr, mac_addr, ETH_ALEN);
 211
 212         return 0;
 213 }
 214
 215
 216 static int wps_process_cred_eap_type(struct wps_credential *cred,
 217                                      const u8 *eap_type, size_t eap_type_len)
 218 {
 219         if (eap_type == NULL)
 220                 return 0; /* optional attribute */
 221
 222         wpa_hexdump(MSG_DEBUG, "WPS: EAP Type", eap_type, eap_type_len);
 223
 224         return 0;
 225 }
 226
 227
 228 static int wps_process_cred_eap_identity(struct wps_credential *cred,
 229                                          const u8 *identity,
 230                                          size_t identity_len)
 231 {
 232         if (identity == NULL)
 233                 return 0; /* optional attribute */
 234
 235         wpa_hexdump_ascii(MSG_DEBUG, "WPS: EAP Identity",
 236                           identity, identity_len);
 237
 238         return 0;
 239 }
 240
 241
 242 static int wps_process_cred_key_prov_auto(struct wps_credential *cred,
 243                                           const u8 *key_prov_auto)
 244 {
 245         if (key_prov_auto == NULL)
 246                 return 0; /* optional attribute */
 247
 248         wpa_printf(MSG_DEBUG, "WPS: Key Provided Automatically: %d",
 249                    *key_prov_auto);
 250
 251         return 0;
 252 }
 253
 254
 255 static int wps_process_cred_802_1x_enabled(struct wps_credential *cred,
 256                                            const u8 *dot1x_enabled)
 257 {
 258         if (dot1x_enabled == NULL)
 259                 return 0; /* optional attribute */
 260
 261         wpa_printf(MSG_DEBUG, "WPS: 802.1X Enabled: %d", *dot1x_enabled);
 262
 263         return 0;
 264 }
 265
 266
 267 static int wps_workaround_cred_key(struct wps_credential *cred)
 268 {
 269         if (cred->auth_type & (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK) &&
 270             cred->key_len > 8 && cred->key_len < 64 &&
 271             cred->key[cred->key_len - 1] == 0) {
 272 #ifdef CONFIG_WPS_STRICT
 273                 wpa_printf(MSG_INFO, "WPS: WPA/WPA2-Personal passphrase uses "
 274                            "forbidden NULL termination");
 275                 wpa_hexdump_ascii_key(MSG_INFO, "WPS: Network Key",
 276                                       cred->key, cred->key_len);
 277                 return -1;
 278 #else /* CONFIG_WPS_STRICT */
 279                 /*
 280                  * A deployed external registrar is known to encode ASCII
 281                  * passphrases incorrectly. Remove the extra NULL termination
 282                  * to fix the encoding.
 283                  */
 284                 wpa_printf(MSG_DEBUG, "WPS: Workaround - remove NULL "
 285                            "termination from ASCII passphrase");
 286                 cred->key_len--;
 287 #endif /* CONFIG_WPS_STRICT */
 288         }
 289         return 0;
 290 }
 291
 292
 293 int wps_process_cred(struct wps_parse_attr *attr,
 294                      struct wps_credential *cred)
 295 {
 296         wpa_printf(MSG_DEBUG, "WPS: Process Credential");
 297
 298         /* TODO: support multiple Network Keys */
 299         if (wps_process_cred_network_idx(cred, attr->network_idx) ||
 300             wps_process_cred_ssid(cred, attr->ssid, attr->ssid_len) ||
 301             wps_process_cred_auth_type(cred, attr->auth_type) ||
 302             wps_process_cred_encr_type(cred, attr->encr_type) ||
 303             wps_process_cred_network_key_idx(cred, attr->network_key_idx) ||
 304             wps_process_cred_network_key(cred, attr->network_key,
 305                                          attr->network_key_len) ||
 306             wps_process_cred_mac_addr(cred, attr->mac_addr) ||
 307             wps_process_cred_eap_type(cred, attr->eap_type,
 308                                       attr->eap_type_len) ||
 309             wps_process_cred_eap_identity(cred, attr->eap_identity,
 310                                           attr->eap_identity_len) ||
 311             wps_process_cred_key_prov_auto(cred, attr->key_prov_auto) ||
 312             wps_process_cred_802_1x_enabled(cred, attr->dot1x_enabled))
 313                 return -1;
 314
 315         return wps_workaround_cred_key(cred);
 316 }
 317
 318
 319 int wps_process_ap_settings(struct wps_parse_attr *attr,
 320                             struct wps_credential *cred)
 321 {
 322         wpa_printf(MSG_DEBUG, "WPS: Processing AP Settings");
 323         os_memset(cred, 0, sizeof(*cred));
 324         /* TODO: optional attributes New Password and Device Password ID */
 325         if (wps_process_cred_ssid(cred, attr->ssid, attr->ssid_len) ||
 326             wps_process_cred_auth_type(cred, attr->auth_type) ||
 327             wps_process_cred_encr_type(cred, attr->encr_type) ||
 328             wps_process_cred_network_key_idx(cred, attr->network_key_idx) ||
 329             wps_process_cred_network_key(cred, attr->network_key,
 330                                          attr->network_key_len) ||
 331             wps_process_cred_mac_addr(cred, attr->mac_addr))
 332                 return -1;
 333
 334         return wps_workaround_cred_key(cred);
 335 }