/src/hostap/src/wps/wps_enrollee.c

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/*
 * Wi-Fi Protected Setup - Enrollee
 * Copyright (c) 2008, Jouni Malinen <j@w1.fi>
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 */

#include "includes.h"

#include "common.h"
#include "crypto/crypto.h"
#include "crypto/sha256.h"
#include "crypto/random.h"
#include "wps_i.h"
#include "wps_dev_attr.h"


static int wps_build_wps_state(struct wps_data *wps, struct wpabuf *msg)
{
  u8 state;
  if (wps->wps->ap)
    state = wps->wps->wps_state;
  else
    state = WPS_STATE_NOT_CONFIGURED;
  wpa_printf(MSG_DEBUG, "WPS:  * Wi-Fi Protected Setup State (%d)",
       state);
  wpabuf_put_be16(msg, ATTR_WPS_STATE);
  wpabuf_put_be16(msg, 1);
  wpabuf_put_u8(msg, state);
  return 0;
}


static int wps_build_e_hash(struct wps_data *wps, struct wpabuf *msg)
{
  u8 *hash;
  const u8 *addr[4];
  size_t len[4];

  if (random_get_bytes(wps->snonce, 2 * WPS_SECRET_NONCE_LEN) < 0)
    return -1;
  wpa_hexdump(MSG_DEBUG, "WPS: E-S1", wps->snonce, WPS_SECRET_NONCE_LEN);
  wpa_hexdump(MSG_DEBUG, "WPS: E-S2",
        wps->snonce + WPS_SECRET_NONCE_LEN, WPS_SECRET_NONCE_LEN);

  if (wps->dh_pubkey_e == NULL || wps->dh_pubkey_r == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: DH public keys not available for "
         "E-Hash derivation");
    return -1;
  }

  wpa_printf(MSG_DEBUG, "WPS:  * E-Hash1");
  wpabuf_put_be16(msg, ATTR_E_HASH1);
  wpabuf_put_be16(msg, SHA256_MAC_LEN);
  hash = wpabuf_put(msg, SHA256_MAC_LEN);
  /* E-Hash1 = HMAC_AuthKey(E-S1 || PSK1 || PK_E || PK_R) */
  addr[0] = wps->snonce;
  len[0] = WPS_SECRET_NONCE_LEN;
  addr[1] = wps->psk1;
  len[1] = WPS_PSK_LEN;
  addr[2] = wpabuf_head(wps->dh_pubkey_e);
  len[2] = wpabuf_len(wps->dh_pubkey_e);
  addr[3] = wpabuf_head(wps->dh_pubkey_r);
  len[3] = wpabuf_len(wps->dh_pubkey_r);
  hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);
  wpa_hexdump(MSG_DEBUG, "WPS: E-Hash1", hash, SHA256_MAC_LEN);

  wpa_printf(MSG_DEBUG, "WPS:  * E-Hash2");
  wpabuf_put_be16(msg, ATTR_E_HASH2);
  wpabuf_put_be16(msg, SHA256_MAC_LEN);
  hash = wpabuf_put(msg, SHA256_MAC_LEN);
  /* E-Hash2 = HMAC_AuthKey(E-S2 || PSK2 || PK_E || PK_R) */
  addr[0] = wps->snonce + WPS_SECRET_NONCE_LEN;
  addr[1] = wps->psk2;
  hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);
  wpa_hexdump(MSG_DEBUG, "WPS: E-Hash2", hash, SHA256_MAC_LEN);

  return 0;
}


static int wps_build_e_snonce1(struct wps_data *wps, struct wpabuf *msg)
{
  wpa_printf(MSG_DEBUG, "WPS:  * E-SNonce1");
  wpabuf_put_be16(msg, ATTR_E_SNONCE1);
  wpabuf_put_be16(msg, WPS_SECRET_NONCE_LEN);
  wpabuf_put_data(msg, wps->snonce, WPS_SECRET_NONCE_LEN);
  return 0;
}


static int wps_build_e_snonce2(struct wps_data *wps, struct wpabuf *msg)
{
  wpa_printf(MSG_DEBUG, "WPS:  * E-SNonce2");
  wpabuf_put_be16(msg, ATTR_E_SNONCE2);
  wpabuf_put_be16(msg, WPS_SECRET_NONCE_LEN);
  wpabuf_put_data(msg, wps->snonce + WPS_SECRET_NONCE_LEN,
      WPS_SECRET_NONCE_LEN);
  return 0;
}


static struct wpabuf * wps_build_m1(struct wps_data *wps)
{
  struct wpabuf *msg;
  u16 config_methods;
  u8 multi_ap_backhaul_sta = 0;

  if (random_get_bytes(wps->nonce_e, WPS_NONCE_LEN) < 0)
    return NULL;
  wpa_hexdump(MSG_DEBUG, "WPS: Enrollee Nonce",
        wps->nonce_e, WPS_NONCE_LEN);

  wpa_printf(MSG_DEBUG, "WPS: Building Message M1");
  msg = wpabuf_alloc(1000);
  if (msg == NULL)
    return NULL;

  config_methods = wps->wps->config_methods;
  if (wps->wps->ap && !wps->pbc_in_m1 &&
      (wps->dev_password_len != 0 ||
       (config_methods & WPS_CONFIG_DISPLAY))) {
    /*
     * These are the methods that the AP supports as an Enrollee
     * for adding external Registrars, so remove PushButton.
     *
     * As a workaround for Windows 7 mechanism for probing WPS
     * capabilities from M1, leave PushButton option if no PIN
     * method is available or if WPS configuration enables PBC
     * workaround.
     */
    config_methods &= ~WPS_CONFIG_PUSHBUTTON;
    config_methods &= ~(WPS_CONFIG_VIRT_PUSHBUTTON |
            WPS_CONFIG_PHY_PUSHBUTTON);
  }

  if (wps->multi_ap_backhaul_sta)
    multi_ap_backhaul_sta = MULTI_AP_BACKHAUL_STA;

  if (wps_build_version(msg) ||
      wps_build_msg_type(msg, WPS_M1) ||
      wps_build_uuid_e(msg, wps->uuid_e) ||
      wps_build_mac_addr(msg, wps->mac_addr_e) ||
      wps_build_enrollee_nonce(wps, msg) ||
      wps_build_public_key(wps, msg) ||
      wps_build_auth_type_flags(wps, msg) ||
      wps_build_encr_type_flags(wps, msg) ||
      wps_build_conn_type_flags(wps, msg) ||
      wps_build_config_methods(msg, config_methods) ||
      wps_build_wps_state(wps, msg) ||
      wps_build_device_attrs(&wps->wps->dev, msg) ||
      wps_build_rf_bands(&wps->wps->dev, msg,
             wps->wps->rf_band_cb(wps->wps->cb_ctx)) ||
      wps_build_assoc_state(wps, msg) ||
      wps_build_dev_password_id(msg, wps->dev_pw_id) ||
      wps_build_config_error(msg, WPS_CFG_NO_ERROR) ||
      wps_build_os_version(&wps->wps->dev, msg) ||
      wps_build_wfa_ext(msg, 0, NULL, 0, multi_ap_backhaul_sta) ||
      wps_build_vendor_ext_m1(&wps->wps->dev, msg)) {
    wpabuf_free(msg);
    return NULL;
  }

  wps->state = RECV_M2;
  return msg;
}


static struct wpabuf * wps_build_m3(struct wps_data *wps)
{
  struct wpabuf *msg;

  wpa_printf(MSG_DEBUG, "WPS: Building Message M3");

  if (wps->dev_password == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: No Device Password available");
    return NULL;
  }
  if (wps_derive_psk(wps, wps->dev_password, wps->dev_password_len) < 0)
    return NULL;

  if (wps->wps->ap && random_pool_ready() != 1) {
    wpa_printf(MSG_INFO,
         "WPS: Not enough entropy in random pool to proceed - do not allow AP PIN to be used");
    return NULL;
  }

  msg = wpabuf_alloc(1000);
  if (msg == NULL)
    return NULL;

  if (wps_build_version(msg) ||
      wps_build_msg_type(msg, WPS_M3) ||
      wps_build_registrar_nonce(wps, msg) ||
      wps_build_e_hash(wps, msg) ||
      wps_build_wfa_ext(msg, 0, NULL, 0, 0) ||
      wps_build_authenticator(wps, msg)) {
    wpabuf_free(msg);
    return NULL;
  }

  wps->state = RECV_M4;
  return msg;
}


static struct wpabuf * wps_build_m5(struct wps_data *wps)
{
  struct wpabuf *msg, *plain;

  wpa_printf(MSG_DEBUG, "WPS: Building Message M5");

  plain = wpabuf_alloc(200);
  if (plain == NULL)
    return NULL;

  msg = wpabuf_alloc(1000);
  if (msg == NULL) {
    wpabuf_free(plain);
    return NULL;
  }

  if (wps_build_version(msg) ||
      wps_build_msg_type(msg, WPS_M5) ||
      wps_build_registrar_nonce(wps, msg) ||
      wps_build_e_snonce1(wps, plain) ||
      wps_build_key_wrap_auth(wps, plain) ||
      wps_build_encr_settings(wps, msg, plain) ||
      wps_build_wfa_ext(msg, 0, NULL, 0, 0) ||
      wps_build_authenticator(wps, msg)) {
    wpabuf_clear_free(plain);
    wpabuf_free(msg);
    return NULL;
  }
  wpabuf_clear_free(plain);

  wps->state = RECV_M6;
  return msg;
}


static int wps_build_cred_ssid(struct wps_data *wps, struct wpabuf *msg)
{
  wpa_printf(MSG_DEBUG, "WPS:  * SSID");
  wpabuf_put_be16(msg, ATTR_SSID);
  wpabuf_put_be16(msg, wps->wps->ssid_len);
  wpabuf_put_data(msg, wps->wps->ssid, wps->wps->ssid_len);
  return 0;
}


static int wps_build_cred_auth_type(struct wps_data *wps, struct wpabuf *msg)
{
  u16 auth_type = wps->wps->ap_auth_type;

  /*
   * Work around issues with Windows 7 WPS implementation not liking
   * multiple Authentication Type bits in M7 AP Settings attribute by
   * showing only the most secure option from current configuration.
   */
  if (auth_type & WPS_AUTH_WPA2PSK)
    auth_type = WPS_AUTH_WPA2PSK;
  else if (auth_type & WPS_AUTH_WPAPSK)
    auth_type = WPS_AUTH_WPAPSK;
  else if (auth_type & WPS_AUTH_OPEN)
    auth_type = WPS_AUTH_OPEN;

  wpa_printf(MSG_DEBUG, "WPS:  * Authentication Type (0x%x)", auth_type);
  wpabuf_put_be16(msg, ATTR_AUTH_TYPE);
  wpabuf_put_be16(msg, 2);
  wpabuf_put_be16(msg, auth_type);
  return 0;
}


static int wps_build_cred_encr_type(struct wps_data *wps, struct wpabuf *msg)
{
  u16 encr_type = wps->wps->ap_encr_type;

  /*
   * Work around issues with Windows 7 WPS implementation not liking
   * multiple Encryption Type bits in M7 AP Settings attribute by
   * showing only the most secure option from current configuration.
   */
  if (wps->wps->ap_auth_type & (WPS_AUTH_WPA2PSK | WPS_AUTH_WPAPSK)) {
    if (encr_type & WPS_ENCR_AES)
      encr_type = WPS_ENCR_AES;
    else if (encr_type & WPS_ENCR_TKIP)
      encr_type = WPS_ENCR_TKIP;
  }

  wpa_printf(MSG_DEBUG, "WPS:  * Encryption Type (0x%x)", encr_type);
  wpabuf_put_be16(msg, ATTR_ENCR_TYPE);
  wpabuf_put_be16(msg, 2);
  wpabuf_put_be16(msg, encr_type);
  return 0;
}


static int wps_build_cred_network_key(struct wps_data *wps, struct wpabuf *msg)
{
  if ((wps->wps->ap_auth_type & (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK)) &&
      wps->wps->network_key_len == 0) {
    char hex[65];
    u8 psk[32];
    /* Generate a random per-device PSK */
    if (random_pool_ready() != 1 ||
        random_get_bytes(psk, sizeof(psk)) < 0) {
      wpa_printf(MSG_INFO,
           "WPS: Could not generate random PSK");
      return -1;
    }
    wpa_hexdump_key(MSG_DEBUG, "WPS: Generated per-device PSK",
        psk, sizeof(psk));
    wpa_printf(MSG_DEBUG, "WPS:  * Network Key (len=%u)",
         (unsigned int) wps->new_psk_len * 2);
    wpa_snprintf_hex(hex, sizeof(hex), psk, sizeof(psk));
    wpabuf_put_be16(msg, ATTR_NETWORK_KEY);
    wpabuf_put_be16(msg, sizeof(psk) * 2);
    wpabuf_put_data(msg, hex, sizeof(psk) * 2);
    if (wps->wps->registrar) {
      wps_cb_new_psk(wps->wps->registrar,
               wps->peer_dev.mac_addr,
               wps->p2p_dev_addr, psk, sizeof(psk));
    }
    return 0;
  }

  wpa_printf(MSG_DEBUG, "WPS:  * Network Key (len=%u)",
       (unsigned int) wps->wps->network_key_len);
  wpabuf_put_be16(msg, ATTR_NETWORK_KEY);
  wpabuf_put_be16(msg, wps->wps->network_key_len);
  wpabuf_put_data(msg, wps->wps->network_key, wps->wps->network_key_len);
  return 0;
}


static int wps_build_cred_mac_addr(struct wps_data *wps, struct wpabuf *msg)
{
  wpa_printf(MSG_DEBUG, "WPS:  * MAC Address (AP BSSID)");
  wpabuf_put_be16(msg, ATTR_MAC_ADDR);
  wpabuf_put_be16(msg, ETH_ALEN);
  wpabuf_put_data(msg, wps->wps->dev.mac_addr, ETH_ALEN);
  return 0;
}


static int wps_build_ap_settings(struct wps_data *wps, struct wpabuf *plain)
{
  const u8 *start, *end;
  int ret;

  if (wps->wps->ap_settings) {
    wpa_printf(MSG_DEBUG, "WPS:  * AP Settings (pre-configured)");
    wpabuf_put_data(plain, wps->wps->ap_settings,
        wps->wps->ap_settings_len);
    return 0;
  }

  wpa_printf(MSG_DEBUG, "WPS:  * AP Settings based on current configuration");
  start = wpabuf_put(plain, 0);
  ret = wps_build_cred_ssid(wps, plain) ||
    wps_build_cred_mac_addr(wps, plain) ||
    wps_build_cred_auth_type(wps, plain) ||
    wps_build_cred_encr_type(wps, plain) ||
    wps_build_cred_network_key(wps, plain);
  end = wpabuf_put(plain, 0);

  wpa_hexdump_key(MSG_DEBUG, "WPS: Plaintext AP Settings",
      start, end - start);

  return ret;
}


static struct wpabuf * wps_build_m7(struct wps_data *wps)
{
  struct wpabuf *msg, *plain;

  wpa_printf(MSG_DEBUG, "WPS: Building Message M7");

  plain = wpabuf_alloc(500 + wps->wps->ap_settings_len);
  if (plain == NULL)
    return NULL;

  msg = wpabuf_alloc(1000 + wps->wps->ap_settings_len);
  if (msg == NULL) {
    wpabuf_free(plain);
    return NULL;
  }

  if (wps_build_version(msg) ||
      wps_build_msg_type(msg, WPS_M7) ||
      wps_build_registrar_nonce(wps, msg) ||
      wps_build_e_snonce2(wps, plain) ||
      (wps->wps->ap && wps_build_ap_settings(wps, plain)) ||
      wps_build_key_wrap_auth(wps, plain) ||
      wps_build_encr_settings(wps, msg, plain) ||
      wps_build_wfa_ext(msg, 0, NULL, 0, 0) ||
      wps_build_authenticator(wps, msg)) {
    wpabuf_clear_free(plain);
    wpabuf_free(msg);
    return NULL;
  }
  wpabuf_clear_free(plain);

  if (wps->wps->ap && wps->wps->registrar) {
    /*
     * If the Registrar is only learning our current configuration,
     * it may not continue protocol run to successful completion.
     * Store information here to make sure it remains available.
     */
    wps_device_store(wps->wps->registrar, &wps->peer_dev,
         wps->uuid_r);
  }

  wps->state = RECV_M8;
  return msg;
}


static struct wpabuf * wps_build_wsc_done(struct wps_data *wps)
{
  struct wpabuf *msg;

  wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_Done");

  msg = wpabuf_alloc(1000);
  if (msg == NULL)
    return NULL;

  if (wps_build_version(msg) ||
      wps_build_msg_type(msg, WPS_WSC_DONE) ||
      wps_build_enrollee_nonce(wps, msg) ||
      wps_build_registrar_nonce(wps, msg) ||
      wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
    wpabuf_free(msg);
    return NULL;
  }

  if (wps->wps->ap)
    wps->state = RECV_ACK;
  else {
    wps_success_event(wps->wps, wps->peer_dev.mac_addr);
    wps->state = WPS_FINISHED;
  }
  return msg;
}


struct wpabuf * wps_enrollee_get_msg(struct wps_data *wps,
             enum wsc_op_code *op_code)
{
  struct wpabuf *msg;

  switch (wps->state) {
  case SEND_M1:
    msg = wps_build_m1(wps);
    *op_code = WSC_MSG;
    break;
  case SEND_M3:
    msg = wps_build_m3(wps);
    *op_code = WSC_MSG;
    break;
  case SEND_M5:
    msg = wps_build_m5(wps);
    *op_code = WSC_MSG;
    break;
  case SEND_M7:
    msg = wps_build_m7(wps);
    *op_code = WSC_MSG;
    break;
  case RECEIVED_M2D:
    if (wps->wps->ap) {
      msg = wps_build_wsc_nack(wps);
      *op_code = WSC_NACK;
      break;
    }
    msg = wps_build_wsc_ack(wps);
    *op_code = WSC_ACK;
    if (msg) {
      /* Another M2/M2D may be received */
      wps->state = RECV_M2;
    }
    break;
  case SEND_WSC_NACK:
    msg = wps_build_wsc_nack(wps);
    *op_code = WSC_NACK;
    break;
  case WPS_MSG_DONE:
    msg = wps_build_wsc_done(wps);
    *op_code = WSC_Done;
    break;
  default:
    wpa_printf(MSG_DEBUG, "WPS: Unsupported state %d for building "
         "a message", wps->state);
    msg = NULL;
    break;
  }

  if (*op_code == WSC_MSG && msg) {
    /* Save a copy of the last message for Authenticator derivation
     */
    wpabuf_free(wps->last_msg);
    wps->last_msg = wpabuf_dup(msg);
  }

  return msg;
}


static int wps_process_registrar_nonce(struct wps_data *wps, const u8 *r_nonce)
{
  if (r_nonce == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: No Registrar Nonce received");
    return -1;
  }

  os_memcpy(wps->nonce_r, r_nonce, WPS_NONCE_LEN);
  wpa_hexdump(MSG_DEBUG, "WPS: Registrar Nonce",
        wps->nonce_r, WPS_NONCE_LEN);

  return 0;
}


static int wps_process_enrollee_nonce(struct wps_data *wps, const u8 *e_nonce)
{
  if (e_nonce == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: No Enrollee Nonce received");
    return -1;
  }

  if (os_memcmp(wps->nonce_e, e_nonce, WPS_NONCE_LEN) != 0) {
    wpa_printf(MSG_DEBUG, "WPS: Invalid Enrollee Nonce received");
    return -1;
  }

  return 0;
}


static int wps_process_uuid_r(struct wps_data *wps, const u8 *uuid_r)
{
  if (uuid_r == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: No UUID-R received");
    return -1;
  }

  os_memcpy(wps->uuid_r, uuid_r, WPS_UUID_LEN);
  wpa_hexdump(MSG_DEBUG, "WPS: UUID-R", wps->uuid_r, WPS_UUID_LEN);

  return 0;
}


static int wps_process_pubkey(struct wps_data *wps, const u8 *pk,
            size_t pk_len)
{
  if (pk == NULL || pk_len == 0) {
    wpa_printf(MSG_DEBUG, "WPS: No Public Key received");
    return -1;
  }

  if (wps->peer_pubkey_hash_set) {
    u8 hash[WPS_HASH_LEN];
    sha256_vector(1, &pk, &pk_len, hash);
    if (os_memcmp_const(hash, wps->peer_pubkey_hash,
            WPS_OOB_PUBKEY_HASH_LEN) != 0) {
      wpa_printf(MSG_ERROR, "WPS: Public Key hash mismatch");
      wpa_hexdump(MSG_DEBUG, "WPS: Received public key",
            pk, pk_len);
      wpa_hexdump(MSG_DEBUG, "WPS: Calculated public key "
            "hash", hash, WPS_OOB_PUBKEY_HASH_LEN);
      wpa_hexdump(MSG_DEBUG, "WPS: Expected public key hash",
            wps->peer_pubkey_hash,
            WPS_OOB_PUBKEY_HASH_LEN);
      wps->config_error = WPS_CFG_PUBLIC_KEY_HASH_MISMATCH;
      return -1;
    }
  }

  wpabuf_free(wps->dh_pubkey_r);
  wps->dh_pubkey_r = wpabuf_alloc_copy(pk, pk_len);
  if (wps->dh_pubkey_r == NULL)
    return -1;

  if (wps_derive_keys(wps) < 0)
    return -1;

  return 0;
}


static int wps_process_r_hash1(struct wps_data *wps, const u8 *r_hash1)
{
  if (r_hash1 == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: No R-Hash1 received");
    return -1;
  }

  os_memcpy(wps->peer_hash1, r_hash1, WPS_HASH_LEN);
  wpa_hexdump(MSG_DEBUG, "WPS: R-Hash1", wps->peer_hash1, WPS_HASH_LEN);

  return 0;
}


static int wps_process_r_hash2(struct wps_data *wps, const u8 *r_hash2)
{
  if (r_hash2 == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: No R-Hash2 received");
    return -1;
  }

  os_memcpy(wps->peer_hash2, r_hash2, WPS_HASH_LEN);
  wpa_hexdump(MSG_DEBUG, "WPS: R-Hash2", wps->peer_hash2, WPS_HASH_LEN);

  return 0;
}


static int wps_process_r_snonce1(struct wps_data *wps, const u8 *r_snonce1)
{
  u8 hash[SHA256_MAC_LEN];
  const u8 *addr[4];
  size_t len[4];

  if (r_snonce1 == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: No R-SNonce1 received");
    return -1;
  }

  wpa_hexdump_key(MSG_DEBUG, "WPS: R-SNonce1", r_snonce1,
      WPS_SECRET_NONCE_LEN);

  /* R-Hash1 = HMAC_AuthKey(R-S1 || PSK1 || PK_E || PK_R) */
  addr[0] = r_snonce1;
  len[0] = WPS_SECRET_NONCE_LEN;
  addr[1] = wps->psk1;
  len[1] = WPS_PSK_LEN;
  addr[2] = wpabuf_head(wps->dh_pubkey_e);
  len[2] = wpabuf_len(wps->dh_pubkey_e);
  addr[3] = wpabuf_head(wps->dh_pubkey_r);
  len[3] = wpabuf_len(wps->dh_pubkey_r);
  hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);

  if (os_memcmp_const(wps->peer_hash1, hash, WPS_HASH_LEN) != 0) {
    wpa_printf(MSG_DEBUG, "WPS: R-Hash1 derived from R-S1 does "
         "not match with the pre-committed value");
    wps->config_error = WPS_CFG_DEV_PASSWORD_AUTH_FAILURE;
    wps_pwd_auth_fail_event(wps->wps, 1, 1, wps->peer_dev.mac_addr);
    return -1;
  }

  wpa_printf(MSG_DEBUG, "WPS: Registrar proved knowledge of the first "
       "half of the device password");

  return 0;
}


static int wps_process_r_snonce2(struct wps_data *wps, const u8 *r_snonce2)
{
  u8 hash[SHA256_MAC_LEN];
  const u8 *addr[4];
  size_t len[4];

  if (r_snonce2 == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: No R-SNonce2 received");
    return -1;
  }

  wpa_hexdump_key(MSG_DEBUG, "WPS: R-SNonce2", r_snonce2,
      WPS_SECRET_NONCE_LEN);

  /* R-Hash2 = HMAC_AuthKey(R-S2 || PSK2 || PK_E || PK_R) */
  addr[0] = r_snonce2;
  len[0] = WPS_SECRET_NONCE_LEN;
  addr[1] = wps->psk2;
  len[1] = WPS_PSK_LEN;
  addr[2] = wpabuf_head(wps->dh_pubkey_e);
  len[2] = wpabuf_len(wps->dh_pubkey_e);
  addr[3] = wpabuf_head(wps->dh_pubkey_r);
  len[3] = wpabuf_len(wps->dh_pubkey_r);
  hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);

  if (os_memcmp_const(wps->peer_hash2, hash, WPS_HASH_LEN) != 0) {
    wpa_printf(MSG_DEBUG, "WPS: R-Hash2 derived from R-S2 does "
         "not match with the pre-committed value");
    wps->config_error = WPS_CFG_DEV_PASSWORD_AUTH_FAILURE;
    wps_pwd_auth_fail_event(wps->wps, 1, 2, wps->peer_dev.mac_addr);
    return -1;
  }

  wpa_printf(MSG_DEBUG, "WPS: Registrar proved knowledge of the second "
       "half of the device password");

  return 0;
}


static int wps_process_cred_e(struct wps_data *wps, const u8 *cred,
            size_t cred_len, int wps2)
{
  struct wps_parse_attr attr;
  struct wpabuf msg;
  int ret = 0;

  wpa_printf(MSG_DEBUG, "WPS: Received Credential");
  os_memset(&wps->cred, 0, sizeof(wps->cred));
  wpabuf_set(&msg, cred, cred_len);
  if (wps_parse_msg(&msg, &attr) < 0 ||
      wps_process_cred(&attr, &wps->cred))
    return -1;

  if (!ether_addr_equal(wps->cred.mac_addr, wps->wps->dev.mac_addr)) {
    wpa_printf(MSG_DEBUG, "WPS: MAC Address in the Credential ("
         MACSTR ") does not match with own address (" MACSTR
         ")", MAC2STR(wps->cred.mac_addr),
         MAC2STR(wps->wps->dev.mac_addr));
    /*
     * In theory, this could be consider fatal error, but there are
     * number of deployed implementations using other address here
     * due to unclarity in the specification. For interoperability
     * reasons, allow this to be processed since we do not really
     * use the MAC Address information for anything.
     */
#ifdef CONFIG_WPS_STRICT
    if (wps2) {
      wpa_printf(MSG_INFO, "WPS: Do not accept incorrect "
           "MAC Address in AP Settings");
      return -1;
    }
#endif /* CONFIG_WPS_STRICT */
  }

  if (!(wps->cred.encr_type &
        (WPS_ENCR_NONE | WPS_ENCR_TKIP | WPS_ENCR_AES))) {
    if (wps->cred.encr_type & WPS_ENCR_WEP) {
      wpa_printf(MSG_INFO, "WPS: Reject Credential "
           "due to WEP configuration");
      wps->error_indication = WPS_EI_SECURITY_WEP_PROHIBITED;
      return -2;
    }

    wpa_printf(MSG_INFO, "WPS: Reject Credential due to "
         "invalid encr_type 0x%x", wps->cred.encr_type);
    return -1;
  }

  if (wps->wps->cred_cb) {
    wps->cred.cred_attr = cred - 4;
    wps->cred.cred_attr_len = cred_len + 4;
    ret = wps->wps->cred_cb(wps->wps->cb_ctx, &wps->cred);
    wps->cred.cred_attr = NULL;
    wps->cred.cred_attr_len = 0;
  }

  return ret;
}


static int wps_process_creds(struct wps_data *wps, const u8 *cred[],
           u16 cred_len[], unsigned int num_cred, int wps2)
{
  size_t i;
  int ok = 0;

  if (wps->wps->ap)
    return 0;

  if (num_cred == 0) {
    wpa_printf(MSG_DEBUG, "WPS: No Credential attributes "
         "received");
    return -1;
  }

  for (i = 0; i < num_cred; i++) {
    int res;
    res = wps_process_cred_e(wps, cred[i], cred_len[i], wps2);
    if (res == 0)
      ok++;
    else if (res == -2)
      wpa_printf(MSG_DEBUG, "WPS: WEP credential skipped");
    else
      return -1;
  }

  if (ok == 0) {
    wpa_printf(MSG_DEBUG, "WPS: No valid Credential attribute "
         "received");
    return -1;
  }

  return 0;
}


static int wps_process_ap_settings_e(struct wps_data *wps,
             struct wps_parse_attr *attr,
             struct wpabuf *attrs, int wps2)
{
  struct wps_credential cred;
  int ret = 0;

  if (!wps->wps->ap)
    return 0;

  if (wps_process_ap_settings(attr, &cred) < 0)
    return -1;

  wpa_printf(MSG_INFO, "WPS: Received new AP configuration from "
       "Registrar");

  if (!ether_addr_equal(cred.mac_addr, wps->wps->dev.mac_addr)) {
    wpa_printf(MSG_DEBUG, "WPS: MAC Address in the AP Settings ("
         MACSTR ") does not match with own address (" MACSTR
         ")", MAC2STR(cred.mac_addr),
         MAC2STR(wps->wps->dev.mac_addr));
    /*
     * In theory, this could be consider fatal error, but there are
     * number of deployed implementations using other address here
     * due to unclarity in the specification. For interoperability
     * reasons, allow this to be processed since we do not really
     * use the MAC Address information for anything.
     */
#ifdef CONFIG_WPS_STRICT
    if (wps2) {
      wpa_printf(MSG_INFO, "WPS: Do not accept incorrect "
           "MAC Address in AP Settings");
      return -1;
    }
#endif /* CONFIG_WPS_STRICT */
  }

  if (!(cred.encr_type & (WPS_ENCR_NONE | WPS_ENCR_TKIP | WPS_ENCR_AES)))
  {
    if (cred.encr_type & WPS_ENCR_WEP) {
      wpa_printf(MSG_INFO, "WPS: Reject new AP settings "
           "due to WEP configuration");
      wps->error_indication = WPS_EI_SECURITY_WEP_PROHIBITED;
      return -1;
    }

    wpa_printf(MSG_INFO, "WPS: Reject new AP settings due to "
         "invalid encr_type 0x%x", cred.encr_type);
    return -1;
  }

#ifdef CONFIG_WPS_STRICT
  if (wps2) {
    if ((cred.encr_type & (WPS_ENCR_TKIP | WPS_ENCR_AES)) ==
        WPS_ENCR_TKIP ||
        (cred.auth_type & (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK)) ==
        WPS_AUTH_WPAPSK) {
      wpa_printf(MSG_INFO, "WPS-STRICT: Invalid WSC 2.0 "
           "AP Settings: WPA-Personal/TKIP only");
      wps->error_indication =
        WPS_EI_SECURITY_TKIP_ONLY_PROHIBITED;
      return -1;
    }
  }
#endif /* CONFIG_WPS_STRICT */

  if ((cred.encr_type & (WPS_ENCR_TKIP | WPS_ENCR_AES)) == WPS_ENCR_TKIP)
  {
    wpa_printf(MSG_DEBUG, "WPS: Upgrade encr_type TKIP -> "
         "TKIP+AES");
    cred.encr_type |= WPS_ENCR_AES;
  }

  if ((cred.auth_type & (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK)) ==
      WPS_AUTH_WPAPSK) {
    wpa_printf(MSG_DEBUG, "WPS: Upgrade auth_type WPAPSK -> "
         "WPAPSK+WPA2PSK");
    cred.auth_type |= WPS_AUTH_WPA2PSK;
  }

#ifdef CONFIG_NO_TKIP
  if (cred.encr_type & WPS_ENCR_TKIP) {
    wpa_printf(MSG_DEBUG, "WPS: Disable encr_type TKIP");
    cred.encr_type &= ~WPS_ENCR_TKIP;
  }
  if (cred.auth_type & WPS_AUTH_WPAPSK) {
    wpa_printf(MSG_DEBUG, "WPS: Disable auth_type WPAPSK");
    cred.auth_type &= ~WPS_AUTH_WPAPSK;
  }
#endif /* CONFIG_NO_TKIP */

  if (wps->wps->cred_cb) {
    cred.cred_attr = wpabuf_head(attrs);
    cred.cred_attr_len = wpabuf_len(attrs);
    ret = wps->wps->cred_cb(wps->wps->cb_ctx, &cred);
  }

  return ret;
}


static int wps_process_dev_pw_id(struct wps_data *wps, const u8 *dev_pw_id)
{
  u16 id;

  if (dev_pw_id == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: Device Password ID");
    return -1;
  }

  id = WPA_GET_BE16(dev_pw_id);
  if (wps->dev_pw_id == id) {
    wpa_printf(MSG_DEBUG, "WPS: Device Password ID %u", id);
    return 0;
  }

#ifdef CONFIG_P2P
  if ((id == DEV_PW_DEFAULT &&
       wps->dev_pw_id == DEV_PW_REGISTRAR_SPECIFIED) ||
      (id == DEV_PW_REGISTRAR_SPECIFIED &&
       wps->dev_pw_id == DEV_PW_DEFAULT)) {
    /*
     * Common P2P use cases indicate whether the PIN is from the
     * client or GO using Device Password Id in M1/M2 in a way that
     * does not look fully compliant with WSC specification. Anyway,
     * this is deployed and needs to be allowed, so ignore changes
     * between Registrar-Specified and Default PIN.
     */
    wpa_printf(MSG_DEBUG, "WPS: Allow PIN Device Password ID "
         "change");
    return 0;
  }
#endif /* CONFIG_P2P */

  wpa_printf(MSG_DEBUG, "WPS: Registrar trying to change Device Password "
       "ID from %u to %u", wps->dev_pw_id, id);

  if (wps->dev_pw_id == DEV_PW_PUSHBUTTON && id == DEV_PW_DEFAULT) {
    wpa_printf(MSG_DEBUG,
         "WPS: Workaround - ignore PBC-to-PIN change");
    return 0;
  }

  if (wps->alt_dev_password && wps->alt_dev_pw_id == id) {
    wpa_printf(MSG_DEBUG, "WPS: Found a matching Device Password");
    bin_clear_free(wps->dev_password, wps->dev_password_len);
    wps->dev_pw_id = wps->alt_dev_pw_id;
    wps->dev_password = wps->alt_dev_password;
    wps->dev_password_len = wps->alt_dev_password_len;
    wps->alt_dev_password = NULL;
    wps->alt_dev_password_len = 0;
    return 0;
  }

  return -1;
}


static enum wps_process_res wps_process_m2(struct wps_data *wps,
             const struct wpabuf *msg,
             struct wps_parse_attr *attr)
{
  wpa_printf(MSG_DEBUG, "WPS: Received M2");

  if (wps->state != RECV_M2) {
    wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
         "receiving M2", wps->state);
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  if (wps_process_registrar_nonce(wps, attr->registrar_nonce) ||
      wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
      wps_process_uuid_r(wps, attr->uuid_r) ||
      wps_process_dev_pw_id(wps, attr->dev_password_id)) {
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  /*
   * Stop here on an AP as an Enrollee if AP Setup is locked unless the
   * special locked mode is used to allow protocol run up to M7 in order
   * to support external Registrars that only learn the current AP
   * configuration without changing it.
   */
  if (wps->wps->ap &&
      ((wps->wps->ap_setup_locked && wps->wps->ap_setup_locked != 2) ||
       wps->dev_password == NULL)) {
    wpa_printf(MSG_DEBUG, "WPS: AP Setup is locked - refuse "
         "registration of a new Registrar");
    wps->config_error = WPS_CFG_SETUP_LOCKED;
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  if (wps_process_pubkey(wps, attr->public_key, attr->public_key_len) ||
      wps_process_authenticator(wps, attr->authenticator, msg) ||
      wps_process_device_attrs(&wps->peer_dev, attr)) {
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

#ifdef CONFIG_WPS_NFC
  if (wps->peer_pubkey_hash_set) {
    struct wpabuf *decrypted;
    struct wps_parse_attr eattr;

    decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
                  attr->encr_settings_len);
    if (decrypted == NULL) {
      wpa_printf(MSG_DEBUG, "WPS: Failed to decrypt "
           "Encrypted Settings attribute");
      wps->state = SEND_WSC_NACK;
      return WPS_CONTINUE;
    }

    wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted "
         "Settings attribute");
    if (wps_parse_msg(decrypted, &eattr) < 0 ||
        wps_process_key_wrap_auth(wps, decrypted,
                eattr.key_wrap_auth) ||
        wps_process_creds(wps, eattr.cred, eattr.cred_len,
              eattr.num_cred, attr->version2 != NULL)) {
      wpabuf_clear_free(decrypted);
      wps->state = SEND_WSC_NACK;
      return WPS_CONTINUE;
    }
    wpabuf_clear_free(decrypted);

    wps->state = WPS_MSG_DONE;
    return WPS_CONTINUE;
  }
#endif /* CONFIG_WPS_NFC */

  wps->state = SEND_M3;
  return WPS_CONTINUE;
}


static enum wps_process_res wps_process_m2d(struct wps_data *wps,
              struct wps_parse_attr *attr)
{
  wpa_printf(MSG_DEBUG, "WPS: Received M2D");

  if (wps->state != RECV_M2) {
    wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
         "receiving M2D", wps->state);
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  wpa_hexdump_ascii(MSG_DEBUG, "WPS: Manufacturer",
        attr->manufacturer, attr->manufacturer_len);
  wpa_hexdump_ascii(MSG_DEBUG, "WPS: Model Name",
        attr->model_name, attr->model_name_len);
  wpa_hexdump_ascii(MSG_DEBUG, "WPS: Model Number",
        attr->model_number, attr->model_number_len);
  wpa_hexdump_ascii(MSG_DEBUG, "WPS: Serial Number",
        attr->serial_number, attr->serial_number_len);
  wpa_hexdump_ascii(MSG_DEBUG, "WPS: Device Name",
        attr->dev_name, attr->dev_name_len);

  if (wps->wps->event_cb) {
    union wps_event_data data;
    struct wps_event_m2d *m2d = &data.m2d;
    os_memset(&data, 0, sizeof(data));
    if (attr->config_methods)
      m2d->config_methods =
        WPA_GET_BE16(attr->config_methods);
    m2d->manufacturer = attr->manufacturer;
    m2d->manufacturer_len = attr->manufacturer_len;
    m2d->model_name = attr->model_name;
    m2d->model_name_len = attr->model_name_len;
    m2d->model_number = attr->model_number;
    m2d->model_number_len = attr->model_number_len;
    m2d->serial_number = attr->serial_number;
    m2d->serial_number_len = attr->serial_number_len;
    m2d->dev_name = attr->dev_name;
    m2d->dev_name_len = attr->dev_name_len;
    m2d->primary_dev_type = attr->primary_dev_type;
    if (attr->config_error)
      m2d->config_error =
        WPA_GET_BE16(attr->config_error);
    if (attr->dev_password_id)
      m2d->dev_password_id =
        WPA_GET_BE16(attr->dev_password_id);
    wps->wps->event_cb(wps->wps->cb_ctx, WPS_EV_M2D, &data);
  }

  wps->state = RECEIVED_M2D;
  return WPS_CONTINUE;
}


static enum wps_process_res wps_process_m4(struct wps_data *wps,
             const struct wpabuf *msg,
             struct wps_parse_attr *attr)
{
  struct wpabuf *decrypted;
  struct wps_parse_attr eattr;

  wpa_printf(MSG_DEBUG, "WPS: Received M4");

  if (wps->state != RECV_M4) {
    wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
         "receiving M4", wps->state);
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  if (wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
      wps_process_authenticator(wps, attr->authenticator, msg) ||
      wps_process_r_hash1(wps, attr->r_hash1) ||
      wps_process_r_hash2(wps, attr->r_hash2)) {
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
                attr->encr_settings_len);
  if (decrypted == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: Failed to decrypted Encrypted "
         "Settings attribute");
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  if (wps_validate_m4_encr(decrypted, attr->version2 != NULL) < 0) {
    wpabuf_clear_free(decrypted);
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted Settings "
       "attribute");
  if (wps_parse_msg(decrypted, &eattr) < 0 ||
      wps_process_key_wrap_auth(wps, decrypted, eattr.key_wrap_auth) ||
      wps_process_r_snonce1(wps, eattr.r_snonce1)) {
    wpabuf_clear_free(decrypted);
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }
  wpabuf_clear_free(decrypted);

  wps->state = SEND_M5;
  return WPS_CONTINUE;
}


static enum wps_process_res wps_process_m6(struct wps_data *wps,
             const struct wpabuf *msg,
             struct wps_parse_attr *attr)
{
  struct wpabuf *decrypted;
  struct wps_parse_attr eattr;

  wpa_printf(MSG_DEBUG, "WPS: Received M6");

  if (wps->state != RECV_M6) {
    wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
         "receiving M6", wps->state);
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  if (wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
      wps_process_authenticator(wps, attr->authenticator, msg)) {
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
                attr->encr_settings_len);
  if (decrypted == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: Failed to decrypted Encrypted "
         "Settings attribute");
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  if (wps_validate_m6_encr(decrypted, attr->version2 != NULL) < 0) {
    wpabuf_clear_free(decrypted);
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted Settings "
       "attribute");
  if (wps_parse_msg(decrypted, &eattr) < 0 ||
      wps_process_key_wrap_auth(wps, decrypted, eattr.key_wrap_auth) ||
      wps_process_r_snonce2(wps, eattr.r_snonce2)) {
    wpabuf_clear_free(decrypted);
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }
  wpabuf_clear_free(decrypted);

  if (wps->wps->ap)
    wps->wps->event_cb(wps->wps->cb_ctx, WPS_EV_AP_PIN_SUCCESS,
           NULL);

  wps->state = SEND_M7;
  return WPS_CONTINUE;
}


static enum wps_process_res wps_process_m8(struct wps_data *wps,
             const struct wpabuf *msg,
             struct wps_parse_attr *attr)
{
  struct wpabuf *decrypted;
  struct wps_parse_attr eattr;

  wpa_printf(MSG_DEBUG, "WPS: Received M8");

  if (wps->state != RECV_M8) {
    wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
         "receiving M8", wps->state);
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  if (wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
      wps_process_authenticator(wps, attr->authenticator, msg)) {
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  if (wps->wps->ap && wps->wps->ap_setup_locked) {
    /*
     * Stop here if special ap_setup_locked == 2 mode allowed the
     * protocol to continue beyond M2. This allows ER to learn the
     * current AP settings without changing them.
     */
    wpa_printf(MSG_DEBUG, "WPS: AP Setup is locked - refuse "
         "registration of a new Registrar");
    wps->config_error = WPS_CFG_SETUP_LOCKED;
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
                attr->encr_settings_len);
  if (decrypted == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: Failed to decrypted Encrypted "
         "Settings attribute");
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  if (wps_validate_m8_encr(decrypted, wps->wps->ap,
         attr->version2 != NULL) < 0) {
    wpabuf_clear_free(decrypted);
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted Settings "
       "attribute");
  if (wps_parse_msg(decrypted, &eattr) < 0 ||
      wps_process_key_wrap_auth(wps, decrypted, eattr.key_wrap_auth) ||
      wps_process_creds(wps, eattr.cred, eattr.cred_len,
            eattr.num_cred, attr->version2 != NULL) ||
      wps_process_ap_settings_e(wps, &eattr, decrypted,
              attr->version2 != NULL)) {
    wpabuf_clear_free(decrypted);
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }
  wpabuf_clear_free(decrypted);

  wps->state = WPS_MSG_DONE;
  return WPS_CONTINUE;
}


static enum wps_process_res wps_process_wsc_msg(struct wps_data *wps,
            const struct wpabuf *msg)
{
  struct wps_parse_attr attr;
  enum wps_process_res ret = WPS_CONTINUE;

  wpa_printf(MSG_DEBUG, "WPS: Received WSC_MSG");

  if (wps_parse_msg(msg, &attr) < 0)
    return WPS_FAILURE;

  if (attr.enrollee_nonce == NULL ||
      os_memcmp(wps->nonce_e, attr.enrollee_nonce, WPS_NONCE_LEN) != 0) {
    wpa_printf(MSG_DEBUG, "WPS: Mismatch in enrollee nonce");
    return WPS_FAILURE;
  }

  if (attr.msg_type == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: No Message Type attribute");
    wps->state = SEND_WSC_NACK;
    return WPS_CONTINUE;
  }

  switch (*attr.msg_type) {
  case WPS_M2:
    if (wps_validate_m2(msg) < 0)
      return WPS_FAILURE;
    ret = wps_process_m2(wps, msg, &attr);
    break;
  case WPS_M2D:
    if (wps_validate_m2d(msg) < 0)
      return WPS_FAILURE;
    ret = wps_process_m2d(wps, &attr);
    break;
  case WPS_M4:
    if (wps_validate_m4(msg) < 0)
      return WPS_FAILURE;
    ret = wps_process_m4(wps, msg, &attr);
    if (ret == WPS_FAILURE || wps->state == SEND_WSC_NACK)
      wps_fail_event(wps->wps, WPS_M4, wps->config_error,
               wps->error_indication,
               wps->peer_dev.mac_addr);
    break;
  case WPS_M6:
    if (wps_validate_m6(msg) < 0)
      return WPS_FAILURE;
    ret = wps_process_m6(wps, msg, &attr);
    if (ret == WPS_FAILURE || wps->state == SEND_WSC_NACK)
      wps_fail_event(wps->wps, WPS_M6, wps->config_error,
               wps->error_indication,
               wps->peer_dev.mac_addr);
    break;
  case WPS_M8:
    if (wps_validate_m8(msg) < 0)
      return WPS_FAILURE;
    ret = wps_process_m8(wps, msg, &attr);
    if (ret == WPS_FAILURE || wps->state == SEND_WSC_NACK)
      wps_fail_event(wps->wps, WPS_M8, wps->config_error,
               wps->error_indication,
               wps->peer_dev.mac_addr);
    break;
  default:
    wpa_printf(MSG_DEBUG, "WPS: Unsupported Message Type %d",
         *attr.msg_type);
    return WPS_FAILURE;
  }

  /*
   * Save a copy of the last message for Authenticator derivation if we
   * are continuing. However, skip M2D since it is not authenticated and
   * neither is the ACK/NACK response frame. This allows the possibly
   * following M2 to be processed correctly by using the previously sent
   * M1 in Authenticator derivation.
   */
  if (ret == WPS_CONTINUE && *attr.msg_type != WPS_M2D) {
    /* Save a copy of the last message for Authenticator derivation
     */
    wpabuf_free(wps->last_msg);
    wps->last_msg = wpabuf_dup(msg);
  }

  return ret;
}


static enum wps_process_res wps_process_wsc_ack(struct wps_data *wps,
            const struct wpabuf *msg)
{
  struct wps_parse_attr attr;

  wpa_printf(MSG_DEBUG, "WPS: Received WSC_ACK");

  if (wps_parse_msg(msg, &attr) < 0)
    return WPS_FAILURE;

  if (attr.msg_type == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: No Message Type attribute");
    return WPS_FAILURE;
  }

  if (*attr.msg_type != WPS_WSC_ACK) {
    wpa_printf(MSG_DEBUG, "WPS: Invalid Message Type %d",
         *attr.msg_type);
    return WPS_FAILURE;
  }

  if (attr.registrar_nonce == NULL ||
      os_memcmp(wps->nonce_r, attr.registrar_nonce, WPS_NONCE_LEN) != 0)
  {
    wpa_printf(MSG_DEBUG, "WPS: Mismatch in registrar nonce");
    return WPS_FAILURE;
  }

  if (attr.enrollee_nonce == NULL ||
      os_memcmp(wps->nonce_e, attr.enrollee_nonce, WPS_NONCE_LEN) != 0) {
    wpa_printf(MSG_DEBUG, "WPS: Mismatch in enrollee nonce");
    return WPS_FAILURE;
  }

  if (wps->state == RECV_ACK && wps->wps->ap) {
    wpa_printf(MSG_DEBUG, "WPS: External Registrar registration "
         "completed successfully");
    wps_success_event(wps->wps, wps->peer_dev.mac_addr);
    wps->state = WPS_FINISHED;
    return WPS_DONE;
  }

  return WPS_FAILURE;
}


static enum wps_process_res wps_process_wsc_nack(struct wps_data *wps,
             const struct wpabuf *msg)
{
  struct wps_parse_attr attr;
  u16 config_error;

  wpa_printf(MSG_DEBUG, "WPS: Received WSC_NACK");

  if (wps_parse_msg(msg, &attr) < 0)
    return WPS_FAILURE;

  if (attr.msg_type == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: No Message Type attribute");
    return WPS_FAILURE;
  }

  if (*attr.msg_type != WPS_WSC_NACK) {
    wpa_printf(MSG_DEBUG, "WPS: Invalid Message Type %d",
         *attr.msg_type);
    return WPS_FAILURE;
  }

  if (attr.registrar_nonce == NULL ||
      os_memcmp(wps->nonce_r, attr.registrar_nonce, WPS_NONCE_LEN) != 0)
  {
    wpa_printf(MSG_DEBUG, "WPS: Mismatch in registrar nonce");
    wpa_hexdump(MSG_DEBUG, "WPS: Received Registrar Nonce",
          attr.registrar_nonce, WPS_NONCE_LEN);
    wpa_hexdump(MSG_DEBUG, "WPS: Expected Registrar Nonce",
          wps->nonce_r, WPS_NONCE_LEN);
    return WPS_FAILURE;
  }

  if (attr.enrollee_nonce == NULL ||
      os_memcmp(wps->nonce_e, attr.enrollee_nonce, WPS_NONCE_LEN) != 0) {
    wpa_printf(MSG_DEBUG, "WPS: Mismatch in enrollee nonce");
    wpa_hexdump(MSG_DEBUG, "WPS: Received Enrollee Nonce",
          attr.enrollee_nonce, WPS_NONCE_LEN);
    wpa_hexdump(MSG_DEBUG, "WPS: Expected Enrollee Nonce",
          wps->nonce_e, WPS_NONCE_LEN);
    return WPS_FAILURE;
  }

  if (attr.config_error == NULL) {
    wpa_printf(MSG_DEBUG, "WPS: No Configuration Error attribute "
         "in WSC_NACK");
    return WPS_FAILURE;
  }

  config_error = WPA_GET_BE16(attr.config_error);
  wpa_printf(MSG_DEBUG, "WPS: Registrar terminated negotiation with "
       "Configuration Error %d", config_error);

  switch (wps->state) {
  case RECV_M4:
    wps_fail_event(wps->wps, WPS_M3, config_error,
             wps->error_indication, wps->peer_dev.mac_addr);
    break;
  case RECV_M6:
    wps_fail_event(wps->wps, WPS_M5, config_error,
             wps->error_indication, wps->peer_dev.mac_addr);
    break;
  case RECV_M8:
    wps_fail_event(wps->wps, WPS_M7, config_error,
             wps->error_indication, wps->peer_dev.mac_addr);
    break;
  default:
    break;
  }

  /* Followed by NACK if Enrollee is Supplicant or EAP-Failure if
   * Enrollee is Authenticator */
  wps->state = SEND_WSC_NACK;

  return WPS_FAILURE;
}


enum wps_process_res wps_enrollee_process_msg(struct wps_data *wps,
                enum wsc_op_code op_code,
                const struct wpabuf *msg)
{

  wpa_printf(MSG_DEBUG, "WPS: Processing received message (len=%lu "
       "op_code=%d)",
       (unsigned long) wpabuf_len(msg), op_code);

  if (op_code == WSC_UPnP) {
    /* Determine the OpCode based on message type attribute */
    struct wps_parse_attr attr;
    if (wps_parse_msg(msg, &attr) == 0 && attr.msg_type) {
      if (*attr.msg_type == WPS_WSC_ACK)
        op_code = WSC_ACK;
      else if (*attr.msg_type == WPS_WSC_NACK)
        op_code = WSC_NACK;
    }
  }

  switch (op_code) {
  case WSC_MSG:
  case WSC_UPnP:
    return wps_process_wsc_msg(wps, msg);
  case WSC_ACK:
    if (wps_validate_wsc_ack(msg) < 0)
      return WPS_FAILURE;
    return wps_process_wsc_ack(wps, msg);
  case WSC_NACK:
    if (wps_validate_wsc_nack(msg) < 0)
      return WPS_FAILURE;
    return wps_process_wsc_nack(wps, msg);
  default:
    wpa_printf(MSG_DEBUG, "WPS: Unsupported op_code %d", op_code);
    return WPS_FAILURE;
  }
}

Coverage Report

Created: 2025-08-26 06:04