AP: Support PASN with SAE key derivation

Signed-off-by: Ilan Peer <ilan.peer@intel.com>

diff --git a/src/ap/ieee802_11.c b/src/ap/ieee802_11.c
index d61c011b6a2b0e4347c114f30da7ac153fe027a2..afb0b4b1b0875e962d581eb07c319a20e2a182ae 100644 (file)
--- a/src/ap/ieee802_11.c
+++ b/src/ap/ieee802_11.c
@@ -470,6 +470,49 @@ static void sae_set_state(struct sta_info *sta, enum sae_state state,
 }
 
 
+static const char * sae_get_password(struct hostapd_data *hapd,
+                                    struct sta_info *sta,
+                                    const char *rx_id,
+                                    struct sae_password_entry **pw_entry,
+                                    struct sae_pt **s_pt,
+                                    const struct sae_pk **s_pk)
+{
+       const char *password = NULL;
+       struct sae_password_entry *pw;
+       struct sae_pt *pt = NULL;
+       const struct sae_pk *pk = NULL;
+
+       for (pw = hapd->conf->sae_passwords; pw; pw = pw->next) {
+               if (!is_broadcast_ether_addr(pw->peer_addr) &&
+                   os_memcmp(pw->peer_addr, sta->addr, ETH_ALEN) != 0)
+                       continue;
+               if ((rx_id && !pw->identifier) || (!rx_id && pw->identifier))
+                       continue;
+               if (rx_id && pw->identifier &&
+                   os_strcmp(rx_id, pw->identifier) != 0)
+                       continue;
+               password = pw->password;
+               pt = pw->pt;
+               if (!(hapd->conf->mesh & MESH_ENABLED))
+                       pk = pw->pk;
+               break;
+       }
+       if (!password) {
+               password = hapd->conf->ssid.wpa_passphrase;
+               pt = hapd->conf->ssid.pt;
+       }
+
+       if (pw_entry)
+               *pw_entry = pw;
+       if (s_pt)
+               *s_pt = pt;
+       if (s_pk)
+               *s_pk = pk;
+
+       return password;
+}
+
+
 static struct wpabuf * auth_build_sae_commit(struct hostapd_data *hapd,
                                             struct sta_info *sta, int update,
                                             int status_code)
@@ -499,25 +542,7 @@ static struct wpabuf * auth_build_sae_commit(struct hostapd_data *hapd,
                 status_code == WLAN_STATUS_SAE_PK)
                use_pt = 1;
 
-       for (pw = hapd->conf->sae_passwords; pw; pw = pw->next) {
-               if (!is_broadcast_ether_addr(pw->peer_addr) &&
-                   os_memcmp(pw->peer_addr, sta->addr, ETH_ALEN) != 0)
-                       continue;
-               if ((rx_id && !pw->identifier) || (!rx_id && pw->identifier))
-                       continue;
-               if (rx_id && pw->identifier &&
-                   os_strcmp(rx_id, pw->identifier) != 0)
-                       continue;
-               password = pw->password;
-               pt = pw->pt;
-               if (!(hapd->conf->mesh & MESH_ENABLED))
-                       pk = pw->pk;
-               break;
-       }
-       if (!password) {
-               password = hapd->conf->ssid.wpa_passphrase;
-               pt = hapd->conf->ssid.pt;
-       }
+       password = sae_get_password(hapd, sta, rx_id, &pw, &pt, &pk);
        if (!password || (use_pt && !pt)) {
                wpa_printf(MSG_DEBUG, "SAE: No password available");
                return NULL;
@@ -2298,6 +2323,182 @@ ieee802_11_set_radius_info(struct hostapd_data *hapd, struct sta_info *sta,
 
 
 #ifdef CONFIG_PASN
+#ifdef CONFIG_SAE
+
+static int pasn_wd_handle_sae_commit(struct hostapd_data *hapd,
+                                    struct sta_info *sta,
+                                    struct wpabuf *wd)
+{
+       struct pasn_data *pasn = sta->pasn;
+       const char *password = NULL;
+       const u8 *data;
+       size_t buf_len;
+       u16 res, alg, seq, status;
+       int groups[] = { pasn->group, 0 };
+       int ret;
+
+       if (!wd)
+               return -1;
+
+       data = wpabuf_head_u8(wd);
+       buf_len = wpabuf_len(wd);
+
+       if (buf_len < 6) {
+               wpa_printf(MSG_DEBUG, "PASN: SAE buffer too short. len=%lu",
+                          buf_len);
+               return -1;
+       }
+
+       alg = WPA_GET_LE16(data);
+       seq = WPA_GET_LE16(data + 2);
+       status = WPA_GET_LE16(data + 4);
+
+       wpa_printf(MSG_DEBUG, "PASN: SAE commit: alg=%u, seq=%u, status=%u",
+                  alg, seq, status);
+
+       /* TODO: SAE H2E */
+       if (alg != WLAN_AUTH_SAE || seq != 1 || status != WLAN_STATUS_SUCCESS) {
+               wpa_printf(MSG_DEBUG, "PASN: Dropping peer SAE commit");
+               return -1;
+       }
+
+       sae_clear_data(&pasn->sae);
+       pasn->sae.state = SAE_NOTHING;
+
+       ret = sae_set_group(&pasn->sae, pasn->group);
+       if (ret) {
+               wpa_printf(MSG_DEBUG, "PASN: Failed to set SAE group");
+               return -1;
+       }
+
+       password = sae_get_password(hapd, sta, NULL, NULL, NULL, NULL);
+       if (!password) {
+               wpa_printf(MSG_DEBUG, "PASN: No SAE password found");
+               return -1;
+       }
+
+       ret = sae_prepare_commit(hapd->own_addr, sta->addr,
+                                (const u8 *) password, os_strlen(password), 0,
+                                &pasn->sae);
+       if (ret) {
+               wpa_printf(MSG_DEBUG, "PASN: Failed to prepare SAE commit");
+               return -1;
+       }
+
+       res = sae_parse_commit(&pasn->sae, data + 6, buf_len - 6, NULL, 0,
+                              groups, 0);
+       if (res != WLAN_STATUS_SUCCESS) {
+               wpa_printf(MSG_DEBUG, "PASN: Failed parsing SAE commit");
+               return -1;
+       }
+
+       /* Process the commit message and derive the PMK */
+       ret = sae_process_commit(&pasn->sae);
+       if (ret) {
+               wpa_printf(MSG_DEBUG, "SAE: Failed to process peer commit");
+               return -1;
+       }
+
+       pasn->sae.state = SAE_COMMITTED;
+
+       return 0;
+}
+
+
+static int pasn_wd_handle_sae_confirm(struct hostapd_data *hapd,
+                                     struct sta_info *sta,
+                                     struct wpabuf *wd)
+{
+       struct pasn_data *pasn = sta->pasn;
+       const u8 *data;
+       size_t buf_len;
+       u16 res, alg, seq, status;
+
+       if (!wd)
+               return -1;
+
+       data = wpabuf_head_u8(wd);
+       buf_len = wpabuf_len(wd);
+
+       if (buf_len < 6) {
+               wpa_printf(MSG_DEBUG, "PASN: SAE buffer too short. len=%lu",
+                          buf_len);
+               return -1;
+       }
+
+       alg = WPA_GET_LE16(data);
+       seq = WPA_GET_LE16(data + 2);
+       status = WPA_GET_LE16(data + 4);
+
+       wpa_printf(MSG_DEBUG, "PASN: SAE confirm: alg=%u, seq=%u, status=%u",
+                  alg, seq, status);
+
+       if (alg != WLAN_AUTH_SAE || seq != 2 || status != WLAN_STATUS_SUCCESS) {
+               wpa_printf(MSG_DEBUG, "PASN: Dropping peer SAE confirm");
+               return -1;
+       }
+
+       res = sae_check_confirm(&pasn->sae, data + 6, buf_len - 6);
+       if (res != WLAN_STATUS_SUCCESS) {
+               wpa_printf(MSG_DEBUG, "PASN: SAE failed checking confirm");
+               return -1;
+       }
+
+       pasn->sae.state = SAE_ACCEPTED;
+
+       /*
+        * TODO: Based on on IEEE P802.11az/D2.6, the PMKSA derived with
+        * PASN/SAE should only be allowed with future PASN only. For now do not
+        * restrict this only for PASN.
+        */
+       wpa_auth_pmksa_add_sae(hapd->wpa_auth, sta->addr,
+                              pasn->sae.pmk, pasn->sae.pmkid);
+       return 0;
+}
+
+
+static struct wpabuf * pasn_get_sae_wd(struct hostapd_data *hapd,
+                                      struct sta_info *sta)
+{
+       struct pasn_data *pasn = sta->pasn;
+       struct wpabuf *buf = NULL;
+       u8 *len_ptr;
+       size_t len;
+
+       /* Need to add the entire Authentication frame body */
+       buf = wpabuf_alloc(8 + SAE_COMMIT_MAX_LEN + 8 + SAE_CONFIRM_MAX_LEN);
+       if (!buf) {
+               wpa_printf(MSG_DEBUG, "PASN: Failed to allocate SAE buffer");
+               return NULL;
+       }
+
+       /* Need to add the entire authentication frame body for the commit */
+       len_ptr = wpabuf_put(buf, 2);
+       wpabuf_put_le16(buf, WLAN_AUTH_SAE);
+       wpabuf_put_le16(buf, 1);
+       wpabuf_put_le16(buf, WLAN_STATUS_SUCCESS);
+
+       /* Write the actual commit and update the length accordingly */
+       sae_write_commit(&pasn->sae, buf, NULL, 0);
+       len = wpabuf_len(buf);
+       WPA_PUT_LE16(len_ptr, len - 2);
+
+       /* Need to add the entire Authentication frame body for the confirm */
+       len_ptr = wpabuf_put(buf, 2);
+       wpabuf_put_le16(buf, WLAN_AUTH_SAE);
+       wpabuf_put_le16(buf, 2);
+       wpabuf_put_le16(buf, WLAN_STATUS_SUCCESS);
+
+       sae_write_confirm(&pasn->sae, buf);
+       WPA_PUT_LE16(len_ptr, wpabuf_len(buf) - len - 2);
+
+       pasn->sae.state = SAE_CONFIRMED;
+
+       return buf;
+}
+
+#endif /* CONFIG_SAE */
+
 
 static struct wpabuf * pasn_get_wrapped_data(struct hostapd_data *hapd,
                                             struct sta_info *sta)
@@ -2307,6 +2508,10 @@ static struct wpabuf * pasn_get_wrapped_data(struct hostapd_data *hapd,
                /* no wrapped data */
                return NULL;
        case WPA_KEY_MGMT_SAE:
+#ifdef CONFIG_SAE
+               return pasn_get_sae_wd(hapd, sta);
+#endif /* CONFIG_SAE */
+               /* fall through */
        case WPA_KEY_MGMT_FILS_SHA256:
        case WPA_KEY_MGMT_FILS_SHA384:
        case WPA_KEY_MGMT_FT_PSK:
@@ -2350,11 +2555,22 @@ pasn_derive_keys(struct hostapd_data *hapd, struct sta_info *sta,
                pmk_len = pmksa->pmk_len;
                os_memcpy(pmk, pmksa->pmk, pmksa->pmk_len);
        } else {
-               /* TODO: Derive PMK based on wrapped data */
-               wpa_printf(MSG_DEBUG,
-                          "PASN: Missing implementation to derive PMK");
-
-               return -1;
+               switch (sta->pasn->akmp) {
+#ifdef CONFIG_SAE
+               case WPA_KEY_MGMT_SAE:
+                       if (sta->pasn->sae.state == SAE_COMMITTED) {
+                               pmk_len = PMK_LEN;
+                               os_memcpy(pmk, sta->pasn->sae.pmk, PMK_LEN);
+                               break;
+                       }
+#endif /* CONFIG_SAE */
+                       /* fall through */
+               default:
+                       /* TODO: Derive PMK based on wrapped data */
+                       wpa_printf(MSG_DEBUG,
+                                  "PASN: Missing PMK derivation");
+                       return -1;
+               }
        }
 
        ret = pasn_pmk_to_ptk(pmk, pmk_len, sta->addr, hapd->own_addr,
@@ -2589,6 +2805,19 @@ static void handle_auth_pasn_1(struct hostapd_data *hapd, struct sta_info *sta,
                        status = WLAN_STATUS_UNSPECIFIED_FAILURE;
                        goto send_resp;
                }
+
+#ifdef CONFIG_SAE
+               if (sta->pasn->akmp == WPA_KEY_MGMT_SAE) {
+                       ret = pasn_wd_handle_sae_commit(hapd, sta,
+                                                       wrapped_data);
+                       if (ret) {
+                               wpa_printf(MSG_DEBUG,
+                                          "PASN: Failed processing SAE commit");
+                               status = WLAN_STATUS_UNSPECIFIED_FAILURE;
+                               goto send_resp;
+                       }
+               }
+#endif /* CONFIG_SAE */
        }
 
        sta->pasn->wrapped_data_format = pasn_params.wrapped_data_format;
@@ -2714,7 +2943,18 @@ static void handle_auth_pasn_3(struct hostapd_data *hapd, struct sta_info *sta,
                        goto fail;
                }
 
-               /* TODO: Handle wrapped data */
+#ifdef CONFIG_SAE
+               if (sta->pasn->akmp == WPA_KEY_MGMT_SAE) {
+                       ret = pasn_wd_handle_sae_confirm(hapd, sta,
+                                                        wrapped_data);
+                       if (ret) {
+                               wpa_printf(MSG_DEBUG,
+                                          "PASN: Failed processing SAE confirm");
+                               wpabuf_free(wrapped_data);
+                               goto fail;
+                       }
+               }
+#endif /* CONFIG_SAE */
                wpabuf_free(wrapped_data);
        }
 

diff --git a/src/ap/sta_info.c b/src/ap/sta_info.c
index d2fa97f903136c213f401cb7bc8254300203d5a8..70c8585ead14f6e96f93668c43a74434655992a6 100644 (file)
--- a/src/ap/sta_info.c
+++ b/src/ap/sta_info.c
@@ -166,6 +166,9 @@ void ap_free_sta_pasn(struct hostapd_data *hapd, struct sta_info *sta)
 
                if (sta->pasn->ecdh)
                        crypto_ecdh_deinit(sta->pasn->ecdh);
+#ifdef CONFIG_SAE
+               sae_clear_data(&sta->pasn->sae);
+#endif /* CONFIG_SAE */
                bin_clear_free(sta->pasn, sizeof(*sta->pasn));
                sta->pasn = NULL;
        }

diff --git a/src/ap/sta_info.h b/src/ap/sta_info.h
index 884ff3e5b71aaf7245a2d11b9401614f55d4cbfc..630ebd608189fa3642b23f9812552f15c1478919 100644 (file)
--- a/src/ap/sta_info.h
+++ b/src/ap/sta_info.h
@@ -14,6 +14,7 @@
 #include "vlan.h"
 #include "common/wpa_common.h"
 #include "common/ieee802_11_defs.h"
+#include "common/sae.h"
 #include "crypto/sha384.h"
 
 /* STA flags */
@@ -74,6 +75,10 @@ struct pasn_data {
        u8 hash[SHA384_MAC_LEN];
        struct wpa_ptk ptk;
        struct crypto_ecdh *ecdh;
+
+#ifdef CONFIG_SAE
+       struct sae_data sae;
+#endif /* CONFIG_SAE */
 };
 
 struct sta_info {