[RFC 38/56] NAN: Add support for adding security attributes
Andrei Otcheretianski
andrei.otcheretianski at intel.com
Sun Dec 7 03:18:47 PST 2025
From: Ilan Peer <ilan.peer at intel.com>
Add support for adding NAN security attributes to
NAFs.
In addition add function to initialize the security
data for the case that the device is going to be
an NDP responder.
Signed-off-by: Ilan Peer <ilan.peer at intel.com>
---
src/nan/nan.h | 1 +
src/nan/nan_i.h | 3 +
src/nan/nan_sec.c | 379 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 383 insertions(+)
diff --git a/src/nan/nan.h b/src/nan/nan.h
index f508c805b1..a792c2bce2 100644
--- a/src/nan/nan.h
+++ b/src/nan/nan.h
@@ -302,6 +302,7 @@ struct nan_channels {
struct nan_config {
void *cb_ctx;
+ u8 nmi_addr[ETH_ALEN];
struct nan_device_capabilities dev_capa;
diff --git a/src/nan/nan_i.h b/src/nan/nan_i.h
index c54ffe713c..6ec0525bd5 100644
--- a/src/nan/nan_i.h
+++ b/src/nan/nan_i.h
@@ -559,4 +559,7 @@ int nan_crypto_key_mic(const u8 *buf, size_t len, const u8 *kck,
void nan_sec_reset(struct nan_data *nan, struct nan_ndp_sec *ndp_sec);
int nan_sec_rx(struct nan_data *nan, struct nan_peer *peer,
struct nan_msg *msg);
+int nan_sec_add_attrs(struct nan_data *nan, struct nan_peer *peer,
+ enum nan_subtype subtype, struct wpabuf *buf);
+int nan_sec_init_resp(struct nan_data *nan, struct nan_peer *peer);
#endif
diff --git a/src/nan/nan_sec.c b/src/nan/nan_sec.c
index 7f84b42a64..33d746eb25 100644
--- a/src/nan/nan_sec.c
+++ b/src/nan/nan_sec.c
@@ -588,3 +588,382 @@ int nan_sec_rx(struct nan_data *nan, struct nan_peer *peer,
return 0;
}
+
+
+/*
+ * nan_sec_add_m1_attrs - Add security attributes to NAN message 1
+ *
+ * @nan: NAN module context from nan_init()
+ * @peer: Peer which is the recipient of the message
+ * @buf: Buffer to which the attribute should be added
+ * Returns: 0 on success, negative on failure
+ *
+ * In addition to building the attributes, the function also initializes the
+ * security context for the NDP security exchange. Assumes that the following
+ * are already set:
+ * - initiator CSID
+ * - PMK
+ * - NDP puslish ID
+ * - initiator address
+ * - peer_nmi
+ */
+static int nan_sec_add_m1_attrs(struct nan_data *nan, struct nan_peer *peer,
+ struct wpabuf *buf)
+{
+ struct nan_ndp_sec *ndp_sec = &peer->ndp_setup.sec;
+ struct wpa_eapol_key *key;
+ u16 info;
+ u8 key_len = sizeof(struct wpa_eapol_key) + 2;
+ int ret;
+
+ if (ndp_sec->i_csid == NAN_CS_SK_CCM_128)
+ key_len += NAN_KEY_MIC_LEN;
+ else if (ndp_sec->i_csid == NAN_CS_SK_GCM_256)
+ key_len += NAN_KEY_MIC_24_LEN;
+ else
+ return -1;
+
+ /* Initialize the initiator security state */
+ os_get_random(ndp_sec->i_nonce, sizeof(ndp_sec->i_nonce));
+ ndp_sec->i_capab = 0;
+ ndp_sec->i_instance_id = peer->ndp_setup.publish_inst_id;
+
+ /* Compute the PMKID */
+ ret = nan_crypto_calc_pmkid(ndp_sec->pmk,
+ nan->cfg->nmi_addr,
+ peer->nmi_addr,
+ peer->ndp_setup.service_id,
+ ndp_sec->i_csid, ndp_sec->i_pmkid);
+ if (ret) {
+ wpa_printf(MSG_DEBUG, "NAN: SEC: Failed to compute PMKID (m1)");
+ return ret;
+ }
+
+ /* Cipher suite information */
+ wpabuf_put_u8(buf, NAN_ATTR_CSIA);
+ wpabuf_put_le16(buf, sizeof(struct nan_cipher_suite_info) +
+ sizeof(struct nan_cipher_suite));
+ wpabuf_put_u8(buf, ndp_sec->i_capab);
+ wpabuf_put_u8(buf, ndp_sec->i_csid);
+ wpabuf_put_u8(buf, ndp_sec->i_instance_id);
+
+ /* Security context information */
+ wpabuf_put_u8(buf, NAN_ATTR_SCIA);
+ wpabuf_put_le16(buf, sizeof(struct nan_sec_ctxt) + PMKID_LEN);
+
+ wpabuf_put_le16(buf, PMKID_LEN);
+ wpabuf_put_u8(buf, NAN_SEC_CTX_TYPE_PMKID);
+ wpabuf_put_u8(buf, ndp_sec->i_instance_id);
+ wpabuf_put_data(buf, ndp_sec->i_pmkid, PMKID_LEN);
+
+ /* Shared key descriptor */
+ wpabuf_put_u8(buf, NAN_ATTR_SHARED_KEY_DESCR);
+ wpabuf_put_le16(buf, sizeof(struct nan_shared_key) + key_len);
+ wpabuf_put_u8(buf, ndp_sec->i_instance_id);
+
+ key = (struct wpa_eapol_key *)wpabuf_put(buf, key_len);
+ os_memset(key, 0, key_len);
+
+ key->type = NAN_KEY_DESC;
+ info = WPA_KEY_INFO_TYPE_AKM_DEFINED | WPA_KEY_INFO_KEY_TYPE |
+ WPA_KEY_INFO_ACK;
+ WPA_PUT_BE16(key->key_info, info);
+
+ /* Copy the initiator nonce */
+ os_memcpy(key->key_nonce, ndp_sec->i_nonce, WPA_NONCE_LEN);
+
+ /* Key length is zero (it can be deduced from the cipher suite) */
+
+ /* Initialize replay counter */
+ WPA_PUT_BE64(ndp_sec->replaycnt, 1ULL);
+ os_memcpy(key->replay_counter, ndp_sec->replaycnt,
+ sizeof(key->replay_counter));
+ ndp_sec->replaycnt_ok = 1;
+
+ ndp_sec->valid = 1;
+ return 0;
+}
+
+
+/*
+ * nan_sec_add_m2_attrs - Add security attributes to NAN message 2
+ *
+ * @nan: NAN module context from nan_init()
+ * @peer: Peer which is the recipient of the message
+ * @buf: Buffer to which the attribute should be added
+ * Returns: 0 on success, negative on failure
+ */
+static int nan_sec_add_m2_attrs(struct nan_data *nan, struct nan_peer *peer,
+ struct wpabuf *buf)
+{
+ struct nan_ndp_sec *ndp_sec = &peer->ndp_setup.sec;
+ struct wpa_eapol_key *key;
+ u16 info;
+ u8 key_len;
+
+ key_len = sizeof(struct wpa_eapol_key) + 2;
+ if (ndp_sec->i_csid == NAN_CS_SK_CCM_128)
+ key_len += NAN_KEY_MIC_LEN;
+ else if (ndp_sec->i_csid == NAN_CS_SK_GCM_256)
+ key_len += NAN_KEY_MIC_24_LEN;
+ else
+ return -1;
+
+ /* Cipher suite information */
+ wpabuf_put_u8(buf, NAN_ATTR_CSIA);
+ wpabuf_put_le16(buf, sizeof(struct nan_cipher_suite_info) +
+ sizeof(struct nan_cipher_suite));
+ wpabuf_put_u8(buf, ndp_sec->r_capab);
+ wpabuf_put_u8(buf, ndp_sec->r_csid);
+ wpabuf_put_u8(buf, ndp_sec->r_instance_id);
+
+ /* Security context information */
+ wpabuf_put_u8(buf, NAN_ATTR_SCIA);
+ wpabuf_put_le16(buf, sizeof(struct nan_sec_ctxt) + PMKID_LEN);
+
+ wpabuf_put_le16(buf, PMKID_LEN);
+ wpabuf_put_u8(buf, NAN_SEC_CTX_TYPE_PMKID);
+ wpabuf_put_u8(buf, ndp_sec->r_instance_id);
+ wpabuf_put_data(buf, ndp_sec->r_pmkid, PMKID_LEN);
+
+ if (peer->ndp_setup.status == NAN_NDP_STATUS_REJECTED)
+ return 0;
+
+ /* Shared key descriptor */
+ wpabuf_put_u8(buf, NAN_ATTR_SHARED_KEY_DESCR);
+ wpabuf_put_le16(buf, sizeof(struct nan_shared_key) + key_len);
+ wpabuf_put_u8(buf, ndp_sec->r_instance_id);
+
+ key = (struct wpa_eapol_key *)wpabuf_put(buf, key_len);
+ os_memset(key, 0, key_len);
+
+ key->type = NAN_KEY_DESC;
+ info = WPA_KEY_INFO_TYPE_AKM_DEFINED | WPA_KEY_INFO_KEY_TYPE |
+ WPA_KEY_INFO_MIC;
+ WPA_PUT_BE16(key->key_info, info);
+
+ /* copy the responders's nonce */
+ os_memcpy(key->key_nonce, ndp_sec->r_nonce, WPA_NONCE_LEN);
+
+ /*
+ * Key length is zero (it can be deduced from the cipher suite).
+ * No additional data is added.
+ */
+
+ /* Copy replay counter */
+ os_memcpy(key->replay_counter, ndp_sec->replaycnt,
+ sizeof(key->replay_counter));
+ ndp_sec->replaycnt_ok = 1;
+
+ return 0;
+}
+
+
+/*
+ * nan_sec_add_m3_attrs - Add security attributes to NAN message 3
+ *
+ * @nan: NAN module context from nan_init()
+ * @peer: Peer which is the recipient of the message
+ * @buf: Buffer to which the attribute should be added
+ * Returns: 0 on success, negative on failure
+ */
+static int nan_sec_add_m3_attrs(struct nan_data *nan, struct nan_peer *peer,
+ struct wpabuf *buf)
+{
+ struct nan_ndp_sec *ndp_sec = &peer->ndp_setup.sec;
+ struct wpa_eapol_key *key;
+ u16 info;
+ u8 key_len = sizeof(struct wpa_eapol_key) + 2;
+
+ if (ndp_sec->i_csid == NAN_CS_SK_CCM_128)
+ key_len += NAN_KEY_MIC_LEN;
+ else if (ndp_sec->i_csid == NAN_CS_SK_GCM_256)
+ key_len += NAN_KEY_MIC_24_LEN;
+ else
+ return -1;
+
+ /* Shared key descriptor */
+ wpabuf_put_u8(buf, NAN_ATTR_SHARED_KEY_DESCR);
+ wpabuf_put_le16(buf, sizeof(struct nan_shared_key) + key_len);
+ wpabuf_put_u8(buf, ndp_sec->i_instance_id);
+
+ key = (struct wpa_eapol_key *)wpabuf_put(buf, key_len);
+ os_memset(key, 0, key_len);
+
+ key->type = NAN_KEY_DESC;
+
+ info = WPA_KEY_INFO_TYPE_AKM_DEFINED | WPA_KEY_INFO_KEY_TYPE |
+ WPA_KEY_INFO_MIC | WPA_KEY_INFO_ACK |
+ WPA_KEY_INFO_INSTALL | WPA_KEY_INFO_SECURE;
+
+ WPA_PUT_BE16(key->key_info, info);
+
+ /* Copy the initiators nonce */
+ os_memcpy(key->key_nonce, ndp_sec->i_nonce, WPA_NONCE_LEN);
+
+ /*
+ * Key length is zero (it can be deduced from the cipher suite).
+ * No additional data is added.
+ *
+ * Copy replay counter. It was already incremented while processing m2
+ * so no need to increment it again
+ */
+ os_memcpy(key->replay_counter, ndp_sec->replaycnt,
+ sizeof(key->replay_counter));
+ return 0;
+}
+
+
+/*
+ * nan_sec_add_m4_attrs - Add security attributes to NAN message 4
+ *
+ * @nan: NAN module context from nan_init()
+ * @peer: Peer which is the recipient of the message
+ * @buf: Buffer to which the attribute should be added
+ * Returns: 0 on success, negative on failure
+ */
+static int nan_sec_add_m4_attrs(struct nan_data *nan, struct nan_peer *peer,
+ struct wpabuf *buf)
+{
+ struct nan_ndp_sec *ndp_sec = &peer->ndp_setup.sec;
+ struct wpa_eapol_key *key;
+ u16 info;
+ u8 key_len = sizeof(struct wpa_eapol_key) + 2;
+
+ if (ndp_sec->i_csid == NAN_CS_SK_CCM_128)
+ key_len += NAN_KEY_MIC_LEN;
+ else if (ndp_sec->i_csid == NAN_CS_SK_GCM_256)
+ key_len += NAN_KEY_MIC_24_LEN;
+ else
+ return -1;
+
+ /* Shared key descriptor */
+ wpabuf_put_u8(buf, NAN_ATTR_SHARED_KEY_DESCR);
+ wpabuf_put_le16(buf, sizeof(struct nan_shared_key) + key_len);
+ wpabuf_put_u8(buf, ndp_sec->r_instance_id);
+
+ key = (struct wpa_eapol_key *)wpabuf_put(buf, key_len);
+ os_memset(key, 0, key_len);
+
+ key->type = NAN_KEY_DESC;
+ info = WPA_KEY_INFO_TYPE_AKM_DEFINED | WPA_KEY_INFO_KEY_TYPE |
+ WPA_KEY_INFO_MIC | WPA_KEY_INFO_SECURE |
+ WPA_KEY_INFO_INSTALL;
+
+ WPA_PUT_BE16(key->key_info, info);
+
+ os_memcpy(key->key_nonce, ndp_sec->r_nonce, WPA_NONCE_LEN);
+
+ os_memcpy(key->replay_counter, ndp_sec->replaycnt,
+ sizeof(key->replay_counter));
+ return 0;
+}
+
+
+/*
+ * nan_sec_add_attrs - Add security attributes to NAN message
+ *
+ * @nan: NAN module context from nan_init()
+ * @peer: Peer which is the recipient of the message
+ * @subtype: Frame subtype
+ * @buf: Buffer to which the attribute should be added
+ * Returns: 0 on success, negative on failure
+ */
+int nan_sec_add_attrs(struct nan_data *nan, struct nan_peer *peer,
+ enum nan_subtype subtype, struct wpabuf *buf)
+{
+ /* NDP establishment is not in progress */
+ if (!peer->ndp_setup.ndp)
+ return 0;
+
+ wpa_printf(MSG_DEBUG, "NAN: SEC: Add security attributes");
+ nan_sec_dump(nan, peer);
+
+ /* No security configuration */
+ if (peer->ndp_setup.sec.i_csid != NAN_CS_SK_CCM_128 &&
+ peer->ndp_setup.sec.i_csid != NAN_CS_SK_GCM_256)
+ return 0;
+
+ switch (subtype) {
+ case NAN_SUBTYPE_DATA_PATH_REQUEST:
+ return nan_sec_add_m1_attrs(nan, peer, buf);
+ case NAN_SUBTYPE_DATA_PATH_RESPONSE:
+ return nan_sec_add_m2_attrs(nan, peer, buf);
+ case NAN_SUBTYPE_DATA_PATH_CONFIRM:
+ return nan_sec_add_m3_attrs(nan, peer, buf);
+ case NAN_SUBTYPE_DATA_PATH_KEY_INSTALL:
+ return nan_sec_add_m4_attrs(nan, peer, buf);
+ case NAN_SUBTYPE_DATA_PATH_TERMINATION:
+ break;
+ default:
+ return -1;
+ }
+
+ return 0;
+}
+
+
+/**
+ * nan_sec_init_resp - Initialize security context for responder
+ *
+ * @nan: NAN module context from nan_init()
+ * @peer: Peer with whom the NDP is being established
+ * Returns: 0 on success, negative on failure
+ *
+ * The function initializes the security context for the NDP security
+ * exchange for the responder. Assumes that the following re already set:
+ * - Initiator CSID
+ * - Responder CSID
+ * - PMK
+ * - NDP publish ID
+ * - Initiator address
+ * - Responder address
+ */
+int nan_sec_init_resp(struct nan_data *nan, struct nan_peer *peer)
+{
+ struct nan_ndp_sec *ndp_sec = &peer->ndp_setup.sec;
+ struct nan_ndp *ndp = peer->ndp_setup.ndp;
+ int ret;
+
+ if (ndp_sec->i_csid != ndp_sec->r_csid)
+ return -1;
+
+ /* Initialize the responder's security state */
+ os_get_random(ndp_sec->r_nonce, sizeof(ndp_sec->r_nonce));
+ ndp_sec->r_capab = 0;
+ ndp_sec->r_instance_id = peer->ndp_setup.publish_inst_id;
+
+ if (ndp_sec->i_instance_id != ndp_sec->r_instance_id) {
+ wpa_printf(MSG_DEBUG,
+ "NAN: SEC: Service instance IDs are different (m2)");
+ return -1;
+ }
+
+ /* Compute the PMKID */
+ ret = nan_crypto_calc_pmkid(ndp_sec->pmk, peer->nmi_addr,
+ nan->cfg->nmi_addr,
+ peer->ndp_setup.service_id,
+ ndp_sec->r_csid, ndp_sec->r_pmkid);
+ if (ret) {
+ wpa_printf(MSG_DEBUG, "NAN: SEC: Failed to compute PMKID (m2)");
+ return -1;
+ }
+
+ /* Sanity check */
+ if (os_memcmp(ndp_sec->i_pmkid, ndp_sec->r_pmkid, PMKID_LEN) != 0) {
+ wpa_printf(MSG_DEBUG,
+ "NAN: SEC: m2: local PMKID differs from remote");
+ return -1;
+ }
+
+ /* PTK should be derived using the NDI address */
+ ret = nan_crypto_pmk_to_ptk(ndp_sec->pmk,
+ ndp->init_ndi, ndp->resp_ndi,
+ ndp_sec->i_nonce, ndp_sec->r_nonce,
+ &ndp_sec->ptk, ndp_sec->i_csid);
+
+ wpa_printf(MSG_DEBUG, "NAN: SEC: derived PTK for responder (m2). ret=%d",
+ ret);
+
+ return ret;
+}
--
2.49.0
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