DPP2: Add a helper function for building Presence Announcement frame

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>

diff --git a/src/common/dpp.c b/src/common/dpp.c
index 6bb1311833bb9a4ef46a32f25bcf8b9ed2d54a3f..ea5d6df57fe00edf0437ab7938c6270b48e39929 100644 (file)
--- a/src/common/dpp.c
+++ b/src/common/dpp.c
@@ -1056,6 +1056,32 @@ static const struct dpp_curve_params * dpp_get_curve_nid(int nid)
 }
 
 
+static int dpp_bi_pubkey_hash(struct dpp_bootstrap_info *bi,
+                             const u8 *data, size_t data_len)
+{
+       const u8 *addr[2];
+       size_t len[2];
+
+       addr[0] = data;
+       len[0] = data_len;
+       if (sha256_vector(1, addr, len, bi->pubkey_hash) < 0)
+               return -1;
+       wpa_hexdump(MSG_DEBUG, "DPP: Public key hash",
+                   bi->pubkey_hash, SHA256_MAC_LEN);
+
+       addr[0] = (const u8 *) "chirp";
+       len[0] = 5;
+       addr[1] = data;
+       len[1] = data_len;
+       if (sha256_vector(2, addr, len, bi->pubkey_hash_chirp) < 0)
+               return -1;
+       wpa_hexdump(MSG_DEBUG, "DPP: Public key hash (chirp)",
+                   bi->pubkey_hash_chirp, SHA256_MAC_LEN);
+
+       return 0;
+}
+
+
 static int dpp_parse_uri_pk(struct dpp_bootstrap_info *bi, const char *info)
 {
        const char *end;
@@ -1094,14 +1120,11 @@ static int dpp_parse_uri_pk(struct dpp_bootstrap_info *bi, const char *info)
        wpa_hexdump(MSG_DEBUG, "DPP: Base64 decoded URI public-key",
                    data, data_len);
 
-       if (sha256_vector(1, (const u8 **) &data, &data_len,
-                         bi->pubkey_hash) < 0) {
+       if (dpp_bi_pubkey_hash(bi, data, data_len) < 0) {
                wpa_printf(MSG_DEBUG, "DPP: Failed to hash public key");
                os_free(data);
                return -1;
        }
-       wpa_hexdump(MSG_DEBUG, "DPP: Public key hash",
-                   bi->pubkey_hash, SHA256_MAC_LEN);
 
        /* DER encoded ASN.1 SubjectPublicKeyInfo
         *
@@ -1519,27 +1542,19 @@ fail:
 }
 
 
-int dpp_bootstrap_key_hash(struct dpp_bootstrap_info *bi)
+static int dpp_bootstrap_key_hash(struct dpp_bootstrap_info *bi)
 {
        struct wpabuf *der;
        int res;
-       const u8 *addr[1];
-       size_t len[1];
 
        der = dpp_bootstrap_key_der(bi->pubkey);
        if (!der)
                return -1;
        wpa_hexdump_buf(MSG_DEBUG, "DPP: Compressed public key (DER)",
                        der);
-
-       addr[0] = wpabuf_head(der);
-       len[0] = wpabuf_len(der);
-       res = sha256_vector(1, addr, len, bi->pubkey_hash);
+       res = dpp_bi_pubkey_hash(bi, wpabuf_head(der), wpabuf_len(der));
        if (res < 0)
                wpa_printf(MSG_DEBUG, "DPP: Failed to hash public key");
-       else
-               wpa_hexdump(MSG_DEBUG, "DPP: Public key hash", bi->pubkey_hash,
-                           SHA256_MAC_LEN);
        wpabuf_free(der);
        return res;
 }
@@ -1552,8 +1567,6 @@ static int dpp_keygen(struct dpp_bootstrap_info *bi, const char *curve,
        char *pos, *end;
        size_t len;
        struct wpabuf *der = NULL;
-       const u8 *addr[1];
-       int res;
 
        if (!curve) {
                bi->curve = &dpp_curves[0];
@@ -1579,15 +1592,10 @@ static int dpp_keygen(struct dpp_bootstrap_info *bi, const char *curve,
        wpa_hexdump_buf(MSG_DEBUG, "DPP: Compressed public key (DER)",
                        der);
 
-       addr[0] = wpabuf_head(der);
-       len = wpabuf_len(der);
-       res = sha256_vector(1, addr, &len, bi->pubkey_hash);
-       if (res < 0) {
+       if (dpp_bi_pubkey_hash(bi, wpabuf_head(der), wpabuf_len(der)) < 0) {
                wpa_printf(MSG_DEBUG, "DPP: Failed to hash public key");
                goto fail;
        }
-       wpa_hexdump(MSG_DEBUG, "DPP: Public key hash", bi->pubkey_hash,
-                   SHA256_MAC_LEN);
 
        base64 = base64_encode(wpabuf_head(der), wpabuf_len(der), &len);
        wpabuf_free(der);
@@ -12211,4 +12219,22 @@ void dpp_controller_stop(struct dpp_global *dpp)
        }
 }
 
+
+struct wpabuf * dpp_build_presence_announcement(struct dpp_bootstrap_info *bi)
+{
+       struct wpabuf *msg;
+
+       wpa_printf(MSG_DEBUG, "DPP: Build Presence Announcement frame");
+
+       msg = dpp_alloc_msg(DPP_PA_PRESENCE_ANNOUNCEMENT, 4 + SHA256_MAC_LEN);
+       if (!msg)
+               return NULL;
+
+       /* Responder Bootstrapping Key Hash */
+       dpp_build_attr_r_bootstrap_key_hash(msg, bi->pubkey_hash_chirp);
+       wpa_hexdump_buf(MSG_DEBUG,
+                       "DPP: Presence Announcement frame attributes", msg);
+       return msg;
+}
+
 #endif /* CONFIG_DPP2 */

diff --git a/src/common/dpp.h b/src/common/dpp.h
index 9f3e04820cef8ab30df4dcaad94f4a82110a8aea..d544fba6679532a03977ff4d3abada8b5a40c79b 100644 (file)
--- a/src/common/dpp.h
+++ b/src/common/dpp.h
@@ -134,6 +134,7 @@ struct dpp_bootstrap_info {
        int own;
        EVP_PKEY *pubkey;
        u8 pubkey_hash[SHA256_MAC_LEN];
+       u8 pubkey_hash_chirp[SHA256_MAC_LEN];
        const struct dpp_curve_params *curve;
        unsigned int pkex_t; /* number of failures before dpp_pkex
                              * instantiation */
@@ -436,7 +437,6 @@ extern size_t dpp_nonce_override_len;
 
 void dpp_bootstrap_info_free(struct dpp_bootstrap_info *info);
 const char * dpp_bootstrap_type_txt(enum dpp_bootstrap_type type);
-int dpp_bootstrap_key_hash(struct dpp_bootstrap_info *bi);
 int dpp_parse_uri_chan_list(struct dpp_bootstrap_info *bi,
                            const char *chan_list);
 int dpp_parse_uri_mac(struct dpp_bootstrap_info *bi, const char *mac);
@@ -596,6 +596,7 @@ int dpp_controller_start(struct dpp_global *dpp,
 void dpp_controller_stop(struct dpp_global *dpp);
 int dpp_tcp_init(struct dpp_global *dpp, struct dpp_authentication *auth,
                 const struct hostapd_ip_addr *addr, int port);
+struct wpabuf * dpp_build_presence_announcement(struct dpp_bootstrap_info *bi);
 
 struct dpp_global_config {
        void *msg_ctx;