DPP: Network Introduction protocol
This commit adds generic helper functions for going through Network Introduction protocol. Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
This commit is contained in:
Jouni Malinen
Jouni Malinen
parent
56c7549587
commit
650a70a72a
2 changed files with 511 additions and 0 deletions
498
src/common/dpp.c
498
src/common/dpp.c
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@ -4146,3 +4146,501 @@ fail:
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conf = NULL;
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goto out;
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}
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static int dpp_compatible_netrole(const char *role1, const char *role2)
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{
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return (os_strcmp(role1, "sta") == 0 && os_strcmp(role2, "ap") == 0) ||
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(os_strcmp(role1, "ap") == 0 && os_strcmp(role2, "sta") == 0);
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}
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static int dpp_connector_compatible_group(struct json_token *root,
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const char *group_id,
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const char *net_role)
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{
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struct json_token *groups, *token;
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groups = json_get_member(root, "groups");
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if (!groups || groups->type != JSON_ARRAY)
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return 0;
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for (token = groups->child; token; token = token->sibling) {
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struct json_token *id, *role;
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id = json_get_member(token, "groupId");
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if (!id || id->type != JSON_STRING)
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continue;
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role = json_get_member(token, "netRole");
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if (!role || role->type != JSON_STRING)
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continue;
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if (os_strcmp(id->string, "*") != 0 &&
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os_strcmp(group_id, "*") != 0 &&
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os_strcmp(id->string, group_id) != 0)
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continue;
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if (dpp_compatible_netrole(role->string, net_role))
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return 1;
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}
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return 0;
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}
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static int dpp_connector_match_groups(struct json_token *own_root,
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struct json_token *peer_root)
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{
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struct json_token *groups, *token;
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groups = json_get_member(peer_root, "groups");
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if (!groups || groups->type != JSON_ARRAY) {
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wpa_printf(MSG_DEBUG, "DPP: No peer groups array found");
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return 0;
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}
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for (token = groups->child; token; token = token->sibling) {
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struct json_token *id, *role;
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id = json_get_member(token, "groupId");
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if (!id || id->type != JSON_STRING) {
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wpa_printf(MSG_DEBUG,
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"DPP: Missing peer groupId string");
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continue;
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}
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role = json_get_member(token, "netRole");
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if (!role || role->type != JSON_STRING) {
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wpa_printf(MSG_DEBUG,
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"DPP: Missing peer groups::netRole string");
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continue;
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}
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wpa_printf(MSG_DEBUG,
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"DPP: peer connector group: groupId='%s' netRole='%s'",
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id->string, role->string);
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if (dpp_connector_compatible_group(own_root, id->string,
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role->string)) {
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wpa_printf(MSG_DEBUG,
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"DPP: Compatible group/netRole in own connector");
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return 1;
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}
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}
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return 0;
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}
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static int dpp_connector_compatible_device(struct json_token *root,
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const char *device_id,
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const char *net_role)
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{
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struct json_token *groups, *token;
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groups = json_get_member(root, "devices");
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if (!groups || groups->type != JSON_ARRAY)
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return 0;
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for (token = groups->child; token; token = token->sibling) {
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struct json_token *id, *role;
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id = json_get_member(token, "deviceId");
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if (!id || id->type != JSON_STRING)
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continue;
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role = json_get_member(token, "netRole");
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if (!role || role->type != JSON_STRING)
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continue;
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if (os_strcmp(id->string, device_id) != 0)
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continue;
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if (dpp_compatible_netrole(role->string, net_role))
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return 1;
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}
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return 0;
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}
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static int dpp_connector_match_devices(struct json_token *own_root,
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struct json_token *peer_root,
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const char *own_deviceid)
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{
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struct json_token *devices, *token;
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devices = json_get_member(peer_root, "devices");
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if (!devices || devices->type != JSON_ARRAY) {
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wpa_printf(MSG_DEBUG, "DPP: No peer devices array found");
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return 0;
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}
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for (token = devices->child; token; token = token->sibling) {
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struct json_token *id, *role;
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id = json_get_member(token, "deviceId");
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if (!id || id->type != JSON_STRING) {
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wpa_printf(MSG_DEBUG,
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"DPP: Missing or invalid deviceId string");
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continue;
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}
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role = json_get_member(token, "netRole");
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if (!role || role->type != JSON_STRING) {
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wpa_printf(MSG_DEBUG, "DPP: Missing netRole string");
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continue;
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}
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wpa_printf(MSG_DEBUG,
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"DPP: connector device deviceId='%s' netRole='%s'",
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id->string, role->string);
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if (os_strcmp(id->string, own_deviceid) != 0)
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continue;
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wpa_printf(MSG_DEBUG,
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"DPP: Listed deviceId matches own deviceId");
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/* TODO: Is this next step required? */
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if (dpp_connector_compatible_device(own_root, id->string,
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role->string)) {
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wpa_printf(MSG_DEBUG,
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"DPP: Compatible device/netRole in own connector");
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return 1;
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}
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/* TODO: For now, accept this for interop testing purposes based
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* on a simple match of deviceId while ignoring netRole. Once
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* the spec is clearer on the expected behavior, either this
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* comment or the following return 1 statement needs to be
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* removed.
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*/
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return 1;
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}
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return 0;
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}
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static int dpp_connector_match(struct json_token *own_root,
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struct json_token *peer_root,
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const char *own_deviceid)
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{
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return dpp_connector_match_groups(own_root, peer_root) ||
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dpp_connector_match_devices(own_root, peer_root, own_deviceid);
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}
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static int dpp_derive_pmk(const u8 *Nx, size_t Nx_len, u8 *pmk,
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unsigned int hash_len)
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{
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u8 salt[DPP_MAX_HASH_LEN], prk[DPP_MAX_HASH_LEN];
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const char *info = "DPP PMK";
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int res = -1;
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/* PMK = HKDF(<>, "DPP PMK", N.x) */
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/* HKDF-Extract(<>, N.x) */
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os_memset(salt, 0, hash_len);
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if (hash_len == 32) {
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if (hmac_sha256(salt, SHA256_MAC_LEN, Nx, Nx_len, prk) < 0)
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return -1;
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} else if (hash_len == 48) {
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if (hmac_sha384(salt, SHA384_MAC_LEN, Nx, Nx_len, prk) < 0)
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return -1;
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} else if (hash_len == 64) {
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if (hmac_sha512(salt, SHA512_MAC_LEN, Nx, Nx_len, prk) < 0)
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return -1;
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} else {
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return -1;
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}
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wpa_hexdump_key(MSG_DEBUG, "DPP: PRK = HKDF-Extract(<>, IKM=N.x)",
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prk, hash_len);
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/* HKDF-Expand(PRK, info, L) */
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if (hash_len == 32)
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res = hmac_sha256_kdf(prk, SHA256_MAC_LEN, NULL,
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(const u8 *) info, os_strlen(info),
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pmk, SHA256_MAC_LEN);
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else if (hash_len == 48)
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res = hmac_sha384_kdf(prk, SHA384_MAC_LEN, NULL,
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(const u8 *) info, os_strlen(info),
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pmk, SHA384_MAC_LEN);
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else if (hash_len == 64)
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res = hmac_sha512_kdf(prk, SHA512_MAC_LEN, NULL,
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(const u8 *) info, os_strlen(info),
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pmk, SHA512_MAC_LEN);
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os_memset(prk, 0, hash_len);
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if (res < 0)
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return -1;
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wpa_hexdump_key(MSG_DEBUG, "DPP: PMK = HKDF-Expand(PRK, info, L)",
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pmk, hash_len);
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return 0;
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}
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static int dpp_derive_pmkid(const struct dpp_curve_params *curve,
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EVP_PKEY *own_key, EVP_PKEY *peer_key, u8 *pmkid)
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{
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struct wpabuf *nkx, *pkx;
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int ret = -1, res;
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const u8 *addr[2];
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size_t len[2];
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u8 hash[DPP_MAX_HASH_LEN];
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/* PMKID = Truncate-128(H(min(NK.x, PK.x) | max(NK.x, PK.x))) */
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nkx = dpp_get_pubkey_point(own_key, 0);
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pkx = dpp_get_pubkey_point(peer_key, 0);
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if (!nkx || !pkx)
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goto fail;
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addr[0] = wpabuf_head(nkx);
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len[0] = wpabuf_len(nkx) / 2;
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addr[1] = wpabuf_head(pkx);
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len[1] = wpabuf_len(pkx) / 2;
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if (len[0] != len[1])
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goto fail;
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if (os_memcmp(addr[0], addr[1], len[0]) > 0) {
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addr[0] = wpabuf_head(pkx);
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addr[1] = wpabuf_head(nkx);
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}
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wpa_printf(MSG_DEBUG, "DPP: PMKID H=SHA%u",
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(unsigned int) curve->hash_len * 8);
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wpa_hexdump(MSG_DEBUG, "DPP: PMKID hash payload 1", addr[0], len[0]);
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wpa_hexdump(MSG_DEBUG, "DPP: PMKID hash payload 2", addr[1], len[1]);
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if (curve->hash_len == 32)
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res = sha256_vector(2, addr, len, hash);
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else if (curve->hash_len == 48)
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res = sha384_vector(2, addr, len, hash);
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else if (curve->hash_len == 64)
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res = sha512_vector(2, addr, len, hash);
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else
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res = -1;
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if (res < 0)
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goto fail;
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wpa_hexdump(MSG_DEBUG, "DPP: PMKID hash output",
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hash, curve->hash_len);
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os_memcpy(pmkid, hash, PMKID_LEN);
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wpa_hexdump(MSG_DEBUG, "DPP: PMKID", pmkid, PMKID_LEN);
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ret = 0;
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fail:
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wpabuf_free(nkx);
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wpabuf_free(pkx);
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return ret;
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}
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static int dpp_netkey_hash(EVP_PKEY *key, u8 *hash)
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{
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EC_KEY *eckey;
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unsigned char *der = NULL;
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int ret, der_len;
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const u8 *addr[1];
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size_t len[1];
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eckey = EVP_PKEY_get1_EC_KEY(key);
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if (!eckey)
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return -1;
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EC_KEY_set_conv_form(eckey, POINT_CONVERSION_COMPRESSED);
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der_len = i2d_EC_PUBKEY(eckey, &der);
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EC_KEY_free(eckey);
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if (der_len <= 0)
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return -1;
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addr[0] = der;
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len[0] = der_len;
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ret = sha256_vector(1, addr, len, hash);
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OPENSSL_free(der);
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return ret;
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}
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int dpp_peer_intro(struct dpp_introduction *intro, const char *own_connector,
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const u8 *net_access_key, size_t net_access_key_len,
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const u8 *csign_key, size_t csign_key_len,
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const u8 *peer_connector, size_t peer_connector_len)
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{
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struct json_token *root = NULL, *netkey, *token;
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struct json_token *own_root = NULL;
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int ret = -1;
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EVP_PKEY *own_key = NULL, *peer_key = NULL;
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struct wpabuf *own_key_pub = NULL;
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char *own_deviceid = NULL;
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const struct dpp_curve_params *curve, *own_curve;
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struct dpp_signed_connector_info info;
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const unsigned char *p;
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EVP_PKEY *csign = NULL;
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char *signed_connector = NULL;
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const char *pos, *end;
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unsigned char *own_conn = NULL;
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size_t own_conn_len;
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EVP_PKEY_CTX *ctx = NULL;
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size_t Nx_len;
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u8 Nx[DPP_MAX_SHARED_SECRET_LEN];
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u8 hash[SHA256_MAC_LEN];
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const u8 *addr[1];
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size_t len[1];
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os_memset(intro, 0, sizeof(*intro));
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os_memset(&info, 0, sizeof(info));
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p = csign_key;
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csign = d2i_PUBKEY(NULL, &p, csign_key_len);
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if (!csign) {
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wpa_printf(MSG_ERROR,
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"DPP: Failed to parse local C-sign-key information");
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goto fail;
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}
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own_key = dpp_set_keypair(&own_curve, net_access_key,
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net_access_key_len);
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if (!own_key) {
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wpa_printf(MSG_ERROR, "DPP: Failed to parse own netAccessKey");
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goto fail;
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}
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/* deviceId = SHA256(ANSI X9.63 uncompressed netAccessKey) */
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own_key_pub = dpp_get_pubkey_point(own_key, 1);
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if (!own_key_pub)
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goto fail;
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wpa_hexdump_buf(MSG_DEBUG,
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"DPP: ANSI X9.63 uncompressed public key of own netAccessKey",
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own_key_pub);
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addr[0] = wpabuf_head(own_key_pub);
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len[0] = wpabuf_len(own_key_pub);
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if (sha256_vector(1, addr, len, hash) < 0)
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goto fail;
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wpa_hexdump(MSG_DEBUG,
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"DPP: SHA256 hash of ANSI X9.63 uncompressed form",
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hash, SHA256_MAC_LEN);
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own_deviceid = (char *) base64_url_encode(hash, sizeof(hash), NULL, 0);
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if (!own_deviceid)
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goto fail;
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wpa_printf(MSG_DEBUG,
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"DPP: Own deviceId (base64url encoded hash value): %s",
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own_deviceid);
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pos = os_strchr(own_connector, '.');
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if (!pos)
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goto fail;
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pos++;
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end = os_strchr(pos, '.');
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if (!end)
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goto fail;
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own_conn = base64_url_decode((const unsigned char *) pos,
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end - pos, &own_conn_len);
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if (!own_conn) {
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wpa_printf(MSG_DEBUG,
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"DPP: Failed to base64url decode own signedConnector JWS Payload");
|
||||
goto fail;
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||||
}
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own_root = json_parse((const char *) own_conn, own_conn_len);
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if (!own_root) {
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wpa_printf(MSG_DEBUG, "DPP: Failed to parse local connector");
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goto fail;
|
||||
}
|
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|
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wpa_hexdump_ascii(MSG_DEBUG, "DPP: Peer signedConnector",
|
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peer_connector, peer_connector_len);
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signed_connector = os_malloc(peer_connector_len + 1);
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if (!signed_connector)
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goto fail;
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os_memcpy(signed_connector, peer_connector, peer_connector_len);
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signed_connector[peer_connector_len] = '\0';
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|
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if (dpp_process_signed_connector(&info, csign, signed_connector) < 0)
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goto fail;
|
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|
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root = json_parse((const char *) info.payload, info.payload_len);
|
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if (!root) {
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wpa_printf(MSG_DEBUG, "DPP: JSON parsing of connector failed");
|
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goto fail;
|
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}
|
||||
|
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if (!dpp_connector_match(own_root, root, own_deviceid)) {
|
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wpa_printf(MSG_DEBUG,
|
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"DPP: Peer connector does not include compatible group/device netrole with own connector");
|
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goto fail;
|
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}
|
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|
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token = json_get_member(root, "expiry");
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if (!token || token->type != JSON_STRING) {
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wpa_printf(MSG_DEBUG,
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"DPP: No expiry string found - connector does not expire");
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} else {
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wpa_printf(MSG_DEBUG, "DPP: expiry = %s", token->string);
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if (dpp_key_expired(token->string, NULL)) {
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wpa_printf(MSG_DEBUG,
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"DPP: Connector (netAccessKey) has expired");
|
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goto fail;
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}
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}
|
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|
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netkey = json_get_member(root, "netAccessKey");
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if (!netkey || netkey->type != JSON_OBJECT) {
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wpa_printf(MSG_DEBUG, "DPP: No netAccessKey object found");
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goto fail;
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}
|
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|
||||
peer_key = dpp_parse_jwk(netkey, &curve);
|
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if (!peer_key)
|
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goto fail;
|
||||
dpp_debug_print_key("DPP: Received netAccessKey", peer_key);
|
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|
||||
if (own_curve != curve) {
|
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wpa_printf(MSG_DEBUG,
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"DPP: Mismatching netAccessKey curves (%s != %s)",
|
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own_curve->name, curve->name);
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goto fail;
|
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}
|
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|
||||
/* ECDH: N = nk * PK */
|
||||
ctx = EVP_PKEY_CTX_new(own_key, NULL);
|
||||
if (!ctx ||
|
||||
EVP_PKEY_derive_init(ctx) != 1 ||
|
||||
EVP_PKEY_derive_set_peer(ctx, peer_key) != 1 ||
|
||||
EVP_PKEY_derive(ctx, NULL, &Nx_len) != 1 ||
|
||||
Nx_len > DPP_MAX_SHARED_SECRET_LEN ||
|
||||
EVP_PKEY_derive(ctx, Nx, &Nx_len) != 1) {
|
||||
wpa_printf(MSG_ERROR,
|
||||
"DPP: Failed to derive ECDH shared secret: %s",
|
||||
ERR_error_string(ERR_get_error(), NULL));
|
||||
goto fail;
|
||||
}
|
||||
|
||||
wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (N.x)",
|
||||
Nx, Nx_len);
|
||||
|
||||
/* PMK = HKDF(<>, "DPP PMK", N.x) */
|
||||
if (dpp_derive_pmk(Nx, Nx_len, intro->pmk, curve->hash_len) < 0) {
|
||||
wpa_printf(MSG_ERROR, "DPP: Failed to derive PMK");
|
||||
goto fail;
|
||||
}
|
||||
intro->pmk_len = curve->hash_len;
|
||||
|
||||
/* PMKID = Truncate-128(H(min(NK.x, PK.x) | max(NK.x, PK.x))) */
|
||||
if (dpp_derive_pmkid(curve, own_key, peer_key, intro->pmkid) < 0) {
|
||||
wpa_printf(MSG_ERROR, "DPP: Failed to derive PMKID");
|
||||
goto fail;
|
||||
}
|
||||
|
||||
if (dpp_netkey_hash(own_key, intro->nk_hash) < 0 ||
|
||||
dpp_netkey_hash(peer_key, intro->pk_hash) < 0) {
|
||||
wpa_printf(MSG_ERROR, "DPP: Failed to derive NK/PK hash");
|
||||
goto fail;
|
||||
}
|
||||
|
||||
ret = 0;
|
||||
fail:
|
||||
if (ret < 0)
|
||||
os_memset(intro, 0, sizeof(*intro));
|
||||
os_memset(Nx, 0, sizeof(Nx));
|
||||
EVP_PKEY_CTX_free(ctx);
|
||||
os_free(own_conn);
|
||||
os_free(signed_connector);
|
||||
os_free(info.payload);
|
||||
EVP_PKEY_free(own_key);
|
||||
wpabuf_free(own_key_pub);
|
||||
os_free(own_deviceid);
|
||||
EVP_PKEY_free(peer_key);
|
||||
EVP_PKEY_free(csign);
|
||||
json_free(root);
|
||||
json_free(own_root);
|
||||
return ret;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -12,6 +12,7 @@
|
|||
#include <openssl/x509.h>
|
||||
|
||||
#include "utils/list.h"
|
||||
#include "common/wpa_common.h"
|
||||
#include "crypto/sha256.h"
|
||||
|
||||
/* DPP Public Action frame identifiers - OUI_WFA */
|
||||
|
|
@ -176,6 +177,14 @@ struct dpp_configurator {
|
|||
os_time_t csign_expiry;
|
||||
};
|
||||
|
||||
struct dpp_introduction {
|
||||
u8 pmkid[PMKID_LEN];
|
||||
u8 pmk[PMK_LEN_MAX];
|
||||
size_t pmk_len;
|
||||
u8 pk_hash[SHA256_MAC_LEN];
|
||||
u8 nk_hash[SHA256_MAC_LEN];
|
||||
};
|
||||
|
||||
void dpp_bootstrap_info_free(struct dpp_bootstrap_info *info);
|
||||
int dpp_parse_uri_chan_list(struct dpp_bootstrap_info *bi,
|
||||
const char *chan_list);
|
||||
|
|
@ -219,5 +228,9 @@ void dpp_configurator_free(struct dpp_configurator *conf);
|
|||
struct dpp_configurator *
|
||||
dpp_keygen_configurator(const char *curve, const u8 *privkey,
|
||||
size_t privkey_len);
|
||||
int dpp_peer_intro(struct dpp_introduction *intro, const char *own_connector,
|
||||
const u8 *net_access_key, size_t net_access_key_len,
|
||||
const u8 *csign_key, size_t csign_key_len,
|
||||
const u8 *peer_connector, size_t peer_connector_len);
|
||||
|
||||
#endif /* DPP_H */
|
||||
|
|
|
|||
Loading…
Reference in a new issue