EAP-pwd peer: Move PWE derivation to commit exchange

There is no need to do this during the ID exchange, so move PWE
deriation into the following commit exchange in preparation for adding
support for salted passwords.

Signed-off-by: Dan Harkins <dharkins@lounge.org>

diff --git a/src/eap_peer/eap_pwd.c b/src/eap_peer/eap_pwd.c
index ae0f9a47c4643613cf207f5aa1bac40b34faf47b..3c5d5a8162f8532de8ff97b66be966a6aecd49b2 100644 (file)
--- a/src/eap_peer/eap_pwd.c
+++ b/src/eap_peer/eap_pwd.c
@@ -29,6 +29,8 @@ struct eap_pwd_data {
        size_t password_len;
        int password_hash;
        u16 group_num;
+       u8 prep;
+       u8 token[4];
        EAP_PWD_group *grp;
 
        struct wpabuf *inbuf;
@@ -206,10 +208,6 @@ eap_pwd_perform_id_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
                            const u8 *payload, size_t payload_len)
 {
        struct eap_pwd_id *id;
-       const u8 *password;
-       size_t password_len;
-       u8 pwhashhash[16];
-       int res;
 
        if (data->state != PWD_ID_Req) {
                ret->ignore = TRUE;
@@ -254,6 +252,9 @@ eap_pwd_perform_id_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
        wpa_printf(MSG_DEBUG, "EAP-PWD (peer): using group %d",
                   data->group_num);
 
+       data->prep = id->prep;
+       os_memcpy(data->token, id->token, sizeof(id->token));
+
        data->id_server = os_malloc(payload_len - sizeof(struct eap_pwd_id));
        if (data->id_server == NULL) {
                wpa_printf(MSG_INFO, "EAP-PWD: memory allocation id fail");
@@ -273,7 +274,63 @@ eap_pwd_perform_id_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
                return;
        }
 
-       if (id->prep == EAP_PWD_PREP_MS) {
+       data->outbuf = wpabuf_alloc(sizeof(struct eap_pwd_id) +
+                                   data->id_peer_len);
+       if (data->outbuf == NULL) {
+               eap_pwd_state(data, FAILURE);
+               return;
+       }
+       wpabuf_put_be16(data->outbuf, data->group_num);
+       wpabuf_put_u8(data->outbuf, EAP_PWD_DEFAULT_RAND_FUNC);
+       wpabuf_put_u8(data->outbuf, EAP_PWD_DEFAULT_PRF);
+       wpabuf_put_data(data->outbuf, id->token, sizeof(id->token));
+       wpabuf_put_u8(data->outbuf, id->prep);
+       wpabuf_put_data(data->outbuf, data->id_peer, data->id_peer_len);
+
+       eap_pwd_state(data, PWD_Commit_Req);
+}
+
+
+static void
+eap_pwd_perform_commit_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
+                               struct eap_method_ret *ret,
+                               const struct wpabuf *reqData,
+                               const u8 *payload, size_t payload_len)
+{
+       struct crypto_ec_point *K = NULL, *point = NULL;
+       struct crypto_bignum *mask = NULL, *cofactor = NULL;
+       const u8 *ptr;
+       u8 *scalar = NULL, *element = NULL;
+       size_t prime_len, order_len;
+       const u8 *password;
+       size_t password_len;
+       u8 pwhashhash[16];
+       int res;
+
+       if (data->state != PWD_Commit_Req) {
+               ret->ignore = TRUE;
+               goto fin;
+       }
+
+       if (!data->grp) {
+               wpa_printf(MSG_DEBUG,
+                          "EAP-PWD (client): uninitialized EAP-pwd group");
+               ret->ignore = TRUE;
+               goto fin;
+       }
+
+       prime_len = crypto_ec_prime_len(data->grp->group);
+       order_len = crypto_ec_order_len(data->grp->group);
+
+       if (payload_len != 2 * prime_len + order_len) {
+               wpa_printf(MSG_INFO,
+                          "EAP-pwd: Unexpected Commit payload length %u (expected %u)",
+                          (unsigned int) payload_len,
+                          (unsigned int) (2 * prime_len + order_len));
+               goto fin;
+       }
+
+       if (data->prep == EAP_PWD_PREP_MS) {
 #ifdef CONFIG_FIPS
                wpa_printf(MSG_ERROR,
                           "EAP-PWD (peer): MS password hash not supported in FIPS mode");
@@ -310,7 +367,7 @@ eap_pwd_perform_id_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
                                       password, password_len,
                                       data->id_server, data->id_server_len,
                                       data->id_peer, data->id_peer_len,
-                                      id->token);
+                                      data->token);
        os_memset(pwhashhash, 0, sizeof(pwhashhash));
        if (res) {
                wpa_printf(MSG_INFO, "EAP-PWD (peer): unable to compute PWE");
@@ -321,51 +378,6 @@ eap_pwd_perform_id_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
        wpa_printf(MSG_DEBUG, "EAP-PWD (peer): computed %d bit PWE...",
                   (int) crypto_ec_prime_len_bits(data->grp->group));
 
-       data->outbuf = wpabuf_alloc(sizeof(struct eap_pwd_id) +
-                                   data->id_peer_len);
-       if (data->outbuf == NULL) {
-               eap_pwd_state(data, FAILURE);
-               return;
-       }
-       wpabuf_put_be16(data->outbuf, data->group_num);
-       wpabuf_put_u8(data->outbuf, EAP_PWD_DEFAULT_RAND_FUNC);
-       wpabuf_put_u8(data->outbuf, EAP_PWD_DEFAULT_PRF);
-       wpabuf_put_data(data->outbuf, id->token, sizeof(id->token));
-       wpabuf_put_u8(data->outbuf, id->prep);
-       wpabuf_put_data(data->outbuf, data->id_peer, data->id_peer_len);
-
-       eap_pwd_state(data, PWD_Commit_Req);
-}
-
-
-static void
-eap_pwd_perform_commit_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
-                               struct eap_method_ret *ret,
-                               const struct wpabuf *reqData,
-                               const u8 *payload, size_t payload_len)
-{
-       struct crypto_ec_point *K = NULL, *point = NULL;
-       struct crypto_bignum *mask = NULL, *cofactor = NULL;
-       const u8 *ptr;
-       u8 *scalar = NULL, *element = NULL;
-       size_t prime_len, order_len;
-
-       if (data->state != PWD_Commit_Req) {
-               ret->ignore = TRUE;
-               goto fin;
-       }
-
-       prime_len = crypto_ec_prime_len(data->grp->group);
-       order_len = crypto_ec_order_len(data->grp->group);
-
-       if (payload_len != 2 * prime_len + order_len) {
-               wpa_printf(MSG_INFO,
-                          "EAP-pwd: Unexpected Commit payload length %u (expected %u)",
-                          (unsigned int) payload_len,
-                          (unsigned int) (2 * prime_len + order_len));
-               goto fin;
-       }
-
        data->private_value = crypto_bignum_init();
        data->my_element = crypto_ec_point_init(data->grp->group);
        cofactor = crypto_bignum_init();