EAP-pwd: Remove struct eap_pwd_hdr

This structure was not really used for anything apart from figuring out
length of the EAP-pwd header (and even that in a way that would not work
with fragmentation). Since the bitfields in the structure could have
been problematic depending on target endianness, remove this unnecessary
structure.

Signed-hostap: Jouni Malinen <j@w1.fi>

src/eap_common/eap_pwd_common.h

@@ -35,13 +35,8 @@ typedef struct group_definition_ {
 
 /*
  * EAP-pwd header, included on all payloads
+ * L(1 bit) | M(1 bit) | exch(6 bits) | total_length(if L is set)
  */
-struct eap_pwd_hdr {
-	u8 l_bit:1;
-	u8 m_bit:1;
-	u8 exch:6;
-	u8 total_length[0];         /* included when l_bit is set */
-} STRUCT_PACKED;
 
 #define EAP_PWD_OPCODE_ID_EXCH          1
 #define EAP_PWD_OPCODE_COMMIT_EXCH      2

src/eap_peer/eap_pwd.c

@@ -423,8 +423,7 @@ eap_pwd_perform_commit_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
 	BN_bn2bin(y, element + BN_num_bytes(data->grp->prime) + offset);
 
 	resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD,
-			     sizeof(struct eap_pwd_hdr) +
-			     BN_num_bytes(data->grp->order) +
+			     1 + BN_num_bytes(data->grp->order) +
 			     (2 * BN_num_bytes(data->grp->prime)),
 			     EAP_CODE_RESPONSE, eap_get_id(reqData));
 	if (resp == NULL)
@@ -633,7 +632,7 @@ eap_pwd_perform_confirm_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
 	H_Final(&ctx, conf);
 
 	resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD,
-			     sizeof(struct eap_pwd_hdr) + SHA256_DIGEST_LENGTH,
+			     1 + SHA256_DIGEST_LENGTH,
 			     EAP_CODE_RESPONSE, eap_get_id(reqData));
 	if (resp == NULL)
 		goto fin;

src/eap_server/eap_server_pwd.c

@@ -156,8 +156,8 @@ eap_pwd_build_id_req(struct eap_sm *sm, struct eap_pwd_data *data, u8 id)
 
 	wpa_printf(MSG_DEBUG, "EAP-pwd: ID/Request");
 	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD,
-			    sizeof(struct eap_pwd_hdr) +
-			    sizeof(struct eap_pwd_id) + data->id_server_len,
+			    1 + sizeof(struct eap_pwd_id) +
+			    data->id_server_len,
 			    EAP_CODE_REQUEST, id);
 	if (req == NULL) {
 		eap_pwd_state(data, FAILURE);
@@ -257,8 +257,7 @@ eap_pwd_build_commit_req(struct eap_sm *sm, struct eap_pwd_data *data, u8 id)
 	BN_bn2bin(y, element + BN_num_bytes(data->grp->prime) + offset);
 
 	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD,
-			    sizeof(struct eap_pwd_hdr) +
-			    (2 * BN_num_bytes(data->grp->prime)) +
+			    1 + (2 * BN_num_bytes(data->grp->prime)) +
 			    BN_num_bytes(data->grp->order),
 			    EAP_CODE_REQUEST, id);
 	if (req == NULL)
@@ -385,7 +384,7 @@ eap_pwd_build_confirm_req(struct eap_sm *sm, struct eap_pwd_data *data, u8 id)
 	os_memcpy(data->my_confirm, conf, SHA256_DIGEST_LENGTH);
 
 	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD,
-			    sizeof(struct eap_pwd_hdr) + SHA256_DIGEST_LENGTH,
+			    1 + SHA256_DIGEST_LENGTH,
 			    EAP_CODE_REQUEST, id);
 	if (req == NULL)
 		goto fin;