RADIUS: Redesign Request Authenticator generation

Simplify and make properly random the generation of the Request
Authenticator.

Signed-off-by: Nick Lowe <nick.lowe@lugatech.com>

radius_example/radius_example.c

@@ -61,7 +61,7 @@ static void start_example(void *eloop_ctx, void *timeout_ctx)
 		return;
 	}
 
-	radius_msg_make_authenticator(msg, (u8 *) ctx, sizeof(*ctx));
+	radius_msg_make_authenticator(msg);
 
 	if (!radius_msg_add_attr(msg, RADIUS_ATTR_USER_NAME,
 				 (u8 *) "user", 4)) {

src/ap/accounting.c

@@ -50,10 +50,9 @@ static struct radius_msg * accounting_msg(struct hostapd_data *hapd,
 		return NULL;
 	}
 
-	if (sta) {
+	if (radius_msg_make_authenticator(msg) < 0) {
-		radius_msg_make_authenticator(msg, (u8 *) sta, sizeof(*sta));
+		wpa_printf(MSG_INFO, "Could not make Request Authenticator");
-	} else {
+		goto fail;
-		radius_msg_make_authenticator(msg, (u8 *) hapd, sizeof(*hapd));
 	}
 
 	if (!radius_msg_add_attr_int32(msg, RADIUS_ATTR_ACCT_STATUS_TYPE,

src/ap/ieee802_11_auth.c

@@ -165,7 +165,10 @@ static int hostapd_radius_acl_query(struct hostapd_data *hapd, const u8 *addr,
 	if (msg == NULL)
 		return -1;
 
-	radius_msg_make_authenticator(msg, addr, ETH_ALEN);
+	if (radius_msg_make_authenticator(msg) < 0) {
+		wpa_printf(MSG_INFO, "Could not make Request Authenticator");
+		goto fail;
+	}
 
 	os_snprintf(buf, sizeof(buf), RADIUS_ADDR_FORMAT, MAC2STR(addr));
 	if (!radius_msg_add_attr(msg, RADIUS_ATTR_USER_NAME, (u8 *) buf,

src/ap/ieee802_1x.c

@@ -602,7 +602,10 @@ static void ieee802_1x_encapsulate_radius(struct hostapd_data *hapd,
 		return;
 	}
 
-	radius_msg_make_authenticator(msg, (u8 *) sta, sizeof(*sta));
+	if (radius_msg_make_authenticator(msg) < 0) {
+		wpa_printf(MSG_INFO, "Could not make Request Authenticator");
+		goto fail;
+	}
 
 	if (sm->identity &&
 	    !radius_msg_add_attr(msg, RADIUS_ATTR_USER_NAME,

src/radius/radius.c

@@ -893,25 +893,11 @@ int radius_msg_copy_attr(struct radius_msg *dst, struct radius_msg *src,
 
 /* Create Request Authenticator. The value should be unique over the lifetime
  * of the shared secret between authenticator and authentication server.
- * Use one-way MD5 hash calculated from current timestamp and some data given
+ */
- * by the caller. */
+int radius_msg_make_authenticator(struct radius_msg *msg)
-void radius_msg_make_authenticator(struct radius_msg *msg,
-				   const u8 *data, size_t len)
 {
-	struct os_time tv;
+	return os_get_random((u8 *) &msg->hdr->authenticator,
-	long int l;
+			     sizeof(msg->hdr->authenticator));
-	const u8 *addr[3];
-	size_t elen[3];
-
-	os_get_time(&tv);
-	l = os_random();
-	addr[0] = (u8 *) &tv;
-	elen[0] = sizeof(tv);
-	addr[1] = data;
-	elen[1] = len;
-	addr[2] = (u8 *) &l;
-	elen[2] = sizeof(l);
-	md5_vector(3, addr, elen, msg->hdr->authenticator);
 }
 
 

src/radius/radius.h

@@ -251,8 +251,7 @@ int radius_msg_verify_msg_auth(struct radius_msg *msg, const u8 *secret,
 			       size_t secret_len, const u8 *req_auth);
 int radius_msg_copy_attr(struct radius_msg *dst, struct radius_msg *src,
 			 u8 type);
-void radius_msg_make_authenticator(struct radius_msg *msg,
+int radius_msg_make_authenticator(struct radius_msg *msg);
-				   const u8 *data, size_t len);
 struct radius_ms_mppe_keys *
 radius_msg_get_ms_keys(struct radius_msg *msg, struct radius_msg *sent_msg,
 		       const u8 *secret, size_t secret_len);

wpa_supplicant/eapol_test.c

@@ -193,7 +193,7 @@ static void ieee802_1x_encapsulate_radius(struct eapol_test_data *e,
 		return;
 	}
 
-	radius_msg_make_authenticator(msg, (u8 *) e, sizeof(*e));
+	radius_msg_make_authenticator(msg);
 
 	hdr = (const struct eap_hdr *) eap;
 	pos = (const u8 *) (hdr + 1);