EAP server: Extend EAP-TLS Commitment Message use to PEAP and EAP-TTLS

Use the explicit Commitment Message per draft-ietf-emu-eap-tls13-13
Section 2.5 and extend this functionality to PEAP and EAP-TTLS when
using TLS 1.3.

Signed-off-by: Alexander Clouter <alex@digriz.org.uk>

diff --git a/src/eap_server/eap_server_peap.c b/src/eap_server/eap_server_peap.c
index fdfc14b0a1320113831266a5b6c262ac1a814186..f526e8bf7377c7df56d0860dfcdec34199df8a7b 100644 (file)
--- a/src/eap_server/eap_server_peap.c
+++ b/src/eap_server/eap_server_peap.c
@@ -512,7 +512,25 @@ static struct wpabuf * eap_peap_build_phase2_term(struct eap_sm *sm,
        encr_req = eap_server_tls_encrypt(sm, &data->ssl, &msgbuf);
        os_free(hdr);
 
-       return encr_req;
+       if (!data->ssl.tls_v13 ||
+           !tls_connection_resumed(sm->cfg->ssl_ctx, data->ssl.conn)) {
+               wpabuf_free(data->ssl.tls_out);
+               data->ssl.tls_out_pos = 0;
+               return encr_req;
+       }
+
+       if (wpabuf_resize(&data->ssl.tls_out, wpabuf_len(encr_req)) < 0) {
+               wpa_printf(MSG_INFO,
+                          "EAP-PEAP: Failed to resize output buffer");
+               wpabuf_free(encr_req);
+               return NULL;
+       }
+       wpabuf_put_buf(data->ssl.tls_out, encr_req);
+       wpa_hexdump_buf(MSG_DEBUG,
+                       "EAP-PEAP: Data appended to the message", encr_req);
+       os_free(encr_req);
+
+       return data->ssl.tls_out;
 }
 
 
@@ -561,8 +579,6 @@ static struct wpabuf * eap_peap_buildReq(struct eap_sm *sm, void *priv, u8 id)
                data->ssl.tls_out = eap_peap_build_phase2_tlv(sm, data, id);
                break;
        case SUCCESS_REQ:
-               wpabuf_free(data->ssl.tls_out);
-               data->ssl.tls_out_pos = 0;
                data->ssl.tls_out = eap_peap_build_phase2_term(sm, data, id,
                                                               1);
                break;

diff --git a/src/eap_server/eap_server_tls.c b/src/eap_server/eap_server_tls.c
index 769fd1fe0dc403c09fb3328e8ae9bed1185dc7b8..00a496f2c61f5c62f17e6896f8582fea441b654e 100644 (file)
--- a/src/eap_server/eap_server_tls.c
+++ b/src/eap_server/eap_server_tls.c
@@ -266,39 +266,6 @@ static void eap_tls_process_msg(struct eap_sm *sm, void *priv,
                eap_tls_state(data, FAILURE);
                return;
        }
-
-       if (data->ssl.tls_v13 &&
-           tls_connection_established(sm->cfg->ssl_ctx, data->ssl.conn)) {
-               struct wpabuf *plain, *encr;
-
-               wpa_printf(MSG_DEBUG,
-                          "EAP-TLS: Send empty application data to indicate end of exchange");
-               /* FIX: This should be an empty application data based on
-                * draft-ietf-emu-eap-tls13-05, but OpenSSL does not allow zero
-                * length payload (SSL_write() documentation explicitly
-                * describes this as not allowed), so work around that for now
-                * by sending out a payload of one octet. Hopefully the draft
-                * specification will change to allow this so that no crypto
-                * library changes are needed. */
-               plain = wpabuf_alloc(1);
-               if (!plain)
-                       return;
-               wpabuf_put_u8(plain, 0);
-               encr = eap_server_tls_encrypt(sm, &data->ssl, plain);
-               wpabuf_free(plain);
-               if (!encr)
-                       return;
-               if (wpabuf_resize(&data->ssl.tls_out, wpabuf_len(encr)) < 0) {
-                       wpa_printf(MSG_INFO,
-                                  "EAP-TLS: Failed to resize output buffer");
-                       wpabuf_free(encr);
-                       return;
-               }
-               wpabuf_put_buf(data->ssl.tls_out, encr);
-               wpa_hexdump_buf(MSG_DEBUG,
-                               "EAP-TLS: Data appended to the message", encr);
-               wpabuf_free(encr);
-       }
 }
 
 

diff --git a/src/eap_server/eap_server_tls_common.c b/src/eap_server/eap_server_tls_common.c
index 4b832d09725982b9f65ee129682a2eb51ba6089a..a9b53b1a06546a4efa661bb8cd618ff3544a63dc 100644 (file)
--- a/src/eap_server/eap_server_tls_common.c
+++ b/src/eap_server/eap_server_tls_common.c
@@ -366,6 +366,56 @@ int eap_server_tls_phase1(struct eap_sm *sm, struct eap_ssl_data *data)
                sm->serial_num = tls_connection_peer_serial_num(
                        sm->cfg->ssl_ctx, data->conn);
 
+       /*
+        * https://tools.ietf.org/html/draft-ietf-emu-eap-tls13#section-2.5
+        *
+        * We need to signal the other end that TLS negotiation is done. We
+        * can't send a zero-length application data message, so we send
+        * application data which is one byte of zero.
+        *
+        * Note this is only done for when there is no application data to be
+        * sent. So this is done always for EAP-TLS but notibly not for PEAP
+        * even on resumption.
+        */
+       if (data->tls_v13 &&
+           tls_connection_established(sm->cfg->ssl_ctx, data->conn)) {
+               struct wpabuf *plain, *encr;
+
+               switch (sm->currentMethod) {
+               case EAP_TYPE_PEAP:
+                       break;
+               default:
+                       if (!tls_connection_resumed(sm->cfg->ssl_ctx,
+                                                   data->conn))
+                               break;
+                       /* fallthrough */
+               case EAP_TYPE_TLS:
+                       wpa_printf(MSG_DEBUG,
+                                  "EAP-TLS: Send Commitment Message");
+
+                       plain = wpabuf_alloc(1);
+                       if (!plain)
+                               return -1;
+                       wpabuf_put_u8(plain, 0);
+                       encr = eap_server_tls_encrypt(sm, data, plain);
+                       wpabuf_free(plain);
+                       if (!encr)
+                               return -1;
+                       if (wpabuf_resize(&data->tls_out, wpabuf_len(encr)) < 0)
+                       {
+                               wpa_printf(MSG_INFO,
+                                          "EAP-TLS: Failed to resize output buffer");
+                               wpabuf_free(encr);
+                               return -1;
+                       }
+                       wpabuf_put_buf(data->tls_out, encr);
+                       wpa_hexdump_buf(MSG_DEBUG,
+                                       "EAP-TLS: Data appended to the message",
+                                       encr);
+                       wpabuf_free(encr);
+               }
+       }
+
        return 0;
 }