Changeset 5855 for pjproject/trunk/pjmedia/src/pjmedia/transport_srtp.c

Timestamp:

Aug 15, 2018 2:44:53 AM (6 years ago)

Author:

nanang

Message:

Re #2096: Answer with one SRTP keying only when offered both (thanks Wei-Wei for the feedback).

File:

• pjproject/trunk/pjmedia/src/pjmedia/transport_srtp.c (modified) (7 diffs)

pjproject/trunk/pjmedia/src/pjmedia/transport_srtp.c

@@ -267 +267 @@
     pjmedia_transport   *member_tp; /**< Underlying transport.       */
     pj_bool_t            member_tp_attached;
+    pj_bool_t            started;
 
     /* SRTP usage policy of peer. This field is updated when media is starting.
@@ -1051 +1052 @@
         if (status != PJ_SUCCESS)
             return status;
+
+        PJ_LOG(4, (srtp->pool->obj_name,
+                   "SRTP started, keying=%s, crypto=%s",
+                   (srtp->keying[0]->type==PJMEDIA_SRTP_KEYING_SDES?
+                    "SDES":"DTLS-SRTP"),
+                   srtp->tx_policy.name.ptr));
     }
 
@@ -1579 +1586 @@
     srtp->offerer_side = (sdp_remote == NULL);
 
+    if (!srtp->offerer_side && srtp->started) {
+        /* This is may be incoming reoffer that may change keying */
+        srtp->bypass_srtp = PJ_FALSE;
+        srtp->keying_cnt = srtp->all_keying_cnt;
+        for (i = 0; i < srtp->all_keying_cnt; ++i)
+            srtp->keying[i] = srtp->all_keying[i];
+    }
+
     status = pjmedia_transport_encode_sdp(srtp->member_tp, sdp_pool,
                                           sdp_local, sdp_remote, media_index);
@@ -1611 +1626 @@
             keying_status = st;
             continue;
-        }
-
-        if (!srtp_crypto_empty(&srtp->tx_policy_neg) &&
-            !srtp_crypto_empty(&srtp->rx_policy_neg))
-        {
-            /* SRTP nego is done */
+        } else if (!srtp->offerer_side) {
+            /* Answer with one keying only */
+            srtp->keying[0] = srtp->keying[i];
             srtp->keying_cnt = 1;
-            srtp->keying[0] = srtp->keying[i];
-            srtp->keying_pending_cnt = 0;
             break;
         }
@@ -1629 +1639 @@
     if (srtp->keying_cnt == 0)
         return keying_status;
+
+    /* Bypass SRTP & skip keying as SRTP is disabled and verification on
+     * remote SDP has been done.
+     */
+    if (srtp->setting.use == PJMEDIA_SRTP_DISABLED) {
+        srtp->bypass_srtp = PJ_TRUE;
+        srtp->keying_cnt = 0;
+    }
+
+    if (srtp->keying_cnt != 0) {
+        /* At this point for now, keying count should be 1 */
+        pj_assert(srtp->keying_cnt == 1);
+        PJ_LOG(4, (srtp->pool->obj_name, "SRTP uses keying method %s",
+                   (srtp->keying[0]->type==PJMEDIA_SRTP_KEYING_SDES?
+                    "SDES":"DTLS-SRTP")));
+    }
 
     return PJ_SUCCESS;
@@ -1646 +1672 @@
 
     PJ_ASSERT_RETURN(tp, PJ_EINVAL);
+
+    /* At this point for now, keying count should be 0 or 1 */
+    pj_assert(srtp->keying_cnt <= 1);
+
+    srtp->started = PJ_TRUE;
 
     status = pjmedia_transport_media_start(srtp->member_tp, pool,
@@ -1717 +1748 @@
     PJ_ASSERT_RETURN(tp, PJ_EINVAL);
 
+    srtp->started = PJ_FALSE;
+
     /* Invoke media_stop() of all keying methods */
     for (i=0; i < srtp->keying_cnt; ++i) {