RTCPeerConnection-mid-length-validation.html

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This WPT test may be referenced by the following Test IDs:
- /webrtc/RTCPeerConnection-mid-length-validation.html - WPT Dashboard Interop Dashboard

<!doctype html>

<meta charset=utf-8>

<meta name="timeout" content="long">

<title>RTCPeerConnection MID Length Validation (Mozilla-specific)</title>

<script src="/resources/testharness.js"></script>

<script src="/resources/testharnessreport.js"></script>

<script src="/webrtc/RTCPeerConnection-helper.js"></script>

<script>

'use strict';

// This test is in the mozilla subdirectory because it tests behavior that is not

// mandated by the WebRTC specification: the spec does not require a specific MID

// length limit. RFC 8285 actually allows longer MID values in RTP headers when

// two-byte header extensions are used; the 16-byte maximum comes from RTCP-SDES,

// and the WebRTC spec recommends very short MID values. Browsers converge on a

// 16-byte maximum, so this test is expected to pass in Chrome and Safari as well.

// The MID length limit is enforced while parsing a description. A locally

// generated MID cannot be changed via setLocalDescription, so the limit is

// exercised by delivering a MID of the desired length in a remote offer.

// Builds an otherwise-valid single-m-section offer whose MID (and matching

// BUNDLE tag) is set to |mid|.

async function offerSdpWithMid(mid) {

  const pc = new RTCPeerConnection();

  pc.addTransceiver('audio');

  const offer = await pc.createOffer();

  pc.close();

  return offer.sdp

    .replace(/a=group:BUNDLE [^\r\n]+/, `a=group:BUNDLE ${mid}`)

    .replace(/a=mid:[^\r\n]+/, `a=mid:${mid}`);

promise_test(async t => {

  const pc = new RTCPeerConnection();

  t.add_cleanup(() => pc.close());

  const mid16 = '0123456789ABCDEF'; // exactly 16 characters

  const sdp = await offerSdpWithMid(mid16);

  await pc.setRemoteDescription({type: 'offer', sdp});

  // Should succeed without throwing

}, 'MID with 16 bytes should be accepted (maximum for RTCP-SDES)');

promise_test(async t => {

  const pc = new RTCPeerConnection();

  t.add_cleanup(() => pc.close());

  const mid17 = '0123456789ABCDEFG'; // 17 characters

  const sdp = await offerSdpWithMid(mid17);

  return promise_rejects_dom(t, 'OperationError',

        pc.setRemoteDescription({type: 'offer', sdp}));

}, 'MID with 17 bytes should be rejected (exceeds 16-byte limit for RTCP-SDES)');

promise_test(async t => {

  const pc = new RTCPeerConnection();

  t.add_cleanup(() => pc.close());

  const midNormal = 'audio-1'; // 7 characters

  const sdp = await offerSdpWithMid(midNormal);

  await pc.setRemoteDescription({type: 'offer', sdp});

  // Should succeed without throwing

}, 'MID with normal length should be accepted');

</script>