webrtc/RTCCertificate.html

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<title>RTCCertificate Tests</title>
<script src="/resources/testharness.js"></script>
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<script>
  'use strict';

  // Test is based on the Candidate Recommendation:
  // https://www.w3.org/TR/webrtc/

  /*
    4.2.1. RTCConfiguration Dictionary
      dictionary RTCConfiguration {
        sequence<RTCCertificate> certificates;
        ...
      };

      certificates of type sequence<RTCCertificate>
        If this value is absent, then a default set of certificates is
        generated for each RTCPeerConnection instance.

        The value for this configuration option cannot change after its
        value is initially selected.

    4.10.2. RTCCertificate Interface
      interface RTCCertificate {
        readonly attribute DOMTimeStamp expires;
        static sequence<AlgorithmIdentifier> getSupportedAlgorithms();
        sequence<RTCDtlsFingerprint>    getFingerprints();
      };

    5.5.1 The RTCDtlsFingerprint Dictionary
      dictionary RTCDtlsFingerprint {
        DOMString algorithm;
        DOMString value;
      };

    [RFC4572] Comedia over TLS in SDP
    5.  Fingerprint Attribute
      Figure 2. Augmented Backus-Naur Syntax for the Fingerprint Attribute

        attribute              =/ fingerprint-attribute

        fingerprint-attribute  =  "fingerprint" ":" hash-func SP fingerprint

        hash-func              =  "sha-1" / "sha-224" / "sha-256" /
                                  "sha-384" / "sha-512" /
                                  "md5" / "md2" / token
                                  ; Additional hash functions can only come
                                  ; from updates to RFC 3279

        fingerprint            =  2UHEX *(":" 2UHEX)
                                  ; Each byte in upper-case hex, separated
                                  ; by colons.

        UHEX                   =  DIGIT / %x41-46 ; A-F uppercase
   */

  // Helper function to generate certificate with a set of
  // default parameters
  function generateCertificate() {
    return RTCPeerConnection.generateCertificate({
      name: 'ECDSA',
      namedCurve: 'P-256'
    });
  }

  // Helper function that takes in an RTCDtlsFingerprint
  // and return an a=fingerprint SDP line
  function fingerprintToSdpLine(fingerprint) {
    return `\r\na=fingerprint:${fingerprint.algorithm} ${fingerprint.value.toUpperCase()}\r\n`;
  }

  // Assert that an SDP string has fingerprint line for all the cert's fingerprints
  function assert_sdp_has_cert_fingerprints(sdp, cert) {
    for(const fingerprint of cert.getFingerprints()) {
      const fingerprintLine = fingerprintToSdpLine(fingerprint);
      assert_true(sdp.includes(fingerprintLine),
        'Expect fingerprint line to be found in SDP');
    }
  }

  /*
    4.3.1. Operation
      When the RTCPeerConnection() constructor is invoked
        2.  If the certificates value in configuration is non-empty,
            check that the expires on each value is in the future.
            If a certificate has expired, throw an InvalidAccessError;
            otherwise, store the certificates. If no certificates value
            was specified, one or more new RTCCertificate instances are
            generated for use with this RTCPeerConnection instance.
            This may happen asynchronously and the value of certificates
            remains undefined for the subsequent steps.
   */
  promise_test(t => {
    return RTCPeerConnection.generateCertificate({
      name: 'ECDSA',
      namedCurve: 'P-256',
      expires: 0
    }).then(cert => {
      assert_less_than_equal(cert.expires, Date.now());
      assert_throws_dom('InvalidAccessError', () =>
        new RTCPeerConnection({ certificates: [cert] }));
    });
  }, 'Constructing RTCPeerConnection with expired certificate should reject with InvalidAccessError');

  /*
    4.3.2 Interface Definition
      setConfiguration
        4.  If configuration.certificates is set and the set of
            certificates differs from the ones used when connection
            was constructed, throw an InvalidModificationError.
   */
  promise_test(t => {
    return Promise.all([
      generateCertificate(),
      generateCertificate()
    ]).then(([cert1, cert2]) => {
      const pc = new RTCPeerConnection({
        certificates: [cert1]
      });

      // should not throw
      pc.setConfiguration({
        certificates: [cert1]
      });

      assert_throws_dom('InvalidModificationError', () =>
        pc.setConfiguration({
          certificates: [cert2]
        }));

      assert_throws_dom('InvalidModificationError', () =>
        pc.setConfiguration({
          certificates: [cert1, cert2]
        }));
    });
  }, 'Calling setConfiguration with different set of certs should reject with InvalidModificationError');

  /*
    4.10.2. RTCCertificate Interface
      getFingerprints
        Returns the list of certificate fingerprints, one of which is
        computed with the digest algorithm used in the certificate signature.

    5.5.1 The RTCDtlsFingerprint Dictionary
      algorithm of type DOMString
        One of the the hash function algorithms defined in the 'Hash function
        Textual Names' registry, initially specified in [RFC4572] Section 8.
        As noted in [JSEP] Section 5.2.1, the digest algorithm used for the
        fingerprint matches that used in the certificate signature.

      value of type DOMString
        The value of the certificate fingerprint in lowercase hex string as
        expressed utilizing the syntax of 'fingerprint' in [ RFC4572] Section 5.

   */
  promise_test(t => {
    return generateCertificate()
    .then(cert => {
      assert_idl_attribute(cert, 'getFingerprints');

      const fingerprints = cert.getFingerprints();
      assert_true(Array.isArray(fingerprints),
        'Expect fingerprints to return an array');

      assert_greater_than_equal(fingerprints.length, 1,
        'Expect at last one fingerprint in array');

      for(const fingerprint of fingerprints) {
        assert_equals(typeof fingerprint, 'object',
          'Expect fingerprint to be an object (dictionary)');

        // https://www.iana.org/assignments/hash-function-text-names/hash-function-text-names.xml
        const algorithms = ['md2', 'md5', 'sha-1', 'sha-224', 'sha-256', 'sha-384', 'sha-512'];
        assert_in_array(fingerprint.algorithm, algorithms,
          'Expect fingerprint.algorithm to be string of algorithm identifier');

        assert_true(/^([0-9a-f]{2}\:)+[0-9a-f]{2}$/.test(fingerprint.value),
          'Expect fingerprint.value to be lowercase hexadecimal separated by colon');
      }
    });
  }, 'RTCCertificate should have at least one fingerprint');

  /*
    4.3.2 Interface Definition
      createOffer
        The value for certificates in the RTCConfiguration for the
        RTCPeerConnection is used to produce a set of certificate
        fingerprints. These certificate fingerprints are used in the
        construction of SDP and as input to requests for identity
        assertions.

    [JSEP]
    5.2.1.  Initial Offers
      For DTLS, all m= sections MUST use all the certificate(s) that have
      been specified for the PeerConnection; as a result, they MUST all
      have the same [I-D.ietf-mmusic-4572-update] fingerprint value(s), or
      these value(s) MUST be session-level attributes.

      The following attributes, which are of category IDENTICAL or
      TRANSPORT, MUST appear only in "m=" sections which either have a
      unique address or which are associated with the bundle-tag.  (In
      initial offers, this means those "m=" sections which do not contain
      an "a=bundle-only" attribute.)

        - An "a=fingerprint" line for each of the endpoint's certificates,
          as specified in [RFC4572], Section 5; the digest algorithm used
          for the fingerprint MUST match that used in the certificate
          signature.

      Each m= section which is not bundled into another m= section, MUST
      contain the following attributes (which are of category IDENTICAL or
      TRANSPORT):

        - An "a=fingerprint" line for each of the endpoint's certificates,
          as specified in [RFC4572], Section 5; the digest algorithm used
          for the fingerprint MUST match that used in the certificate
          signature.
   */
  promise_test(t => {
    return generateCertificate()
    .then(cert => {
      const pc = new RTCPeerConnection({
        certificates: [cert]
      });
      pc.createDataChannel('test');

      return pc.createOffer()
      .then(offer => {
        assert_sdp_has_cert_fingerprints(offer.sdp, cert);
      });
    });
  }, 'RTCPeerConnection({ certificates }) should generate offer SDP with fingerprint of provided certificate');

  promise_test(t => {
    return Promise.all([
      generateCertificate(),
      generateCertificate()
    ]).then(certs => {
      const pc = new RTCPeerConnection({
        certificates: certs
      });
      pc.createDataChannel('test');

      return pc.createOffer()
      .then(offer => {
        for(const cert of certs) {
          assert_sdp_has_cert_fingerprints(offer.sdp, cert);
        }
      });
    });
  }, 'RTCPeerConnection({ certificates }) should generate offer SDP with fingerprint of all provided certificates');

  /*
    TODO

    4.10.2. RTCCertificate Interface
      getSupportedAlgorithms
           Returns a sequence providing a representative set of supported
           certificate algorithms. At least one algorithm MUST be returned.

      The RTCCertificate object can be stored and retrieved from persistent
      storage by an application. When a user agent is required to obtain a
      structured clone [HTML5] of a RTCCertificate object, it performs the
      following steps:
        1.  Let input and memory be the corresponding inputs defined by the
            internal structured cloning algorithm, where input represents a
            RTCCertificate object to be cloned.
        2.  Let output be a newly constructed RTCCertificate object.
        3.  Copy the value of the expires attribute from input to output.
        4.  Let the [[certificate]] internal slot of output be set to the
            result of invoking the internal structured clone algorithm
            recursively on the corresponding internal slots of input, with
            the slot contents as the new " input" argument and memory as
            the new " memory" argument.
        5.  Let the [[handle]] internal slot of output refer to the same
            private keying material represented by the [[handle]] internal
            slot of input.
   */

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