/*! @license
* Shaka Player
* Copyright 2016 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
goog.provide('shaka.util.FairPlayUtils');
goog.require('goog.Uri');
goog.require('goog.asserts');
goog.require('shaka.net.NetworkingEngine');
goog.require('shaka.util.BufferUtils');
goog.require('shaka.util.Error');
goog.require('shaka.util.StringUtils');
goog.require('shaka.util.Uint8ArrayUtils');
/**
* @summary A set of FairPlay utility functions.
* @export
*/
shaka.util.FairPlayUtils = class {
/**
* Check if FairPlay is supported.
*
* @return {!Promise.<boolean>}
* @export
*/
static async isFairPlaySupported() {
const config = {
initDataTypes: ['cenc', 'sinf', 'skd'],
videoCapabilities: [
{
contentType: 'video/mp4; codecs="avc1.42E01E"',
},
],
};
try {
await navigator.requestMediaKeySystemAccess('com.apple.fps', [config]);
return true;
} catch (err) {
return false;
}
}
/**
* Using the default method, extract a content ID from the init data. This is
* based on the FairPlay example documentation.
*
* @param {!BufferSource} initData
* @return {string}
* @export
*/
static defaultGetContentId(initData) {
const uriString = shaka.util.StringUtils.fromBytesAutoDetect(initData);
// The domain of that URI is the content ID according to Apple's FPS
// sample.
const uri = new goog.Uri(uriString);
return uri.getDomain();
}
/**
* Transforms the init data buffer using the given data. The format is:
*
* <pre>
* [4 bytes] initDataSize
* [initDataSize bytes] initData
* [4 bytes] contentIdSize
* [contentIdSize bytes] contentId
* [4 bytes] certSize
* [certSize bytes] cert
* </pre>
*
* @param {!BufferSource} initData
* @param {!BufferSource|string} contentId
* @param {?BufferSource} cert The server certificate; this will throw if not
* provided.
* @return {!Uint8Array}
* @export
*/
static initDataTransform(initData, contentId, cert) {
if (!cert || !cert.byteLength) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.DRM,
shaka.util.Error.Code.SERVER_CERTIFICATE_REQUIRED);
}
// From that, we build a new init data to use in the session. This is
// composed of several parts. First, the init data as a UTF-16 sdk:// URL.
// Second, a 4-byte LE length followed by the content ID in UTF-16-LE.
// Third, a 4-byte LE length followed by the certificate.
/** @type {BufferSource} */
let contentIdArray;
if (typeof contentId == 'string') {
contentIdArray =
shaka.util.StringUtils.toUTF16(contentId, /* littleEndian= */ true);
} else {
contentIdArray = contentId;
}
// The init data we get is a UTF-8 string; convert that to a UTF-16 string.
const sdkUri = shaka.util.StringUtils.fromBytesAutoDetect(initData);
const utf16 =
shaka.util.StringUtils.toUTF16(sdkUri, /* littleEndian= */ true);
const rebuiltInitData = new Uint8Array(
12 + utf16.byteLength + contentIdArray.byteLength + cert.byteLength);
let offset = 0;
/** @param {BufferSource} array */
const append = (array) => {
rebuiltInitData.set(shaka.util.BufferUtils.toUint8(array), offset);
offset += array.byteLength;
};
/** @param {BufferSource} array */
const appendWithLength = (array) => {
const view = shaka.util.BufferUtils.toDataView(rebuiltInitData);
const value = array.byteLength;
view.setUint32(offset, value, /* littleEndian= */ true);
offset += 4;
append(array);
};
appendWithLength(utf16);
appendWithLength(contentIdArray);
appendWithLength(cert);
goog.asserts.assert(
offset == rebuiltInitData.length, 'Inconsistent init data length');
return rebuiltInitData;
}
/**
* SPC FairPlay request.
*
* @param {shaka.net.NetworkingEngine.RequestType} type
* @param {shaka.extern.Request} request
* @export
*/
static spcFairPlayRequest(type, request) {
if (type !== shaka.net.NetworkingEngine.RequestType.LICENSE) {
return;
}
const body = /** @type {!(ArrayBuffer|ArrayBufferView)} */(request.body);
const originalPayload = shaka.util.BufferUtils.toUint8(body);
const base64Payload = shaka.util.Uint8ArrayUtils.toBase64(originalPayload);
request.headers['Content-Type'] = 'application/x-www-form-urlencoded';
request.body = shaka.util.StringUtils.toUTF8('spc=' + base64Payload);
}
/**
* Common FairPlay response transform for some DRMs providers.
*
* @param {shaka.net.NetworkingEngine.RequestType} type
* @param {shaka.extern.Response} response
* @export
*/
static commonFairPlayResponse(type, response) {
if (type !== shaka.net.NetworkingEngine.RequestType.LICENSE) {
return;
}
// In Apple's docs, responses can be of the form:
// '\n<ckc>base64encoded</ckc>\n' or 'base64encoded'
// We have also seen responses in JSON format from some of our partners.
// In all of these text-based formats, the CKC data is base64-encoded.
let responseText;
try {
// Convert it to text for further processing.
responseText = shaka.util.StringUtils.fromUTF8(response.data);
} catch (error) {
// Assume it's not a text format of any kind and leave it alone.
return;
}
let licenseProcessing = false;
// Trim whitespace.
responseText = responseText.trim();
// Look for <ckc> wrapper and remove it.
if (responseText.substr(0, 5) === '<ckc>' &&
responseText.substr(-6) === '</ckc>') {
responseText = responseText.slice(5, -6);
licenseProcessing = true;
}
// Look for a JSON wrapper and remove it.
try {
const responseObject = /** @type {!Object} */(JSON.parse(responseText));
if (responseObject['ckc']) {
responseText = responseObject['ckc'];
licenseProcessing = true;
}
if (responseObject['CkcMessage']) {
responseText = responseObject['CkcMessage'];
licenseProcessing = true;
}
if (responseObject['License']) {
responseText = responseObject['License'];
licenseProcessing = true;
}
} catch (err) {
// It wasn't JSON. Fall through with other transformations.
}
if (licenseProcessing) {
// Decode the base64-encoded data into the format the browser expects.
// It's not clear why FairPlay license servers don't just serve this
// directly.
response.data = shaka.util.BufferUtils.toArrayBuffer(
shaka.util.Uint8ArrayUtils.fromBase64(responseText));
}
}
};