refactor: extract DRM challenge detection and handling for fetch and XHR requests

This commit is contained in:
voldemort 2025-07-21 20:25:47 +07:00
parent f8712d7726
commit 867294f7f6

View File

@ -714,6 +714,81 @@ MediaKeySession.prototype.update = function (response) {
return updatePromise; return updatePromise;
}; };
// Helpers
function detectDRMChallenge(body) {
// Handles ArrayBuffer, Uint8Array, string, and JSON string
// Returns: { type: "Widevine"|"PlayReady"|null, base64: string|null, bodyType: "buffer"|"string"|"json"|null }
if (body instanceof ArrayBuffer || body instanceof Uint8Array) {
const buffer = body instanceof Uint8Array ? body : new Uint8Array(body);
const base64Body = window.btoa(String.fromCharCode(...buffer));
if (base64Body.startsWith(DRM_SIGNATURES.WIDEVINE)) {
return { type: "Widevine", base64: base64Body, bodyType: "buffer" };
}
if (base64Body.startsWith(DRM_SIGNATURES.PLAYREADY)) {
return { type: "PlayReady", base64: base64Body, bodyType: "buffer" };
}
} else if (typeof body === "string" && !isJson(body)) {
const base64EncodedBody = btoa(body);
if (base64EncodedBody.startsWith(DRM_SIGNATURES.WIDEVINE)) {
return { type: "Widevine", base64: base64EncodedBody, bodyType: "string" };
}
if (base64EncodedBody.startsWith(DRM_SIGNATURES.PLAYREADY)) {
return { type: "PlayReady", base64: base64EncodedBody, bodyType: "string" };
}
} else if (typeof body === "string" && isJson(body)) {
const jsonBody = JSON.parse(body);
if (jsonContainsValue(jsonBody, DRM_SIGNATURES.WIDEVINE)) {
return { type: "Widevine", base64: null, bodyType: "json" };
}
if (jsonContainsValue(jsonBody, DRM_SIGNATURES.PLAYREADY)) {
return { type: "PlayReady", base64: null, bodyType: "json" };
}
}
return { type: null, base64: null, bodyType: null };
}
function handleLicenseMode({
drmInfo,
body,
setBody, // function to set the new body (for fetch: (b) => config.body = b, for XHR: (b) => originalSend.call(this, b))
urlOrResource,
getWidevinePssh,
getPlayreadyPssh,
widevineDeviceInfo,
playreadyDeviceInfo,
}) {
foundChallengeInBody = true;
window.postMessage({ type: "__LICENSE_URL__", data: urlOrResource }, "*");
// Create remoteCDM if needed
if (!remoteCDM) {
if (drmInfo.type === "Widevine") {
remoteCDM = createAndOpenRemoteCDM("Widevine", widevineDeviceInfo, getWidevinePssh());
}
if (drmInfo.type === "PlayReady") {
remoteCDM = createAndOpenRemoteCDM(
"PlayReady",
playreadyDeviceInfo,
getPlayreadyPssh()
);
}
}
if (remoteCDM && remoteCDM.challenge === null) {
remoteCDM.getChallenge(getWidevinePssh());
}
// Inject the new challenge into the request body
if (drmInfo.bodyType === "json") {
const jsonBody = JSON.parse(body);
const injectedBody = jsonReplaceValue(jsonBody, remoteCDM.challenge);
setBody(JSON.stringify(injectedBody));
} else if (drmInfo.bodyType === "buffer") {
setBody(base64ToUint8Array(remoteCDM.challenge));
} else {
setBody(atob(remoteCDM.challenge));
}
}
// fetch POST interceptor // fetch POST interceptor
(function () { (function () {
const originalFetch = window.fetch; const originalFetch = window.fetch;
@ -724,108 +799,14 @@ MediaKeySession.prototype.update = function (response) {
if (method === "POST") { if (method === "POST") {
let body = config.body; let body = config.body;
if (body) { if (body) {
if (body instanceof ArrayBuffer || body instanceof Uint8Array) { const drmInfo = detectDRMChallenge(body);
const buffer = body instanceof Uint8Array ? body : new Uint8Array(body);
const base64Body = window.btoa(String.fromCharCode(...buffer));
if (
(base64Body.startsWith(DRM_SIGNATURES.WIDEVINE) ||
base64Body.startsWith(DRM_SIGNATURES.PLAYREADY)) &&
(!remoteCDM ||
remoteCDM.challenge === null ||
base64Body !== remoteCDM.challenge) &&
interceptType === "EME"
) {
foundChallengeInBody = true;
window.postMessage({ type: "__LICENSE_URL__", data: resource }, "*");
// Block the request
return;
}
if (
(base64Body.startsWith(DRM_SIGNATURES.WIDEVINE) ||
base64Body.startsWith(DRM_SIGNATURES.PLAYREADY)) &&
interceptType == "LICENSE" &&
!foundChallengeInBody
) {
foundChallengeInBody = true;
window.postMessage({ type: "__LICENSE_URL__", data: resource }, "*");
if (!remoteCDM) {
if (base64Body.startsWith(DRM_SIGNATURES.WIDEVINE)) {
remoteCDM = createAndOpenRemoteCDM(
"Widevine",
widevineDeviceInfo,
foundWidevinePssh
);
}
if (base64Body.startsWith(DRM_SIGNATURES.PLAYREADY)) {
remoteCDM = createAndOpenRemoteCDM(
"PlayReady",
playreadyDeviceInfo,
foundPlayreadyPssh
);
}
}
if (remoteCDM && remoteCDM.challenge === null) {
remoteCDM.getChallenge(foundWidevinePssh);
}
const injectedBody = base64ToUint8Array(remoteCDM.challenge);
config.body = injectedBody;
return originalFetch(resource, config);
}
}
if (typeof body === "string" && !isJson(body)) {
const base64EncodedBody = btoa(body);
if (
(base64EncodedBody.startsWith(DRM_SIGNATURES.WIDEVINE) ||
base64EncodedBody.startsWith(DRM_SIGNATURES.PLAYREADY)) &&
(!remoteCDM ||
remoteCDM.challenge === null ||
base64EncodedBody !== remoteCDM.challenge) &&
interceptType === "EME"
) {
foundChallengeInBody = true;
window.postMessage({ type: "__LICENSE_URL__", data: resource }, "*");
// Block the request
return;
}
if (
(base64EncodedBody.startsWith(DRM_SIGNATURES.WIDEVINE) ||
base64EncodedBody.startsWith(DRM_SIGNATURES.PLAYREADY)) &&
interceptType == "LICENSE" &&
!foundChallengeInBody
) {
foundChallengeInBody = true;
window.postMessage({ type: "__LICENSE_URL__", data: resource }, "*");
if (!remoteCDM) {
if (base64EncodedBody.startsWith(DRM_SIGNATURES.WIDEVINE)) {
remoteCDM = createAndOpenRemoteCDM(
"Widevine",
widevineDeviceInfo,
foundWidevinePssh
);
}
if (base64EncodedBody.startsWith(DRM_SIGNATURES.PLAYREADY)) {
remoteCDM = createAndOpenRemoteCDM(
"PlayReady",
playreadyDeviceInfo,
foundPlayreadyPssh
);
}
}
if (remoteCDM && remoteCDM.challenge === null) {
remoteCDM.getChallenge(foundWidevinePssh);
}
const injectedBody = atob(remoteCDM.challenge);
config.body = injectedBody;
return originalFetch(resource, config);
}
}
if (typeof body === "string" && isJson(body)) {
const jsonBody = JSON.parse(body);
// EME mode: block the request if a DRM challenge is detected
if ( if (
(jsonContainsValue(jsonBody, DRM_SIGNATURES.WIDEVINE) || drmInfo.type &&
jsonContainsValue(jsonBody, DRM_SIGNATURES.PLAYREADY)) && (!remoteCDM ||
(!remoteCDM || remoteCDM.challenge === null) && remoteCDM.challenge === null ||
drmInfo.base64 !== remoteCDM.challenge) &&
interceptType === "EME" interceptType === "EME"
) { ) {
foundChallengeInBody = true; foundChallengeInBody = true;
@ -834,36 +815,21 @@ MediaKeySession.prototype.update = function (response) {
return; return;
} }
if ( // LICENSE mode: replace the challenge in the request
(jsonContainsValue(jsonBody, DRM_SIGNATURES.WIDEVINE) || if (drmInfo.type && interceptType === "LICENSE" && !foundChallengeInBody) {
jsonContainsValue(jsonBody, DRM_SIGNATURES.PLAYREADY)) && handleLicenseMode({
interceptType === "LICENSE" && drmInfo,
!foundChallengeInBody body,
) { setBody: (b) => {
foundChallengeInBody = true; config.body = b;
window.postMessage({ type: "__LICENSE_URL__", data: resource }, "*"); },
if (!remoteCDM) { urlOrResource: resource,
if (jsonContainsValue(jsonBody, DRM_SIGNATURES.WIDEVINE)) { getWidevinePssh: () => foundWidevinePssh,
remoteCDM = createAndOpenRemoteCDM( getPlayreadyPssh: () => foundPlayreadyPssh,
"Widevine",
widevineDeviceInfo, widevineDeviceInfo,
foundWidevinePssh
);
}
if (jsonContainsValue(jsonBody, DRM_SIGNATURES.PLAYREADY)) {
remoteCDM = createAndOpenRemoteCDM(
"PlayReady",
playreadyDeviceInfo, playreadyDeviceInfo,
foundPlayreadyPssh });
); return originalFetch(resource, config);
}
}
if (remoteCDM && remoteCDM.challenge === null) {
remoteCDM.getChallenge(foundWidevinePssh);
}
const injectedBody = jsonReplaceValue(jsonBody, remoteCDM.challenge);
config.body = JSON.stringify(injectedBody);
}
} }
} }
} }
@ -886,108 +852,14 @@ MediaKeySession.prototype.update = function (response) {
XMLHttpRequest.prototype.send = function (body) { XMLHttpRequest.prototype.send = function (body) {
if (this._method && this._method.toUpperCase() === "POST") { if (this._method && this._method.toUpperCase() === "POST") {
if (body) { if (body) {
if (body instanceof ArrayBuffer || body instanceof Uint8Array) { const drmInfo = detectDRMChallenge(body);
const buffer = body instanceof Uint8Array ? body : new Uint8Array(body);
const base64Body = window.btoa(String.fromCharCode(...buffer)); // EME mode: block the request if a DRM challenge is detected
if ( if (
(base64Body.startsWith(DRM_SIGNATURES.WIDEVINE) || drmInfo.type &&
base64Body.startsWith(DRM_SIGNATURES.PLAYREADY)) &&
(!remoteCDM || (!remoteCDM ||
remoteCDM.challenge === null || remoteCDM.challenge === null ||
base64Body !== remoteCDM.challenge) && drmInfo.base64 !== remoteCDM.challenge) &&
interceptType === "EME"
) {
foundChallengeInBody = true;
window.postMessage({ type: "__LICENSE_URL__", data: this._url }, "*");
// Block the request
return;
}
if (
(base64Body.startsWith(DRM_SIGNATURES.WIDEVINE) ||
base64Body.startsWith(DRM_SIGNATURES.PLAYREADY)) &&
interceptType == "LICENSE" &&
!foundChallengeInBody
) {
foundChallengeInBody = true;
window.postMessage({ type: "__LICENSE_URL__", data: this._url }, "*");
if (!remoteCDM) {
if (base64Body.startsWith(DRM_SIGNATURES.WIDEVINE)) {
remoteCDM = createAndOpenRemoteCDM(
"Widevine",
widevineDeviceInfo,
foundWidevinePssh
);
}
if (base64Body.startsWith(DRM_SIGNATURES.PLAYREADY)) {
remoteCDM = createAndOpenRemoteCDM(
"PlayReady",
playreadyDeviceInfo,
foundPlayreadyPssh
);
}
}
if (remoteCDM && remoteCDM.challenge === null) {
remoteCDM.getChallenge(foundWidevinePssh);
}
const injectedBody = base64ToUint8Array(remoteCDM.challenge);
return originalSend.call(this, injectedBody);
}
}
if (typeof body === "string" && !isJson(body)) {
const base64EncodedBody = btoa(body);
if (
(base64EncodedBody.startsWith(DRM_SIGNATURES.WIDEVINE) ||
base64EncodedBody.startsWith(DRM_SIGNATURES.PLAYREADY)) &&
(!remoteCDM ||
remoteCDM.challenge === null ||
base64EncodedBody !== remoteCDM.challenge) &&
interceptType === "EME"
) {
foundChallengeInBody = true;
window.postMessage({ type: "__LICENSE_URL__", data: this._url }, "*");
// Block the request
return;
}
if (
(base64EncodedBody.startsWith(DRM_SIGNATURES.WIDEVINE) ||
base64EncodedBody.startsWith(DRM_SIGNATURES.PLAYREADY)) &&
interceptType == "LICENSE" &&
!foundChallengeInBody
) {
foundChallengeInBody = true;
window.postMessage({ type: "__LICENSE_URL__", data: this._url }, "*");
if (!remoteCDM) {
if (base64EncodedBody.startsWith(DRM_SIGNATURES.WIDEVINE)) {
remoteCDM = createAndOpenRemoteCDM(
"Widevine",
widevineDeviceInfo,
foundWidevinePssh
);
}
if (base64EncodedBody.startsWith(DRM_SIGNATURES.PLAYREADY)) {
remoteCDM = createAndOpenRemoteCDM(
"PlayReady",
playreadyDeviceInfo,
foundPlayreadyPssh
);
}
}
if (remoteCDM && remoteCDM.challenge === null) {
remoteCDM.getChallenge(foundWidevinePssh);
}
const injectedBody = atob(remoteCDM.challenge);
return originalSend.call(this, injectedBody);
}
}
if (typeof body === "string" && isJson(body)) {
const jsonBody = JSON.parse(body);
if (
(jsonContainsValue(jsonBody, DRM_SIGNATURES.WIDEVINE) ||
jsonContainsValue(jsonBody, DRM_SIGNATURES.PLAYREADY)) &&
(!remoteCDM || remoteCDM.challenge === null) &&
interceptType === "EME" interceptType === "EME"
) { ) {
foundChallengeInBody = true; foundChallengeInBody = true;
@ -996,36 +868,18 @@ MediaKeySession.prototype.update = function (response) {
return; return;
} }
if ( // LICENSE mode: replace the challenge in the request
(jsonContainsValue(jsonBody, DRM_SIGNATURES.WIDEVINE) || if (drmInfo.type && interceptType === "LICENSE" && !foundChallengeInBody) {
jsonContainsValue(jsonBody, DRM_SIGNATURES.PLAYREADY)) && return handleLicenseMode({
interceptType === "LICENSE" && drmInfo,
!foundChallengeInBody body,
) { setBody: (b) => originalSend.call(this, b),
foundChallengeInBody = true; urlOrResource: this._url,
window.postMessage({ type: "__LICENSE_URL__", data: this._url }, "*"); getWidevinePssh: () => foundWidevinePssh,
if (!remoteCDM) { getPlayreadyPssh: () => foundPlayreadyPssh,
if (jsonContainsValue(jsonBody, DRM_SIGNATURES.WIDEVINE)) {
remoteCDM = createAndOpenRemoteCDM(
"Widevine",
widevineDeviceInfo, widevineDeviceInfo,
foundWidevinePssh
);
}
if (jsonContainsValue(jsonBody, DRM_SIGNATURES.PLAYREADY)) {
remoteCDM = createAndOpenRemoteCDM(
"PlayReady",
playreadyDeviceInfo, playreadyDeviceInfo,
foundPlayreadyPssh });
);
}
}
if (remoteCDM && remoteCDM.challenge === null) {
remoteCDM.getChallenge(foundWidevinePssh);
}
const injectedBody = jsonReplaceValue(jsonBody, remoteCDM.challenge);
return originalSend.call(this, JSON.stringify(injectedBody));
}
} }
} }
} }