Allow user to specify crypto_period_index, algorithm, protection_scheme

emarsden · Feb 25, 2024 · cc717f2 · cc717f2
1 parent 08dbdfb
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diff --git a/www-zola/content/decode.md b/www-zola/content/decode.md
@@ -39,6 +39,7 @@ following <abbr title="Digital Rights Management">DRM</abbr> systems:
 - <a href="https://irdeto.com/video-entertainment/multi-drm/">Irdeto</a>
 - <a href="https://www.marlin-community.com/">Marlin</a>
 - <a href="https://developer.huawei.com/consumer/en/hms/huawei-wiseplay/">WisePlay</a>, owned by Huawei
+- The unofficial variant of Apple Fairplay that is used for DASH-like streaming by Netflix
 - Common Encryption (CENC)
 
 

diff --git a/www-zola/content/generate.md b/www-zola/content/generate.md
@@ -3,35 +3,73 @@ title = "PSSH box generator"
 description = "Generate a Widevine PSSH box directly in your browser (WASM)."
 +++
 
-Note: all fields except for key ID can be left empty.
+Given a Key ID and other optional arguments, this tool generates a Widevine PSSH box and encodes it
+in Base 64 format.
 
 
 <form>
-  <label data-tooltip="Key ID (32 hex characters)">Key ID
-    <input id="kid" type="text" minlength="32" maxlength="36"
-      pattern="[0-9ABCDEFabcdef]{8}-?[0-9ABCDEFabcdef]{4}-?[0-9ABCDEFabcdef]{4}-?[0-9ABCDEFabcdef]{4}-?[0-9ABCDEFabcdef]{12}" /></label>
-  <label>Content provider name <input id="provider" type="text"/></label>
-  <label>Content ID <input id="contentid" type="text"/></label>
-  <label>Policy <input id="policy" type="text"/></label>
-  <label>Crypto period index, for media using key rotation (an uint32)
+  <article>
+    <header><h3>Mandatory field</h3></header>
+      <label data-tooltip="Key ID (32 hex characters)">Key ID or KID (required argument)
+        <input id="kid" type="text" minlength="32" maxlength="36"
+        pattern="[0-9ABCDEFabcdef]{8}-?[0-9ABCDEFabcdef]{4}-?[0-9ABCDEFabcdef]{4}-?[0-9ABCDEFabcdef]{4}-?[0-9ABCDEFabcdef]{12}"
+  />
+      </label>
+  </article>
+
+  <article>
+  <header><h3>Optional fields</h3>
+
+  <p>All fields below can be left blank or at their default values.</p>
+  </header>
+
+  <fieldset>
+    <legend>PSSH box version:</legend>
+    <input id="v0" type="radio" name="version" value="0" checked />
+    <label htmlFor="v0">Version 0 (recommended)</label>
+    <input id="v1" type="radio" name="version" value="1" />
+    <label htmlFor="v1">Version 1</label>
+  </fieldset>
+  <small>v0 PSSH boxes are more widely supported by Widevine license servers</small>
+
+
+  <label>Content provider name (optional) <input id="provider" type="text"/></label>
+
+  <label>Content ID (optional) <input id="contentid" type="text" aria-describedby="contentid-help"/>
+  <small id="contentid-help">An identifier supplied by a content provider, used to identify a piece of content and
+  derive key IDs and content keys</small>
+  </label>
+
+  <label>Policy (optional) <input id="policy" type="text" aria-describedby="policy-help"/>
+    <small id="policy-help">A policy name that refers to a stored policy in Widevine service</small></label>
+
+  <fieldset>
+    <legend>Encryption algorithm (optional)</legend>
+    <label><input type="radio" name="algorithm" value="unspecified" checked />Unspecified (recommended)</label>
+    <label><input type="radio" name="algorithm" value="0"/>Unencrypted (algorithm = 0)</label>
+    <label><input type="radio" name="algorithm" value="1"/>AES-CTR (algorithm = 1)</label>
+  </fieldset>
+
+  <label>Crypto period index, for media using key rotation (an uint32, optional)
     <input id="crypto_period_index" type="number"/></label>
+
   <fieldset>
     <legend>Protection scheme</legend>
-    <label><input type="radio" name="protection_scheme" value="cenc" checked/>cenc (AES-CTR)</label>
-    <label><input type="radio" name="protection_scheme" value="cbc1"/>cbc1 (AES-CBC)</label>
-    <label><input type="radio" name="protection_scheme" value="cens"/>cens (AES-CTR subsample)</label>
-    <label><input type="radio" name="protection_scheme" value="cbcs"/>cbcs (AES-CBC subsample)</label>
+    <label><input type="radio" name="protection_scheme" value="unspecified" checked/>Unspecified</label>
+    <label><input type="radio" name="protection_scheme" value="CENC"/>cenc (AES-CTR)</label>
+    <label><input type="radio" name="protection_scheme" value="CBC1"/>cbc1 (AES-CBC)</label>
+    <label><input type="radio" name="protection_scheme" value="CENS"/>cens (AES-CTR subsample)</label>
+    <label><input type="radio" name="protection_scheme" value="CBCS"/>cbcs (AES-CBC subsample)</label>
   </fieldset>
+  </article>
+
   <button id="go" data-tooltip="Generate PSSH">Generate</button>
 </form>
 
 <div style="margin-top:1.5em;margin-bottom:1.5em;padding:1em" id="output"></div>
 
-Given a Key ID, this tool generates a Widevine PSSH box and encodes it in Base 64 format.
-
 **Privacy**: this tool is implemented in [WebAssembly](https://webassembly.org/) (WASM)
 and runs fully inside your web browser (there is no server backend).
 
 
-
 <script type="module" src="../js/generate-pssh.js"></script>
diff --git a/www-zola/static/js/generate-pssh.js b/www-zola/static/js/generate-pssh.js
@@ -5,15 +5,35 @@ init().then(() => {
 
 document.getElementById("go").addEventListener("click", function(e) {
     e.preventDefault();
-    let kid = document.getElementById("kid").value.trim();
-    let provider = document.getElementById("provider").value.trim();
-    let contentid = document.getElementById("contentid").value.trim();
-    let policy = document.getElementById("policy").value.trim();
-    let crypto_period_index = document.getElementById("crypto_period_index").value.trim();
-    let protection_scheme = document.querySelector("input[name='protection_scheme']:checked").value;
+    const kid = document.getElementById("kid").value.trim();
+    const version_str = document.querySelector("input[name='version']:checked").value;
+    const provider = document.getElementById("provider").value.trim();
+    const contentid = document.getElementById("contentid").value.trim();
+    const policy = document.getElementById("policy").value.trim();
+    const crypto_period_idx_str = document.getElementById("crypto_period_index").value.trim();
+    var protection_scheme = document.querySelector("input[name='protection_scheme']:checked").value;
+    const algorithm_str = document.querySelector("input[name='algorithm']:checked").value;
     let out = document.getElementById("output");
     try {
-        let encoded = generate_widevine_pssh_b64([kid], provider, contentid, policy);
+        let version = 0;
+        if (version_str === "1") {
+            version = 1;
+        }
+        let cpi = null;  // maps to None in Rust
+        if (crypto_period_idx_str.length > 0) {
+            cpi = Number(crypto_period_idx_str);
+        }
+        if (protection_scheme === "unspecified") {
+            protection_scheme = "";
+        }
+        let algorithm = null;
+        if (algorithm_str === "0") {
+            algorithm = 0;
+        } else if (algorithm_str === "1") {
+            algorithm = 1;
+        }
+        let encoded = generate_widevine_pssh_b64(version, [kid], provider, contentid, policy,
+                                                 cpi, protection_scheme, algorithm);
         out.innerHTML = "<h3>Generated PSSH in Base 64</h3>" + "<p>" + encoded;
         out.style.backgroundColor = "#CCC";
     } catch (e) {
@@ -38,7 +58,7 @@ function initValidation(form) {
 
     const fields = Array.from(form.elements);
     fields.forEach(field => {
-        if (!(field.type == "radio")) {
+        if (field.pattern && !(field.type == "radio")) {
             field.setAttribute("aria-invalid", false);
             const helpBox = document.createElement("small");
             const helpId = field.id + "Helper";