Add decryption/encryption dedicated APIs

index.bs

@@ -81,15 +81,16 @@ It uses an additional API on {{RTCRtpSender}} and {{RTCRtpReceiver}} to
 insert the processing into the pipeline.
 
 <pre class="idl">
-typedef (SFrameTransform or RTCRtpScriptTransform) RTCRtpTransform;
+typedef (SFrameSenderTransform or RTCRtpScriptTransform) RTCRtpSenderTransform;
+typedef (SFrameReceiverTransform or RTCRtpScriptTransform) RTCRtpReceierTransform;
 
 // New methods for RTCRtpSender and RTCRtpReceiver
 partial interface RTCRtpSender {
-    attribute RTCRtpTransform? transform;
+    attribute RTCRtpSenderTransform? transform;
 };
 
 partial interface RTCRtpReceiver {
-    attribute RTCRtpTransform? transform;
+    attribute RTCRtpReceiverTransform? transform;
 };
 </pre>
 
@@ -214,7 +215,7 @@ There is no guarantee on which frame will happen the switch from the previous tr
 If a web application sets the transform synchronously at creation of the {{RTCRtpSender}} (for instance when calling addTrack), the transform will receive the first frame generated by the {{RTCRtpSender}}'s encoder.
 Similarly, if a web application sets the transform synchronously at creation of the {{RTCRtpReceiver}} (for instance when calling addTrack, or at track event handler), the transform will receive the first full frame generated by the {{RTCRtpReceiver}}'s packetizer.
 
-# SFrameTransform # {#sframe}
+# SFrame transforms # {#sframe}
 
 <p>
 The APIs presented in this section allow applications to process SFrame data using specific cipher suites defined in [[RFC9605]].
@@ -237,30 +238,42 @@ dictionary SFrameTransformOptions {
 typedef [EnforceRange] unsigned long long SmallCryptoKeyID;
 typedef (SmallCryptoKeyID or bigint) CryptoKeyID;
 
-interface mixin SFrameKeyManagement {
+interface mixin SFrameEncrypterManagement {
     Promise<undefined> setEncryptionKey(CryptoKey key, optional CryptoKeyID keyID);
     attribute EventHandler onerror;
 };
 
+interface mixin SFrameDecrypterManagement {
+    Promise<undefined> addDecryptionKey(CryptoKey key, CryptoKeyID keyID);
+    Promise<undefined> removeDecryptionKey(CryptoKeyID keyID);
+    attribute EventHandler onerror;
+};
+
+[Exposed=Window]
+interface SFrameSenderTransform {
+    constructor(optional SFrameTransformOptions options = {});
+};
+SFrameSenderTransform includes SFrameEncrypterKeyManagement;
+
 [Exposed=Window]
-interface SFrameTransform : EventTarget {
+interface SFrameReceiverTransform : EventTarget {
     constructor(optional SFrameTransformOptions options = {});
 };
-SFrameTransform includes SFrameKeyManagement;
+SFrameReceiverTransform includes SFrameDecrypterKeyManagement;
 
 [Exposed=(Window,DedicatedWorker)]
 interface SFrameEncrypterStream : EventTarget {
     constructor(optional SFrameTransformOptions options = {});
 };
 SFrameEncrypterStream includes GenericTransformStream;
-SFrameEncrypterStream includes SFrameKeyManagement;
+SFrameEncrypterStream includes SFrameEncrypterManagement;
 
 [Exposed=(Window,DedicatedWorker)]
 interface SFrameDecrypterStream : EventTarget {
     constructor(optional SFrameTransformOptions options = {});
 };
 SFrameDecrypterStream includes GenericTransformStream;
-SFrameDecrypterStream includes SFrameKeyManagement;
+SFrameDecrypterStream includes SFrameDecrypterManagement;
 
 enum SFrameTransformErrorEventType {
     "authentication",
@@ -284,9 +297,15 @@ dictionary SFrameTransformErrorEventInit : EventInit {
 };
 </xmp>
 
-The <dfn constructor for="SFrameTransform" lt="SFrameTransform(options)"><code>new SFrameTransform(<var>options</var>)</code></dfn> constructor steps are:
+The <dfn constructor for="SFrameSenderTransform" lt="SFrameSenderTransform(options)"><code>new SFrameSenderTransform(<var>options</var>)</code></dfn> constructor steps are:
+1. Let |options| be the method's first argument.
+1. Run the [=SFrame initialization algorithm=] with |this| and |options|.
+1. Set |this|.`[[role]]` to 'encrypt'.
+
+The <dfn constructor for="SFrameReceiverTransform" lt="SFrameReceiverTransform(options)"><code>new SFrameReceiverTransform(<var>options</var>)</code></dfn> constructor steps are:
 1. Let |options| be the method's first argument.
 1. Run the [=SFrame initialization algorithm=] with |this| and |options|.
+1. Set |this|.`[[role]]` to 'decrypt'.
 
 The <dfn constructor for="SFrameEncrypterStream" lt="SFrameEncrypterStream(options)"><code>new SFrameEncrypterStream(<var>options</var>)</code></dfn> constructor steps are:
 1. Let |options| be the method's first argument.
@@ -335,14 +354,40 @@ The <dfn>SFrame transform algorithm</dfn>, given |this| and |frame|, runs these
 1. [=ReadableStream/Enqueue=] |frame| in |this|.`[[transform]]`.
 
 ## Methods ## {#sframe-transform-methods}
-The <dfn method for="SFrameTransform">setEncryptionKey(|key|, |keyID|)</dfn> method steps are:
+The <dfn method for="SFrameEncrypterKeyManager">setEncryptionKey(|key|, |keyID|)</dfn> method steps are:
 1. Let |promise| be [=a new promise=].
-2. If |keyID| is a {{bigint}} which cannot be represented as a integer between 0 and 2<sup>64</sup>-1 inclusive, [=reject=] |promise| with a {{RangeError}} exception.
-3. Otherwise, [=in parallel=], run the following steps:
-    1. Set |key| with its optional |keyID| as key material to use for the SFrame transform algorithm, as defined by [[RFC9605]].
-    2. If setting the key material fails, [=reject=] |promise| with an {{InvalidModificationError}} exception and abort these steps.
-    3. [=Resolve=] |promise| with undefined.
-4. Return |promise|.
+1. If |keyId| is <code>undefined</code>, run the following steps:
+   1. Let |currentKeyId| be |this|.`[[currentKeyId]]` if not undefined or 0 otherwise.
+   1. If |currentKeyId| is greater or equal to 2<sup>64</sup>-1, [=reject=] |promise| with a {{RangeError}} exception and abort these steps.
+   1. Set |keyId| to |currentKeyId| incremented by 1.
+1. If |keyID| is a {{bigint}} which cannot be represented as a integer between 0 and 2<sup>64</sup>-1 inclusive, [=reject=] |promise| with a {{RangeError}} exception and abort these steps.
+1.  Set |this|.`[[currentKeyId]]` to |keyId|.
+1. [=In parallel=], run the following steps:
+    1. Set |key| and |keyID| as key material to use for the SFrame transform encryption algorithm, as defined by [[RFC9605]].
+    1. If setting the key material fails, [=queue a task=] to [=reject=] |promise| with an {{InvalidModificationError}} exception and abort these steps.
+    1. [=Queue a task=] to [=resolve=] |promise| with undefined.
+1. Return |promise|.
+
+The <dfn method for="SFrameDecrypterKeyManager">addEncryptionKey(|key|, |keyID|)</dfn> method steps are:
+1. Let |promise| be [=a new promise=].
+1. If |keyID| is a {{bigint}} which cannot be represented as a integer between 0 and 2<sup>64</sup>-1 inclusive, [=reject=] |promise| with a {{RangeError}} exception, and abort these steps..
+1. [=In parallel=], run the following steps:
+    1. Let |keyStore| be the key store used for the SFrame transform algorithm, as defined by [[RFC9605]].
+    1. Set an entry to |keyStore| with |keyId| as key and |keyValue| as value. This overrides any existing entry to |keyId|.
+    1. If setting the key material fails, [=queue a task=] to [=reject=] |promise| with an {{InvalidModificationError}} exception and abort these steps.
+    1. [=Resolve=] |promise| with undefined.
+1. Return |promise|.
+
+// FIXME: Should SFrameTransform receiver be made aware of the current key in use, so that it would call removeEncryptionKey appropriately.
+// Or should we add an option to let the UA remove the key automatically on new KeyID?
+The <dfn method for="SFrameDecrypterKeyManager">removeEncryptionKey(|key|, |keyID|)</dfn> method steps are:
+1. Let |promise| be [=a new promise=].
+1. If |keyID| is a {{bigint}} which cannot be represented as a integer between 0 and 2<sup>64</sup>-1 inclusive, [=reject=] |promise| with a {{RangeError}} exception, and abort these steps.
+1. [=In parallel=], run the following steps:
+    1. Let |keyStore| be the key store used for the SFrame transform algorithm, as defined by [[RFC9605]].
+    1. Remove the entry of |keyStore| at |keyId| if it exits.
+    1. [=Resolve=] |promise| with undefined.
+1. Return |promise|.
 
 
 # RTCRtpScriptTransform # {#scriptTransform}