Add a method to associate MediaDrm session with MediaCrypto

Previously, to associate a MediaDrm session with MediaCrypto,
the MediaDrm sessionId was passed as initData to the MediaCrypto
constructor.  This is not ideal for two reasons: it's pretty
obscure and you can't change the association without tearing
down the MediaCodec/MediaCrypto and starting all over.  Use
cases like key rotation require being able to update the
MediaDrm session post-construction.  This CL addresses both of
these issues.

bug: 19570317
Change-Id: Ieb32d04d61742fc1dee2105dd904690d44c46c7b

3 files changed, 54 insertions, 0 deletions

diff --git a/media/libmedia/ICrypto.cpp b/media/libmedia/ICrypto.cpp
index 23308c1..9246a7c 100644
--- a/media/libmedia/ICrypto.cpp
+++ b/media/libmedia/ICrypto.cpp
@@ -35,6 +35,7 @@ enum {
     REQUIRES_SECURE_COMPONENT,
     DECRYPT,
     NOTIFY_RESOLUTION,
+    SET_MEDIADRM_SESSION,
 };
 
 struct BpCrypto : public BpInterface<ICrypto> {
@@ -161,7 +162,28 @@ struct BpCrypto : public BpInterface<ICrypto> {
         remote()->transact(NOTIFY_RESOLUTION, data, &reply);
     }
 
+    virtual status_t setMediaDrmSession(const Vector<uint8_t> &sessionId) {
+        Parcel data, reply;
+        data.writeInterfaceToken(ICrypto::getInterfaceDescriptor());
+
+        writeVector(data, sessionId);
+        remote()->transact(SET_MEDIADRM_SESSION, data, &reply);
+
+        return reply.readInt32();
+    }
+
 private:
+    void readVector(Parcel &reply, Vector<uint8_t> &vector) const {
+        uint32_t size = reply.readInt32();
+        vector.insertAt((size_t)0, size);
+        reply.read(vector.editArray(), size);
+    }
+
+    void writeVector(Parcel &data, Vector<uint8_t> const &vector) const {
+        data.writeInt32(vector.size());
+        data.write(vector.array(), vector.size());
+    }
+
     DISALLOW_EVIL_CONSTRUCTORS(BpCrypto);
 };
 
@@ -169,6 +191,17 @@ IMPLEMENT_META_INTERFACE(Crypto, "android.hardware.ICrypto");
 
 ////////////////////////////////////////////////////////////////////////////////
 
+void BnCrypto::readVector(const Parcel &data, Vector<uint8_t> &vector) const {
+    uint32_t size = data.readInt32();
+    vector.insertAt((size_t)0, size);
+    data.read(vector.editArray(), size);
+}
+
+void BnCrypto::writeVector(Parcel *reply, Vector<uint8_t> const &vector) const {
+    reply->writeInt32(vector.size());
+    reply->write(vector.array(), vector.size());
+}
+
 status_t BnCrypto::onTransact(
     uint32_t code, const Parcel &data, Parcel *reply, uint32_t flags) {
     switch (code) {
@@ -317,6 +350,15 @@ status_t BnCrypto::onTransact(
             return OK;
         }
 
+        case SET_MEDIADRM_SESSION:
+        {
+            CHECK_INTERFACE(IDrm, data, reply);
+            Vector<uint8_t> sessionId;
+            readVector(data, sessionId);
+            reply->writeInt32(setMediaDrmSession(sessionId));
+            return OK;
+        }
+
         default:
             return BBinder::onTransact(code, data, reply, flags);
     }
diff --git a/media/libmediaplayerservice/Crypto.cpp b/media/libmediaplayerservice/Crypto.cpp
index e768772..f639193 100644
--- a/media/libmediaplayerservice/Crypto.cpp
+++ b/media/libmediaplayerservice/Crypto.cpp
@@ -268,4 +268,14 @@ void Crypto::notifyResolution(uint32_t width, uint32_t height) {
     }
 }
 
+status_t Crypto::setMediaDrmSession(const Vector<uint8_t> &sessionId) {
+    Mutex::Autolock autoLock(mLock);
+
+    status_t result = NO_INIT;
+    if (mInitCheck == OK && mPlugin != NULL) {
+        result = mPlugin->setMediaDrmSession(sessionId);
+    }
+    return result;
+}
+
 }  // namespace android
diff --git a/media/libmediaplayerservice/Crypto.h b/media/libmediaplayerservice/Crypto.h
index d5f3c50..99ea95d 100644
--- a/media/libmediaplayerservice/Crypto.h
+++ b/media/libmediaplayerservice/Crypto.h
@@ -47,6 +47,8 @@ struct Crypto : public BnCrypto {
 
     virtual void notifyResolution(uint32_t width, uint32_t height);
 
+    virtual status_t setMediaDrmSession(const Vector<uint8_t> &sessionId);
+
     virtual ssize_t decrypt(
             bool secure,
             const uint8_t key[16],