Move encryptor creation out of EncryptorSource::Initialize.

Use EncryptorSource::CreateEncryptor for encryptor creation.
EncryptorSource no longer owns the created encryptor.

Change-Id: I34d1f32262b7692bcb347d3b084fd06cbae7850f

media/base/encryptor_source.cc

@@ -4,8 +4,13 @@
 
 #include "media/base/encryptor_source.h"
 
+#include "media/base/aes_encryptor.h"
+
 namespace {
-const char kWidevineSystemId[] = {0xed, 0xef, 0x8b, 0xa9, 0x79, 0xd6,
+// Generate 64bit IV by default.
+const size_t kDefaultIvSize = 8u;
+
+const uint8 kWidevineSystemId[] = {0xed, 0xef, 0x8b, 0xa9, 0x79, 0xd6,
                                    0x4a, 0xce, 0xa3, 0xc8, 0x27, 0xdc,
                                    0xd5, 0x1d, 0x21, 0xed};
 }  // namespace
@@ -13,10 +18,22 @@ const char kWidevineSystemId[] = {0xed, 0xef, 0x8b, 0xa9, 0x79, 0xd6,
 namespace media {
 
 EncryptorSource::EncryptorSource()
-    : key_system_id_(kWidevineSystemId,
-                     kWidevineSystemId + arraysize(kWidevineSystemId)),
-      clear_milliseconds_(0) {}
+    : iv_size_(kDefaultIvSize),
+      key_system_id_(kWidevineSystemId,
+                     kWidevineSystemId + arraysize(kWidevineSystemId)) {}
 
 EncryptorSource::~EncryptorSource() {}
 
+scoped_ptr<AesCtrEncryptor> EncryptorSource::CreateEncryptor() {
+  scoped_ptr<AesCtrEncryptor> encryptor(new AesCtrEncryptor());
+  const bool initialized =
+      iv_.empty() ? encryptor->InitializeWithRandomIv(key_, iv_size_)
+                  : encryptor->InitializeWithIv(key_, iv_);
+  if (!initialized) {
+    LOG(ERROR) << "Failed to the initialize encryptor.";
+    return scoped_ptr<AesCtrEncryptor>();
+  }
+  return encryptor.Pass();
+}
+
 }  // namespace media

media/base/encryptor_source.h

@@ -15,45 +15,51 @@
 
 namespace media {
 
+class AesCtrEncryptor;
+
 class EncryptorSource {
  public:
   EncryptorSource();
   virtual ~EncryptorSource();
 
+  // Initialize the encryptor source. Calling other public methods of this
+  // class without this method returning Status::OK, results in an undefined
+  // behavior.
   virtual Status Initialize() = 0;
 
-  // Refreshes the encryptor. NOP except for key rotation encryptor source.
+  // Refresh the encryptor. NOP except for key rotation encryptor source.
   // TODO(kqyang): Do we need to pass in duration or fragment number?
   virtual void RefreshEncryptor() {}
 
-  // EncryptorSource retains the ownership of |encryptor_|.
-  AesCtrEncryptor* encryptor() { return encryptor_.get(); }
+  // Create an encryptor from this encryptor source. The encryptor will be
+  // initialized with a random IV of the default size by default. The behavior
+  // can be adjusted using set_iv_size or set_iv (exclusive).
+  scoped_ptr<AesCtrEncryptor> CreateEncryptor();
+
   const std::vector<uint8>& key_id() const { return key_id_; }
   const std::vector<uint8>& key() const { return key_; }
   const std::vector<uint8>& pssh() const { return pssh_; }
-  uint32 clear_milliseconds() const { return clear_milliseconds_; }
   const std::vector<uint8>& key_system_id() const { return key_system_id_; }
+  size_t iv_size() const { return iv_.empty() ? iv_size_ : iv_.size(); }
+
+  // Set IV size. The encryptor will be initialized with a random IV of the
+  // specified size. Mutally exclusive with set_iv.
+  void set_iv_size(size_t iv_size) { iv_size_ = iv_size; }
+  // Set IV. The encryptor will be initialized with the specified IV.
+  // Mutally exclusive with set_iv_size.
+  void set_iv(std::vector<uint8>& iv) { iv_ = iv; }
 
  protected:
-  // EncryptorSource takes ownership of |encryptor|.
-  void set_encryptor(scoped_ptr<AesCtrEncryptor> encryptor) {
-    encryptor_ = encryptor.Pass();
-  }
   void set_key_id(const std::vector<uint8>& key_id) { key_id_ = key_id; }
   void set_key(const std::vector<uint8>& key) { key_ = key; }
   void set_pssh(const std::vector<uint8>& pssh) { pssh_ = pssh; }
-  void set_clear_milliseconds(uint32 clear_milliseconds) {
-    clear_milliseconds_ = clear_milliseconds;
-  }
 
  private:
-  scoped_ptr<AesCtrEncryptor> encryptor_;
   std::vector<uint8> key_id_;
   std::vector<uint8> key_;
   std::vector<uint8> pssh_;
-  // The first |clear_milliseconds_| of the result media should be in the clear
-  // text, i.e. should not be encrypted.
-  uint32 clear_milliseconds_;
+  size_t iv_size_;
+  std::vector<uint8> iv_;
   const std::vector<uint8> key_system_id_;
 
   DISALLOW_COPY_AND_ASSIGN(EncryptorSource);

media/base/fixed_encryptor_source.cc

@@ -6,24 +6,13 @@
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
-#include "media/base/aes_encryptor.h"
-
-namespace {
-// The size of generated IV for this encryptor source.
-const uint8 kIvSize = 8;
-}  // namespace
 
 namespace media {
 
 FixedEncryptorSource::FixedEncryptorSource(const std::string& key_id_hex,
                                            const std::string& key_hex,
-                                           const std::string& pssh_hex,
-                                           uint32 clear_milliseconds)
-    : key_id_hex_(key_id_hex),
-      key_hex_(key_hex),
-      pssh_hex_(pssh_hex) {
-  set_clear_milliseconds(clear_milliseconds);
-}
+                                           const std::string& pssh_hex)
+    : key_id_hex_(key_id_hex), key_hex_(key_hex), pssh_hex_(pssh_hex) {}
 
 FixedEncryptorSource::~FixedEncryptorSource() {}
 
@@ -46,11 +35,6 @@ Status FixedEncryptorSource::Initialize() {
     return Status(error::INVALID_ARGUMENT, "Cannot parse input pssh_hex.");
   }
 
-  scoped_ptr<AesCtrEncryptor> encryptor(new AesCtrEncryptor());
-  if (!encryptor->InitializeWithRandomIv(key, kIvSize))
-    return Status(error::UNKNOWN, "Failed to initialize the encryptor.");
-
-  set_encryptor(encryptor.Pass());
   set_key_id(key_id);
   set_key(key);
   set_pssh(pssh);

media/base/fixed_encryptor_source.h

@@ -15,8 +15,7 @@ class FixedEncryptorSource : public EncryptorSource {
  public:
   FixedEncryptorSource(const std::string& key_id_hex,
                        const std::string& key_hex,
-                       const std::string& pssh_hex,
-                       uint32 clear_milliseconds);
+                       const std::string& pssh_hex);
   virtual ~FixedEncryptorSource();
 
   // EncryptorSource implementation.

media/base/widevine_encryptor_source.cc

@@ -25,9 +25,6 @@
 
 namespace {
 
-// The size of generated IV for this encryptor source.
-const uint8 kIvSize = 8;
-
 bool Base64StringToBytes(const std::string& base64_string,
                          std::vector<uint8>* bytes) {
   DCHECK(bytes);
@@ -117,7 +114,7 @@ bool WidevineEncryptorSource::SetAesSigningKey(const std::string& signer,
   }
 
   scoped_ptr<AesCbcEncryptor> encryptor(new AesCbcEncryptor());
-  if (!encryptor->Initialize(aes_key, iv)) {
+  if (!encryptor->InitializeWithIv(aes_key, iv)) {
     LOG(ERROR) << "Failed to initialize encryptor with key: " << aes_key_hex
                << " iv:" << iv_hex;
     return false;
@@ -166,11 +163,6 @@ Status WidevineEncryptorSource::Initialize() {
                   "Failed to extract encryption key from '" + response + "'.");
   }
 
-  // TODO(kqyang): Move the creation of encryptor to Muxer.
-  scoped_ptr<AesCtrEncryptor> encryptor(new AesCtrEncryptor());
-  CHECK(encryptor->InitializeWithRandomIv(key, kIvSize));
-
-  set_encryptor(encryptor.Pass());
   set_key_id(key_id);
   set_key(key);
   set_pssh(pssh);