Change WebM parser to treat IVs from encrypted WebM as raw data.

media/crypto/aes_decryptor_unittest.cc

Index: media/crypto/aes_decryptor_unittest.cc
diff --git a/media/crypto/aes_decryptor_unittest.cc b/media/crypto/aes_decryptor_unittest.cc
index 1b9d52e51b24be3322e45c14441b07f60adf2a8c..bb6ed2f176a78efd366769c67521118f6cb1ec4e 100644
--- a/media/crypto/aes_decryptor_unittest.cc
+++ b/media/crypto/aes_decryptor_unittest.cc
@@ -7,7 +7,6 @@
 
 #include "base/basictypes.h"
 #include "base/bind.h"
-#include "base/sys_byteorder.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/decrypt_config.h"
 #include "media/base/mock_filters.h"
@@ -92,8 +91,8 @@ const WebmEncryptedData kWebmEncryptedFrames[] = {
       0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40
       }, 16,
     // encrypted_data
-    { 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-      0x01, 0x9c, 0x71, 0x26, 0x57, 0x3e, 0x25, 0x37,
+    { 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+      0x00, 0x9c, 0x71, 0x26, 0x57, 0x3e, 0x25, 0x37,
       0xf7, 0x31, 0x81, 0x19, 0x64, 0xce, 0xbc
       }, 23
   },
@@ -161,16 +160,16 @@ static const SubsampleEntry kSubsampleEntries[] = {
   { 1, 0 }
 };
 
-// Returns a 16 byte CTR counter block. The CTR counter block format is a
-// CTR IV appended with a CTR block counter. |iv| is a CTR IV. |iv_size| is
-// the size of |iv| in bytes.
+// Generates a 16 byte CTR counter block. The CTR counter block format is a
+// CTR IV appended with a CTR block counter. |iv| is an 8 byte CTR IV.
+// |iv_size| is the size of |iv| in btyes. Returns a string of
+// kDecryptionKeySize bytes.
 static std::string GenerateCounterBlock(const uint8* iv, int iv_size) {
-  const int kDecryptionKeySize = 16;
   CHECK_GT(iv_size, 0);
-  CHECK_LE(iv_size, kDecryptionKeySize);
+  CHECK_LE(iv_size, DecryptConfig::kDecryptionKeySize);
 
   std::string counter_block(reinterpret_cast<const char*>(iv), iv_size);
-  counter_block.append(kDecryptionKeySize - iv_size, 0);
+  counter_block.append(DecryptConfig::kDecryptionKeySize - iv_size, 0);
   return counter_block;
 }
 
@@ -189,7 +188,7 @@ static scoped_refptr<DecoderBuffer> CreateWebMEncryptedBuffer(
   CHECK(encrypted_buffer);
 
   uint8 signal_byte = data[0];
-  int data_offset = sizeof(signal_byte);
+  int data_offset = kWebMSignalByteSize;

[xhwang, 2012/10/15 20:09:04]

nit: dcheck that kWebMSignalByteSize == 1 before we do "uint8 signal_byte =
data[0];"?

[fgalligan1, 2012/10/15 21:07:52]

Done.

 
   // Setting the DecryptConfig object of the buffer while leaving the
   // initialization vector empty will tell the decryptor that the frame is
@@ -197,12 +196,8 @@ static scoped_refptr<DecoderBuffer> CreateWebMEncryptedBuffer(
   std::string counter_block_str;
 
   if (signal_byte & kWebMFlagEncryptedFrame) {
-    uint64 network_iv;
-    memcpy(&network_iv, data + data_offset, sizeof(network_iv));
-    const uint64 iv = base::NetToHost64(network_iv);
-    counter_block_str =
-        GenerateCounterBlock(reinterpret_cast<const uint8*>(&iv), sizeof(iv));
-    data_offset += sizeof(iv);
+    counter_block_str = GenerateCounterBlock(data + data_offset, kWebMIvSize);
+    data_offset += kWebMIvSize;
   }
 
   encrypted_buffer->SetDecryptConfig(