Use 'pssh' data to determine key_id properly

media/cdm/cenc_utils_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/cdm/cenc_utils.h"
 
 #include "base/logging.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace media {
@@ skipping 162 matching lines @@
   std::vector<uint8_t> key1_;
   std::vector<uint8_t> key2_;
   std::vector<uint8_t> key3_;
   std::vector<uint8_t> key4_;
   std::vector<uint8_t> common_system_system_id_;
 };
 
 TEST_F(CencUtilsTest, EmptyPSSH) {
   KeyIdList key_ids;
   EXPECT_TRUE(ValidatePsshInput(std::vector<uint8_t>()));
-  EXPECT_TRUE(GetKeyIdsForCommonSystemId(std::vector<uint8_t>(), &key_ids));
-  EXPECT_EQ(0u, key_ids.size());
+  EXPECT_FALSE(GetKeyIdsForCommonSystemId(std::vector<uint8_t>(), &key_ids));
 }
 
 TEST_F(CencUtilsTest, PSSHVersion0) {
   std::vector<uint8_t> box = MakePSSHBox(0);
   KeyIdList key_ids;
   EXPECT_TRUE(ValidatePsshInput(box));
-  EXPECT_TRUE(GetKeyIdsForCommonSystemId(box, &key_ids));
-  EXPECT_EQ(0u, key_ids.size());
+  EXPECT_FALSE(GetKeyIdsForCommonSystemId(box, &key_ids));
 }
 
 TEST_F(CencUtilsTest, PSSHVersion1WithNoKeys) {
   std::vector<uint8_t> box = MakePSSHBox(1);
   KeyIdList key_ids;
   EXPECT_TRUE(ValidatePsshInput(box));
-  EXPECT_TRUE(GetKeyIdsForCommonSystemId(box, &key_ids));
-  EXPECT_EQ(0u, key_ids.size());
+  EXPECT_FALSE(GetKeyIdsForCommonSystemId(box, &key_ids));
 }
 
 TEST_F(CencUtilsTest, PSSHVersion1WithOneKey) {
   std::vector<uint8_t> box = MakePSSHBox(1, Key1());
   KeyIdList key_ids;
   EXPECT_TRUE(ValidatePsshInput(box));
   EXPECT_TRUE(GetKeyIdsForCommonSystemId(box, &key_ids));
   EXPECT_EQ(1u, key_ids.size());
   EXPECT_EQ(key_ids[0], Key1());
 }
@@ skipping 40 matching lines @@
   std::vector<uint8_t> box = MakePSSHBox(1, Key1(), Key2());
   std::vector<uint8_t> box1 = MakePSSHBox(1, Key3());
   std::vector<uint8_t> box2 = MakePSSHBox(1, Key4());
 
   // Concatentate box1 and box2 onto end of box.
   box.insert(box.end(), box1.begin(), box1.end());
   box.insert(box.end(), box2.begin(), box2.end());
 
   KeyIdList key_ids;
   EXPECT_TRUE(ValidatePsshInput(box));
+  // TODO(jrummell): GetKeyIdsForCommonSystemId() returns the key IDs out of
+  // all matching boxes. It should only return the key IDs from the first
+  // matching box.
   EXPECT_TRUE(GetKeyIdsForCommonSystemId(box, &key_ids));
   EXPECT_EQ(4u, key_ids.size());
   EXPECT_EQ(key_ids[0], Key1());
   EXPECT_EQ(key_ids[1], Key2());
   EXPECT_EQ(key_ids[2], Key3());
   EXPECT_EQ(key_ids[3], Key4());
 }
 
-TEST_F(CencUtilsTest, InvalidPSSH) {
+TEST_F(CencUtilsTest, PsshBoxSmallerThanSize) {
   std::vector<uint8_t> box = MakePSSHBox(1, Key1(), Key2());
   KeyIdList key_ids;
+
+  // Tries every size less than the actual size.

[ddorwin, 2015/06/18 01:02:15]

This was my previous interpretation (perhaps based on the comment below), but I
think it is the opposite that you are testing.

[jrummell, 2015/06/18 02:04:12]

Modified.

   for (size_t i = 1; i < box.size(); ++i) {
-    // Modify size of data passed to be less than real size.
+    // Modify size of box passed to be less than real size.

[ddorwin, 2015/06/18 01:02:15]

"Modify size of box" confused me as modifying the size value. Perhaps "Truncate
the box to be..."

[jrummell, 2015/06/18 02:04:12]

Done.

     std::vector<uint8_t> truncated(&box[0], &box[0] + i);
     EXPECT_FALSE(ValidatePsshInput(truncated)) << "Failed for length " << i;
     EXPECT_FALSE(GetKeyIdsForCommonSystemId(truncated, &key_ids));
-    // Modify starting point.
+  }
+}
+
+TEST_F(CencUtilsTest, PsshBoxLargerThanSize) {
+  std::vector<uint8_t> box = MakePSSHBox(1, Key1(), Key2());
+  KeyIdList key_ids;
+
+  // Add 20 additional bytes to |box|.
+  size_t original_size = box.size();
+  for (size_t i = 0; i < 20; ++i)
+    box.push_back(i);
+
+  // Tries every size greater than |original_size|.
+  for (size_t i = original_size + 1; i < box.size(); ++i) {
+    // Modify size of box passed to be less than current size.
+    std::vector<uint8_t> truncated(&box[0], &box[0] + i);
+    EXPECT_FALSE(ValidatePsshInput(truncated)) << "Failed for length " << i;
+    EXPECT_FALSE(GetKeyIdsForCommonSystemId(truncated, &key_ids));
+  }
+}
+
+TEST_F(CencUtilsTest, PsshBoxOffsetFromStart) {

[ddorwin, 2015/06/18 01:02:14]

You could probably just test that anything that doesn't start with 'pssh' fails.

[jrummell, 2015/06/18 02:04:12]

Removed as testing non-pssh boxes is done in
https://codereview.chromium.org/1189073004/.

+  std::vector<uint8_t> box = MakePSSHBox(1, Key1(), Key2());
+  KeyIdList key_ids;
+
+  // Try every possible starting position.
+  for (size_t i = 1; i < box.size(); ++i) {
+    // Modify starting point of box. This should always fail as the modified
+    // box won't be a properly formatted 'pssh' box.
     std::vector<uint8_t> changed_offset(&box[i], &box[i] + box.size() - i);
     EXPECT_FALSE(ValidatePsshInput(changed_offset)) << "Failed for offset "
                                                     << i;
     EXPECT_FALSE(GetKeyIdsForCommonSystemId(changed_offset, &key_ids));
   }
 }
 
-TEST_F(CencUtilsTest, InvalidSystemID) {
+TEST_F(CencUtilsTest, UnrecognizedSystemID) {
   std::vector<uint8_t> box = MakePSSHBox(1, Key1(), Key2());
 
   // Modify the System ID.
   ++box[20];
 
   KeyIdList key_ids;
-  EXPECT_TRUE(GetKeyIdsForCommonSystemId(box, &key_ids));
-  EXPECT_EQ(0u, key_ids.size());
+  EXPECT_FALSE(GetKeyIdsForCommonSystemId(box, &key_ids));
 }
 
 TEST_F(CencUtilsTest, InvalidFlags) {
   std::vector<uint8_t> box = MakePSSHBox(1, Key1(), Key2());
 
   // Modify flags.
   box[10] = 3;
 
   KeyIdList key_ids;
   EXPECT_FALSE(GetKeyIdsForCommonSystemId(box, &key_ids));
@@ skipping 17 matching lines @@
   };
 
   KeyIdList key_ids;
   EXPECT_TRUE(
       ValidatePsshInput(std::vector<uint8_t>(data, data + arraysize(data))));
   EXPECT_TRUE(GetKeyIdsForCommonSystemId(
       std::vector<uint8_t>(data, data + arraysize(data)), &key_ids));
   EXPECT_EQ(2u, key_ids.size());
 }
 
-TEST_F(CencUtilsTest, NoSize) {
+TEST_F(CencUtilsTest, SizeIsZero) {
   const uint8_t data[] = {
       0x00, 0x00, 0x00, 0x00,                          // size = 0
       0x70, 0x73, 0x73, 0x68,                          // 'pssh'
       0x01,                                            // version
       0x00, 0x00, 0x00,                                // flags
       0x10, 0x77, 0xEF, 0xEC, 0xC0, 0xB2, 0x4D, 0x02,  // SystemID
       0xAC, 0xE3, 0x3C, 0x1E, 0x52, 0xE2, 0xFB, 0x4B,
       0x00, 0x00, 0x00, 0x02,                          // key count
       0x7E, 0x57, 0x1D, 0x03, 0x7E, 0x57, 0x1D, 0x03,  // key1
       0x7E, 0x57, 0x1D, 0x03, 0x7E, 0x57, 0x1D, 0x03,
@@ skipping 21 matching lines @@
       0xAC, 0xE3, 0x3C, 0x1E, 0x52, 0xE2, 0xFB, 0x4B,
       0x00, 0x00, 0x00, 0x02,                          // key count
       0x7E, 0x57, 0x1D, 0x03, 0x7E, 0x57, 0x1D, 0x03,  // key1
       0x7E, 0x57, 0x1D, 0x03, 0x7E, 0x57, 0x1D, 0x03,
       0x7E, 0x57, 0x1D, 0x04, 0x7E, 0x57, 0x1D, 0x04,  // key2
       0x7E, 0x57, 0x1D, 0x04, 0x7E, 0x57, 0x1D, 0x04,
       0x00, 0x00, 0x00, 0x00  // datasize
   };
 
   KeyIdList key_ids;
+  // These calls fail as the box size is huge (0xffffffffffffffff) and there
+  // is not enough bytes in |data|.
   EXPECT_FALSE(
       ValidatePsshInput(std::vector<uint8_t>(data, data + arraysize(data))));
   EXPECT_FALSE(GetKeyIdsForCommonSystemId(
       std::vector<uint8_t>(data, data + arraysize(data)), &key_ids));
 }
 
 TEST_F(CencUtilsTest, GetPsshData_Version0) {
   const uint8_t data_bytes[] = {0x01, 0x02, 0x03, 0x04};
   std::vector<uint8_t> pssh_data;
 
@@ skipping 123 matching lines @@
   std::vector<uint8_t> box2 = MakePSSHBox(0);
   std::vector<uint8_t> data2(data2_bytes, data2_bytes + arraysize(data2_bytes));
   AppendData(box2, data2);
 
   box1.insert(box1.end(), box2.begin(), box2.end());
   EXPECT_TRUE(GetPsshData(box1, CommonSystemSystemId(), &pssh_data));
   EXPECT_EQ(data1, pssh_data);
   EXPECT_NE(data2, pssh_data);
 }
 }  // namespace media