Added unittests for WV CRC-32 implementation.

[ Merge of http://go/wvgerrit/115549 ]

Our WV CRC-32 implementation is for CRC-32/MPEG-2 (rather than the
documented CRC-32-IEEE).  The OEMCrypto document has been updated to
reflect the reference implementation.

Test: oemcrypto_partner_tests
Bug: 135283522
Change-Id: Iea8fc4ec500aec96bdb27102c51dfcca77d7bffb

libwvdrmengine/oemcrypto/ref/src/wvcrc.cpp

@@ -2,7 +2,7 @@
 // source code may only be used and distributed under the Widevine Master
 // License Agreement.
 //
-// Compute CRC32 Checksum. Needed for verification of WV Keybox.
+// Compute CRC32/MPEG2 Checksum. Needed for verification of WV Keybox.
 //
 #include "platform.h"
 #include "wvcrc32.h"

libwvdrmengine/oemcrypto/ref/test/oemcrypto_wvcrc32_unittest.cpp

@@ -0,0 +1,74 @@
+// Copyright 2021 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine License
+// Agreement.
+//
+//  Reference implementation of OEMCrypto APIs
+//
+#include <gtest/gtest.h>
+
+#include "wvcrc32.h"
+
+namespace wvoec_ref {
+
+uint32_t ComputeCrc32(const std::string& s) {
+  return wvcrc32(reinterpret_cast<const uint8_t*>(s.data()), s.size());
+}
+
+uint32_t ComputeCrc32Cont(const std::string& s, uint32_t prev_crc) {
+  return wvcrc32Cont(reinterpret_cast<const uint8_t*>(s.data()), s.size(),
+                     prev_crc);
+}
+
+TEST(OEMCryptoWvCrc32Test, BasicTest) {
+  EXPECT_EQ(0xF88AC628, ComputeCrc32("abcdefg"));
+  EXPECT_EQ(0xDF520F72, ComputeCrc32("Widevine"));
+  EXPECT_EQ(0x0376E6E7, ComputeCrc32("123456789"));
+  EXPECT_EQ(0xBA62119E,
+            ComputeCrc32("The quick brown fox jumps over the lazy dog"));
+}
+
+TEST(OEMCryptoWvCrc32Test, StreamTest) {
+  const std::vector<std::string> parts = {"The ",  "quick",   " brown ",
+                                          "fox",   " jumps ", "over",
+                                          " the ", "lazy",    " dog"};
+  uint32_t crc = wvcrc32Init();
+  for (const auto& part : parts) {
+    crc = ComputeCrc32Cont(part, crc);
+  }
+  EXPECT_EQ(0xBA62119E, crc);
+}
+
+TEST(OEMCryptoWvCrc32Test, Keybox) {
+  // clang-format off
+  const uint8_t kKeyboxData[128] = {
+    // deviceID = WidevineCRCTestKeyBox
+    0x57, 0x69, 0x64, 0x65, 0x76, 0x69, 0x6e, 0x65,
+    0x43, 0x52, 0x43, 0x54, 0x65, 0x73, 0x74, 0x4b,
+    0x65, 0x79, 0x62, 0x6f, 0x78, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    // key = random
+    0x8a, 0x7c, 0xda, 0x3e, 0x09, 0xd9, 0x8e, 0xd5,
+    0x47, 0x47, 0x00, 0x84, 0x5a, 0x1f, 0x52, 0xd4,
+    // data = random
+    0x98, 0xa5, 0x00, 0x19, 0x8b, 0xfe, 0x54, 0xfd,
+    0xca, 0x4d, 0x26, 0xa3, 0xfa, 0xaa, 0x3b, 0x6c,
+    0x35, 0xfe, 0x03, 0x7c, 0xbf, 0x35, 0xba, 0xce,
+    0x31, 0xb5, 0x1e, 0x3c, 0x49, 0xd6, 0x3f, 0x9c,
+    0x3a, 0xde, 0x9b, 0x58, 0xcc, 0x54, 0x8d, 0xc0,
+    0x4b, 0x04, 0xcc, 0xee, 0xae, 0x4d, 0x9f, 0x90,
+    0xd3, 0xf3, 0xfe, 0x23, 0x26, 0x13, 0x56, 0x80,
+    0xe4, 0x3b, 0x79, 0x22, 0x69, 0x5d, 0xd6, 0xb7,
+    0xa0, 0x0e, 0x7e, 0x07, 0xcd, 0x1a, 0x15, 0xca,
+    // magic
+    'k', 'b', 'o', 'x',
+    // crc
+    0x09, 0x7b, 0x7e, 0xcc
+  };
+  // clang-format on
+  const uint32_t crc_computed = wvcrc32n(kKeyboxData, 124);
+  uint32_t crc_current;
+  memcpy(&crc_current, &kKeyboxData[124], 4);
+  EXPECT_EQ(crc_computed, crc_current);
+}
+
+}  // namespace wvoec_ref