Widevine MediaCas client code that works with Android R

oemcrypto/ref/src/oemcrypto_keybox_ref.cpp

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+// Copyright 2018 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine Master
+// License Agreement.
+//
+//  Reference implementation of OEMCrypto APIs
+//
+#include "oemcrypto_keybox_ref.h"
+
+#include <string.h>
+
+#include <cstdint>
+#include <string>
+
+#include "log.h"
+#include "oemcrypto_types.h"
+#include "platform.h"
+#include "wvcrc32.h"
+
+namespace wvoec_ref {
+
+WvKeybox::WvKeybox() : loaded_(false) {
+  static std::string fake_device_id = "device_with_no_keybox";
+  device_id_.assign(fake_device_id.begin(), fake_device_id.end());
+}
+
+KeyboxError WvKeybox::Validate() {
+  if (!loaded_) {
+    LOGE("[KEYBOX NOT LOADED]");
+    return OTHER_ERROR;
+  }
+  if (strncmp(reinterpret_cast<char*>(magic_), "kbox", 4) != 0) {
+    LOGE("[KEYBOX HAS BAD MAGIC]");
+    return BAD_MAGIC;
+  }
+  uint32_t crc_computed;
+  uint32_t crc_stored;
+  uint8_t* crc_stored_bytes = (uint8_t*)&crc_stored;
+  memcpy(crc_stored_bytes, crc_, sizeof(crc_));
+  wvoec::WidevineKeybox keybox;
+  memset(&keybox, 0, sizeof(keybox));
+  memcpy(keybox.device_id_, &device_id_[0], device_id_.size());
+  memcpy(keybox.device_key_, &device_key_[0], sizeof(keybox.device_key_));
+  memcpy(keybox.data_, key_data_, sizeof(keybox.data_));
+  memcpy(keybox.magic_, magic_, sizeof(keybox.magic_));
+
+  crc_computed = ntohl(wvcrc32(reinterpret_cast<uint8_t*>(&keybox),
+                               sizeof(keybox) - 4));  // Drop last 4 bytes.
+  if (crc_computed != crc_stored) {
+    LOGE("[KEYBOX CRC problem: computed = %08x,  stored = %08x]\n",
+         crc_computed, crc_stored);
+    return BAD_CRC;
+  }
+  return NO_ERROR;
+}
+
+bool WvKeybox::InstallKeybox(const uint8_t* buffer, size_t keyBoxLength) {
+  if (keyBoxLength != 128) {
+    return false;
+  }
+  const wvoec::WidevineKeybox* keybox =
+      reinterpret_cast<const wvoec::WidevineKeybox*>(buffer);
+  size_t device_id_length =
+      strnlen(reinterpret_cast<const char*>(keybox->device_id_), 32);
+  device_id_.assign(keybox->device_id_, keybox->device_id_ + device_id_length);
+  device_key_.assign(keybox->device_key_,
+                     keybox->device_key_ + sizeof(keybox->device_key_));
+  memcpy(key_data_, keybox->data_, sizeof(keybox->data_));
+  memcpy(magic_, keybox->magic_, sizeof(keybox->magic_));
+  memcpy(crc_, keybox->crc_, sizeof(keybox->crc_));
+  loaded_ = true;
+  return true;
+}
+
+}  // namespace wvoec_ref