Add Bcc validator to oemcrypto util and unit tests

A Bcc validator that can parse and validate BCC. This is to support better
prov40 unit tests regarding OEMCrypto_GetBootCertificateChain() later.

Test: opk_ta_p40
Bug: 300304834
Bug: 307968622
Change-Id: I3cfdad9f1891c6abc83051af1d80a20e0adeb58b

libwvdrmengine/oemcrypto/util/src/cbor_validator.cpp

@@ -0,0 +1,113 @@
+// Copyright 2023 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine License
+// Agreement.
+//
+//  Reference implementation utilities of OEMCrypto APIs
+//
+#include "cbor_validator.h"
+
+#include <stddef.h>
+
+#include <cstdint>
+#include <iomanip>
+#include <iostream>
+#include <string>
+#include <vector>
+
+namespace wvoec {
+namespace util {
+std::string CppborMajorTypeToString(cppbor::MajorType type) {
+  switch (type) {
+    case cppbor::UINT:
+      return "UINT";
+    case cppbor::NINT:
+      return "NINT";
+    case cppbor::BSTR:
+      return "BSTR";
+    case cppbor::TSTR:
+      return "TSTR";
+    case cppbor::ARRAY:
+      return "ARRAY";
+    case cppbor::MAP:
+      return "MAP";
+    case cppbor::SEMANTIC:
+      return "SEMANTIC";
+    case cppbor::SIMPLE:
+      return "SIMPLE";
+  }
+  return "undefined type";
+}
+
+std::string CborMessageStatusToString(CborMessageStatus status) {
+  switch (status) {
+    case kCborUninitialized:
+      return "Uninitialized";
+    case kCborParseOk:
+      return "ParseOk";
+    case kCborParseError:
+      return "ParseError";
+    case kCborValidateOk:
+      return "ValidateOk";
+    case kCborValidateWarning:
+      return "ValidateWarning";
+    case kCborValidateError:
+      return "ValidateError";
+    case kCborValidateFatal:
+      return "ValidateFatal";
+  }
+  return "undefined status";
+}
+
+void CborValidator::Reset() {
+  message_status_ = kCborUninitialized;
+  parse_result_ = {nullptr, nullptr, ""};
+  validate_messages_.clear();
+}
+
+CborMessageStatus CborValidator::Parse(const std::vector<uint8_t>& cbor) {
+  Reset();
+  parse_result_ = cppbor::parse(cbor);
+  message_status_ =
+      (std::get<0>(parse_result_) && std::get<2>(parse_result_).empty())
+          ? kCborParseOk
+          : kCborParseError;
+  return message_status_;
+}
+
+const cppbor::ParseResult* CborValidator::GetParseResult() const {
+  if (message_status_ == kCborUninitialized) {
+    return nullptr;
+  }
+  return &parse_result_;
+}
+
+std::string CborValidator::GetRawMessage() const {
+  if (message_status_ == kCborUninitialized ||
+      message_status_ == kCborParseError) {
+    return std::string();
+  }
+  const cppbor::Item* parsed_item = std::get<0>(parse_result_).get();
+  if (parsed_item == nullptr) {
+    return "<null>";
+  }
+  return cppbor::prettyPrint(parsed_item);
+}
+
+CborMessageStatus CborValidator::Validate() {
+  if (message_status_ != kCborParseOk) return message_status_;
+  // No other validations to be done than Parse() being successful.
+  AddValidationMessage(kCborValidateOk, "No validations are done.");
+  return message_status_;
+}
+
+std::string CborValidator::GetFormattedMessage() const {
+  return GetRawMessage();
+}
+
+void CborValidator::AddValidationMessage(CborMessageStatus status,
+                                         const std::string& msg) {
+  validate_messages_.push_back({status, msg});
+  if (status > message_status_) message_status_ = status;
+}
+}  // namespace util
+}  // namespace wvoec