// Copyright 2026 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

#ifndef THIRD_PARTY_CREDENTIO_COSE_VERIFIER_H_
#define THIRD_PARTY_CREDENTIO_COSE_VERIFIER_H_

#include <memory>

#include "absl/base/nullability.h"
#include "absl/strings/string_view.h"
#include "absl/time/clock_interface.h"
#include "crypto/crypto_read_handler.h"
#include "proto/cose_verification_result.pb.h"
#include "proto/signature_info.pb.h"

namespace credentio {

class CoseVerifier {
 public:
  virtual ~CoseVerifier() = default;

  // Validates the provided COSE_SIGN1 signature (`signature`) against the
  // provided expected data (`data`).
  // Returns a CoseVerificationResult, which contains the SignatureInfo
  // if the signature is valid, and the validation statuses encountered
  // during verification.
  virtual CoseVerificationResult Verify(absl::string_view signature,
                                        absl::string_view data) const = 0;
};

// Whether claim signatures (by the leaf certificate holder) are checked.
// This does not affect trust chain validation.
enum class CoseVerifierSignatureChecks { kDisabledForTest, kEnabled };

// Whether OCSP revocation checks are performed.
// This does not affect trust chain validation.
enum class CoseVerifierRevocationChecks { kDisabledForTest, kEnabled };

struct CoseVerifierOptions {
  std::unique_ptr<CryptoReadHandler> absl_nonnull crypto_read_handler;
  // Clock to use by the verifier.
  absl::Clock* clock = &absl::Clock::GetRealClock();
  // Option to enable/disable signature checks.
  CoseVerifierSignatureChecks signature_checks =
      CoseVerifierSignatureChecks::kEnabled;
  // Option to enable/disable OCSP revocation checks.
  CoseVerifierRevocationChecks revocation_checks =
      CoseVerifierRevocationChecks::kEnabled;
};

// Creates a COSE verifier.
std::unique_ptr<CoseVerifier> CreateCoseVerifier(
    CoseVerifierOptions options = {});

}  // namespace credentio

#endif  // THIRD_PARTY_CREDENTIO_COSE_VERIFIER_H_