crypto/timestamp_read_handler.h

// 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_CRYPTO_TIMESTAMP_READ_HANDLER_H_
#define THIRD_PARTY_CREDENTIO_CRYPTO_TIMESTAMP_READ_HANDLER_H_

#include "absl/status/statusor.h"
#include "absl/strings/string_view.h"
#include "tsp/verified_timestamp.h"

namespace credentio {

// A consumer of RFC3161 TimeStampTokens.
class TimestampReadHandler {
 public:
  // Validates an RFC 3161 TimeStampToken. Checks CMS signature and certificate
  // trustworthiness. Caller must verify that the message imprint of the
  // returned `VerifiedTimestamp` matches the signature to which the timestamp
  // applies.
  //
  // Returns:
  //   - UNAUTHENTICATED if the TSA's certificate cannot be trusted or if the
  //       timestamp's signature is invalid.
  //   - INVALID_ARGUMENT if `cms` cannot be parsed.
  //   - OUT_OF_RANGE if the TSA's certificate was not within its validity
  //       period at the asserted time.
  //   - UNAVAILABLE if the root trust list cannot be accessed (only possible on
  //       platforms where it is not stored in-process.)
  virtual absl::StatusOr<VerifiedTimestamp> VerifyTimestamp(
      absl::string_view cms) const = 0;
  virtual ~TimestampReadHandler() = default;
};

}  // namespace credentio

#endif  // THIRD_PARTY_CREDENTIO_CRYPTO_TIMESTAMP_READ_HANDLER_H_