/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef CTLogVerifier_h

#define CTLogVerifier_h

#include "CTLog.h"

#include "pkix/Input.h"

#include "pkix/pkix.h"

#include "pkix/Result.h"

#include "ScopedNSSTypes.h"

#include "SignedCertificateTimestamp.h"

#include "SignedTreeHead.h"

namespace mozilla { namespace ct {

// Verifies Signed Certificate Timestamps (SCTs) provided by a specific log

// using the public key of that log. Assumes the SCT being verified

// matches the log by log key ID and signature parameters (an error is returned

// otherwise).

// The verification functions return Success if the provided SCT has passed

// verification, ERROR_BAD_SIGNATURE if failed verification, or other result

// on error.

class CTLogVerifier

{

public:

  CTLogVerifier();

  // Initializes the verifier with log-specific information. Only the public

  // key is used for verification, other parameters are purely informational.

  // |subjectPublicKeyInfo| is a DER-encoded SubjectPublicKeyInfo.

  // |operatorId| The numeric ID of the log operator as assigned at

  // https://www.certificate-transparency.org/known-logs .

  // |logStatus| Either "Included" or "Disqualified".

  // |disqualificationTime| Disqualification timestamp (for disqualified logs).

  // An error is returned if |subjectPublicKeyInfo| refers to an unsupported

  // public key.

  pkix::Result Init(pkix::Input subjectPublicKeyInfo,

                    CTLogOperatorId operatorId,

                    CTLogStatus logStatus,

                    uint64_t disqualificationTime);

  // Returns the log's key ID, which is a SHA256 hash of its public key.

  // See RFC 6962, Section 3.2.

  const Buffer& keyId() const { return mKeyId; }

  CTLogOperatorId operatorId() const { return mOperatorId; }

  bool isDisqualified() const { return mDisqualified; }

  uint64_t disqualificationTime() const { return mDisqualificationTime; }

  // Verifies that |sct| contains a valid signature for |entry|.

  // |sct| must be signed by the verifier's log.

  pkix::Result Verify(const LogEntry& entry,

                      const SignedCertificateTimestamp& sct);

  // Verifies the signature in |sth|.

  // |sth| must be signed by the verifier's log.

  pkix::Result VerifySignedTreeHead(const SignedTreeHead& sth);

  // Returns true if the signature and hash algorithms in |signature|

  // match those of the log.

  bool SignatureParametersMatch(const DigitallySigned& signature);

private:

  // Performs the underlying verification using the log's public key. Note

  // that |signature| contains the raw signature data (i.e. without any

  // DigitallySigned struct encoding).

  // Returns Success if passed verification, ERROR_BAD_SIGNATURE if failed

  // verification, or other result on error.

  pkix::Result VerifySignature(pkix::Input data, pkix::Input signature);

  pkix::Result VerifySignature(const Buffer& data, const Buffer& signature);

  // mPublicECKey works around an architectural deficiency in NSS. In the case

  // of EC, if we don't create, import, and cache this key, NSS will import and

  // verify it every signature verification, which is slow. For RSA, this is

  // unused and will be null.

  UniqueSECKEYPublicKey mPublicECKey;

  Buffer mSubjectPublicKeyInfo;

  Buffer mKeyId;

  DigitallySigned::SignatureAlgorithm mSignatureAlgorithm;

  CTLogOperatorId mOperatorId;

  bool mDisqualified;

  uint64_t mDisqualificationTime;

};

} } // namespace mozilla::ct

#endif // CTLogVerifier_h