chromium/third_party/grpc/src/include/grpcpp/security/tls_certificate_provider.h

//
// Copyright 2020 gRPC authors.
//
// 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
//
//     http://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 GRPCPP_SECURITY_TLS_CERTIFICATE_PROVIDER_H
#define GRPCPP_SECURITY_TLS_CERTIFICATE_PROVIDER_H

#include <memory>
#include <vector>

#include <grpc/grpc_security.h>
#include <grpc/grpc_security_constants.h>
#include <grpc/status.h>
#include <grpc/support/log.h>
#include <grpcpp/support/config.h>

namespace grpc {
namespace experimental {

// Interface for a class that handles the process to fetch credential data.
// Implementations should be a wrapper class of an internal provider
// implementation.
class CertificateProviderInterface { … };

// A struct that stores the credential data presented to the peer in handshake
// to show local identity. The private_key and certificate_chain should always
// match.
struct IdentityKeyCertPair { … };

// A basic CertificateProviderInterface implementation that will load credential
// data from static string during initialization. This provider will always
// return the same cert data for all cert names, and reloading is not supported.
class StaticDataCertificateProvider : public CertificateProviderInterface { … };

// A CertificateProviderInterface implementation that will watch the credential
// changes on the file system. This provider will always return the up-to-date
// cert data for all the cert names callers set through |TlsCredentialsOptions|.
// Several things to note:
// 1. This API only supports one key-cert file and hence one set of identity
// key-cert pair, so SNI(Server Name Indication) is not supported.
// 2. The private key and identity certificate should always match. This API
// guarantees atomic read, and it is the callers' responsibility to do atomic
// updates. There are many ways to atomically update the key and certs in the
// file system. To name a few:
//   1)  creating a new directory, renaming the old directory to a new name, and
//   then renaming the new directory to the original name of the old directory.
//   2)  using a symlink for the directory. When need to change, put new
//   credential data in a new directory, and change symlink.
class FileWatcherCertificateProvider final
    : public CertificateProviderInterface { … };

}  // namespace experimental
}  // namespace grpc

#endif  // GRPCPP_SECURITY_TLS_CERTIFICATE_PROVIDER_H