1 //
2 //
3 // Copyright 2019 gRPC authors.
4 //
5 // Licensed under the Apache License, Version 2.0 (the "License");
6 // you may not use this file except in compliance with the License.
7 // You may obtain a copy of the License at
8 //
9 //     http://www.apache.org/licenses/LICENSE-2.0
10 //
11 // Unless required by applicable law or agreed to in writing, software
12 // distributed under the License is distributed on an "AS IS" BASIS,
13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 // See the License for the specific language governing permissions and
15 // limitations under the License.
16 //
17 //
18 
19 #ifndef GRPCPP_SECURITY_TLS_CREDENTIALS_OPTIONS_H
20 #define GRPCPP_SECURITY_TLS_CREDENTIALS_OPTIONS_H
21 
22 #include <memory>
23 #include <vector>
24 
25 #include <grpc/grpc_security.h>
26 #include <grpc/grpc_security_constants.h>
27 #include <grpc/status.h>
28 #include <grpc/support/log.h>
29 #include <grpcpp/security/tls_certificate_provider.h>
30 #include <grpcpp/security/tls_certificate_verifier.h>
31 #include <grpcpp/support/config.h>
32 
33 namespace grpc {
34 namespace experimental {
35 
36 // Base class of configurable options specified by users to configure their
37 // certain security features supported in TLS. It is used for experimental
38 // purposes for now and it is subject to change.
39 class TlsCredentialsOptions {
40  public:
41   // Constructor for base class TlsCredentialsOptions.
42   //
43   // @param certificate_provider the provider which fetches TLS credentials that
44   // will be used in the TLS handshake
45   TlsCredentialsOptions();
46   // ---- Setters for member fields ----
47   // Sets the certificate provider used to store root certs and identity certs.
48   void set_certificate_provider(
49       std::shared_ptr<CertificateProviderInterface> certificate_provider);
50   // Watches the updates of root certificates with name |root_cert_name|.
51   // If used in TLS credentials, setting this field is optional for both the
52   // client side and the server side.
53   // If this is not set on the client side, we will use the root certificates
54   // stored in the default system location, since client side must provide root
55   // certificates in TLS(no matter single-side TLS or mutual TLS).
56   // If this is not set on the server side, we will not watch any root
57   // certificate updates, and assume no root certificates needed for the server
58   // (in the one-side TLS scenario, the server is not required to provide root
59   // certs). We don't support default root certs on server side.
60   void watch_root_certs();
61   // Sets the name of root certificates being watched, if |watch_root_certs| is
62   // called. If not set, an empty string will be used as the name.
63   //
64   // @param root_cert_name the name of root certs being set.
65   void set_root_cert_name(const std::string& root_cert_name);
66   // Watches the updates of identity key-cert pairs with name
67   // |identity_cert_name|. If used in TLS credentials, it is required to be set
68   // on the server side, and optional for the client side(in the one-side
69   // TLS scenario, the client is not required to provide identity certs).
70   void watch_identity_key_cert_pairs();
71   // Sets the name of identity key-cert pairs being watched, if
72   // |watch_identity_key_cert_pairs| is called. If not set, an empty string will
73   // be used as the name.
74   //
75   // @param identity_cert_name the name of identity key-cert pairs being set.
76   void set_identity_cert_name(const std::string& identity_cert_name);
77   // Sets the Tls session key logging configuration. If not set, tls
78   // session key logging is disabled. Note that this should be used only for
79   // debugging purposes. It should never be used in a production environment
80   // due to security concerns.
81   //
82   // @param tls_session_key_log_file_path: Path where tls session keys would
83   // be logged.
84   void set_tls_session_key_log_file_path(
85       const std::string& tls_session_key_log_file_path);
86   // Sets the certificate verifier used to perform post-handshake peer identity
87   // checks.
88   void set_certificate_verifier(
89       std::shared_ptr<CertificateVerifier> certificate_verifier);
90   // Sets the options of whether to check the hostname of the peer on a per-call
91   // basis. This is usually used in a combination with virtual hosting at the
92   // client side, where each individual call on a channel can have a different
93   // host associated with it.
94   // This check is intended to verify that the host specified for the individual
95   // call is covered by the cert that the peer presented.
96   // We will perform such checks by default. This should be disabled if
97   // verifiers other than the host name verifier is used.
98   void set_check_call_host(bool check_call_host);
99 
100   // TODO(zhenlian): This is an experimental API is likely to change in the
101   // future. Before de-experiementalizing, verify the API is up to date.
102   // If set, gRPC will read all hashed x.509 CRL files in the directory and
103   // enforce the CRL files on all TLS handshakes. Only supported for OpenSSL
104   // version > 1.1.
105   void set_crl_directory(const std::string& path);
106 
107   // ----- Getters for member fields ----
108   // Get the internal c options. This function shall be used only internally.
c_credentials_options()109   grpc_tls_credentials_options* c_credentials_options() const {
110     return c_credentials_options_;
111   }
112 
113  private:
114   std::shared_ptr<CertificateProviderInterface> certificate_provider_;
115   std::shared_ptr<CertificateVerifier> certificate_verifier_;
116   grpc_tls_credentials_options* c_credentials_options_ = nullptr;
117 };
118 
119 // Contains configurable options on the client side.
120 // Client side doesn't need to always use certificate provider. When the
121 // certificate provider is not set, we will use the root certificates stored
122 // in the system default locations, and assume client won't provide any
123 // identity certificates(single side TLS).
124 // It is used for experimental purposes for now and it is subject to change.
125 class TlsChannelCredentialsOptions final : public TlsCredentialsOptions {
126  public:
127   // Sets the decision of whether to do a crypto check on the server certs.
128   // The default is true.
129   void set_verify_server_certs(bool verify_server_certs);
130 
131  private:
132 };
133 
134 // Contains configurable options on the server side.
135 // It is used for experimental purposes for now and it is subject to change.
136 class TlsServerCredentialsOptions final : public TlsCredentialsOptions {
137  public:
138   // Server side is required to use a provider, because server always needs to
139   // use identity certs.
TlsServerCredentialsOptions(std::shared_ptr<CertificateProviderInterface> certificate_provider)140   explicit TlsServerCredentialsOptions(
141       std::shared_ptr<CertificateProviderInterface> certificate_provider)
142       : TlsCredentialsOptions() {
143     set_certificate_provider(certificate_provider);
144   }
145 
146   // Sets option to request the certificates from the client.
147   // The default is GRPC_SSL_DONT_REQUEST_CLIENT_CERTIFICATE.
148   void set_cert_request_type(
149       grpc_ssl_client_certificate_request_type cert_request_type);
150 
151   // Sets whether or not a TLS server should send a list of CA names in the
152   // ServerHello. This list of CA names is read from the server's trust bundle,
153   // so that the client can use this list as a hint to know which certificate it
154   // should send to the server.
155   //
156   // By default, this option is turned off.
157   //
158   // WARNING: This API is extremely dangerous and should not be used. If the
159   // server's trust bundle is too large, then the TLS server will be unable to
160   // form a ServerHello, and hence will be unusable.
161   void set_send_client_ca_list(bool send_client_ca_list);
162 
163  private:
164 };
165 
166 }  // namespace experimental
167 }  // namespace grpc
168 
169 #endif  // GRPCPP_SECURITY_TLS_CREDENTIALS_OPTIONS_H
170