Add various options to verify ssl/tls client cert including letting the

application handle the authentication.

3 files changed, 140 insertions, 27 deletions

diff --git a/include/grpc++/security/server_credentials.h b/include/grpc++/security/server_credentials.h
index 5a9f8a42e2..229bab8d84 100644
--- a/include/grpc++/security/server_credentials.h
+++ b/include/grpc++/security/server_credentials.h
@@ -39,6 +39,7 @@
 
 #include <grpc++/security/auth_metadata_processor.h>
 #include <grpc++/support/config.h>
+#include <grpc/grpc_security_constants.h>
 
 struct grpc_server;
 
@@ -69,7 +70,13 @@ class ServerCredentials {
 
 /// Options to create ServerCredentials with SSL
 struct SslServerCredentialsOptions {
-  SslServerCredentialsOptions() : force_client_auth(false) {}
+  // Deprecated
+  SslServerCredentialsOptions()
+      : force_client_auth(false),
+        client_certificate_request(GRPC_SSL_DONT_REQUEST_CLIENT_CERTIFICATE) {}
+  SslServerCredentialsOptions(
+      grpc_ssl_client_certificate_request_type request_type)
+      : force_client_auth(false), client_certificate_request(request_type) {}
 
   struct PemKeyCertPair {
     grpc::string private_key;
@@ -77,7 +84,13 @@ struct SslServerCredentialsOptions {
   };
   grpc::string pem_root_certs;
   std::vector<PemKeyCertPair> pem_key_cert_pairs;
+  // Deprecated
   bool force_client_auth;
+
+  // If both force_client_auth and client_certificate_request fields are set,
+  // force_client_auth takes effect i.e
+  // REQUEST_AND_REQUIRE_CLIENT_CERTIFICATE_AND_VERIFY will be enforced.
+  grpc_ssl_client_certificate_request_type client_certificate_request;
 };
 
 /// Builds SSL ServerCredentials given SSL specific options
diff --git a/include/grpc/grpc_security.h b/include/grpc/grpc_security.h
index a36926b23e..79199cc5d6 100644
--- a/include/grpc/grpc_security.h
+++ b/include/grpc/grpc_security.h
@@ -35,6 +35,7 @@
 #define GRPC_GRPC_SECURITY_H
 
 #include <grpc/grpc.h>
+#include <grpc/grpc_security_constants.h>
 #include <grpc/status.h>
 
 #ifdef __cplusplus
@@ -43,13 +44,6 @@ extern "C" {
 
 /* --- Authentication Context. --- */
 
-#define GRPC_TRANSPORT_SECURITY_TYPE_PROPERTY_NAME "transport_security_type"
-#define GRPC_SSL_TRANSPORT_SECURITY_TYPE "ssl"
-
-#define GRPC_X509_CN_PROPERTY_NAME "x509_common_name"
-#define GRPC_X509_SAN_PROPERTY_NAME "x509_subject_alternative_name"
-#define GRPC_X509_PEM_CERT_PROPERTY_NAME "x509_pem_cert"
-
 typedef struct grpc_auth_context grpc_auth_context;
 
 typedef struct grpc_auth_property_iterator {
@@ -130,29 +124,11 @@ typedef struct grpc_channel_credentials grpc_channel_credentials;
    The creator of the credentials object is responsible for its release. */
 GRPCAPI void grpc_channel_credentials_release(grpc_channel_credentials *creds);
 
-/* Environment variable that points to the google default application
-   credentials json key or refresh token. Used in the
-   grpc_google_default_credentials_create function. */
-#define GRPC_GOOGLE_CREDENTIALS_ENV_VAR "GOOGLE_APPLICATION_CREDENTIALS"
-
 /* Creates default credentials to connect to a google gRPC service.
    WARNING: Do NOT use this credentials to connect to a non-google service as
    this could result in an oauth2 token leak. */
 GRPCAPI grpc_channel_credentials *grpc_google_default_credentials_create(void);
 
-/* Environment variable that points to the default SSL roots file. This file
-   must be a PEM encoded file with all the roots such as the one that can be
-   downloaded from https://pki.google.com/roots.pem.  */
-#define GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR \
-  "GRPC_DEFAULT_SSL_ROOTS_FILE_PATH"
-
-/* Results for the SSL roots override callback. */
-typedef enum {
-  GRPC_SSL_ROOTS_OVERRIDE_OK,
-  GRPC_SSL_ROOTS_OVERRIDE_FAIL_PERMANENTLY, /* Do not try fallback options. */
-  GRPC_SSL_ROOTS_OVERRIDE_FAIL
-} grpc_ssl_roots_override_result;
-
 /* Callback for getting the SSL roots override from the application.
    In case of success, *pem_roots_certs must be set to a NULL terminated string
    containing the list of PEM encoded root certificates. The ownership is passed
@@ -334,7 +310,8 @@ typedef struct grpc_server_credentials grpc_server_credentials;
    */
 GRPCAPI void grpc_server_credentials_release(grpc_server_credentials *creds);
 
-/* Creates an SSL server_credentials object.
+/* Deprecated in favor of grpc_ssl_server_credentials_create_ex.
+   Creates an SSL server_credentials object.
    - pem_roots_cert is the NULL-terminated string containing the PEM encoding of
      the client root certificates. This parameter may be NULL if the server does
      not want the client to be authenticated with SSL.
@@ -349,6 +326,15 @@ GRPCAPI grpc_server_credentials *grpc_ssl_server_credentials_create(
     const char *pem_root_certs, grpc_ssl_pem_key_cert_pair *pem_key_cert_pairs,
     size_t num_key_cert_pairs, int force_client_auth, void *reserved);
 
+/* Same as grpc_ssl_server_credentials_create method except uses
+   grpc_ssl_client_certificate_request_type enum to support more ways to
+   authenticate client cerificates.*/
+GRPCAPI grpc_server_credentials *grpc_ssl_server_credentials_create_ex(
+    const char *pem_root_certs, grpc_ssl_pem_key_cert_pair *pem_key_cert_pairs,
+    size_t num_key_cert_pairs,
+    grpc_ssl_client_certificate_request_type client_certificate_request,
+    void *reserved);
+
 /* --- Server-side secure ports. --- */
 
 /* Add a HTTP2 over an encrypted link over tcp listener.
diff --git a/include/grpc/grpc_security_constants.h b/include/grpc/grpc_security_constants.h
new file mode 100644
index 0000000000..da05c5a97b
--- /dev/null
+++ b/include/grpc/grpc_security_constants.h
@@ -0,0 +1,114 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_GRPC_SECURITY_CONSTANTS_H
+#define GRPC_GRPC_SECURITY_CONSTANTS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define GRPC_TRANSPORT_SECURITY_TYPE_PROPERTY_NAME "transport_security_type"
+#define GRPC_SSL_TRANSPORT_SECURITY_TYPE "ssl"
+
+#define GRPC_X509_CN_PROPERTY_NAME "x509_common_name"
+#define GRPC_X509_SAN_PROPERTY_NAME "x509_subject_alternative_name"
+#define GRPC_X509_PEM_CERT_PROPERTY_NAME "x509_pem_cert"
+
+/* Environment variable that points to the default SSL roots file. This file
+   must be a PEM encoded file with all the roots such as the one that can be
+   downloaded from https://pki.google.com/roots.pem.  */
+#define GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR \
+  "GRPC_DEFAULT_SSL_ROOTS_FILE_PATH"
+
+/* Environment variable that points to the google default application
+   credentials json key or refresh token. Used in the
+   grpc_google_default_credentials_create function. */
+#define GRPC_GOOGLE_CREDENTIALS_ENV_VAR "GOOGLE_APPLICATION_CREDENTIALS"
+
+/* Results for the SSL roots override callback. */
+typedef enum {
+  GRPC_SSL_ROOTS_OVERRIDE_OK,
+  GRPC_SSL_ROOTS_OVERRIDE_FAIL_PERMANENTLY, /* Do not try fallback options. */
+  GRPC_SSL_ROOTS_OVERRIDE_FAIL
+} grpc_ssl_roots_override_result;
+
+typedef enum {
+  /* Server does not request client certificate. A client can present a self
+     signed or signed certificates if it wishes to do so and they would be
+     accepted. */
+  GRPC_SSL_DONT_REQUEST_CLIENT_CERTIFICATE,
+  /* Server requests client certificate but does not enforce that the client
+     presents a certificate.
+
+     If the client presents a certificate, the client authentication is left to
+     the application based on the metadata like certificate etc.
+
+     The key cert pair should still be valid for the SSL connection to be
+     established. */
+  GRPC_SSL_REQUEST_CLIENT_CERTIFICATE_BUT_DONT_VERIFY,
+  /* Server requests client certificate but does not enforce that the client
+     presents a certificate.
+
+     If the client presents a certificate, the client authentication is done by
+     grpc framework (The client needs to either present a signed cert or skip no
+     certificate for a successful connection).
+
+     The key cert pair should still be valid for the SSL connection to be
+     established. */
+  GRPC_SSL_REQUEST_CLIENT_CERTIFICATE_AND_VERIFY,
+  /* Server requests client certificate but enforces that the client presents a
+     certificate.
+
+     If the client presents a certificate, the client authentication is left to
+     the application based on the metadata like certificate etc.
+
+     The key cert pair should still be valid for the SSL connection to be
+     established. */
+  GRPC_SSL_REQUEST_AND_REQUIRE_CLIENT_CERTIFICATE_BUT_DONT_VERIFY,
+  /* Server requests client certificate but enforces that the client presents a
+     certificate.
+
+     The cerificate presented by the client is verified by grpc framework (The
+     client needs to present signed certs for a successful connection).
+
+     The key cert pair should still be valid for the SSL connection to be
+     established. */
+  GRPC_SSL_REQUEST_AND_REQUIRE_CLIENT_CERTIFICATE_AND_VERIFY
+} grpc_ssl_client_certificate_request_type;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_GRPC_SECURITY_CONSTANTS_H */