/*
 *
 * Copyright 2015 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.
 *
 */

#include <stdio.h>
#include <string.h>

#include <grpc/grpc_security.h>
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>

#include "src/core/lib/gpr/string.h"
#include "src/core/lib/gpr/tmpfile.h"
#include "src/core/lib/gprpp/ref_counted_ptr.h"
#include "src/core/lib/security/context/security_context.h"
#include "src/core/lib/security/security_connector/security_connector.h"
#include "src/core/lib/security/security_connector/ssl_utils.h"
#include "src/core/lib/slice/slice_string_helpers.h"
#include "src/core/tsi/ssl_transport_security.h"
#include "src/core/tsi/transport_security.h"
#include "test/core/util/test_config.h"

#ifndef TSI_OPENSSL_ALPN_SUPPORT
#define TSI_OPENSSL_ALPN_SUPPORT 1
#endif

static int check_transport_security_type(const grpc_auth_context* ctx) {
  grpc_auth_property_iterator it = grpc_auth_context_find_properties_by_name(
      ctx, GRPC_TRANSPORT_SECURITY_TYPE_PROPERTY_NAME);
  const grpc_auth_property* prop = grpc_auth_property_iterator_next(&it);
  if (prop == nullptr) return 0;
  if (strncmp(prop->value, GRPC_SSL_TRANSPORT_SECURITY_TYPE,
              prop->value_length) != 0) {
    return 0;
  }
  /* Check that we have only one property with this name. */
  if (grpc_auth_property_iterator_next(&it) != nullptr) return 0;
  return 1;
}

static int check_peer_property(const tsi_peer* peer,
                               const tsi_peer_property* expected) {
  size_t i;
  for (i = 0; i < peer->property_count; i++) {
    const tsi_peer_property* prop = &peer->properties[i];
    if ((strcmp(prop->name, expected->name) == 0) &&
        (prop->value.length == expected->value.length) &&
        (memcmp(prop->value.data, expected->value.data,
                expected->value.length) == 0)) {
      return 1;
    }
  }
  return 0; /* Not found... */
}

static int check_ssl_peer_equivalence(const tsi_peer* original,
                                      const tsi_peer* reconstructed) {
  /* The reconstructed peer only has CN, SAN and pem cert properties. */
  size_t i;
  for (i = 0; i < original->property_count; i++) {
    const tsi_peer_property* prop = &original->properties[i];
    if ((strcmp(prop->name, TSI_X509_SUBJECT_COMMON_NAME_PEER_PROPERTY) == 0) ||
        (strcmp(prop->name, TSI_X509_SUBJECT_ALTERNATIVE_NAME_PEER_PROPERTY) ==
         0) ||
        (strcmp(prop->name, TSI_X509_PEM_CERT_PROPERTY) == 0)) {
      if (!check_peer_property(reconstructed, prop)) return 0;
    }
  }
  return 1;
}

static void test_unauthenticated_ssl_peer(void) {
  tsi_peer peer;
  tsi_peer rpeer;
  GPR_ASSERT(tsi_construct_peer(1, &peer) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_CERTIFICATE_TYPE_PEER_PROPERTY, TSI_X509_CERTIFICATE_TYPE,
                 &peer.properties[0]) == TSI_OK);
  grpc_core::RefCountedPtr<grpc_auth_context> ctx =
      grpc_ssl_peer_to_auth_context(&peer, GRPC_SSL_TRANSPORT_SECURITY_TYPE);
  GPR_ASSERT(ctx != nullptr);
  GPR_ASSERT(!grpc_auth_context_peer_is_authenticated(ctx.get()));
  GPR_ASSERT(check_transport_security_type(ctx.get()));

  rpeer = grpc_shallow_peer_from_ssl_auth_context(ctx.get());
  GPR_ASSERT(check_ssl_peer_equivalence(&peer, &rpeer));

  grpc_shallow_peer_destruct(&rpeer);
  tsi_peer_destruct(&peer);
  ctx.reset(DEBUG_LOCATION, "test");
}

static int check_identity(const grpc_auth_context* ctx,
                          const char* expected_property_name,
                          const char** expected_identities,
                          size_t num_identities) {
  grpc_auth_property_iterator it;
  const grpc_auth_property* prop;
  size_t i;
  GPR_ASSERT(grpc_auth_context_peer_is_authenticated(ctx));
  it = grpc_auth_context_peer_identity(ctx);
  for (i = 0; i < num_identities; i++) {
    prop = grpc_auth_property_iterator_next(&it);
    if (prop == nullptr) {
      gpr_log(GPR_ERROR, "Expected identity value %s not found.",
              expected_identities[i]);
      return 0;
    }
    if (strcmp(prop->name, expected_property_name) != 0) {
      gpr_log(GPR_ERROR, "Expected peer identity property name %s and got %s.",
              expected_property_name, prop->name);
      return 0;
    }
    if (strncmp(prop->value, expected_identities[i], prop->value_length) != 0) {
      gpr_log(GPR_ERROR, "Expected peer identity %s and got %s.",
              expected_identities[i], prop->value);
      return 0;
    }
  }
  return 1;
}

static int check_x509_cn(const grpc_auth_context* ctx,
                         const char* expected_cn) {
  grpc_auth_property_iterator it = grpc_auth_context_find_properties_by_name(
      ctx, GRPC_X509_CN_PROPERTY_NAME);
  const grpc_auth_property* prop = grpc_auth_property_iterator_next(&it);
  if (prop == nullptr) {
    gpr_log(GPR_ERROR, "CN property not found.");
    return 0;
  }
  if (strncmp(prop->value, expected_cn, prop->value_length) != 0) {
    gpr_log(GPR_ERROR, "Expected CN %s and got %s", expected_cn, prop->value);
    return 0;
  }
  if (grpc_auth_property_iterator_next(&it) != nullptr) {
    gpr_log(GPR_ERROR, "Expected only one property for CN.");
    return 0;
  }
  return 1;
}

static int check_x509_pem_cert(const grpc_auth_context* ctx,
                               const char* expected_pem_cert) {
  grpc_auth_property_iterator it = grpc_auth_context_find_properties_by_name(
      ctx, GRPC_X509_PEM_CERT_PROPERTY_NAME);
  const grpc_auth_property* prop = grpc_auth_property_iterator_next(&it);
  if (prop == nullptr) {
    gpr_log(GPR_ERROR, "Pem certificate property not found.");
    return 0;
  }
  if (strncmp(prop->value, expected_pem_cert, prop->value_length) != 0) {
    gpr_log(GPR_ERROR, "Expected pem cert %s and got %s", expected_pem_cert,
            prop->value);
    return 0;
  }
  if (grpc_auth_property_iterator_next(&it) != nullptr) {
    gpr_log(GPR_ERROR, "Expected only one property for pem cert.");
    return 0;
  }
  return 1;
}

static void test_cn_only_ssl_peer_to_auth_context(void) {
  tsi_peer peer;
  tsi_peer rpeer;
  const char* expected_cn = "cn1";
  const char* expected_pem_cert = "pem_cert1";
  GPR_ASSERT(tsi_construct_peer(3, &peer) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_CERTIFICATE_TYPE_PEER_PROPERTY, TSI_X509_CERTIFICATE_TYPE,
                 &peer.properties[0]) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_X509_SUBJECT_COMMON_NAME_PEER_PROPERTY, expected_cn,
                 &peer.properties[1]) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_X509_PEM_CERT_PROPERTY, expected_pem_cert,
                 &peer.properties[2]) == TSI_OK);
  grpc_core::RefCountedPtr<grpc_auth_context> ctx =
      grpc_ssl_peer_to_auth_context(&peer, GRPC_SSL_TRANSPORT_SECURITY_TYPE);
  GPR_ASSERT(ctx != nullptr);
  GPR_ASSERT(grpc_auth_context_peer_is_authenticated(ctx.get()));
  GPR_ASSERT(
      check_identity(ctx.get(), GRPC_X509_CN_PROPERTY_NAME, &expected_cn, 1));
  GPR_ASSERT(check_transport_security_type(ctx.get()));
  GPR_ASSERT(check_x509_cn(ctx.get(), expected_cn));
  GPR_ASSERT(check_x509_pem_cert(ctx.get(), expected_pem_cert));

  rpeer = grpc_shallow_peer_from_ssl_auth_context(ctx.get());
  GPR_ASSERT(check_ssl_peer_equivalence(&peer, &rpeer));

  grpc_shallow_peer_destruct(&rpeer);
  tsi_peer_destruct(&peer);
  ctx.reset(DEBUG_LOCATION, "test");
}

static void test_cn_and_one_san_ssl_peer_to_auth_context(void) {
  tsi_peer peer;
  tsi_peer rpeer;
  const char* expected_cn = "cn1";
  const char* expected_san = "san1";
  const char* expected_pem_cert = "pem_cert1";
  GPR_ASSERT(tsi_construct_peer(4, &peer) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_CERTIFICATE_TYPE_PEER_PROPERTY, TSI_X509_CERTIFICATE_TYPE,
                 &peer.properties[0]) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_X509_SUBJECT_COMMON_NAME_PEER_PROPERTY, expected_cn,
                 &peer.properties[1]) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_X509_SUBJECT_ALTERNATIVE_NAME_PEER_PROPERTY, expected_san,
                 &peer.properties[2]) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_X509_PEM_CERT_PROPERTY, expected_pem_cert,
                 &peer.properties[3]) == TSI_OK);

  grpc_core::RefCountedPtr<grpc_auth_context> ctx =
      grpc_ssl_peer_to_auth_context(&peer, GRPC_SSL_TRANSPORT_SECURITY_TYPE);
  GPR_ASSERT(ctx != nullptr);
  GPR_ASSERT(grpc_auth_context_peer_is_authenticated(ctx.get()));
  GPR_ASSERT(
      check_identity(ctx.get(), GRPC_X509_SAN_PROPERTY_NAME, &expected_san, 1));
  GPR_ASSERT(check_transport_security_type(ctx.get()));
  GPR_ASSERT(check_x509_cn(ctx.get(), expected_cn));
  GPR_ASSERT(check_x509_pem_cert(ctx.get(), expected_pem_cert));

  rpeer = grpc_shallow_peer_from_ssl_auth_context(ctx.get());
  GPR_ASSERT(check_ssl_peer_equivalence(&peer, &rpeer));

  grpc_shallow_peer_destruct(&rpeer);
  tsi_peer_destruct(&peer);
  ctx.reset(DEBUG_LOCATION, "test");
}

static void test_cn_and_multiple_sans_ssl_peer_to_auth_context(void) {
  tsi_peer peer;
  tsi_peer rpeer;
  const char* expected_cn = "cn1";
  const char* expected_sans[] = {"san1", "san2", "san3"};
  const char* expected_pem_cert = "pem_cert1";
  size_t i;
  GPR_ASSERT(tsi_construct_peer(3 + GPR_ARRAY_SIZE(expected_sans), &peer) ==
             TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_CERTIFICATE_TYPE_PEER_PROPERTY, TSI_X509_CERTIFICATE_TYPE,
                 &peer.properties[0]) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_X509_SUBJECT_COMMON_NAME_PEER_PROPERTY, expected_cn,
                 &peer.properties[1]) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_X509_PEM_CERT_PROPERTY, expected_pem_cert,
                 &peer.properties[2]) == TSI_OK);
  for (i = 0; i < GPR_ARRAY_SIZE(expected_sans); i++) {
    GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                   TSI_X509_SUBJECT_ALTERNATIVE_NAME_PEER_PROPERTY,
                   expected_sans[i], &peer.properties[3 + i]) == TSI_OK);
  }
  grpc_core::RefCountedPtr<grpc_auth_context> ctx =
      grpc_ssl_peer_to_auth_context(&peer, GRPC_SSL_TRANSPORT_SECURITY_TYPE);
  GPR_ASSERT(ctx != nullptr);
  GPR_ASSERT(grpc_auth_context_peer_is_authenticated(ctx.get()));
  GPR_ASSERT(check_identity(ctx.get(), GRPC_X509_SAN_PROPERTY_NAME,
                            expected_sans, GPR_ARRAY_SIZE(expected_sans)));
  GPR_ASSERT(check_transport_security_type(ctx.get()));
  GPR_ASSERT(check_x509_cn(ctx.get(), expected_cn));
  GPR_ASSERT(check_x509_pem_cert(ctx.get(), expected_pem_cert));

  rpeer = grpc_shallow_peer_from_ssl_auth_context(ctx.get());
  GPR_ASSERT(check_ssl_peer_equivalence(&peer, &rpeer));

  grpc_shallow_peer_destruct(&rpeer);
  tsi_peer_destruct(&peer);
  ctx.reset(DEBUG_LOCATION, "test");
}

static void test_cn_and_multiple_sans_and_others_ssl_peer_to_auth_context(
    void) {
  tsi_peer peer;
  tsi_peer rpeer;
  const char* expected_cn = "cn1";
  const char* expected_pem_cert = "pem_cert1";
  const char* expected_sans[] = {"san1", "san2", "san3"};
  size_t i;
  GPR_ASSERT(tsi_construct_peer(5 + GPR_ARRAY_SIZE(expected_sans), &peer) ==
             TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_CERTIFICATE_TYPE_PEER_PROPERTY, TSI_X509_CERTIFICATE_TYPE,
                 &peer.properties[0]) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 "foo", "bar", &peer.properties[1]) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_X509_SUBJECT_COMMON_NAME_PEER_PROPERTY, expected_cn,
                 &peer.properties[2]) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 "chapi", "chapo", &peer.properties[3]) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                 TSI_X509_PEM_CERT_PROPERTY, expected_pem_cert,
                 &peer.properties[4]) == TSI_OK);
  for (i = 0; i < GPR_ARRAY_SIZE(expected_sans); i++) {
    GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                   TSI_X509_SUBJECT_ALTERNATIVE_NAME_PEER_PROPERTY,
                   expected_sans[i], &peer.properties[5 + i]) == TSI_OK);
  }
  grpc_core::RefCountedPtr<grpc_auth_context> ctx =
      grpc_ssl_peer_to_auth_context(&peer, GRPC_SSL_TRANSPORT_SECURITY_TYPE);
  GPR_ASSERT(ctx != nullptr);
  GPR_ASSERT(grpc_auth_context_peer_is_authenticated(ctx.get()));
  GPR_ASSERT(check_identity(ctx.get(), GRPC_X509_SAN_PROPERTY_NAME,
                            expected_sans, GPR_ARRAY_SIZE(expected_sans)));
  GPR_ASSERT(check_transport_security_type(ctx.get()));
  GPR_ASSERT(check_x509_cn(ctx.get(), expected_cn));
  GPR_ASSERT(check_x509_pem_cert(ctx.get(), expected_pem_cert));

  rpeer = grpc_shallow_peer_from_ssl_auth_context(ctx.get());
  GPR_ASSERT(check_ssl_peer_equivalence(&peer, &rpeer));

  grpc_shallow_peer_destruct(&rpeer);
  tsi_peer_destruct(&peer);
  ctx.reset(DEBUG_LOCATION, "test");
}

static const char* roots_for_override_api = "roots for override api";

static grpc_ssl_roots_override_result override_roots_success(
    char** pem_root_certs) {
  *pem_root_certs = gpr_strdup(roots_for_override_api);
  return GRPC_SSL_ROOTS_OVERRIDE_OK;
}

static grpc_ssl_roots_override_result override_roots_permanent_failure(
    char** /*pem_root_certs*/) {
  return GRPC_SSL_ROOTS_OVERRIDE_FAIL_PERMANENTLY;
}

static void test_ipv6_address_san(void) {
  const char* addresses[] = {
      "2001:db8::1",     "fe80::abcd:ef65:4321%em0", "fd11:feed:beef:0:cafe::4",
      "128.10.0.1:8888", "[2001:db8::1]:8080",       "[2001:db8::1%em1]:8080",
  };
  const char* san_ips[] = {
      "2001:db8::1", "fe80::abcd:ef65:4321", "fd11:feed:beef:0:cafe::4",
      "128.10.0.1",  "2001:db8::1",          "2001:db8::1",
  };
  tsi_peer peer;
  GPR_ASSERT(tsi_construct_peer(1, &peer) == TSI_OK);
  for (size_t i = 0; i < GPR_ARRAY_SIZE(addresses); i++) {
    GPR_ASSERT(tsi_construct_string_peer_property_from_cstring(
                   TSI_X509_SUBJECT_ALTERNATIVE_NAME_PEER_PROPERTY, san_ips[i],
                   &peer.properties[0]) == TSI_OK);
    GPR_ASSERT(grpc_ssl_host_matches_name(&peer, addresses[i]));
    tsi_peer_property_destruct(&peer.properties[0]);
  }
  tsi_peer_destruct(&peer);
}
namespace grpc_core {
namespace {

class TestDefaultSslRootStore : public DefaultSslRootStore {
 public:
  static grpc_slice ComputePemRootCertsForTesting() {
    return ComputePemRootCerts();
  }
};

}  // namespace
}  // namespace grpc_core

// TODO: Convert this test to C++ test when security_connector implementation
// is converted to C++.
static void test_default_ssl_roots(void) {
  const char* roots_for_env_var = "roots for env var";

  char* roots_env_var_file_path;
  FILE* roots_env_var_file =
      gpr_tmpfile("test_roots_for_env_var", &roots_env_var_file_path);
  fwrite(roots_for_env_var, 1, strlen(roots_for_env_var), roots_env_var_file);
  fclose(roots_env_var_file);

  /* First let's get the root through the override: set the env to an invalid
     value. */
  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, "");
  grpc_set_ssl_roots_override_callback(override_roots_success);
  grpc_slice roots =
      grpc_core::TestDefaultSslRootStore::ComputePemRootCertsForTesting();
  char* roots_contents = grpc_slice_to_c_string(roots);
  grpc_slice_unref(roots);
  GPR_ASSERT(strcmp(roots_contents, roots_for_override_api) == 0);
  gpr_free(roots_contents);

  /* Now let's set the env var: We should get the contents pointed value
     instead. */
  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path,
                        roots_env_var_file_path);
  roots = grpc_core::TestDefaultSslRootStore::ComputePemRootCertsForTesting();
  roots_contents = grpc_slice_to_c_string(roots);
  grpc_slice_unref(roots);
  GPR_ASSERT(strcmp(roots_contents, roots_for_env_var) == 0);
  gpr_free(roots_contents);

  /* Now reset the env var. We should fall back to the value overridden using
     the api. */
  GPR_GLOBAL_CONFIG_SET(grpc_default_ssl_roots_file_path, "");
  roots = grpc_core::TestDefaultSslRootStore::ComputePemRootCertsForTesting();
  roots_contents = grpc_slice_to_c_string(roots);
  grpc_slice_unref(roots);
  GPR_ASSERT(strcmp(roots_contents, roots_for_override_api) == 0);
  gpr_free(roots_contents);

  /* Now setup a permanent failure for the overridden roots and we should get
     an empty slice. */
  GPR_GLOBAL_CONFIG_SET(grpc_not_use_system_ssl_roots, true);
  grpc_set_ssl_roots_override_callback(override_roots_permanent_failure);
  roots = grpc_core::TestDefaultSslRootStore::ComputePemRootCertsForTesting();
  GPR_ASSERT(GRPC_SLICE_IS_EMPTY(roots));
  const tsi_ssl_root_certs_store* root_store =
      grpc_core::TestDefaultSslRootStore::GetRootStore();
  GPR_ASSERT(root_store == nullptr);

  /* Cleanup. */
  remove(roots_env_var_file_path);
  gpr_free(roots_env_var_file_path);
}

static void test_peer_alpn_check(void) {
#if TSI_OPENSSL_ALPN_SUPPORT
  tsi_peer peer;
  const char* alpn = "grpc";
  const char* wrong_alpn = "wrong";
  // peer does not have a TSI_SSL_ALPN_SELECTED_PROTOCOL property.
  GPR_ASSERT(tsi_construct_peer(1, &peer) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property("wrong peer property name",
                                                alpn, strlen(alpn),
                                                &peer.properties[0]) == TSI_OK);
  grpc_error* error = grpc_ssl_check_alpn(&peer);
  GPR_ASSERT(error != GRPC_ERROR_NONE);
  tsi_peer_destruct(&peer);
  GRPC_ERROR_UNREF(error);
  // peer has a TSI_SSL_ALPN_SELECTED_PROTOCOL property but with an incorrect
  // property value.
  GPR_ASSERT(tsi_construct_peer(1, &peer) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property(TSI_SSL_ALPN_SELECTED_PROTOCOL,
                                                wrong_alpn, strlen(wrong_alpn),
                                                &peer.properties[0]) == TSI_OK);
  error = grpc_ssl_check_alpn(&peer);
  GPR_ASSERT(error != GRPC_ERROR_NONE);
  tsi_peer_destruct(&peer);
  GRPC_ERROR_UNREF(error);
  // peer has a TSI_SSL_ALPN_SELECTED_PROTOCOL property with a correct property
  // value.
  GPR_ASSERT(tsi_construct_peer(1, &peer) == TSI_OK);
  GPR_ASSERT(tsi_construct_string_peer_property(TSI_SSL_ALPN_SELECTED_PROTOCOL,
                                                alpn, strlen(alpn),
                                                &peer.properties[0]) == TSI_OK);
  GPR_ASSERT(grpc_ssl_check_alpn(&peer) == GRPC_ERROR_NONE);
  tsi_peer_destruct(&peer);
#else
  GPR_ASSERT(grpc_ssl_check_alpn(nullptr) == GRPC_ERROR_NONE);
#endif
}

int main(int argc, char** argv) {
  grpc::testing::TestEnvironment env(argc, argv);
  grpc_init();

  test_unauthenticated_ssl_peer();
  test_cn_only_ssl_peer_to_auth_context();
  test_cn_and_one_san_ssl_peer_to_auth_context();
  test_cn_and_multiple_sans_ssl_peer_to_auth_context();
  test_cn_and_multiple_sans_and_others_ssl_peer_to_auth_context();
  test_ipv6_address_san();
  test_default_ssl_roots();
  test_peer_alpn_check();
  grpc_shutdown();
  return 0;
}
