/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you 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.

 */

/***************************************************************************

 * Copyright (C) 2017-2026 ZmartZone Holding BV

 * All rights reserved.

 *

 * DISCLAIMER OF WARRANTIES:

 *

 * THE SOFTWARE PROVIDED HEREUNDER IS PROVIDED ON AN "AS IS" BASIS, WITHOUT

 * ANY WARRANTIES OR REPRESENTATIONS EXPRESS, IMPLIED OR STATUTORY; INCLUDING,

 * WITHOUT LIMITATION, WARRANTIES OF QUALITY, PERFORMANCE, NONINFRINGEMENT,

 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  NOR ARE THERE ANY

 * WARRANTIES CREATED BY A COURSE OR DEALING, COURSE OF PERFORMANCE OR TRADE

 * USAGE.  FURTHERMORE, THERE ARE NO WARRANTIES THAT THE SOFTWARE WILL MEET

 * YOUR NEEDS OR BE FREE FROM ERRORS, OR THAT THE OPERATION OF THE SOFTWARE

 * WILL BE UNINTERRUPTED.  IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES 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.

 *

 * @Author: Hans Zandbelt - hans.zandbelt@openidc.com

 */

#include "cfg/dir.h"

#include "metadata.h"

#include "metrics.h"

#include "proto/proto.h"

#include "util/util.h"

/*

 * Configured extras may replace module-owned parameters; request-supplied values, including

 * "#" forwards, may not. One shared "added" table distinguishes both directives' parameters

 * from module-owned ones, allowing repeats such as RFC 8707 "resource" across either directive.

 */

static void oidc_proto_request_auth_params_add(request_rec *r, apr_table_t *params, apr_table_t *added,

                 const char *auth_request_params, apr_byte_t configured) {

  char *key = NULL;

  char *val = NULL;

  if (auth_request_params == NULL)

    return;

  while (*auth_request_params) {

    apr_byte_t from_request = FALSE;

    val = ap_getword(r->pool, &auth_request_params, OIDC_CHAR_AMP);

    if (val == NULL)

      break;

    key = ap_getword(r->pool, (const char **)&val, OIDC_CHAR_EQUAL);

    ap_unescape_url(key);

    ap_unescape_url(val);

    if (_oidc_strcmp(val, OIDC_STR_HASH) == 0) {

      if (oidc_util_url_has_parameter(r, key) == FALSE)

        continue;

      oidc_util_url_parameter_get(r, key, &val);

      from_request = TRUE;

    }

    if ((apr_table_get(params, key) != NULL) && (apr_table_get(added, key) == NULL)) {

      if ((configured == FALSE) || (from_request == TRUE)) {

        oidc_warn(r,

            "dropping authorization request parameter \"%s\": it would duplicate one "

            "that this module sets itself",

            key);

        continue;

      }

      apr_table_set(params, key, val);

      apr_table_setn(added, key, "");

      continue;

    }

    apr_table_add(params, key, val);

    apr_table_setn(added, key, "");

  }

}

/*

 * send a Pushed Authorization Request (PAR) to the Provider

 */

int oidc_proto_request_auth_push(request_rec *r, oidc_cfg_t *cfg, const struct oidc_provider_t *provider,

         apr_table_t *params) {

  char *response = NULL;

  char *basic_auth = NULL;

  char *bearer_auth = NULL;

  char *request_uri = NULL;

  int expires_in = 0;

  const char *authorization_request = NULL;

  const char *scope = NULL;

  oidc_json_t *j_result = NULL;

  int rv = HTTP_INTERNAL_SERVER_ERROR;

  const char *endpoint_url = oidc_cfg_provider_pushed_authorization_request_endpoint_url_get(provider);

  oidc_debug(r, "enter");

  if (endpoint_url == NULL) {

    oidc_error(r, "the Provider's OAuth 2.0 Pushed Authorization Request endpoint URL is not set, PAR "

            "cannot be used");

    rv = oidc_util_html_send_error(

        r, "Pushed Authorization Request Endpoint not set",

        "the Provider's OAuth 2.0 Pushed Authorization Request endpoint URL is not set, PAR cannot be used",

        HTTP_INTERNAL_SERVER_ERROR);

    goto out;

  }

  /* add the token endpoint authentication credentials to the pushed authorization request */

  if (oidc_proto_token_endpoint_auth(

    r, cfg, oidc_cfg_provider_token_endpoint_auth_get(provider),

    oidc_cfg_provider_token_endpoint_auth_alg_get(provider), oidc_cfg_provider_client_id_get(provider),

    oidc_cfg_provider_client_secret_get(provider), oidc_cfg_provider_client_keys_get(provider),

    oidc_proto_profile_token_endpoint_auth_aud(provider), params, NULL, &basic_auth, &bearer_auth) == FALSE)

    goto out;

  OIDC_METRICS_TIMING_START(r, cfg);

  if (oidc_http_post_form(r, endpoint_url, params, basic_auth, bearer_auth, NULL,

        oidc_cfg_provider_ssl_validate_server_get(provider), &response, NULL, NULL,

        oidc_cfg_http_timeout_long_get(cfg), oidc_cfg_outgoing_proxy_get(cfg),

        oidc_cfg_dir_pass_cookies_get(r),

        oidc_cfg_provider_token_endpoint_tls_client_cert_get(provider),

        oidc_cfg_provider_token_endpoint_tls_client_key_get(provider),

        oidc_cfg_provider_token_endpoint_tls_client_key_pwd_get(provider)) == FALSE) {

    OIDC_METRICS_COUNTER_INC(r, cfg, OM_PROVIDER_PAR_ERROR);

    goto out;

  }

  OIDC_METRICS_TIMING_ADD(r, cfg, OM_PROVIDER_PAR);

  /* check for errors, the response itself will have been logged already */

  if (oidc_json_decode_and_check_error(r, response, &j_result) == FALSE) {

    OIDC_METRICS_COUNTER_INC(r, cfg, OM_PROVIDER_PAR_ERROR);

    goto out;

  }

  /* get the request_uri from the parsed response */

  oidc_json_object_get_string(r->pool, j_result, OIDC_PROTO_REQUEST_URI, &request_uri, NULL);

  /* get the expires_in value from the parsed response */

  oidc_json_object_get_int(j_result, OIDC_PROTO_EXPIRES_IN, &expires_in, 60);

  /* assemble the resulting authentication request and redirect */

  apr_table_clear(params);

  apr_table_setn(params, OIDC_PROTO_CLIENT_ID, oidc_cfg_provider_client_id_get(provider));

  apr_table_setn(params, OIDC_PROTO_REQUEST_URI, request_uri);

  /*

   * OIDC requires scope=openid beside request_uri; FAPI 2.0 restricts the request to

   * client_id and request_uri.

   */

  scope = oidc_proto_profile_request_uri_scope_get(provider);

  if (scope != NULL)

    apr_table_setn(params, OIDC_PROTO_SCOPE, scope);

  authorization_request =

      oidc_http_query_encoded_url(r, oidc_cfg_provider_authorization_endpoint_url_get(provider), params);

  oidc_http_hdr_out_location_set(r, authorization_request);

  rv = HTTP_MOVED_TEMPORARILY;

out:

  if (j_result)

    oidc_json_decref(j_result);

  return rv;

}

/*

 * concatenate per-path scopes with per-provider scopes, warn if "openid" is missing, and add the result to params

 */

static void oidc_proto_request_auth_scope_set(request_rec *r, const struct oidc_provider_t *provider,

                const char *path_scope, apr_table_t *params) {

  const char *scope = oidc_cfg_provider_scope_get(provider);

  if (path_scope != NULL)

    scope = ((scope != NULL) && (_oidc_strcmp(scope, "") != 0))

          ? apr_pstrcat(r->pool, scope, OIDC_STR_SPACE, path_scope, NULL)

          : path_scope;

  if (scope == NULL)

    return;

  if (!oidc_util_spaced_string_contains(r->pool, scope, OIDC_PROTO_SCOPE_OPENID))

    oidc_warn(r,

        "the configuration for the \"%s\" parameter does not include the \"%s\" scope, your "

        "provider may not return an \"id_token\": %s",

        OIDC_PROTO_SCOPE, OIDC_PROTO_SCOPE_OPENID, scope);

  apr_table_setn(params, OIDC_PROTO_SCOPE, scope);

}

/*

 * assemble all parameters that go into the authentication request

 */

void oidc_proto_request_auth_params_set(request_rec *r, oidc_cfg_t *cfg, const struct oidc_provider_t *provider,

          const char *login_hint, const char *redirect_uri, const char *state,

          const oidc_proto_state_t *proto_state, const char *id_token_hint,

          const char *code_challenge, const char *auth_request_params,

          const char *path_scope, apr_table_t *params) {

  /* add the response type */

  apr_table_setn(params, OIDC_PROTO_RESPONSE_TYPE, oidc_proto_state_get_response_type(proto_state));

  /* concat the per-path scopes with the per-provider scopes */

  oidc_proto_request_auth_scope_set(r, provider, path_scope, params);

  /* add the client ID */

  apr_table_setn(params, OIDC_PROTO_CLIENT_ID, oidc_cfg_provider_client_id_get(provider));

  /* add the state */

  apr_table_setn(params, OIDC_PROTO_STATE, state);

  /* add the redirect uri */

  apr_table_setn(params, OIDC_PROTO_REDIRECT_URI, redirect_uri);

  /* add the nonce if set */

  const char *nonce = oidc_proto_state_get_nonce(proto_state);

  if (nonce != NULL)

    apr_table_setn(params, OIDC_PROTO_NONCE, nonce);

  /* add PKCE code challenge if set */

  if ((code_challenge != NULL) && (oidc_proto_profile_pkce_get(provider) != &oidc_pkce_none)) {

    apr_table_setn(params, OIDC_PROTO_CODE_CHALLENGE, code_challenge);

    apr_table_setn(params, OIDC_PROTO_CODE_CHALLENGE_METHOD, oidc_proto_profile_pkce_get(provider)->method);

  }

  /* add the response_mode if explicitly set */

  const char *response_mode = oidc_proto_state_get_response_mode(proto_state);

  if (response_mode != NULL)

    apr_table_setn(params, OIDC_PROTO_RESPONSE_MODE, response_mode);

  /* add the login_hint if provided */

  if (login_hint != NULL)

    apr_table_setn(params, OIDC_PROTO_LOGIN_HINT, login_hint);

  /* add the id_token_hint if provided */

  if (id_token_hint != NULL)

    apr_table_setn(params, OIDC_PROTO_ID_TOKEN_HINT, id_token_hint);

  /* add the prompt setting if provided (e.g. "none" for no-GUI checks) */

  const char *prompt = oidc_proto_state_get_prompt(proto_state);

  if (prompt != NULL)

    apr_table_setn(params, OIDC_PROTO_PROMPT, prompt);

  /* the keys the two directives below add, shared between their invocations so that a

   * parameter the first one added is not mistaken for one this module owns by the second */

  apr_table_t *added = apr_table_make(r->pool, 4);

  /* add any statically configured custom authorization request parameters */

  oidc_proto_request_auth_params_add(r, params, added, oidc_cfg_provider_auth_request_params_get(provider), TRUE);

  /* add any dynamically configured custom authorization request parameters */

  oidc_proto_request_auth_params_add(r, params, added, auth_request_params, FALSE);

  /* add request parameter (request or request_uri) if set */

  if (oidc_cfg_provider_request_object_get(provider) != NULL)

    oidc_proto_request_object_param_add(r, cfg, provider, redirect_uri, params);

}