/*
 *
 * Copyright 2015, Google Inc.
 * All rights reserved.
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 * 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
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 */

#ifndef GRPC_CORE_LIB_SECURITY_JSON_TOKEN_H
#define GRPC_CORE_LIB_SECURITY_JSON_TOKEN_H

#include <grpc/support/slice.h>
#include <openssl/rsa.h>

#include "src/core/lib/json/json.h"

/* --- Constants. --- */

#define GRPC_JWT_OAUTH2_AUDIENCE "https://www.googleapis.com/oauth2/v3/token"

#define GRPC_AUTH_JSON_TYPE_INVALID "invalid"
#define GRPC_AUTH_JSON_TYPE_SERVICE_ACCOUNT "service_account"
#define GRPC_AUTH_JSON_TYPE_AUTHORIZED_USER "authorized_user"

/* --- auth_json_key parsing. --- */

typedef struct {
  const char *type;
  char *private_key_id;
  char *client_id;
  char *client_email;
  RSA *private_key;
} grpc_auth_json_key;

/* Returns 1 if the object is valid, 0 otherwise. */
int grpc_auth_json_key_is_valid(const grpc_auth_json_key *json_key);

/* Creates a json_key object from string. Returns an invalid object if a parsing
   error has been encountered. */
grpc_auth_json_key grpc_auth_json_key_create_from_string(
    const char *json_string);

/* Creates a json_key object from parsed json. Returns an invalid object if a
   parsing error has been encountered. */
grpc_auth_json_key grpc_auth_json_key_create_from_json(const grpc_json *json);

/* Destructs the object. */
void grpc_auth_json_key_destruct(grpc_auth_json_key *json_key);

/* --- json token encoding and signing. --- */

/* Caller is responsible for calling gpr_free on the returned value. May return
   NULL on invalid input. The scope parameter may be NULL. */
char *grpc_jwt_encode_and_sign(const grpc_auth_json_key *json_key,
                               const char *audience,
                               gpr_timespec token_lifetime, const char *scope);

/* Override encode_and_sign function for testing. */
typedef char *(*grpc_jwt_encode_and_sign_override)(
    const grpc_auth_json_key *json_key, const char *audience,
    gpr_timespec token_lifetime, const char *scope);

/* Set a custom encode_and_sign override for testing. */
void grpc_jwt_encode_and_sign_set_override(
    grpc_jwt_encode_and_sign_override func);

/* --- auth_refresh_token parsing. --- */

typedef struct {
  const char *type;
  char *client_id;
  char *client_secret;
  char *refresh_token;
} grpc_auth_refresh_token;

/* Returns 1 if the object is valid, 0 otherwise. */
int grpc_auth_refresh_token_is_valid(
    const grpc_auth_refresh_token *refresh_token);

/* Creates a refresh token object from string. Returns an invalid object if a
   parsing error has been encountered. */
grpc_auth_refresh_token grpc_auth_refresh_token_create_from_string(
    const char *json_string);

/* Creates a refresh token object from parsed json. Returns an invalid object if
   a parsing error has been encountered. */
grpc_auth_refresh_token grpc_auth_refresh_token_create_from_json(
    const grpc_json *json);

/* Destructs the object. */
void grpc_auth_refresh_token_destruct(grpc_auth_refresh_token *refresh_token);

#endif /* GRPC_CORE_LIB_SECURITY_JSON_TOKEN_H */