/*

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

 * contributor license agreements.  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

 *

 * Copyright (C) 2017-2026 ZmartZone Holding BV - hans.zandbelt@openidc.com

 *

 * Fuzz target for the JWK / JWK Set parsers: a JWKS document is fetched from

 * the provider's jwks_uri, so its contents are under the control of whoever

 * answers at that URL -- the OP, or anyone who can influence the document in

 * a multi-provider (discovery / dynamic registration) setup. The same parser

 * handles the JWKs a client_secret-less client publishes for its own keys.

 *

 * The decoded JSON is routed the way the module routes it: a "keys" array is

 * parsed as a set (oidc_jwks_parse_json), a bare "kty" object as a single key

 * (oidc_jwk_parse_json). That covers the per-kty material parsing in

 * jose/jwk.c -- RSA n/e/d, EC crv/x/y, oct k, the optional x5c certificate

 * chain and x5t thumbprints -- and the re-serialization and default-alg

 * helpers are run over every key that parsed, so the round trip is stressed

 * with whatever the parser accepted rather than only with what it rejects.

 */

#include "fuzz.h"

/* util.h pulls in const.h before any Apache header does, so config.h's

 * PACKAGE_* defines win the race against Apache's own (empty) ones in

 * ap_config_auto.h -- json.h includes httpd.h directly; keep util.h ahead

 * of it (clang-format's include sorting would undo exactly that, hence the

 * guard) */

/* clang-format off */

#include "util.h"      /* test fixture */

#include "json.h"

#include "jose.h"

#include "util/util.h" /* oidc_json_decode_object */

/* clang-format on */

#include <apr_pools.h>

#include <apr_strings.h>

static int g_ready = 0;

/* engine-called one-time init, pre-forkserver on AFL++: see fuzz.h */

int LLVMFuzzerInitialize(int *argc, char ***argv) {

  (void)argc;

  (void)argv;

  if (!g_ready) {

    oidc_test_setup();

    g_ready = 1;

  }

  return 0;

}

/* run the helpers that consume a parsed key: serialization (full and public-only) and the default-alg lookup */

static void fuzz_jwk_use(apr_pool_t *pool, const oidc_jwk_t *jwk) {

  char *s_json = NULL;

  oidc_jose_error_t err;

  oidc_jwk_to_json(pool, jwk, &s_json, &err);

  oidc_jwk_to_public_json(pool, jwk, &s_json, &err);

  oidc_jwk_default_jws_alg(jwk);

  /* a copy duplicates the OpenSSL key material outside the pool; destroy it the same way */

  oidc_jwk_t *copy = oidc_jwk_copy(pool, jwk);

  if (copy != NULL)

    oidc_jwk_destroy(copy);

}

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {

  if (!g_ready)

    LLVMFuzzerInitialize(NULL, NULL);

  apr_pool_t *pool = NULL;

  apr_pool_create(&pool, oidc_test_pool_get());

  request_rec r = *oidc_test_request_get();

  r.pool = pool;

  char *s = apr_pstrmemdup(pool, (const char *)data, size);

  oidc_json_t *json = NULL;

  if ((oidc_json_decode_object(&r, s, &json) == TRUE) && (json != NULL)) {

    oidc_jose_error_t err;

    if (oidc_is_jwks(json) == TRUE) {

      apr_array_header_t *jwk_list = NULL;

      apr_byte_t ok = oidc_jwks_parse_json(pool, json, &jwk_list, &err);

      if ((ok == TRUE) && (jwk_list != NULL))

        for (int i = 0; i < jwk_list->nelts; i++)

          fuzz_jwk_use(pool, APR_ARRAY_IDX(jwk_list, i, const oidc_jwk_t *));

      /* the keys wrap cjose/OpenSSL objects allocated outside the pool */

      if (jwk_list != NULL)

        oidc_jwk_list_destroy(jwk_list);

    } else if (oidc_is_jwk(json) == TRUE) {

      oidc_jwk_t *jwk = NULL;

      if ((oidc_jwk_parse_json(pool, json, &jwk, &err) == TRUE) && (jwk != NULL)) {

        fuzz_jwk_use(pool, jwk);

        oidc_jwk_destroy(jwk);

      }

    }

    oidc_json_decref(json); /* jansson value is refcounted, not pooled */

  }

  apr_pool_destroy(pool);

  return 0;

}