/* Copyright 2020 Google Inc.

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 <stdint.h>

#include <stddef.h>

#include <stdlib.h>

#include <stdio.h>

#include <stdbool.h>

#include <ftw.h>

#include "config.h"

#include "gpg.h"

#include "../common/types.h"

#include "../common/iobuf.h"

#include "keydb.h"

#include "keyedit.h"

#include "../common/util.h"

#include "main.h"

#include "trustdb.h"

#include <sys/stat.h>

#include <fcntl.h>

#include <sys/types.h>

#include <unistd.h>

#include <sys/mount.h>

static bool initialized = false;

ctrl_t ctrlGlobal;

int fd;

char *filename;

//hack not to include gpg.c which has main function

extern int g10_errors_seen;

extern int assert_signer_true;

extern int assert_pubkey_algo_false;

void

g10_exit( int rc )

{

    gcry_control (GCRYCTL_UPDATE_RANDOM_SEED_FILE);

    gcry_control (GCRYCTL_TERM_SECMEM );

    /* Don't exit in fuzzer - just return to allow fuzzing to continue */

    (void)rc;

    return;

}

static void

gpg_deinit_default_ctrl (ctrl_t ctrl)

{

#ifdef USE_TOFU

    tofu_closedbs (ctrl);

#endif

    gpg_dirmngr_deinit_session_data (ctrl);

    keydb_release (ctrl->cached_getkey_kdb);

}

static void

my_gcry_logger (void *dummy, int level, const char *format, va_list arg_ptr)

{

    return;

}

static int unlink_cb(const char *fpath, const struct stat *sb, int typeflag)

{

    if (typeflag == FTW_F){

        unlink(fpath);

    }

    return 0;

}

static void rmrfdir(char *path)

{

    ftw(path, unlink_cb, 16);

    if (rmdir(path) != 0) {

        printf("failed rmdir, errno=%d\n", errno);

    }

}

// 65kb should be enough ;-)

#define MAX_LEN 0x10000

int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {

    if (! initialized) {

        ctrlGlobal = (ctrl_t) malloc(sizeof(*ctrlGlobal));

        if (!ctrlGlobal) {

            exit(1);

        }

        //deletes previous tmp dir and (re)create it as a ramfs

        //system("umount /tmp/fuzzdirdecrypt");

        rmrfdir("/tmp/fuzzdirdecrypt");

        mkdir("/tmp/fuzzdirdecrypt", 0700);

        //system("mount -t tmpfs -o size=64M tmpfs /tmp/fuzzdirdecrypt");

        filename=strdup("/tmp/fuzzdirdecrypt/fuzz.gpg");

        if (!filename) {

            free(ctrlGlobal);

            return 0;

        }

        fd = open("/tmp/fuzzdirdecrypt/fuzz.gpg", O_RDWR | O_CREAT, 0600);

        if (fd == -1) {

            free(ctrlGlobal);

            free(filename);

            return 0;

        }

        gnupg_set_homedir("/tmp/fuzzdirdecrypt/");

        if (keydb_add_resource ("pubring" EXTSEP_S GPGEXT_GPG,

                                KEYDB_RESOURCE_FLAG_DEFAULT) != GPG_ERR_NO_ERROR) {

            free(filename);

            free(ctrlGlobal);

            close(fd);

            return 0;

        }

        if (setup_trustdb (1, NULL) != GPG_ERR_NO_ERROR) {

            free(filename);

            free(ctrlGlobal);

            close(fd);

            return 0;

        }

        //populate /tmp/fuzzdirdecrypt/ as homedir ~/.gnupg

        strlist_t sl = NULL;

        public_key_list (ctrlGlobal, sl, 0, 0);

        free_strlist(sl);

        //no output for stderr

        log_set_file("/dev/null");

        gcry_set_log_handler (my_gcry_logger, NULL);

        //gnupg_initialize_compliance (GNUPG_MODULE_NAME_GPG);

        //overwrite output file

        //opt.batch = 1;

        //opt.answer_yes = 1;

        initialized = true;

    }

    memset(ctrlGlobal, 0, sizeof(*ctrlGlobal));

    ctrlGlobal->magic = SERVER_CONTROL_MAGIC;

    if (Size > MAX_LEN) {

        // limit maximum size to avoid long computing times

        Size = MAX_LEN;

    }

    if (ftruncate(fd, Size) == -1) {

        return 0;

    }

    if (lseek (fd, 0, SEEK_SET) < 0) {

        return 0;

    }

    if (write (fd, Data, Size) != Size) {

        return 0;

    }

    decrypt_messages(ctrlGlobal, 1, &filename);

    gpg_deinit_default_ctrl (ctrlGlobal);

    memset(ctrlGlobal, 0, sizeof(*ctrlGlobal));

    ctrlGlobal->magic = SERVER_CONTROL_MAGIC;

    decrypt_message(ctrlGlobal, filename, NULL);

    gpg_deinit_default_ctrl (ctrlGlobal);

    return 0;

}