/*

 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")

 *

 * SPDX-License-Identifier: MPL-2.0

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, you can obtain one at https://mozilla.org/MPL/2.0/.

 *

 * See the COPYRIGHT file distributed with this work for additional

 * information regarding copyright ownership.

 */

#include <inttypes.h>

#include <stdbool.h>

#include <stdlib.h>

#include <unistd.h>

#include <isc/buffer.h>

#include <isc/commandline.h>

#include <isc/file.h>

#include <isc/mem.h>

#include <isc/result.h>

#include <isc/string.h>

#include <isc/tid.h>

#include <isc/util.h>

#include <dns/fixedname.h>

#include <dns/message.h>

#include <dns/name.h>

#include <dns/rcode.h>

#include <dns/tsig.h>

#include <dns/view.h>

#include <dns/zone.h>

#include <dns/zoneproperties.h>

#include "fuzz.h"

bool debug = false;

static isc_mem_t *mctx = NULL;

/*

 *  Packet dumps of validily signed request ./IN/SOA

 *  requests.

 *

 *  TSIG:

 *

 *  0x0000:  600b 0900 006a 1140 0000 0000 0000 0000

 *  0x0010:  0000 0000 0000 0001 0000 0000 0000 0000

 *  0x0020:  0000 0000 0000 0001 cc88 0035 006a 007d

 *  0x0030:  1dfa 0000 0001 0000 0000 0001 0000 0600

 *  0x0040:  0108 7473 6967 2d6b 6579 0000 fa00 ff00

 *  0x0050:  0000 0000 3d0b 686d 6163 2d73 6861 3235

 *  0x0060:  3600 0000 622a cce1 012c 0020 224d 5807

 *  0x0070:  648d 1400 9d8e fc1c d049 55e9 cc90 2187

 *  0x0080:  3b5f af5c 8899 dc27 c8df b34b 1dfa 0000

 *  0x0090:  0000

 *

 *  SIG(0):

 *

 *  0x0000:  6004 0e00 013f 1140 0000 0000 0000 0000

 *  0x0010:  0000 0000 0000 0001 0000 0000 0000 0000

 *  0x0020:  0000 0000 0000 0001 c0a7 0035 013f 0152

 *  0x0030:  0000 0000 0001 0000 0000 0001 0000 0600

 *  0x0040:  0100 0018 00ff 0000 0000 011b 0000 0800

 *  0x0050:  0000 0000 622a ce0d 622a cbb5 da71 0773

 *  0x0060:  6967 306b 6579 0068 988b 27bf 5c89 5270

 *  0x0070:  c5ba ea8b 2e10 0512 9b44 48d3 69de b7ec

 *  0x0080:  7c67 15f3 6bc7 b0dc 277b e8f1 6979 4c89

 *  0x0090:  149a 0203 30a1 c0b7 a711 ee8a 8d90 ebb9

 *  0x00a0:  9e33 dd65 33d5 5d1d 90db cf9c bb6a b346

 *  0x00b0:  568f a399 71d7 c877 616d 2fb7 0f86 963f

 *  0x00c0:  aa00 850d 180a 9f83 cd4b d115 c79f 64c9

 *  0x00d0:  ff05 e751 6810 28b3 2249 c4ba 2d8d 57ba

 *  0x00e0:  9aad f1fc b34e c237 9465 04fd fe4d 19c9

 *  0x00f0:  2368 ec8e 7097 eaea e067 2b9c 06eb c383

 *  0x0100:  e901 a11e 606b 4cce c12a 0e57 8c09 b7cb

 *  0x0110:  23bb ec05 b68b 1852 9288 b665 fe89 cf62

 *  0x0120:  0a41 5e5a acbe 6903 cbb7 e7b6 cab4 e4a2

 *  0x0130:  b98f 884f c09d 5b39 c695 c84c 9a92 f110

 *  0x0140:  ccc3 f2ee 313f a2a1 1cda 5aa2 faec d593

 *  0x0150:  4514 724a 868f 94b9 0547 4dc9 7b73 c85e

 *  0x0160:  544c 73d4 e892 f9

 */

#define HMACSHA256 "\x0bhmac-sha256"

static isc_stdtime_t fuzztime = 0x622acce1;

static dns_view_t *view = NULL;

static dns_tsigkey_t *tsigkey = NULL;

static dns_tsigkeyring_t *ring = NULL;

static dns_tsigkeyring_t *emptyring = NULL;

static char *wd = NULL;

static char template[] = "/tmp/dns-message-checksig-XXXXXX";

static char f1[] = "Ksig0key.+008+55921.key";

static char c1[] = "sig0key. IN KEY 512 3 8 "

       "AwEAAa22lgHi1vAbQvu5ETdTrm2H8rwga9tvyMa6LFiSDyevLvSv0Uo5 "

       "uvfrXnxaLdtBMts6e1Ly2piSH9JRbOGMNibOK4EXWhWAn8MII4SWgQAs "

       "bFwtiz4HyPn2wScrUQdo8DocKiQJBanesr7vDO8fdA6Rg1e0yAtSeNti "

       "e8avx46/HJa6CFs3CoE0sf6oOFSxM954AgCBTXOGNBt1Nt3Bhfqt2qyA "

       "TLFii5K1jLDTZDVkoiyDXL1M7wcTwKf9METgj1eQmH3GGlRM/OJ/j8xk "

       "ZiFGbL3cipWdiH48031jiV2hlc92mKn8Ya0d9AN6c44piza/JSFydZXw "

       "sY32nxzjDbs=\n";

static char f2[] = "Ksig0key.+008+55921.private";

static char c2[] = "Private-key-format: v1.3\n\

Algorithm: 8 (RSASHA256)\n\

Modulus: rbaWAeLW8BtC+7kRN1OubYfyvCBr22/IxrosWJIPJ68u9K/RSjm69+tefFot20Ey2zp7UvLamJIf0lFs4Yw2Js4rgRdaFYCfwwgjhJaBACxsXC2LPgfI+fbBJytRB2jwOhwqJAkFqd6yvu8M7x90DpGDV7TIC1J422J7xq/Hjr8clroIWzcKgTSx/qg4VLEz3ngCAIFNc4Y0G3U23cGF+q3arIBMsWKLkrWMsNNkNWSiLINcvUzvBxPAp/0wROCPV5CYfcYaVEz84n+PzGRmIUZsvdyKlZ2IfjzTfWOJXaGVz3aYqfxhrR30A3pzjimLNr8lIXJ1lfCxjfafHOMNuw==\n\

PublicExponent: AQAB\n\

PrivateExponent: GDfclFkR5ToFGH9rMTRMnP73Q5dzjLgkx4vyHcuzKtxcvAans4+hNj+NazckAy2E+mpzV2j95TJ4wZjSM2RvB5xLwBIc4Dg6oyAHL6Ikoae6gw64cHFOaYb808n8CyqWqfX+QWAz9sRSVZXnTuPViX3A+svR7ejVak9Bzr1NTDm0DFlrhaKVCYA++dKVZerfuNiXT/jQvrc4wMCa7WWsfLsFO8aTNkEhqUnmS9c5VYgr7MkCV4ENDBcISpQc9wElI0hl12QPaSj8iSdk9liYp+HTiOxOyp6BGGuecKAoQijMwrZy4qExdOxvowptll8+nZLtwGRn/un/xvIZY5OLAQ==\n\

Prime1: ww3C6jwnrLQik/zxSgC0KuqgHq68cCjiRjwK2/euzs7NkMevFpXvV0cWO8x1/wKC1mszVLsUaKTvH6fzRsXfz5MPihzNzUYFwvobKVLserSxEwHNk+FKUU+q07Kf8WWnCqX5nX9QzVG1q4J8Q44N49I5S480jHLGYbyLZrEYMQE=\n\

Prime2: 4/3Ozq/8vRgcO4bieFs4CbZR7C98HiTi65SiLBIKY09mDfCleZI0uurAYBluZJgHS5AC5cdyHFuJr3uKxvD+Mgdlru40U6cSCEdK7HAhyUGZUndWl28wyMEB6Kke1/owxVn0S4RKLPOgFI2668H6JObaqXf0wyY89RdVQP6VQrs=\n\

Exponent1: Tbr9MyVX1j5PDVSev5P6OKQZvUB7PeM9ESo6VaCl3CqTxx+cic6ke86LcLcxSrewdkxwP1LydiVMWfwvOcP/RhRf+/Uwmp5OC35qNpSiQuAhNObiCw2b9T1fYU/s52FQKTEtgXNMOxZV5IxyguVoaaLMTG08TsAqiKZ/kyP99QE=\n\

Exponent2: Q4qSNKrwLbixzHS2LL+hR0dK17RtiaSV0QKUVIf3qdoAusp6yxwkIOegnBeMm6JqLtl38kh2pq37iRAJWcxVEc8dMYiB2fJZpjgwmwDREYUsfcC611vqUN7UyO8pIwSMZDq045ZKPyzhVJV0NZmemEYHq0LNMO7oCheiewGwiDc=\n\

Coefficient: T2u/J4NgyO+OqoLpXBIpTBzqrvDk8tb0feYgsp5d16hHvbXxNkMUR8cI07RdbI9HnEldtmhAnbQ6SvFiy2YYjpw/1Fz2WwdxRqLaDV7UlhrT+CqltvU9d/N/xThBNKDa23Wf5Vat+HRiLHSgzsY1PseVCWN+g4azuK2D8+DLeHE=\n\

Created: 20220311073606\n\

Publish: 20220311073606\n\

Activate: 20220311073606\n";

static char f3[] = "sig0key.db";

static char c3[] = "sig0key. 0 IN SOA . . 0 0 0 0 0\n\

sig0key. 0 IN NS .\n\

sig0key. 0 IN KEY 512 3 8 AwEAAa22lgHi1vAbQvu5ETdTrm2H8rwga9tvyMa6LFiSDyevLvSv0Uo5 uvfrXnxaLdtBMts6e1Ly2piSH9JRbOGMNibOK4EXWhWAn8MII4SWgQAs bFwtiz4HyPn2wScrUQdo8DocKiQJBanesr7vDO8fdA6Rg1e0yAtSeNti e8avx46/HJa6CFs3CoE0sf6oOFSxM954AgCBTXOGNBt1Nt3Bhfqt2qyA TLFii5K1jLDTZDVkoiyDXL1M7wcTwKf9METgj1eQmH3GGlRM/OJ/j8xk ZiFGbL3cipWdiH48031jiV2hlc92mKn8Ya0d9AN6c44piza/JSFydZXw sY32nxzjDbs=\n";

int

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

  isc_result_t result;

  dns_fixedname_t fixed;

  dns_name_t *name = dns_fixedname_initname(&fixed);

  unsigned char secret[16] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

             0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

             0xff, 0xff, 0xff, 0xff };

  dns_zone_t *zone = NULL;

  char pathbuf[PATH_MAX];

  FILE *fd;

  wd = mkdtemp(template);

  if (wd == NULL) {

    fprintf(stderr, "mkdtemp failed\n");

    return 1;

  }

  snprintf(pathbuf, sizeof(pathbuf), "%s/%s", wd, f1);

  fd = fopen(pathbuf, "w");

  if (fd == NULL) {

    fprintf(stderr, "fopen(%s) failed\n", pathbuf);

    return 1;

  }

  fputs(c1, fd);

  fclose(fd);

  snprintf(pathbuf, sizeof(pathbuf), "%s/%s", wd, f2);

  fd = fopen(pathbuf, "w");

  if (fd == NULL) {

    fprintf(stderr, "fopen(%s) failed\n", pathbuf);

    return 1;

  }

  fputs(c2, fd);

  fclose(fd);

  snprintf(pathbuf, sizeof(pathbuf), "%s/%s", wd, f3);

  fd = fopen(pathbuf, "w");

  if (fd == NULL) {

    fprintf(stderr, "fopen(%s) failed\n", pathbuf);

    return 1;

  }

  fputs(c3, fd);

  fclose(fd);

  isc_mem_create("fuzz", &mctx);

  isc_loopmgr_create(mctx, 1);

  dns_view_create(mctx, NULL, dns_rdataclass_in, "view", &view);

  dns_tsigkeyring_create(mctx, &ring);

  dns_tsigkeyring_create(mctx, &emptyring);

  result = dns_name_fromstring(name, "tsig-key", dns_rootname, 0, NULL);

  if (result != ISC_R_SUCCESS) {

    fprintf(stderr, "dns_name_fromstring failed: %s\n",

      isc_result_totext(result));

    return 1;

  }

  result = dns_tsigkey_create(name, DST_ALG_HMACSHA256, secret,

            sizeof(secret), mctx, &tsigkey);

  if (result != ISC_R_SUCCESS) {

    fprintf(stderr, "dns_tsigkey_create failed: %s\n",

      isc_result_totext(result));

    return 1;

  }

  result = dns_tsigkeyring_add(ring, tsigkey);

  if (result != ISC_R_SUCCESS) {

    fprintf(stderr, "dns_tsigkeyring_add failed: %s\n",

      isc_result_totext(result));

    return 1;

  }

  result = dns_name_fromstring(name, "sig0key", dns_rootname, 0, NULL);

  if (result != ISC_R_SUCCESS) {

    fprintf(stderr, "dns_name_fromstring failed: %s\n",

      isc_result_totext(result));

    return 1;

  }

  dns_zone_create(&zone, mctx, 0);

  dns_zone_setorigin(zone, name);

  dns_zone_setclass(zone, view->rdclass);

  dns_zone_settype(zone, dns_zone_primary);

  dns_zone_setkeydirectory(zone, wd);

  dns_zone_setfile(zone, pathbuf, NULL, dns_masterformat_text,

       &dns_master_style_default);

  result = dns_zone_load(zone, false);

  if (result != ISC_R_SUCCESS) {

    fprintf(stderr, "dns_zone_load failed: %s\n",

      isc_result_totext(result));

    return 1;

  }

  result = dns_view_addzone(view, zone);

  if (result != ISC_R_SUCCESS) {

    fprintf(stderr, "dns_view_addzone failed: %s\n",

      isc_result_totext(result));

    return 1;

  }

  dns_zone_setview(zone, view);

  dns_view_freeze(view);

  dns_zone_detach(&zone);

  return 0;

}

static isc_result_t

create_message(dns_message_t **messagep, const uint8_t *data, size_t size,

         bool addasig, bool addtsig) {

  isc_result_t result;

  dns_message_t *message = NULL;

  isc_buffer_t b;

  static unsigned char buf[65535];

  isc_buffer_init(&b, buf, sizeof(buf));

  /* Message ID */

  isc_buffer_putuint16(&b, 0);

  /* QR, Opcode, other flags = 0, rcode = 0 */

  isc_buffer_putuint16(&b, (*data & 0x1f) << 11);

  /* Counts */

  isc_buffer_putuint16(&b, 1);

  isc_buffer_putuint16(&b, 0);

  isc_buffer_putuint16(&b, 0);

  isc_buffer_putuint16(&b, addasig ? 1 : 0);

  /* Question ./IN/SOA */

  isc_buffer_putuint8(&b, 0);

  isc_buffer_putuint16(&b, 6);

  isc_buffer_putuint16(&b, 1);

  if (addasig) {

    /* Signature */

    if (addtsig) {

      const unsigned char keyname[] = "\x08tsig-key";

      isc_buffer_putmem(&b, keyname, sizeof(keyname));

      isc_buffer_putuint16(&b, dns_rdatatype_tsig);

      isc_buffer_putuint16(&b, dns_rdataclass_any);

    } else {

      isc_buffer_putuint8(&b, 0); /* '.' */

      isc_buffer_putuint16(&b, dns_rdatatype_sig);

      isc_buffer_putuint16(&b, dns_rdataclass_in);

    }

    isc_buffer_putuint32(&b, 0); /* ttl */

    data++;

    size--;

    if (size > isc_buffer_availablelength(&b) - 2) {

      size = isc_buffer_availablelength(&b) - 2;

    }

    isc_buffer_putuint16(&b, size);

    isc_buffer_putmem(&b, data, size);

  }

  dns_message_create(mctx, NULL, NULL, DNS_MESSAGE_INTENTPARSE, &message);

  result = dns_message_parse(message, &b, 0);

  if (debug) {

    fprintf(stderr, "dns_message_parse => %s\n",

      isc_result_totext(result));

  }

  if (result != ISC_R_SUCCESS) {

    dns_message_detach(&message);

  } else {

    if (debug) {

      char text[200000];

      isc_buffer_init(&b, text, sizeof(text));

      result = dns_message_totext(

        message, &dns_master_style_debug, 0, &b);

      if (result == ISC_R_SUCCESS) {

        fprintf(stderr, "%.*s", (int)b.used, text);

      } else {

        fprintf(stderr, "dns_message_totext => %s\n",

          isc_result_totext(result));

      }

    }

    *messagep = message;

  }

  return result;

}

int

LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {

  isc_result_t result;

  dns_message_t *message = NULL;

  unsigned char query_tsig[23 + 32 + 6] = { 0 };

  bool addasig = false;

  bool addtime = false;

  bool addtsig = false;

  bool setquerytsig = false;

  bool settsigkey = false;

  bool subtime = false;

  bool withring = false;

  bool withview = false;

  /*

   * The first 2 octets affect setup.

   * Octet 1 determines whether a signature is added and which type

   * (addasig, addtsig), whether time should be adjusted (addtime,

   * subtime), whether dns_message_setquerytsig and dns_message_settsigkey

   * have been called, whether there is a keyring available with the

   * TSIG key or a view is defined.

   *

   * The second octet defines if the message is a response and the

   * opcode.

   */

  if (size > 65535 || size < 2) {

    return 0;

  }

  addasig = (*data & 0x80) != 0;

  addtime = (*data & 0x40) != 0;

  addtsig = (*data & 0x20) != 0;

  setquerytsig = (*data & 0x10) != 0;

  settsigkey = (*data & 0x08) != 0;

  subtime = (*data & 0x04) != 0;

  withring = (*data & 0x02) != 0;

  withview = (*data & 0x01) != 0;

  data++;

  size--;

  if (debug) {

    fprintf(stderr,

      "addasig=%u addtime=%u addtsig=%u setquerytsig=%u "

      "settsigkey=%u subtime=%u withring=%u\nwithview=%u\n",

      addasig, addtime, addtsig, setquerytsig, settsigkey,

      subtime, withring, withview);

  }

  result = create_message(&message, data, size, addasig, addtsig);

  if (result != ISC_R_SUCCESS) {

    return 0;

  }

  /*

   * Make time calculations consistent.

   */

  message->fuzzing = 1;

  message->fuzztime = fuzztime;

  if (addtime) {

    message->fuzztime += 1200;

  }

  if (subtime) {

    message->fuzztime -= 1200;

  }

  if ((message->flags & DNS_MESSAGEFLAG_QR) != 0) {

    if (setquerytsig) {

      isc_buffer_t b;

      unsigned char hmacname[] = HMACSHA256;

      unsigned char hmacvalue[32] = {

        0x22, 0x4d, 0x58, 0x07, 0x64, 0x8d, 0x14, 0x00,

        0x9d, 0x8e, 0xfc, 0x1c, 0xd0, 0x49, 0x55, 0xe9,

        0xcc, 0x90, 0x21, 0x87, 0x3b, 0x5f, 0xaf, 0x5c,

        0x88, 0x99, 0xdc, 0x27, 0xc8, 0xdf, 0xb3, 0x4b

      };

      /*

       * Valid TSIG rdata for tsig-key over a plain

       * DNS QUERY for ./SOA/IN with no flags set.

       */

      isc_buffer_init(&b, query_tsig, sizeof(query_tsig));

      isc_buffer_putmem(&b, hmacname, sizeof(hmacname));

      isc_buffer_putuint16(&b, 0);        /* time high */

      isc_buffer_putuint32(&b, 0x622abec0); /* time low */

      isc_buffer_putuint16(&b, 300);        /* Fudge */

      isc_buffer_putuint16(&b, 32);       /* Mac Length */

      /* Mac */

      isc_buffer_putmem(&b, hmacvalue, 32);

      isc_buffer_putuint16(&b, 7674); /* Original Id */

      isc_buffer_putuint16(&b, 0);  /* Error */

      isc_buffer_putuint16(&b, 0);  /* Other len */

      dns_message_setquerytsig(message, &b);

    }

  }

  if (settsigkey) {

    result = dns_message_settsigkey(message, tsigkey);

    if (debug) {

      fprintf(stderr, "dns_message_settsigkey => %s\n",

        isc_result_totext(result));

    }

  }

  dns_view_setkeyring(view, withring ? ring : emptyring);

  result = dns_message_checksig(message, withview ? view : NULL);

  if (debug) {

    char textbuf[64];

    isc_buffer_t b;

    fprintf(stderr, "dns_message_checksig => %s\n",

      isc_result_totext(result));

    isc_buffer_init(&b, textbuf, sizeof(textbuf));

    dns_tsigrcode_totext(message->tsigstatus, &b);

    fprintf(stderr, "tsigstatus=%.*s\n", (int)b.used, textbuf);

    isc_buffer_init(&b, textbuf, sizeof(textbuf));

    dns_tsigrcode_totext(message->sig0status, &b);

    fprintf(stderr, "sig0status=%.*s\n", (int)b.used, textbuf);

  }

  if (result != ISC_R_SUCCESS) {

    goto cleanup;

  }

cleanup:

  if (message != NULL) {

    dns_message_detach(&message);

  }

  return 0;

}