/*
 * 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.
 */

/*! \file */

/*%
 * DNSSEC Support Routines.
 */

#include <ctype.h>
#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <stdbool.h>
#include <stdlib.h>
#include <unistd.h>

#include <isc/base32.h>
#include <isc/buffer.h>
#include <isc/commandline.h>
#include <isc/dir.h>
#include <isc/heap.h>
#include <isc/list.h>
#include <isc/log.h>
#include <isc/mem.h>
#include <isc/result.h>
#include <isc/string.h>
#include <isc/time.h>
#include <isc/tls.h>
#include <isc/tm.h>
#include <isc/util.h>

#include <dns/db.h>
#include <dns/dbiterator.h>
#include <dns/dnssec.h>
#include <dns/fixedname.h>
#include <dns/journal.h>
#include <dns/keyvalues.h>
#include <dns/name.h>
#include <dns/nsec.h>
#include <dns/nsec3.h>
#include <dns/rdataclass.h>
#include <dns/rdataset.h>
#include <dns/rdatasetiter.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/secalg.h>
#include <dns/time.h>

#include "dnssectool.h"

#define KEYSTATES_NVALUES 4
static const char *keystates[KEYSTATES_NVALUES] = {
	"hidden",
	"rumoured",
	"omnipresent",
	"unretentive",
};

int verbose = 0;
bool quiet = false;
const char *journal = NULL;
dns_dsdigest_t dtype[8];

static fatalcallback_t *fatalcallback = NULL;

void
fatal(const char *format, ...) {
	va_list args;

	fprintf(stderr, "%s: fatal: ", isc_commandline_progname);
	va_start(args, format);
	vfprintf(stderr, format, args);
	va_end(args);
	fprintf(stderr, "\n");
	if (fatalcallback != NULL) {
		(*fatalcallback)();
	}
	_exit(EXIT_FAILURE);
}

void
setfatalcallback(fatalcallback_t *callback) {
	fatalcallback = callback;
}

void
check_result(isc_result_t result, const char *message) {
	if (result != ISC_R_SUCCESS) {
		fatal("%s: %s", message, isc_result_totext(result));
	}
}

void
vbprintf(int level, const char *fmt, ...) {
	va_list ap;
	if (level > verbose) {
		return;
	}
	va_start(ap, fmt);
	fprintf(stderr, "%s: ", isc_commandline_progname);
	vfprintf(stderr, fmt, ap);
	va_end(ap);
}

void
version(const char *name) {
	printf("%s %s\n", name, PACKAGE_VERSION);
	exit(EXIT_SUCCESS);
}

void
sig_format(dns_rdata_rrsig_t *sig, char *cp, unsigned int size) {
	char namestr[DNS_NAME_FORMATSIZE];
	char algstr[DNS_NAME_FORMATSIZE];
	dst_algorithm_t algorithm = dst_algorithm_fromdata(
		sig->algorithm, sig->signature, sig->siglen);

	dns_name_format(&sig->signer, namestr, sizeof(namestr));
	dst_algorithm_format(algorithm, algstr, sizeof(algstr));
	snprintf(cp, size, "%s/%s/%d", namestr, algstr, sig->keyid);
}

void
setup_logging(void) {
	isc_logconfig_t *logconfig = NULL;
	int level;

	if (verbose < 0) {
		verbose = 0;
	}
	switch (verbose) {
	case 0:
		/*
		 * We want to see warnings about things like out-of-zone
		 * data in the master file even when not verbose.
		 */
		level = ISC_LOG_WARNING;
		break;
	case 1:
		level = ISC_LOG_INFO;
		break;
	default:
		level = ISC_LOG_DEBUG(verbose - 2 + 1);
		break;
	}

	logconfig = isc_logconfig_get();

	isc_log_settag(logconfig, isc_commandline_progname);

	/*
	 * Set up a channel similar to default_stderr except:
	 *  - the logging level is passed in
	 *  - the program name and logging level are printed
	 *  - no time stamp is printed
	 */
	isc_log_createandusechannel(
		logconfig, "default_stderr", ISC_LOG_TOFILEDESC, level,
		ISC_LOGDESTINATION_STDERR,
		ISC_LOG_PRINTTAG | ISC_LOG_PRINTLEVEL, ISC_LOGCATEGORY_DEFAULT,
		ISC_LOGMODULE_DEFAULT);
}

static isc_stdtime_t
time_units(isc_stdtime_t offset, char *suffix, const char *str) {
	switch (suffix[0]) {
	case 'Y':
	case 'y':
		return offset * (365 * 24 * 3600);
	case 'M':
	case 'm':
		switch (suffix[1]) {
		case 'O':
		case 'o':
			return offset * (30 * 24 * 3600);
		case 'I':
		case 'i':
			return offset * 60;
		case '\0':
			fatal("'%s' ambiguous: use 'mi' for minutes "
			      "or 'mo' for months",
			      str);
		default:
			fatal("time value %s is invalid", str);
		}
		UNREACHABLE();
		break;
	case 'W':
	case 'w':
		return offset * (7 * 24 * 3600);
	case 'D':
	case 'd':
		return offset * (24 * 3600);
	case 'H':
	case 'h':
		return offset * 3600;
	case 'S':
	case 's':
	case '\0':
		return offset;
	default:
		fatal("time value %s is invalid", str);
	}
	UNREACHABLE();
	return 0; /* silence compiler warning */
}

static bool
isnone(const char *str) {
	return (strcasecmp(str, "none") == 0) ||
	       (strcasecmp(str, "never") == 0) ||
	       (strcasecmp(str, "unset") == 0);
}

dns_ttl_t
strtottl(const char *str) {
	const char *orig = str;
	const char *p = str;
	unsigned long val;
	char *endp;

	if (isnone(str)) {
		return (dns_ttl_t)0;
	}

	/*
	 * strtoul() silently negates a leading '-', producing
	 * ULONG_MAX-class values that then truncate to a near-UINT32_MAX
	 * TTL. Reject the sign explicitly before parsing.
	 */
	while (isspace((unsigned char)*p)) {
		p++;
	}
	if (*p == '-') {
		fatal("TTL must be non-negative: %s", orig);
	}

	errno = 0;
	val = strtoul(str, &endp, 0);
	if (endp == str) {
		fatal("TTL must be numeric: %s", orig);
	}
	if (errno == ERANGE || val > UINT32_MAX) {
		fatal("TTL %s out of range (max %u)", orig, UINT32_MAX);
	}
	return time_units((dns_ttl_t)val, endp, orig);
}

dst_key_state_t
strtokeystate(const char *str) {
	if (isnone(str)) {
		return DST_KEY_STATE_NA;
	}

	for (int i = 0; i < KEYSTATES_NVALUES; i++) {
		if (keystates[i] != NULL && strcasecmp(str, keystates[i]) == 0)
		{
			return (dst_key_state_t)i;
		}
	}
	fatal("unknown key state %s", str);
}

isc_stdtime_t
strtotime(const char *str, int64_t now, int64_t base, bool *setp) {
	int64_t val, offset;
	isc_result_t result;
	const char *orig = str;
	char *endp;
	size_t n;
	struct tm tm;

	if (isnone(str)) {
		SET_IF_NOT_NULL(setp, false);
		return (isc_stdtime_t)0;
	}

	SET_IF_NOT_NULL(setp, true);

	if ((str[0] == '0' || str[0] == '-') && str[1] == '\0') {
		return (isc_stdtime_t)0;
	}

	/*
	 * We accept times in the following formats:
	 *   now([+-]offset)
	 *   YYYYMMDD([+-]offset)
	 *   YYYYMMDDhhmmss([+-]offset)
	 *   Day Mon DD HH:MM:SS YYYY([+-]offset)
	 *   1234567890([+-]offset)
	 *   [+-]offset
	 */
	n = strspn(str, "0123456789");
	if ((n == 8u || n == 14u) &&
	    (str[n] == '\0' || str[n] == '-' || str[n] == '+'))
	{
		char timestr[15];

		strlcpy(timestr, str, sizeof(timestr));
		timestr[n] = 0;
		if (n == 8u) {
			strlcat(timestr, "000000", sizeof(timestr));
		}
		result = dns_time64_fromtext(timestr, &val);
		if (result != ISC_R_SUCCESS) {
			fatal("time value %s is invalid: %s", orig,
			      isc_result_totext(result));
		}
		base = val;
		str += n;
	} else if (n == 10u &&
		   (str[n] == '\0' || str[n] == '-' || str[n] == '+'))
	{
		base = strtoll(str, &endp, 0);
		str += 10;
	} else if (strncmp(str, "now", 3) == 0) {
		base = now;
		str += 3;
	} else if (str[0] >= 'A' && str[0] <= 'Z') {
		/* parse ctime() format as written by `dnssec-settime -p` */
		endp = isc_tm_strptime(str, "%a %b %d %H:%M:%S %Y", &tm);
		if (endp != str + 24) {
			fatal("time value %s is invalid", orig);
		}
		base = mktime(&tm);
		str += 24;
	}

	if (str[0] == '\0') {
		return (isc_stdtime_t)base;
	} else if (str[0] == '+') {
		offset = strtol(str + 1, &endp, 0);
		offset = time_units((isc_stdtime_t)offset, endp, orig);
		val = base + offset;
	} else if (str[0] == '-') {
		offset = strtol(str + 1, &endp, 0);
		offset = time_units((isc_stdtime_t)offset, endp, orig);
		val = base - offset;
	} else {
		fatal("time value %s is invalid", orig);
	}

	return (isc_stdtime_t)val;
}

dns_rdataclass_t
strtoclass(const char *str) {
	isc_textregion_t r;
	dns_rdataclass_t rdclass;
	isc_result_t result;

	if (str == NULL) {
		return dns_rdataclass_in;
	}
	r.base = UNCONST(str);
	r.length = strlen(str);
	result = dns_rdataclass_fromtext(&rdclass, &r);
	if (result != ISC_R_SUCCESS) {
		fatal("unknown class %s", str);
	}
	return rdclass;
}

unsigned int
strtodsdigest(const char *str) {
	isc_textregion_t r;
	dns_dsdigest_t alg;
	isc_result_t result;

	r.base = UNCONST(str);
	r.length = strlen(str);
	result = dns_dsdigest_fromtext(&alg, &r);
	if (result != ISC_R_SUCCESS) {
		fatal("unknown DS digest %s", str);
	}
	if (!dst_ds_digest_supported(alg)) {
		fatal("unsupported DS digest %s", str);
	}
	return alg;
}

static int
cmp_dtype(const void *ap, const void *bp) {
	int a = *(const uint8_t *)ap;
	int b = *(const uint8_t *)bp;
	return a - b;
}

void
add_dtype(unsigned int dt) {
	unsigned int i, n;

	/* ensure there is space for a zero terminator */
	n = sizeof(dtype) / sizeof(dtype[0]) - 1;
	for (i = 0; i < n; i++) {
		if (dtype[i] == dt) {
			return;
		}
		if (dtype[i] == 0) {
			dtype[i] = dt;
			qsort(dtype, i + 1, 1, cmp_dtype);
			return;
		}
	}
	fatal("too many -a digest type arguments");
}

isc_result_t
try_dir(const char *dirname) {
	isc_result_t result;
	isc_dir_t d;

	isc_dir_init(&d);
	result = isc_dir_open(&d, dirname);
	if (result == ISC_R_SUCCESS) {
		isc_dir_close(&d);
	}
	return result;
}

/*
 * Check private key version compatibility.
 */
void
check_keyversion(dst_key_t *key, char *keystr) {
	int major, minor;
	dst_key_getprivateformat(key, &major, &minor);
	INSIST(major <= DST_MAJOR_VERSION); /* invalid private key */

	if (major < DST_MAJOR_VERSION || minor < DST_MINOR_VERSION) {
		fatal("Key %s has incompatible format version %d.%d, "
		      "use -f to force upgrade to new version.",
		      keystr, major, minor);
	}
	if (minor > DST_MINOR_VERSION) {
		fatal("Key %s has incompatible format version %d.%d, "
		      "use -f to force downgrade to current version.",
		      keystr, major, minor);
	}
}

bool
key_collision(dst_key_t *dstkey, dns_name_t *name, const char *dir,
	      isc_mem_t *mctx, uint16_t min, uint16_t max, bool *exact) {
	isc_result_t result;
	bool conflict = false;
	dns_dnsseckeylist_t matchkeys;
	dns_dnsseckey_t *key = NULL;
	uint16_t id, oldid;
	uint32_t rid, roldid;
	dns_secalg_t alg;
	isc_stdtime_t now = isc_stdtime_now();

	SET_IF_NOT_NULL(exact, false);

	id = dst_key_id(dstkey);
	rid = dst_key_rid(dstkey);
	alg = dst_key_alg(dstkey);

	if (min != max) {
		if (id < min || id > max) {
			fprintf(stderr, "Key ID %d outside of [%u..%u]\n", id,
				min, max);
			return true;
		}
		if (rid < min || rid > max) {
			fprintf(stderr,
				"Revoked Key ID %d (for tag %d) outside of "
				"[%u..%u]\n",
				rid, id, min, max);
			return true;
		}
	}

	ISC_LIST_INIT(matchkeys);
	bool keykey = false;

	/*
	 * DNSKEY and KEY both use the same file names patterns so
	 * we have to look for both sets of keys.
	 */
again:
	result = dns_dnssec_findmatchingkeys(name, NULL, dir, NULL, now, keykey,
					     mctx, &matchkeys);
	if (result == ISC_R_NOTFOUND) {
		goto try_key;
	}

	while (!ISC_LIST_EMPTY(matchkeys) && !conflict) {
		key = ISC_LIST_HEAD(matchkeys);
		if (dst_key_alg(key->key) != alg) {
			goto next;
		}

		oldid = dst_key_id(key->key);
		roldid = dst_key_rid(key->key);

		if (oldid == rid || roldid == id || id == oldid) {
			conflict = true;
			if (id != oldid) {
				if (verbose > 1) {
					fprintf(stderr,
						"Key ID %d could "
						"collide with %d\n",
						id, oldid);
				}
			} else {
				SET_IF_NOT_NULL(exact, true);
				if (verbose > 1) {
					fprintf(stderr, "Key ID %d exists\n",
						id);
				}
			}
		}

	next:
		ISC_LIST_UNLINK(matchkeys, key, link);
		dns_dnsseckey_destroy(mctx, &key);
	}

	/* Finish freeing the list */
	while (!ISC_LIST_EMPTY(matchkeys)) {
		key = ISC_LIST_HEAD(matchkeys);
		ISC_LIST_UNLINK(matchkeys, key, link);
		dns_dnsseckey_destroy(mctx, &key);
	}

try_key:
	if (!conflict && !keykey) {
		keykey = true;
		goto again;
	}
	return conflict;
}

bool
isoptarg(const char *arg, char **argv, void (*usage)(int ret)) {
	if (!strcasecmp(isc_commandline_argument, arg)) {
		if (argv[isc_commandline_index] == NULL) {
			fprintf(stderr, "%s: missing argument -%c %s\n",
				isc_commandline_progname,
				isc_commandline_option,
				isc_commandline_argument);
			usage(EXIT_FAILURE);
		}
		isc_commandline_argument = argv[isc_commandline_index];
		/* skip to next argument */
		isc_commandline_index++;
		return true;
	}
	return false;
}

void
loadjournal(isc_mem_t *mctx, dns_db_t *db, const char *file) {
	dns_journal_t *jnl = NULL;
	isc_result_t result;

	result = dns_journal_open(mctx, file, DNS_JOURNAL_READ, &jnl);
	if (result == ISC_R_NOTFOUND) {
		fprintf(stderr, "%s: journal file %s not found\n",
			isc_commandline_progname, file);
		goto cleanup;
	} else if (result != ISC_R_SUCCESS) {
		fatal("unable to open journal %s: %s\n", file,
		      isc_result_totext(result));
	}

	if (dns_journal_empty(jnl)) {
		dns_journal_destroy(&jnl);
		return;
	}

	result = dns_journal_rollforward(jnl, db, 0);
	switch (result) {
	case ISC_R_SUCCESS:
	case DNS_R_UPTODATE:
		break;

	case ISC_R_NOTFOUND:
	case ISC_R_RANGE:
		fatal("journal %s out of sync with zone", file);

	default:
		fatal("journal %s: %s\n", file, isc_result_totext(result));
	}

cleanup:
	dns_journal_destroy(&jnl);
}

void
kasp_from_conf(cfg_obj_t *config, isc_mem_t *mctx, const char *name,
	       const char *keydir, dns_kasp_t **kaspp) {
	isc_result_t result = ISC_R_NOTFOUND;
	const cfg_obj_t *kasps = NULL;
	dns_kasplist_t kasplist;
	const cfg_obj_t *keystores = NULL;
	dns_keystore_t *keystore = NULL;
	dns_keystorelist_t kslist;
	unsigned int options = (ISCCFG_KASPCONF_CHECK_ALGORITHMS |
				ISCCFG_KASPCONF_CHECK_KEYLIST |
				ISCCFG_KASPCONF_LOG_ERRORS);

	ISC_LIST_INIT(kasplist);
	ISC_LIST_INIT(kslist);

	(void)cfg_map_get(config, "key-store", &keystores);
	CFG_LIST_FOREACH(keystores, element) {
		cfg_obj_t *kconfig = cfg_listelt_value(element);
		result = cfg_keystore_fromconfig(kconfig, mctx, &kslist, NULL);
		if (result != ISC_R_SUCCESS) {
			fatal("failed to configure key-store '%s': %s",
			      cfg_obj_asstring(cfg_tuple_get(kconfig, "name")),
			      isc_result_totext(result));
		}
	}
	/* Default key-directory key store. */
	(void)cfg_keystore_fromconfig(NULL, mctx, &kslist, &keystore);
	INSIST(keystore != NULL);
	if (keydir != NULL) {
		/* '-K keydir' takes priority */
		dns_keystore_setdirectory(keystore, keydir);
	}
	dns_keystore_detach(&keystore);

	(void)cfg_map_get(config, "dnssec-policy", &kasps);
	CFG_LIST_FOREACH(kasps, element) {
		dns_kasp_t *kasp = NULL;

		cfg_obj_t *kconfig = cfg_listelt_value(element);
		if (strcmp(cfg_obj_asstring(cfg_tuple_get(kconfig, "name")),
			   name) != 0)
		{
			continue;
		}

		result = cfg_kasp_fromconfig(kconfig, NULL, options, mctx,
					     &kslist, &kasplist, &kasp);
		if (result != ISC_R_SUCCESS) {
			fatal("failed to configure dnssec-policy '%s': %s",
			      cfg_obj_asstring(cfg_tuple_get(kconfig, "name")),
			      isc_result_totext(result));
		}
		INSIST(kasp != NULL);
		dns_kasp_freeze(kasp);

		*kaspp = kasp;
		break;
	}

	/*
	 * Cleanup kasp list.
	 */
	ISC_LIST_FOREACH(kasplist, kasp, link) {
		ISC_LIST_UNLINK(kasplist, kasp, link);
		dns_kasp_detach(&kasp);
	}

	/*
	 * Cleanup keystore list.
	 */
	ISC_LIST_FOREACH(kslist, ks, link) {
		ISC_LIST_UNLINK(kslist, ks, link);
		dns_keystore_detach(&ks);
	}
}
